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Oral History Transcript — Dr. Harald Enge

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Interview with Dr. Harald Enge
By Dr. Jan Vaagen
In Cambridge, MA
August 6, 1987

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Harald Enge; August 6, 1987

ABSTRACT: Family background and early education in Bodo, Norway; diploma in engineering from the Technical University in Trondheim, Norway, 1947. University of Bergen, 1948; work with Bjorn Trimpy on spectrometer designs; interest in accelerators; Ph.D. dissertation, Bergen, 1954; the early Norwegian nuclear reactor at Kjeller. Leaves Bergen for MIT, 1955; comments on staff (John Trump, Robert Van de Graaff); comments on students at Bergen and MIT. Re-establishes contact with Bergen in 1963; collaborations between Bergen and MIT (Arnfinn Grane, Eric Casman, Per Hansen, Lee Grodzins); discussion of Enge’s apparatus designs; comments on relation among physics, business, and science technology; comments on his textbook on nuclear physics; teaching and self-assessment.

Transcript

Vaagen:

I'm happy to welcome Professor Harald Enge at MIT for an interview dealing with his professional career, both as a scientist in physics and a businessman in science apparatus. This interview will have some emphasis on Enge's background in Norway, early work at the University of Bergen, and later collaboration and contact with this Institute. First of all, I'd like to know a little about your background, and if I go to the lexicographic information, I can see that you were born in Norway in Fauske in September, 1920.

Enge:

That's correct.

Vaagen:

Also that you're an American citizen, for the moment.

Enge:

Yes. That is correct.

Vaagen:

That you got married in 1947.

Enge:

That's also correct.

Vaagen:

And three children.

Enge:

Yes.

Vaagen:

And that's where we start out. Maybe you could tell me a little about your background from Norway, family background, and also if there were some special mechanisms in the family connection that made you enthusiastic for physics and, in particular, instrumentation.

Enge:

Well, of course, I grew up in Fauske, and my father was a principal of what's called Fylkesskolen, which was a school for youngsters that have only a 7th grade education, to go out into practice and then come back after a couple of years to learn a little bit more. My mother was a home economics teacher in the same school. I went to realskolen in Fauske and gymnasium in Bodo, and got my examen artium [high school diploma] in 1940. I purposely said, I got it. I didn't take it, I got it, because of the war. In Bodo we were not occupied in the beginning, but when the Germans came, I guess it was around the middle of May 1940, we still hadn't taken our exam, so we got it for free, or not quite for free. So after that, I applied for admission to the Tekniske hoyskole [Technical University] in Trondheim and got admitted in 1941. At that time, before you could enter the technical university, you had to take one year of practice. I actually worked as a radio repairman for the first half year -- and a little bit on the side -- while I was in the last year of gymnasium in Bodo. Then during the summer of 1940, I had my own shop in Fauske, and that may tell a little bit about my background of technical things, particularly electronics. And so then after that, I went to Trondheim, I guess that was the fall of 1940, and worked at Edda Radiofabrikk in Trondheim for about half a year, but then because of the requirement of the practice year, I switched to the repair shop for Sulitjelma gruber [Sulitjelma mines], (Sulitjelma of course is a part of Fauske) because I needed some mechanical practice too, before I could enter the technical university. I believe it was January 1941 until the summer of 1941. I worked two months in the plate shop, two months in the foundry, and two months standing by a lathe and putting out wheels and things like that. So I did have quite a bit of technical background from that, and also from growing up; my father was technically oriented, or at least, if not electronics, in practical things, carpentry and so forth.

Vaagen:

Had that tradition been long in the family for practical work?

Enge:

Yes. It has carried on, at least. All my sons are, well, two of my sons are in electronics -- well, we'll come back to that later.

Vaagen:

Nowadays, and in fact the last decade in Norway, has been one where oil activity has been focused --

Enge:

-- yes --

Vaagen:

-- and were electricity and radio in some way the excitement that a young boy could have in the late thirties or comparable to nowadays with oil activity? Where did you read about the newest things in the field, newspapers, or popular articles?

Enge:

Popular articles, yes. I guess I started quite early to play around with making small steam engines and making radio, crystal radio, or one-tube radio, receivers and so forth, so my friends and I were always active in doing something mechanically or electrically or carpentry or whatever. My family had a small farm, just with two cows, so there were lots of things to do with your hands, and --

Vaagen:

Was that a necessity to survive the war?

Enge:

Well, it wasn't exactly a necessity. My father and mother had gone through World War I with a small child, my sister, and swore never again should they be left without having a cow that would provide milk for the family. So long before World War II, they bought a small farm, and that was just on the side, since they both were actively teaching. But there was lots of work to do there.

Vaagen:

That's interesting. Do you feel there was some kind of connection between having participated in practical work at an early age, and later on to feel the temptation to enter into --

Enge:

Oh absolutely, yes. As a matter of fact, I do remember, I got my first Erector set when I was five years old, and always played around with that kind of things. After I'd gotten into radio, I was completely geared in that direction. Because of the fact that I didn't have the highest grades in Norwegian composition, especially landsmal [second Norwegian language] in the gymnasium, I was not immediately accepted in what we call Svakstromslinjen [low voltage studies] in Trondheim and I was practically in despair, because that was the only thing I wanted to study, electronics or radio, and anything in that nature. Fortunately, I did find out that if you entered the power engineering --

Vaagen:

Sterkstromslinjen.

Enge:

Yes, right. That you could get admitted there, and then later switch, and that's exactly what I did. So of course, during the war (most of my college education was during the war), as you know, the Germans confiscated everything, all the radios, so it was impossible to get a good electronic education at the time, so we just had to fill in with power transmission courses and electromachine building. However, a lot of that actually has been very useful for me, because designing magnets, which I have been doing in later years, is essentially the same thing as designing transformers or DC generators or whatever we did. Lots of the same thing, to calculate power dissipation and temperature coefficients and so forth.

Vaagen:

Growing up with these particular interests in Fauske, did you feel that you were special in some way compared to the other kids in the gymnasium, or did you have other friends in school with similar interests?

Enge:

Well, not really. I was more or less alone in that area. No, none of my friends were actually active in the same area. One of my friends from realskolen and gymnasium, Kjell Klette, actually got into electrical engineering too, power engineering, and he's the one I mentioned earlier that died of a brain tumor.

Vaagen:

Of course the war struck just at the time when you were finishing gymnasium. But did you at an earlier point contemplate to perform your studies at a foreign university, England or the continent?

Enge:

No. No, as I said, I was completely myopic, just electronics, radio, that was the only thing I wanted to do, and that meant Trondheim of course. I do remember that my teacher in realskolen (it was a small group, we had only one teacher, he was good, though) said what I should do was to go to Oslo and study physics, and I said, "No, I don't want to study physics, I'm going into electrical engineering." So it's funny, because I ended up in physics.

Vaagen:

Of course, if I go back again to this lexicographic information, it says that you got your diploma in 1947.

Enge:

Right.

Vaagen:

And it also says that you joined the University of Bergen on the staff, first as an assistant, then later on as a lecturer, what we call an assistant or associate professor.

Enge:

Well, OK. What happened there was that after I got my diploma in Trondheim, for half a year -- well, actually for more than half a year, because it started before I got my diploma -- I was assistant to the professor of electronic engineering. It was only one single one at the time.

Vaagen:

Who was that?

Enge:

That was Aanderud. He was actually a telephone guy from Elektrisk Bureau I guess he came. Anyway, I was assistant. I guess I was called a laboratory engineer at the time. And then some of my friends went to Bergen, among others, I think it was P. Th. Hiis -- let's see, and who else was it? He went on to Bergen to join Forsvarets forskningsinstitutts radar avdeling [Norwegian Defense Research Institute's radar branch]. Helmer Dahl visited us in Trondheim and I asked him if he could find a position for me in Bergen. He wrote me then later and said there was an opening for a substitute, for amanuensis Jan Orlin, because Orlin was in the United States. So they had an opening just for a substitute -- "vikar." I took that position on January 1, 1948. Then what happened later was that the University of Bergen was founded in August 1948, and then they had a new position for a second amanuensis in physics. So I got that position.

Vaagen:

But to get it straight, you were assistant in Trondheim?

Enge:

In Trondheim.

Vaagen:

Even before you'd gotten your engineering degree?

Enge:

That's right.

Vaagen:

And that continued also some time past your degree.

Enge:

Yes. Half a year.

Vaagen:

Did you know Professor Bjorn Trumpy in Bergen?

Enge:

No, not before I came down there, no.

Vaagen:

So Helmer Dahl was the one who was enthusiastic about you.

Enge:

Yes, right. Right.

Vaagen:

Did you think about joining forces with Helmer Dahl when it came to telecommunications at that time?

Enge:

Yes, but I guess that he didn't have any opening, and so he suggested this job, and in particular I was put to work on designing a beta spectrometer, which Trumpy felt that he should have. And so again, that's where my engineering background came in useful. And then there were other things that I got involved with. Trumpy, of course, was mostly interested in cosmic radiation. And there was lots of apparatus that had to be modified or modernized and so forth. That was all electronics. That was up my line.

Vaagen:

But before leaving Trondheim. In Trondheim as a student, later as an assistant, did you get to know Holtsmark or Professor Tangen?

Enge:

I didn't think they were there at the time.

Vaagen:

I think they left maybe in 1941, 1942 for Oslo, and the Nuclear Physics Lab in Trondheim was moved to Oslo?

Enge:

Yes.

Vaagen:

But you never really met them in Trondheim?

Enge:

No.

Vaagen:

So there was no enthusiasm for nuclear physics built up during your studies in Trondheim?

Enge:

No, not at all, as a matter of fact. Of course, we had a physics course, and the one that taught the physics there, was Olaf Devik as I recall it, as a docent, and I must say, at that time, I wasn't particularly interested in physics. I was much more interested in electronics.

Vaagen:

When you came to Bergen, I guess you got to know about the accelerators that had been built already, the one at Haukeland

Enge:

Oh yes.

Vaagen:

You didn't know about them previously, maybe?

Enge:

Well, not that I can recall. Of course, we had the Van de Graaff at Fysisk Institutt, or Geofysisk Institutt as it was at the time. I can't recall actually how far that had come. It was being built, wasn't it, in 1948? So it wasn't finished yet.

Vaagen:

That was a new experience to you.

Enge:

Yes, absolutely. I had not been involved in high voltage, that high voltage at least, any time before.

Vaagen:

Thinking about the medical aspects of applying accelerators, Wideroe already around 1950 was building betatrons for the Radium Hospital, at Brown-Bovery I guess.

Enge:

Yes.

Vaagen:

Did you get to know about that too in Bergen?

Enge:

Yes, but I can't recall that I was really very steamed up about it, or had studied it in any detail. Of course, the Van de Graaff machine at Haukeland Sykehus [hospital] was in operation, wasn't it, in 1948?

Vaagen:

Yes, it started in 1942 I think.

Enge:

Yes, and I knew, of course, Odd Dahl. You know Odd Dahl was next door to us. Christian Michelsens Institutt had some rooms in the Geofysisk institutt. So, well, we had quite a bit of contact with Odd Dahl as a matter of fact. The whole atmosphere there was very exciting, and became more and more so. You know, there were Forsvarets forskningsinstitutt, Trumpy's group and Christian Michelsens institutt -- all very active. One thing I recall in particular was that Helmer Dahl was the one that was the driving force in making us all study more, in particular physics. We formed a group or he formed a group of the people from Geofysisk institutt and from Forsvarets forskningsinstitutt to study Slater and Frank. So we systematically went through Slater and Frank, took a section each and presented it in seminars.

Vaagen:

So the atmosphere was that of a pioneering activity.

Enge:

It was. Yes.

Vaagen:

What was the relationship between the younger ones and the more established ones?

Enge:

Well, I don't know exactly what you mean with relationship. It was very friendly, of course. And it was very exciting to see, I remember, Odd Dahl in action. He's an exciting fellow, and he probably still is at 90 or whatever he is at the moment. Helmer, of course, is different, but still, one that always liked to look at new things and be in the forefront of science and engineering. And there were other people there -- Haakon Sandvold for instance. I've forgotten exactly when he came, but it must have been close to the same time as I came there. And later on, Kjell Johnsen and Andreas Tonning; Kjell Johnsen may in fact have come later. I can't specifically remember that he was in on our seminars, but I think probably he was too.

Vaagen:

Did you meet Kjell Johnsen in Trondheim?

Enge:

Oh yes, actually both Kjell and Andreas Tonning and I were assistants at the same time. They were a year after me, but of course, I lingered on, so when they were actually working on their diploma, they were also assistants there -- laboratory assistants I guess they were called.

Vaagen:

I think I heard some stories about Kjell Johnsen -- that he was enthusiastic about accelerators also for practical purposes like studying fish and so on. I asked you earlier about medicine. Was that in your mind, to use technology for medical purposes?

Enge:

Not at the time, no. I have gone quite a bit into that in later years, but at that time, I guess I have to say, I slowly drifted from electrical engineering into physics. But all the time, I must say that I have been on the electrical engineering end of physics. That is, the guy that makes the apparatus, and makes a few measurements, and figuratively speaking, then throws away the apparatus, I'd say, like a toy that you're tired of.

Vaagen:

Coming back to Bergen as a city, and also maybe social aspects, what was it like for one from the northern part of the country to come to the Hansa capital?

Enge:

Well, it was a little tough -- not because of the people, but because of the conditions of where you could find living quarters. I married in 1947, before I left Trondheim, and we struggled for half a year to try to get an exchange of apartments between Trondheim and Bergen. It turned out to be impossible. I had a huge file of letters desperately trying to make a triangular exchange between Oslo, Bergen and Trondheim. Finally after I had been there -- well, no it wasn't as long as half a year, three or four months, I guess it was -- then Trumpy found an apartment for us at Espegrend in what now is Biologisk stasjon. You know, that complex of buildings was bought by the university for making a marine biology station out there, and there was one small building which was actually, I guess, used by the caretaker for the millionaire that lived there before. I've forgotten his name, this guy. I guess he made his money in candy, hard candy. And he was a Nazi. He died, and the property was bought by the University of Bergen. So we got a small house there which we stayed in for, I've forgotten, at least a year -- a year and a half, maybe -- until we were able to buy our own house on Ovsttun. So that was way out in the country, and you know Bergen, it rains and it rains, and that particular year, it was one of the times where the rain started on the 7th of October and then it stopped on the 5th of April or something like that. So it was a little tough, and in order to get to Bergen to work, I had to take a bus there, and there were very few busses that went, so if I missed the bus, I had to walk through the rain to Blomsterdalen, and of course, there was nobody out there that we could associate with, so my wife was quite lonely there. We made a few contacts in Bergen, eventually. And then fortunately after we had lived there for some time, another couple moved in, in the chauffeur's apartment above the garage in the same complex, and we got to be good friends. So, eventually we got our own home in Ovsttun, and then things looked a little better.

Vaagen:

Wives are quite important in many respects also, when it comes to backing your science, so maybe we should also know what the wife's name is, was and still is?

Enge:

OK. Her name is Grete. She was born in Namsos, and I met her in Trondheim. She was divorced and had one son, Kjell, and we married in 1947, in October, so it was three months before I left for Bergen, and she has in later years bloomed as far as education is concerned. She had gone through the gymnasium, majoring in Latin and now she has a Master's degree in art history, specializing in Edvard Munch. Actually, her thesis was on the cultural background for the development of the painting and genius of Edvard Munch.

Vaagen:

Did she choose the esthetic sciences in opposition to her husband's choice of harder fields?

Enge:

Not in opposition, but because that's where her interest in general had been all the time, I guess. Actually, she started studying in Bergen when we were there, but that was a different area. She studied law for a while, but never had a chance to continue. She took the preliminary exam -- what do you call it? It probably doesn't exist in the same form nowadays -- Forberedende prove [preliminary course to be accepted at the university]. But she never actually finished the law course, because then we left for the United States.

Vaagen:

OK, we'll come back to family life also when we move to the United States.

Enge:

OK.

Vaagen:

Professor Trumpy -- was he the automatic leader in this group of people?

Enge:

In his group, yes. Not necessarily of the whole milieu that I talked about, of course. There were several -- Odd Dahl and Helmer Dahl and Trumpy, all of them big stars, as far as I'm concerned -- and Trumpy was an excellent group leader. He was always very very positive, and of course he was also a very outgoing person in social life too in Bergen. He usually came to the Institute a little bit later than the other people, and very many times I guess he had been in some kind of a social gathering the previous evening. I remember many times he came back and had to have several glasses of water to drown his thirst. One time he said, "If I'd known I should be so thirsty today, I would have drunk more yesterday."

Vaagen:

His style is still a legend at the university. Did he, at the time when you came or later on, participate in the scientific work in a direct manner?

Enge:

Oh yes, absolutely. His main interest was cosmic rays, and he had a continuous experiment going. It was very difficult at the time to get the right kind of apparatus, both the GM tubes and the scalers that we used, so we actually produced the tubes, and also built the scalers. There was one scaler in particular that was there when I came, that Jan Orlin had built. I had to repair it often. So it was not first class instruments, I must say, but at least we learned a lot, because we had to do everything ourselves.

Vaagen:

Did you at that time get an impression of Trumpy's visions when it came to having a national activity in nuclear physics, compared to joining in more international collaborations?

Enge:

I can't recall that in particular. Of course, he had his close collaboration with Odd Dahl and their plan for the Kjernefysisk Laboratorium [Nuclear Physics Laboratory], the Van de Graaff machine and the betatron. I wasn't really in on all of that, and part of the time, of course, I was in the United States, when the betatron was built, and also when the Van de Graaff was finished. So I was a little out of touch, but yes, Trumpy was a primus motor, I guess we call it, a driver, and the combination with him and Odd Dahl really produced things there.

Vaagen:

We're coming now to your American connection. How did that all start?

Enge:

It started with a program at MIT which was called the Foreign Students Summer Project. It was a project initiated and completely carried out by an undergraduate group at MIT. They felt they should try to help the engineering and science education in the rest of the world. They got money from the Sloan Foundation and Ford Foundation and other places I think -- Fulbright -- and invited every year 75 scientists and engineers from all over the world. I applied for and got one of the three positions for Norwegians for the year 1950. The program had been active for a few years before that. I've forgotten now whether Andreas Tonning came after me or before. He was one of the other people from Norway who were in on that program.

Vaagen:

Where did he go in the United States, do you recall that?

Enge:

To MIT. It was the Foreign Students Summer Project at MIT.

Vaagen:

All scientists and engineers?

Enge:

Right. So the idea was that we should take summer courses at MIT, also that we could join a research group. I knew of course of the Van de Graaff group. Indeed Van de Graaff himself was in charge of the group at MIT, and we were building a Van de Graaff machine in Bergen, so I said I'd like to do research in the Van de Graaff group. When I came here, I quickly found out that the courses that were taught during the summer were at such a low level that it was of no interest to me, so I simply joined the research group and worked the whole summer on research on the Van de Graaff machine.

Vaagen:

Was that a choice a young man from Norway could do on his own?

Enge:

Yes, that was actually a request, and the request was answered by Professor Buechner, who was the acting leader of the Van de Graaff group. The reason for that was that Van de Graaff had quite a bit of problems with a back injury. I don't know if this is the right time to get into Van de Graaff?

Vaagen:

We can come back again.

Enge:

Well, let's come back to Van de Graaff. Anyway, Professor Buechner was the actual daily leader of the group, so he was my boss then when I came here. And he gave me immediately a problem which one of his students had begun, as a bachelor's thesis. He said, "It needs to be cleaned up," and that was looking at the reaction 27Al(d,p)28Al. The bachelor student incidentally who had done the work before was Kergon Huang who later became professor at MIT in theoretical physics. Anyway, I picked up the work and started to make thin aluminum targets and bombard them, and measure the spectra of protons emitted from aluminum 27, bombarded with about 2 MeV deuterons. I very quickly got some interesting results. The previous work had been done with thicker targets, with poor resolution, and when I came with my thinner targets and also improved on the spectrometer resolution, I could resolve some of the peaks into doublets. In particular the ground state, 28Al, is a true spectroscopic doublet, and that was the first thing I found. Professor Buechner got very interested in it, and recommended, number 1, that I try to stay on, and number 2, that I should give a paper in the American Physical Society about the results. So I worked on it the whole summer, collected an awful lot of data, and that's the data that eventually became the foundation for my doctor's dissertation.

Vaagen:

And that dissertation was for the University of Bergen in 1954?

Enge:

That's right.

Vaagen:

And with the title, "On Heavy Particle Spectroscopy Technique, Its Application to Scattering Mass Analysis and to the 27Al(d,α)25Mg and 27Al(d,p)28Al Reactions." Do you recall that?

Enge:

That's a mouthful.

Vaagen:

That's quite a mouthful, quite a sentence. This scholarship that you had gotten, was that for a year?

Enge:

No, the Foreign Students Summer Project was meant to be for four months. Three months at MIT, and then one month of traveling around the country and looking at various factories and institutes, in particular also going to Washington and looking at American government and so forth. I did take the trip to Washington. Then I jumped off the trip. I didn't want to go and look at all the Ford factories and General Motors and GE and so forth. I scooted back to Boston to continue my work on 27Al(d,p). So the actual Foreign Students Summer Project, as far as I'm concerned, ended after four months, when I did not get any more pay from them, but then Professor Buechner put me on the payroll. The travel from Norway to the United States was paid for by a Fulbright grant.

Vaagen:

At that time, did you know the difference between direct and compound reactions?

Enge:

No. No, not at all.

Vaagen:

Was that of any interest in connection with your thesis?

Enge:

No, not really. That came actually quite a bit later, when we started to get the results of stripping reactions, and of course, for my thesis, all the data was taken at 90 degrees. The spectrometer was set at 90 degrees. So we had no way of measuring angular distributions.

Vaagen:

And Butler's papers I guess came early in 1950 or 1951.

Enge:

Yes, around that time, yes.

Vaagen:

Did you read his papers when you were writing your thesis?

Enge:

No. I can't remember -- well, we heard about the data that other people had taken. I do recall that. I've forgotten whose data that was, but we were aware of the fact that the cross-section was much, much larger in the forward direction, for these types of reactions. So that's one of the reasons why we switched the plans about the spectrometer for this facility here in this building (Bldg. 58 at MIT). Originally, Professor Buechner in 1951 had a student that was looking at bigger so-called annular magnets. The spectrometer we used on the old machine was called the annular magnet because it was an annular region of magnetic field. It was copied from one of Rutherford's alpha particle magnets. Buechner had a student looking into design of a bigger copy, but then we learned about the results of forward peaking, and decided that this was not the right instrument. Then I got involved in studying other types of spectrometers, and the instrument that we actually built here was really my design, but with plenty of input from Ken Bainbridge at Harvard. I worked on the design during 1951 and early 1952, and when I left part of the engineering was done. I also simultaneously made a scaled-down design for the University of Bergen. So then I took off in the spring of 1952 and built the instrument in Bergen, and somebody else took over and finished the instrument here, and that was C.P. Browne. Browne and Buechner wrote the technical publication so the instrument came to be known as the Browne-Buechner spectrometer. They, of course, carried through the whole thing, but the original layout was actually mine. So that's when I first got into designing magnetic spectrometers, and that first one has eventually developed into a much larger number. I don't know how many I've designed by now. I've lost count.

Vaagen:

We'll speak more about that a little later.

Enge:

OK.

Vaagen:

Just to in some way set the atmosphere, around 1950, at that time, 1951, Norway also got the first nuclear reactor for scientific purposes, the first one outside of the big powers, I think.

Enge:

Yes.

Vaagen:

Did you know Randers at that time? Did you have anything to do with that type of physics?

Enge:

Only because the design work was done at Christian Michelsens institutt, and of course, Haakon Sandvold was there, and I followed their work. But I wasn't directly involved, except for one small thing. I designed a flow meter for them. But that's all the involvement I had with the reactor.

Vaagen:

Looking at your later interests for applications and instrumentation, did you see any commercial future for such an activity -- a nuclear power plant in Norway?

Enge:

I can't say that I thought too much about it. Nuclear energy of course was discussed all the time, and was exciting. And I must say, at the time we had not the faintest idea of the kind of problems that nuclear energy would run into, maybe mostly political at this time. But yes, I was interested, but not directly involved in it.

Vaagen:

I've been told there was quite some struggle in Norway -- two groups debating each other heavily when it came to this experimental power plant. Did you take part in that discussion?

Enge:

No, I don't think so. I can't recall that.

Vaagen:

You can't recall that. So later on in life, have you had anything to do with applications of nuclear energy?

Enge:

No. Not directly. I have of course followed it very closely. MIT has been in the middle of it, of course, and one of my friends and colleagues here is Rasmussen, Norman Rasmussen, you probably know the Rasmussen Report. This is an area in which there's a lot of politics involved, a lot of misinformation, and a lot of stupidity, but also some genuine concern, on the part of responsible people. It's a question that there's no answer to. What do we do, as far as energy is concerned? I certainly don't have the answer, but I hope somebody will find it.

Vaagen:

Speaking now more and more about the period here in the United States, still we have to note about your prospects in Norway. When you made up your mind in 1954 to leave the country, was that due to the possibilities to do some very meaningful work in this country, or was it also partly initiated by lack of career possibilities in the Norwegian system?

Enge:

Well, we went back to Norway in 1952 with the intention to stay there, and then in 1954 -- I guess about the time when I got my doctor's degree -- Professor Buechner visited us in Norway. He said he very much wanted me to come back, and he said he would work to get a position for me here. So I said, "I'm interested," and the reason at the time was that the working conditions in Bergen were not good at all. I recall for instance that I was in a meeting in Matematisk-Naturvitenskapelig Fakultetsrad [Science Faculty Council] and I had applied for I think it was 700 kroner to publish a report that Arnfinn Graue and I had written. Some unnamed person in that meeting got up and was furious because the physicists couldn't apply for money when everybody else did, namely in the fall. With those kinds of conditions, I felt I was stymied. I couldn't get anywhere. And of course, at the time, I think there were four professorships in all of Norway, and they were all taken by young people, so it didn't look like there was any future. And I have always had a tendency to say that I'd rather be a small wheel in a big machinery than a big wheel in a small machinery. Now, of course, times have changed completely. We have had tough times here for getting funding for physics and in particular nuclear physics, and I think it has been much much easier to live in the area of physics in Bergen since I left there than before that. So that's really the reason I left, and of course, there's another aspect of it too, and that is, I was instantly promised consulting work, and it has been very rewarding as far as being able to produce something, to create something. I have done much more in my consulting work in designing new instruments than I have done through my actual position at MIT, although there has been some here too. Of course, there's a limit to what MIT can produce, I mean, in magnetic spectrometers. MIT has the policy of letting any faculty member work up to one day a week on so-called outside professional activities, and I think for an engineering school, that's extremely important. If you look around the metropolitan Boston area, with all the high tech firms around here, a lot of them have sprung up from MIT, not from MIT as such, but from faculty members at MIT, because of all their private initiative, and I don't know what the situation is in Norway at the moment. At least when I left there, it was forbidden for a professor to have any consulting work, if you were above a certain pay scale. Is that still true?

Vaagen:

That has all changed.

Enge:

That has changed.

Vaagen:

With oil it has changed. But coming back to the hardships in Bergen, was it so that the faculty maybe felt that physics had been especially well treated since Trumpy had been the first president of the university, the "rektor" as we say in Norway?

Enge:

Not the faculty in general, just certain persons in the faculty.

Vaagen:

Certain strong persons.

Enge:

Certain strong persons in the faculty, correct.

Vaagen:

Was it possible at that time to get some sponsoring from industry, or was that considered a problem?

Enge:

No. I never heard about it. I don't think we could, at the time, get anything, any help from industry.

Vaagen:

What about the medical sector -- Haukeland was still using apparatus, accelerator apparatus, for medical treatment?

Enge:

Yes, and Trumpy was involved in that, but I think, as far as I remember, only as an adviser to the people up there. And others, in the medical area, wanted some advice with the new area of radioactivity, which of course drifted into medical science.

Vaagen:

So they had sufficient problems to put money together for their own purposes, and had nothing left over to invest in any future accelerator developments.

Enge:

Yes, maybe.

Vaagen:

OK. So when we read the local history in Bergen, we see that there was a fire in the Van de Graaff in 1956. That was after you left?

Enge:

That's right. Yes.

Vaagen:

It's also said that you planned a new magnet after the fire. Is that correct?

Enge:

In Bergen? No. We built a spectrometer, of course, which is probably still sitting there.

Vaagen:

That was the one, the old one, before the fire. So they used the same one after the fire?

Enge:

I can't recall that I was involved in any -- I might have been, but I don't remember anything about that.

Vaagen:

Did you go back again to Bergen frequently after 1955?

Enge:

When we left in 1955, we did not go back to Norway for eight years, 1963. And as a matter of fact, I don't think even we touched by Bergen at the time. We went up to my hometown Fauske and to Bodo, and Namsos where my wife comes from. So I didn't have much contact with them for a while, until people started to come over here.

Vaagen:

When I look at the paper production in Bergen, all the way back since 1950, although the statistics are not so overwhelming, still one can see that there was a productive period in the first part of the fifties, and then a drop to almost zero, which lasted till 1962, 1963, and then it picks up again. And that was the period of rebuilding the accelerator, of course, from 1956 on.

Enge:

Yes.

Vaagen:

Would you like to express an opinion on the meaningfulness of rebuilding such a small voltage accelerator?

Enge:

Well, of course, there wasn't very exciting nuclear physics that could come out of it. But one of the areas that I felt, just before I left, it would be very interesting that this accelerator could be used for, was what we called scattering mass spectroscopy -- elastic scattering mass spectroscopy -- which was part of my doctor's thesis. Ivar Aanderaa was a student of mine in 1954 to 1955, working on that, and I thought there might be, maybe not a mainline issue, but at least an important or interesting side issue to use the whole instrumentation for mass spectroscopy.

Vaagen:

Would two million volts be sufficient?

Enge:

Yes. All right. As a matter of fact, the technique is now used at lower voltages too. It has eventually picked up.

Vaagen:

Did you offer that advice to the group?

Enge:

Well, we actually spoke about it with quite a few people, among others one of the professors, I've forgotten his name now, who was interested in cancer research. I felt at the time that it would be possible to produce a deuteron or proton microbeam to actually do a mass analysis of cancer cells and compare with other healthy cells. One could scan across the cell, the nucleus of the cell and everything. A typical cell size, I think, is 10 microns, so, I felt, if you could make a beam of 1 micron diameter and really aim it, then you could make a mass map of the cells, and that might be important in cancer research. That was actually the background for Ivar Aanderaa's thesis.

Vaagen:

Before we come back again to the period starting in roughly 1964, when contact again was established between Bergen and MIT, I'd like to hear a little more about your years at MIT, and I'm thinking about the High Voltage Company that was formed in the fifties, that is Dennis Robinson, John Trump and Van de Graaff. It would be of some interest also to hear about your contact with these people.

Enge:

Yes. I had my first contact actually in 1952, just before I left the United States for Norway, and I did a small piece of work for them as a consultant, and then --

Vaagen:

For High Voltage?

Enge:

For High Voltage Engineering Corporation, yes. And then when Professor Buechner asked me to come back to MIT, he also made a contact with High Voltage, and promised me consulting work. I actually started that work in Bergen, designing a spectrometer for the University of Strasbourg that was built eventually by High Voltage Engineering Corporation. The engineering part was done by me in Bergen, with the help of -- what's the name of the guy that eventually became director of Christian Michelsens institutt? I can't remember his name.

Vaagen:

Andersen?

Enge:

Yes, Jan Andersen. That's right. He helped me with that design. So when I came here, I guess it was about the 20th of August in 1955, Professor Buechner and I met with Dennis Robinson and he promised a retainer as a consultant for High Voltage Engineering Corporation. I must say that with the pay that I got at MIT as an instructor, which I was the first year, we would have turned right away around and gone back to Norway, if it wasn't for the fact that I could augment my salary at MIT with a consulting fee from High Voltage. As I recall it, my beginning salary at MIT as an instructor was $4800 a year, which was increased to $5400 after six months. And well, inflation of course has changed that completely, but even at that time, that was very skimpy to live on for a family of three. Especially we who came from Norway where we had our own home outside Bergen, had a car, and I had a good position at the University of Bergen. We were dumped down here in a small apartment, and it must have been rough on my wife, although she never complained.

Vaagen:

What was the price for housing at that time in the Boston area?

Enge:

Oh, I think we lived in Newton, and we paid $85 a month, I guess it was.

Vaagen:

So that took a substantial fraction out of your salary.

Enge:

That's right. But because I had worked with this consulting job for High Voltage Engineering Corporation, I actually got paid for that instantly when I came over here, and we were able to immediately buy a used car, so we could move around a little bit.

Vaagen:

Had High Voltage at that time redirected its main activity from medicine to more scientific instrumentation?

Enge:

That was just about the time, I would say, that that change took place, and of course, one of the examples was the accelerator for the University of Strasbourg which then included the spectrometer. And High Voltage really took off at that time, and of course, they had a monopoly, partially because the Van de Graaff patent was active, and so there was a long time before anybody else started to compete.

Vaagen:

How long could such a patent be kept? Ten years?

Enge:

No, seventeen. That's the usual running time. I don't know exactly when the patent was taken out, but at least it ran out, but it was quite a few years that High Voltage had a monopoly. Of course, the patent was owned by MIT, but I think since Van de Graaff himself was involved in the High Voltage effort, I guess they were given an exclusive license. Nobody else actually was interested in it, except at the University of Wisconsin. As you probably know, Ray Herb eventually more or less took over the whole business of electrostatic generators with, what's the name of the company -- National Electrostatic Corporation.

Vaagen:

Is it the correct impression that John Trump was the one who had been pushing medical applications?

Enge:

Yes. Oh, absolutely.

Vaagen:

And Van de Graaff was more on the scientific applications side?

Enge:

Right, although Van de Graaff, like me, was a scientist on the technical end of it. He was remarkably inventive. He not only, of course, invented the Van de Graaff machine, but all the new things like the tandem. He was the driving force to build the first tandem accelerator, and he invented the alternating gradient tubes. He invented the so-called insulated core transformer, and so he was really more an inventor than a professor of physics. Of course, as you probably know, he retired from MIT early because he couldn't stand up giving a lecture, because of his back problems. In his college years he was a football player at the University of Alabama, and he got serious injuries in the back and in a knee, and during the war, when his group here at MIT was involved with making Van de Graaff accelerators, two megavolt accelerators for the US Navy, he should have had an operation. He never took time for it, and then after the war it was more or less too late, and the spine had worn so badly that it couldn't be repaired. He had three operations and in one of them, he got infectious hepatitis and almost passed away.

Vaagen:

His taste for good food and also the quality of food is kind of a legend that the "young" men like me have heard. Was that accentuated?

Enge:

Oh, I don't know. At least he showed, physically showed, that he had good taste for good food, that's for sure. I guess I wasn't that close to him really, because he was very little at MIT after I came here. Either he was in a hospital, or he retired. One of the strange things, I must say, is that Van de Graaff, with his name, never was made a full professor at MIT. He retired as an associate professor. And I think that's a black spot on the physics department of MIT.

Vaagen:

Did that reflect some Mafia tendencies within the MIT?

Enge:

To some extent, and of course, it has to be admitted that he was not an outstanding physicist. He was an outstanding inventor. And I think that in later years, of course the physics department has grown. It's by now close to a hundred faculty members here, and whoever has been head of the department in the later years has at least seen that MIT is big enough so you can have people like myself, who's not an outstanding physicist but a designer, and there are more also at the moment at MIT, other people that I could point out that have not made great contributions in physics, but are making contributions in apparatus that other people have used in physics. Stan Livingston of course is an outstanding example.

Vaagen:

Yes, I'm thinking about people from Norwegian stock -- Lawrence, Tuve, Hafstad and so on, and also you -- it seems like the most outstanding physicists have had some definite inclination for engineering, when it comes to Norwegians.

Enge:

Well, maybe we are more geared toward engineering than the rest of the world. At least, you can see that in the earlier years of education. I remember, I don't know if it's like this in Norway now, but when I went to gymnasium, you know, all the boys wanted to take the mathematical, science mathematical line, and all the girls took the English-historical line, and at least I can recall, in Bodo we regarded the boys that went to the English line as sissies. And it's completely different in this country. The interest in science in high school is very, very low, compared to Norway. And it's amazing that in spite of that, such excellent results in development of techniques in science and engineering have been what they have been in this country. It's amazing. But of course it's true that a good deal of the inventions have been made by imported scientists or engineers.

Vaagen:

Although the theorists are sometimes considered being the gurus in some way of science, still it seems like in Norway, theory has struggled harder even than the experimental physics. That may also go along with what you were saying.

Enge:

Yes, that's true.

Vaagen:

So coming back again then to Van de Graaff. I have in front of me a list of the papers written in Bergen in 1952 and 1953, and in 1952 we find a joint paper with you and Van de Graaff with the title, "Search for Alpha Particles from the 16O(d,α)14N* Reaction." How come a young man could coauthor a paper with Van de Graaff at that time?

Enge:

Well, the background for that was that Van de Graaff had been out of circulation for quite a while, because of sickness, and when he came back to the group, he asked Professor Buechner if he could suggest a problem that he could tackle now, and join the group again. So Buechner said, "Well, there is an interesting theoretical problem that has to do with selection rules, and it can be tested with the 16O(d,α)14N* reaction." By chance I had some data lying around that could be used. Oxygen was present as part of the backing of my aluminum targets.

Vaagen:

So that in some way also brought him back again.

Enge:

Right, and he did an analysis of that, and my contribution was simply that I had the data as a byproduct of my other investigation at the time.

Vaagen:

When I read Dennis Robinson's description of Van de Graaff, I get a feeling that Van de Graaff was a person who really sparked off a tremendous number of ideas.

Enge:

He sure was.

Vaagen:

Not only in technical fields, but also fundamental ideas in science.

Enge:

Well, I can't recall that in particular. Of course I didn't have that much contact with him, as Dennis had.

Vaagen:

I think Dennis said at some point that he used to enter the laboratory and tell the engineers about how the universe was created and so on. Did this -- the wider context of science -- is that a correct impression?

Enge:

Yes, I'm sure that's right. With the relatively little contact I had with him, he was a remarkable person. He was very quiet, and very modest. I can remember in particular when I had worked on the first spectrometer -- that eventually became the broad range spectrograph that we had in this building -- he had an idea of a smaller spectrometer that he could still use on the old machine. He came to me with the idea, and asked me to look at it and see if I thought it was any good, and he was so modest. He approached me as the expert in the field, and he was just almost a student. And of course, the situation was completely the other way around. And that's the way he was. And he was also very difficult to communicate with, in the sense that if I had an idea, it was extremely difficult for me to explain it to him. And so, he basically worked alone, and also at High Voltage, because of his back problem, he was spending most of his time lying down. He had a sofa in his office there, lying flat down on his back and dreaming up ideas, and then he conveyed them to other people, so he had people like Peter Rose for instance, as one of his close associates at High Voltage, who was sort of the interpreter of bringing out the ideas to the rest of the company.

Vaagen:

Moving a little ahead to 1964, when Arnfinn Graue came to MIT, was that when the contact picked up again? Or had -- who took the initiative, was it the Bergen group?

Enge:

Yes, I think so. I can't remember the details. But I think probably he wrote me, and I just can't remember --

Vaagen:

At the time you also had a major accelerator breakdown.

Enge:

Yes.

Vaagen:

Previous, prior to his arrival, I guess. And he joined in the reconstruction work? Or how was that, do you recall?

Enge:

Did we have a major breakdown? We had many breakdowns, but I don't recall that we had any major one. We had, probably at that time installed resistors in the Van de Graaff machine to make a more uniform distribution of the voltage down the column. Before that we had used thyristors, which act more like a voltage regulator. After we installed the resistors, the thing didn't want to function properly, and we finally discovered what the reason was. We had an intermediate shell between the terminal and the ground and because of X-rays, produced in the terminal, we had a high ionization chamber effect in the gas of the machine. There was a current going from the terminal to the intermediate shell, and another different current going from the intermediate shell to the ground, and that threw a complete imbalance in the column, and that's the only time I can remember we had a major problem that we had to solve. That might have been the time when Arnfinn was here.

Vaagen:

OK. After 1964, the contact then picks up, and when I look at the paper production, I can see that joint papers are being produced up to 1970.

Enge:

Yes.

Vaagen:

And the group came from Bergen to use the multigap here at MIT.

Enge:

Right.

Vaagen:

Eric Cosman was I think one of the main collaborators also at that time.

Enge:

Yes.

Vaagen:

Was he your student?

Enge:

Yes, he was, and he took both the bachelor's degree and the PhD here. He was a research assistant in the group, while he was working on his PhD, and he later joined the faculty. As a matter of fact, his office is next door. He's still using this building.

Vaagen:

And the reactions being studied were mostly direct reactions.

Enge:

Right.

Vaagen:

(d,p), (d,t) and (p,p) reactions.

Enge:

And (3He,α).

Vaagen:

(3He,α). Was that also a field that was given priority here at MIT?

Enge:

No, we were completely autonomous and on our own. Whatever we wanted to study, we went ahead and did. Any member of the group could decide, "This looks interesting," and go ahead and make a target and put it in the multigap. So there was very little direction from above, even from Professor Buechner. If I had an interest in a given reaction, I just went ahead and did it. Of course, we had a number of ladies that were sitting behind microscopes and counting tracks. After we built the multigap spectrometer, typically we used to say, it takes about two weeks to do the planning and make the targets. It takes about two days to do the exposure. It takes the girls about two months to extract it from the nuclear track plate. And it takes two years before we get it off to the Physical Review. That was roughly the time scale.

Vaagen:

Looking at the pure statistics, one may conclude that for Bergen this contact with MIT really meant the revitalization of nuclear physics, and in fact, at the beginning of the 1970s, the number of graduate students produced in the nuclear physics group was close to 80 percent of the total number produced in Bergen. How did it work the other way? Was this a minor part of your collaboration with universities, or did it play a larger role?

Enge:

Well, we didn't have any collaboration with other universities, other people, on that scale. There were some others. For instance, one summer we had Bengt Elbek here, and one summer Ray Sheline was here, Fay Ajzenberg did some work here too. Bockelman who was a member of this group and then moved to Yale had students, at least one student here. That was Peter Barnes. So there were contacts, but only one-time contacts with other people, and I don't remember how many from the University of Bergen have been here. Do you know?

Vaagen:

I don't know the numbers, but quite a few, I think. Bergen added the manpower on the data treatment end of the project, on the scanning side --

Enge:

-- yes, right.

Vaagen:

And that brings me also to the investment made in Bergen in an automatic plate scanner, which I think was completed in 1973. How did you consider such an investment?

Enge:

Well, you know, we started it here. Per Hanssen was a technician at the University of Bergen when I came back in 1952. And he impressed me as a very capable engineer. He didn't have all that much education, but I guess he had teknisk skole [technical college] or whatever it was called at the time. So I asked him to come over here and design this contraption, and we worked on it, particularly he worked on it here. There are bits and pieces of it lying around as a matter of fact. I guess they've just been cleaned out.

Vaagen:

When was that?

Enge:

When was it? Gee, I don't remember without looking back.

Vaagen:

Before 1970. 1965?

Enge:

Yes, right. And then just as we started to get good results of the instrument he made here, he was swept up by Scanditronix. It was a contract with Scanditronix that produced the instrument for the University of Bergen. I don't know in detail how much that has produced. There were other people working on the same idea. One was at Argonne and the other was at Los Alamos. And in particular the one at Argonne produced an awful lot of data. I don't know, after the Bergen group started to go to Copenhagen, to the multigap there, they must have used the machine to a large extent to analyze data taken on the Elbek spectrometer.

Vaagen:

Mentioning Elbek, it seems like here at MIT, you gave priority to work on spherical nuclei, while the Danes liked to study collective modes in the deformed nuclei. Was that due to your own education or -- ?

Enge:

That's due to the fact that the Danes knew what they were doing. And we were just randomly picking a nucleus, not thinking about the significance of the study. Most of the time, at least, although we did have some directed experiments too, like isotopic spin and mirror nuclei and that kind of thing.

Vaagen:

But you had Lee Grodzins on the staff here at MIT.

Enge:

Yes, still do.

Vaagen:

Still do, yes. Did he interact with you on these studies?

Enge:

No, not at that time. We have merged since, so that the group that was originally the Van de Graaff group and Lee's group, which was originally the beta spectroscopy group joined forces and became the heavy ion group. And it still is, although Lee himself at the moment is maybe more interested in the background measurement of radon. That's what this building is used for at the moment.

Vaagen:

Yes, I noticed it when I entered, that there is some activity of that sort. I think we stop there.

Enge:

OK.

Vaagen:

We start again?

Enge:

Yes.

Vaagen:

Yes. I would like to spend some time on magnets. I'd like to hear you tell about the first magnet you ever designed, or ever constructed.

Enge:

Well, the first one was actually a beta spectrometer at the University of Bergen. That's the job I got when I joined the group there in 1948. And it actually wasn't finished before I left for the United States, so somebody else finished up that particular instrument. Then when I'd worked here for about -- oh, three or four months at MIT, then we started to talk about a new instrument. This was because the new Van de Graaff machine, the ONR machine, so called -- ONR stands for Office of Naval Research, they sponsored the machine -- needed a spectrometer. I had some ideas of using a sector magnet that I presented to Professor Buechner, and we both went up to Harvard to see Ken Bainbridge, famous mass spectroscopist, to get his input. He gave us the idea then of using a sector magnet with circular boundaries which produced second order corrections for the focusing. So I went back to MIT and drew up an instrument using those ideas, and that's the one that was built, one version for MIT and another version for the University of Bergen. The MIT version was finished after I left here by Cornelius Browne, and he and Buechner published the results. I never published the results of the instrument built in Bergen. So therefore it came to be known as the Browne-Buechner spectrometer.

Vaagen:

Was that in some way a pre-runner for the Enge Split Pole?

Enge:

Well, the Split Pole Spectrometer was actually designed, I should say, as part of my consulting work for High Voltage Engineering Corporation. But we are jumping the gun a bit. First I designed a modification to the Browne-Buechner spectrometer for Chalk River. Among other things they wanted to do coincidence work with a spectrometer as one arm. So they needed a large solid angle. I was invited to come up to Chalk River to discuss possible solutions. I remember I asked the group how large a solid angle they wanted, and Harry Gove gave me the memorable answer: "For some experiments 4π steradians are marginal." What I did for them was to put a quadrupole between the target and the Browne-Buechner making it a QD spectrometer in our present notation. The instrument could be rotated to the horizontal position which made it possible to produce "kinematic correction" by displacement of the detector. I believe this was a "first." In my paper I might have called it "Doppler Correction." High Voltage fabricated this instrument and two or three smaller modified versions. But back to the Split Pole. I got a small allowance from High Voltage for designing a new spectrometer, the Split Pole which is actually closest to an instrument that was designed by Bengt Elbek, generally called the Elbek spectrometer. It is a modification of the Elbek spectrometer which has a very broad range, and it also has very good second order correction. The modification was to put the split in it, and that made it double focusing, or stigmatically focusing, and the Elbek spectrometer is not. So the Split Pole was then offered, first to the University of Pittsburgh, and then almost at the same time to the University of Rochester, by High Voltage. They put a very high price on it, and the physicists felt it was too much, so they looked around for other producers, and came in contact with Curt Mileilkowsky in Sweden. He and Bo Sjogren then started a company, first in Switzerland, that took the job of making this instrument for the University of Pittsburgh and for the University of Rochester. The cost, as I recall it, was $120,000 per instrument, and what High Voltage had bid was $300,000.

Vaagen:

When did you do that design work for High Voltage? Was that the end of the fifties or are we in the sixties now?

Enge:

No, I think it was the end of the fifties. I'll have to look at the dates on the papers to recall that. That's probably closer to the truth. So since then, of course, Scanditronix has made about a dozen Split Poles, and I think there's only one that has been built by another company, and that's in Grenoble.

Vaagen:

Did High Voltage ever build the spectrometers?

Enge:

High Voltage built one Browne-Buechner spectrometer, and that was the one for the University of Strasbourg that we talked about earlier. They also built several QD spectrometers I designed.

Vaagen:

Well, I'd like you to tell your own story about this, but of course the Q3D is also an instrument that is linked to your name.

Enge:

Yes, well, the next step actually was the multigap that we built at MIT, and that was conceived, I recall quite clearly, just months after I arrived here in 1955, when I came back here. And I do remember that I presented the idea to Professor Buechner in a party we had in my apartment in Newton, just before Christmas, in 1955. And so, with partial help from Marcos Mazari from the University of Mexico, and also later from Joan Freeman from Harwell, and the rest of the group here, we built this instrument. We first published the idea in, I guess, the 1955 Yearly Report for the Laboratory for Nuclear Science here at MIT. That report was picked up by people at Aldermaston in England. Roy Middleton told me later that his first reaction was that "those guys are crazy." And then one year later he said, "No, they have the right idea." So he got the engineering department at Aldermaston working on the project, and he had an instrument ready to take nuclear data one year before ours was ready. In other words, we built ours in four years, he built it in two years.

Vaagen:

Would it have been possible to take out a patent or an interest on an instrument like that?

Enge:

Probably, although we didn't really think about it at that time.

Vaagen:

But the whole concept of a multiple gap spectrometer, was that sparked off at that time by the understanding that the direct reactions had to be revealed by having many angles to look at?

Enge:

Yes. Of course we had the broad range instrument, the Browne Buechner instrument. We had used that, or I shouldn't say we, because I hadn't been there that long, but in fact it had been used for quite a while then for studying direct reactions. And what we found in general was that we never were able to complete one full angular distribution on one target. We always broke the target, and when we put in a new target, we had to renormalize to get the right angular distribution, and it was generally a pain. And we also had to be very careful about the target angle. If you changed the angle, you changed the effective thickness of the target. So all these considerations, and also the consideration of expediency, I guess, led to the design of the multigap. It was used over a number of years almost exclusively for direct reaction studies, (d,p) and (p,p) and (3He,α). (3He,p). Those types of reactions.

Vaagen:

You mentioned $120,000 for a Split Pole. I suppose it required some courage to come up with an idea for a multiple gap spectrometer. How was the money raised for such a --?

Enge:

OK, the money for the multigap was part of a package that the Laboratory for Nuclear Science got from the Air Force Office of Scientific Research. It was $25,000 for the multigap, believe it or not, and a certain amount which was larger for making a central data collecting station at MIT, with coaxial cables all through the various areas, like here for instance. Well, eventually the multigap I think cost the Laboratory for Nuclear Science something on the order of 70 or 80 thousand dollars.

Vaagen:

Was the cooling a major problem?

Enge:

Well, the coils were made with very large hollow core conductors, so it wasn't too difficult to feed water through those, although eventually, since we used Cambridge city water, they clogged up, but we were able to clean it out again. There was some professional guy that specializes in that, that came around, ran a chemical solution through it, and cleaned out the Cambridge dirt.

Vaagen:

You couldn't afford oil instead of water in the coils?

Enge:

No. Of course what they do mostly nowadays in any laboratory like this is to have a closed water circuit with a heat exchanger for the city water. So we never had that. After we clogged it up and had to clean up, we put filters in the waterline, and that really took care of it. The multigap of course eventually was moved to Brookhaven, when this machine was closed down, and it was used with the Brookhaven tandem accelerator for a number of years before they got the Q3D.

Vaagen:

That was in the early 1970s?

Enge:

Yes.

Vaagen:

What about the Yale multigap? Were you involved in the construction of it?

Enge:

No, that was done by Roy Middleton. And --

Vaagen:

He was in Philadelphia at that time?

Enge:

Yes.

Vaagen:

Did Philadelphia ever get one?

Enge:

Yes, they do have one. I don't know if it's operating now, but yes, they do. I think eventually there were about eight multigaps that were built during -- around the world. One in Heidelberg, one at Aldermaston, one at Yale, one at MIT, one at NBI, one at the University of Mexico, I can't remember -- Philadelphia, right.

Vaagen:

And in some way, from the multigap then we go back again to the single gap, the Q3D?

Enge:

Yes, well, one of the visitors that we had here one summer was Chris Wiedner from Heidelberg. He wrote me later and asked if I would consider redesigning the Split Pole in order to produce a larger solid angle. And so I said, "I'll do that." I've forgotten exactly, but I don't think we had any contractual arrangement; I simply did it on my own. As a matter of fact, I also hired a girl who'd just graduated with a PhD here for a summer to work on the idea, and we did get some semi-decent results. I went to Heidelberg for a week, to discuss with the people there, and also with a group from Munchen that was working on the same problem. So we came to Heidelberg and compared results, and the upshot of the meeting was that the designs didn't really fill the bill for what they were looking for. So I said, "Well, I do have another idea. I'd like to go home and try it out." And again, as I recall it, I think I paid for computer time and assistance and everything out of my pocket -- or my wife's pocket it may be more appropriate to say. That was then what became the Q3D.

Vaagen:

For the record maybe you could mention the main essence of the Q3D.

Enge:

Well, what the Heidelberg group required was this: There had been some recent development in electronic detectors, and what they required was a momentum resolution of one part in 10 to the 4th, with one millimeter spot size on the detector, because that was what they expected the detector resolution to be. So in other words, it had to have a very large dispersion, a dispersion five times that of the split pole, and that was accomplished by having a vertical crossover in the middle of the instrument. This produces quite strong vertical focusing, and as a byproduct a large dispersion in the horizontal plane. The instrument as originally built with a quadrupole and two dipoles, also had a multipole corrector with quadrupole, sextupole, octupole, and decapole built into it. The detailed design of these things are done with the program Raytrace which I originally developed, but later Stan Kowalski, my colleague here, has been the keeper of the program. I have to insert at this time that my collaboration with Stan Kowalski, as far as I'm concerned, has been extremely fruitful. We have collaborated on a large number of things -- MIT magnets, and spectrometers or magnets for other laboratories. He is an expert in computer programming, at the same time as he is a very capable nuclear physicist, and magnet designer. He collaborated with me on the Q3D and particularly the first Q3D for Heidelberg, which was also adopted by the Munchen group. Scanditronix made the two in parallel, one for Heidelberg and one for Munchen. Later then, we, or I, designed several versions of it. I spent one January in Strasbourg, and designed a Q3D with a bit broader range for the University of Strasbourg, and then finally together with Anne Drentje from Groningen in Holland a version which I like best, the QMG2. There are all kinds of names. The one I designed for Strasbourg was called QWTH5. I remember that Andre Galman, the leader of the group, had fun of telling the group assembled to discuss this instrument what that stands for. It was close to the end of my stay in Strasbourg, and I said, "What the hell, let's try one more approach," so the WTH stands for What The Hell.

Vaagen:

And the name for the one in Groningen?

Enge:

QMG2 is Quadrupole Multipole and then we gave up, because there were so many poles that we said simply G for Groningen, and version number 2, QMG2. And that's the one that has been copied for Daresbury and for Peking and for Berlin. Anymore? Altogether, I guess, again, there have been about a dozen of these instruments. There's a patent on it which I own, or my consulting company owns, and that is called Intermediate Image Magnetic Spectrometer.

Vaagen:

What about the Soviet Union? Do they have any similar devices? Did they ever have any similar devices?

Enge:

I frankly don't know. The only thing that I've read about work in the Soviet Union has been in heavy ion physics, and so I don't know anything about their light particle physics or charged particle physics work.

Vaagen:

Would it have created problems to export instruments of that type to Soviet institutes?

Enge:

I wouldn't think so. Of course, these things have all been made in Sweden by Scanditronix, and I don't think there would be any -- there is no secret involved that would concern anybody at all. And of course it was exported to China.

Vaagen:

To China. When it comes to maintenance of such an apparatus, does that require the company people, or may it be done by local people?

Enge:

It's all done by local people. But of course, generally there is a guy that has that as a responsibility, the maintenance, I mean, one of the physicists that is in charge of looking after the instrument. At Brookhaven for instance it's Mike Levine. And at Groningen I guess it's Anne Drentje and so forth, in Strasbourg it is Robert Rebmeister and so there's always a physicist that's involved in it. And generally, of course, these physicists have been here, collaborating with me to some extent, in particular Anne Drentje when we designed the QMG2.

Vaagen:

Would you like to say something about the business aspect of this, your consulting company? Has it turned you into a multimillionaire?

Enge:

Well, the business which is a family corporation called Deuteron Inc., was really started by my wife, believe it or not. She had a company that did work in particular for Argonne National Laboratory counting nuclear track plates, a microscopy company. She had up to three girls working for her, and so she registered a company called Proton Company, which was not incorporated. And then, when I started the work on the Q3D, I decided to join forces and take my consulting work together with her work and then naturally that became Deuteron Inc. And since then, she has long since stopped working. I mean, after they got the automatic plate scanner at Argonne, that work petered out, and so she stopped doing that and started studying instead. Deuteron Inc. owns the patent on the Intermediate Image Spectrometer. We had some income as royalties from Scanditronix, typically on the order of $10,000. Well, sometimes a little higher. So with twelve instruments built, you can see that it hasn't been all that lucrative, but at least it has given us a little bit extra income. But by a long shot it has not made us rich. Deuteron Inc. has been involved in other things. I've been involved from time to time in ideas about making high voltage apparatus, or high voltage power supplies, by various electronic tricks, with rectifiers. I think I have altogether about 20 patents. About half of them are on magnetic spectrometers or that kind of thing, and half of them are on high voltage power supplies. Two other people and I started a company called Delta Corporation, to produce some power supplies, utilizing one of my patents. That company actually started with a contract from the only producer of electron microscopes in the United States, a company called Forge Flow, and we had a capital of about $200,000. We expended all that capital in developing that power supply, and then Forge Flow went broke, and we were sitting holding the bag. But we had taken other contracts too from other places, and sales were going up. But this was in the beginning of the seventies, which was really an impossible period for trying to raise more capital, so eventually we sold out to High Voltage Engineering Corporation. And they continued building these power supplies, mostly for CAT scanners, until the people that made the CAT scanners discovered that they didn't need those high precision power supplies. So they bought cheaper ones, and then the effort petered out at High Voltage. So that was my entry into the high voltage power supply field. I have some other ideas that might perk up again, but right now, they are sleeping.

Vaagen:

We'll come back to that.

Enge:

OK.

Vaagen:

Thank you. We were speaking about companies and magnets and so on. Does it surprise you that so few physicists have become millionaires in the technology boom since the Second World War?

Enge:

Well, some people of course have made money, but not directly in this area. I have a couple of friends that have become millionaires, but both of them broke out completely from the academic environment. One is Dr. Peter Rose who actually is a nuclear physicist. I met him first at MIT in 1950, as a matter of fact, or 1951. He was with High Voltage Engineering Corporation, broke out from there, made his own company together with some other people to produce ion implantation equipment and hit the fields exactly right -- the market, I should say, exactly right -- with the right product, and the company boomed. It wasn't very many years before they had a thousand people working there. And he eventually sold out, but I don't know how much money he made on it. It was some friction there, so that's the reason he sold out -- and he started a new company exactly in the same area, and that grew larger than the first one. He's still the manager there but the shares have been bought out. So he's twice become a millionaire, making a company, and he is now in the process of making a third one. So I don't know. I have another friend who's a Norwegian, actually. You might have seen the name because he's been talking with the Norwegian government about LORAN C Navigation Transmitters. His name is Paul Johannessen. He started his company in 1969 and sold out about four years ago for 18 million dollars. He started with no capital, just a contract and a loan from a bank. He was also at MIT but in electrical engineering, and spent some time in another company first before he made his own. So I've seen it happen, but it hasn't happened to me.

Vaagen:

This was also meant as some kind of threshold, to have your opinion on the relation between industry and science. As you may know, also in Norway we are getting science parks in connection with universities. We are getting one in Bergen and also Oslo it seems now will be getting one, and on the Norwegian scale, and compared with the size of Norwegian universities, this may mean a lot, and I wonder how you feel about such a collaboration between science and industry?

Enge:

Well, I am very positive in that respect. MIT of course has been on that track ever since it started. MIT was founded in 1861, and the statutes of MIT spells out that it's supposed to have its major activities in three areas. One is to educate young people in science and engineering, the second is to give public lectures in science and engineering, and the third is to promote industry in the state of Massachusetts. The second part is of course not really very active now; there are very few public lectures given. But the first and the third part have both been extremely important for Massachusetts. I think I mentioned earlier too that a very large number of very important industrial developments in this state, or Commonwealth as we call it, have sprung out from MIT, and the majority of those that came out of MIT have been started on the private initiative of people that have been allowed to pursue their outside professional activities. I have a little perspective on this, because some years ago I was chairman of the faculty committee on outside professional activities, and I remember, I got a call one time from the Boston Globe. Some reporter there was extremely upset because some ideas that had apparently come out from MIT seemed to be utilized by the private initiative of whoever invented this at MIT, and shouldn't it belong to MIT? Well, sure it does. MIT has very, I shouldn't say relaxed rules, but at least rules about inventions and patents that are very easy to live with. If you make an invention completely on the outside, as an outside professional activity, you have to report it to the MIT patent group, but you own it. If you make an invention on MIT time, and MIT is not interested in pursuing it, you can patent it. If it is a very important invention, well, then MIT does take an interest, and covers the patent costs, but part of the royalties, whenever they start coming in, go to the inventor, the other part to MIT. That was the case with the Van de Graaff patent, for instance. It's an extremely productive policy. The private initiative is the driving force for, not necessarily making a million dollars, but just seeing what you have created being produced. To me, at least, that's more important than the dollars, which, as I told you earlier, I haven't made very many of, but I have seen a lot of the things that I've had fun creating been put into production, because of those liberal policies here at MIT.

Vaagen:

What do you feel about private companies sponsoring certain activities at an institute like MIT, or at the university?

Enge:

Well, that's another aspect. There were two, of course. Here you have something called the industrial liaison group. A large number of companies, US companies and foreign companies too, are members of this group, and they regularly get a monthly newsletter from MIT about new developments. They can turn to MIT with their problems, and they can sponsor a group at MIT, a particular professor and his students, that then will work on their specific project. We in the physics department are, however, mostly sponsored for our research work by government agencies.

Vaagen:

What about patent rights? Would such a company be able to claim something that's been developed?

Enge:

Well, the sponsor can, I would think. I must confess I can't truthfully say I remember the details of these things, but in general, the sponsor owns the patent rights, and that certainly is true when the US government is the sponsor, which of course is the case with all nuclear physics work. You develop an idea, and you use your desk and you use a pencil belonging to the government, but otherwise do everything outside -- technically, the government can come and say they own the invention. I'm not quite sure if it's that strict when the sponsor is a company. There might be agreements between the sponsor and MIT which do not necessarily follow exactly the same pattern all the time. But it certainly is true that there's a lot of sponsored work at MIT, coming from industry. But I would think, although I don't have the figure in front of me, that the majority of the sponsored work comes from the US government, either from the Department of Defense or the Department of Energy or the Department of Health and Human Services. They are the main sponsors.

Vaagen:

Has this close collaboration with industry created problems when it comes to keeping good people at MIT?

Enge:

No. I don't think so. I think on the contrary, the fact that MIT takes in an awful lot of outside money means that a given professor can add people to his group. For our group here, the sponsor is the Department of Energy. But even we have had another contract which happened to be with General Motors, and that was for one PhD student to pay his research assistantship and also some of the equipment that he needed for his thesis. His thesis was on one of the topics of my own thesis, namely, the scattering mass analysis. General Motors at one time was interested in looking at that, for their own laboratory. And so we got a student here that, you know, was another hand in the group. He was working on his project, but also was a member of the general crew -- running the machine and so forth. I would say it's hard to find any negative aspects of this relationship.

Vaagen:

I've been given numbers indicating that research within industry may be four times as costly as research within a university or state-financed institute, and I think Ivar Giaever was the one who told me that there seems to be a shift now back again to have a larger fraction of research done at the cheaper places. Is that a tendency you also seem to notice?

Enge:

Well, I don't particularly think I notice that there has been any change here at MIT in that respect. We have always got good sponsorship, good support from the government in our area, and I know too little about the industrial area to really say anything about it.

Vaagen:

Let's come back again then to your inventions of various sorts. I've been reading that Van de Graaff was fascinated by ideas about transuranic accelerators, towards the end of his life, and I also note that you have constructed a mass spectrometer which is operating at Brookhaven, I guess.

Enge:

Well, it's dismantled now.

Vaagen:

Dismantled now?

Enge:

Yes. I think people have sort of given up on the super-heavies. At least I haven't heard very much about it lately. We designed an instrument for which the main idea was to try to look for super-heavy elements, with heavy-ion reactions of various kinds, usually intermediate heavy on another intermediate heavy target, to produce a super-heavy. Of course, the people that are in the foreground of that are at the UNILAC in GSI in Germany.

Vaagen:

And also Flerov in Dubna.

Enge:

Yes, right. So we were trying to get into that area too, and I designed this, what we call a recoil mass spectrometer. We didn't have much luck with it, the way it was designed originally. We didn't have the right kind of detectors, and I guess we didn't spend enough time developing the detectors. And also it really had a flaw, I must say, in the original design, in that the products, the recoiling products, we were looking at were spread out over too large an area, so there were background problems. So what we ended up with doing for years at Brookhaven was to use only a small part of that instrument, which was a velocity selector in front. We used the velocity selector to separate out the recoiling reaction products from the beam, with some success, and published several papers on that. We did produce some new isotopes of known nuclei, and we also made serious attempts of producing super-heavy elements. In particular, we bombarded uranium with chlorine to -- let's see, uranium and chlorine, 92 and what's chlorine? It's 17, isn't it?

Vaagen:

Yes 17.

Enge:

Well, anyway, we were shooting for a compound nucleus which was quite far removed from known species. We were looking for high energy alpha particles, because according to the systematics, we expected a series of four high energy alpha particles in the cascade from the compound element 109.

Vaagen:

That was at the end of the ridge, in some way, hadn't made it to the island of super-heavies --

Enge:

That's right. That's right. But it was still quite far removed from anything that was known. Much higher neutron number than the element 109 that was produced at GSI. We saw an awful lot of alpha particles, some of which didn't fit into any well known decay scheme. But we couldn't say that they belonged to a chain from 109. They didn't fit that systematic either, so we eventually gave up on it. This was in collaboration with Harvey Wegner at Brookhaven, and also with a young man from the University of Lowell in Massachusetts, Walter Schier. Anyway, the thing petered out, also because at Brookhaven they started to soft-pedal the use of the tandem accelerator for low energy, or relatively low energy, reactions, and use it only as an injector for the AGS. So the group here at MIT, which as I told you earlier was a merging of the Grodzins group and the Van de Graaff group, to become the heavy-ion group, they are now deep into the high energy heavy-ion game. They actually have run a preliminary experiment, although I don't know if they have any interesting results from that. They are, of course, looking at completely different things, namely phase transitions in nuclear matter.

Vaagen:

Quark-gluon plasma.

Enge:

Yes, exactly.

Vaagen:

I'd like to come back again to your perspectives on the field. It's well known almost to any student of nuclear physics that there is a textbook that carries the name of Harald Enge. How did it come about that you wrote a textbook, and at whom did you aim it?

Enge:

Well, I guess I started to teach atomic physics for mostly electrical engineering students here at MIT in 1957, and then the head of the department, which was Ned Frank, said, "We need a course in nuclear physics for undergraduates," and he asked me to develop it. So I did develop a one semester course in nuclear physics for undergraduates, and then I was approached by some publishers. At the time they were extremely hungry for textbook manuscripts. So we had a period where, I remember, my wife and I went to New York on the Physics Society meeting, and I don't think I paid for a single meal myself, because we were wined and dined by publishers that got to know that I was preparing a manuscript, or at least had started one on the basis of my course. So eventually, it became a book and was published by Addison-Wesley. It's been very satisfying, in the sense that it sort of tickles me when somebody comes from Indonesia and say they have studied nuclear physics from my book, or from whatever, and it's brought in some royalties too, but I can't say that it's been very lucrative. Of course, here in this country, if you write a best-seller in fundamental physics, mechanics, electricity and magnetism, you may become a millionaire in a couple of years. Certainly you will not in nuclear physics. And the field has really tapered off completely. Addison-Wesley was a good choice, as a matter of fact, because they are very active in foreign marketing, and they publish a cheaper version -- in the beginning it was printed in Japan, now I guess it's printed other places -- which, when the original book here sold for 12 or 13 dollars, there were some selling overseas for 5 dollars, and there were very few other books that could compete with it, so it's really been spread around the world because of the active marketing by Addison-Wesley. I counted up some time ago, because they were considering a second edition, and it has sold altogether about 40,000 copies.

Vaagen:

That's pretty good for nuclear physics.

Enge:

Yes. Now I have a younger colleague, Robert Redwine (MIT), who is busy rewriting some of the chapters, so eventually we will have a second edition. He will do most of the work. You know, I haven't taught nuclear physics for many many years, so I'm not really competent to rewrite it. But he has been doing that, and is doing the rewriting. I've contributed some things too, more practical things, to that rewriting. In another two years or so, there should be a second edition.

Vaagen:

How do you consider yourself as a lecturer? Are you the type who likes to do glamorous performances, or do you like to have your students sweat and do some work on their own?

Enge:

Well, I don't know. I'm a little discouraged by the fact that when I came to MIT, I was an extremely popular lecturer, and I've sort of tapered off. You know, we have a grading system at MIT, and the students grade the lecturers, and I think before I quit, I was just average. In the beginning, I sort of was floating high on very good reports, although at that time we didn't have any direct reports, but at least I had reason to believe that the students liked my presentations.

Vaagen:

Do you blame this development on the way students have developed more than on the way you have developed?

Enge:

Probably both. Yes. I think.

Vaagen:

But you like the pedagogical work; you find it challenging?

Enge:

Yes, I like to lecture. In later years, what I've done is mostly lecture electricity and magnetism. And most of the time to smaller classes. You know, an MIT freshman class in physics may have 900 students or so. You have to split it in two. But then there is the off semester -- people that either come in ahead of the game, or they have fallen behind. And that typically is a class of 100 to 150 students, and I have enjoyed doing those classes quite a bit. Also, at MIT you don't really teach the same topic for too many years before you switch over to something else, and I have been around in everything, almost every undergraduate course. The hardest one I ever taught was advanced mechanics. You know, the second round of mechanics, where you get up into theoretical physics. That was hard work for me, especially because I hadn't touched the subject myself for 20 years when they asked me to take it on.

Vaagen:

Looking now into the future, do you see any followers, does the type of nuclear physics and nuclear physics instrumentation that you have been involved in, does it have a future, where you see young people carry on the tradition?

Enge:

Well, I think the interest for the kind of nuclear physics that I've been involved with -- the charged particle reactions -- has petered out completely. My sneaking suspicion is that also in heavy-ion physics, the interest isn't that high, among the young people, and neither is it, in the United States, with the sponsoring agencies, which are the Department of Energy and the National Science Foundation. They keep some laboratories going, but it's been going downhill as far as the volume is concerned. The interest in nuclear physics, or low energy nuclear physics such as that I have in my book, is very low. Typically, at MIT, when I started that, I remember one semester, I had 80 students in the course. That was the peak. The last time it was taught was about four years ago, and there were three students. And it was even Feshbach teaching it. I don't know why, but at least at MIT, nuclear physics is not popular. I remember, I talked with a guy from Oxford, and he said, "How could you possibly give a physics degree at MIT without nuclear physics?" He was teaching it to 200 students at Oxford, and here we didn't have it at all.

Vaagen:

That must have been some time ago at Oxford.

Enge:

That was about five years ago.

Vaagen:

What do you think about the hunt for the phase transition?

Enge:

Oh boy, I haven't really been into that. I have to follow it from a distance. I made some contribution to the effort at MIT, but only as far as designing a magnet, and doing the calculations of the optics of the magnet -- that was all my contribution. And I listened to talks, of course, about it, but I haven't followed it closely. It seems to me, at least, that that's an effort which, if you find it, where does it lead? Does it lead to a larger area of physics that is interesting or necessary to pursue? And from my very distant perspective, I don't see it.

Vaagen:

Will the more normal temperature superconductivity that we might have in front of us lead to changes when it comes to magnets and the type of physics that you were involved with?

Enge:

Well, from the practical point of view, yes, certainly. If they really can produce good conductors with this, that will certainly change a good deal of the magnet design both for accelerators and for secondary stations, for spectrometers and beam handling systems. Very exciting, but of course we have to wait and see if they really can produce.

Vaagen:

So you still have a number of ideas you think about, so to be a retired professor at MIT doesn't mean that your office is closed and the professor has left?

Enge:

Well, I don't very often come into MIT, but I do quite a bit of work at home.

Vaagen:

We were speaking about what the retired professor is doing.

Enge:

Yes, I do have some fun still working on basically magnetic spectrometers and similar things. I do have a computer terminal at home, and I'm able to buy cheap computer time from a computer here at MIT. It's the Whitaker College of Health, Science and Technology. And I do work for instance, for the Los Alamos Scientific Laboratory. I've had steady contacts with them over the years. For instance, I and Stan Kowalski, my colleague here, did the original optical design of the so-called high resolution spectrometer at Los Alamos. I don't know if you've seen the huge instrument for 800 MeV protons. That's the biggest job I've had for Los Alamos. I had some other smaller ones though, and occasionally there are people around this country or Canada who call up and ask if I can help them in the design of some beam components or beam line or whatever. So I have enough to do in consultant work. As a matter of fact, I'm just finishing a job now for Darmstadt for the electron facility at the Technical University at Darmstadt. It's about ready to go out, a design I made for them. Other than that, my lawn looks much better than it used to before, and I'm building a bathroom for our summer home for vacationing in Maine.

Vaagen:

Are you a devoted fisherman?

Enge:

No, I'm a devoted man of the water. That is, sailing and water skiing and just simply taking friends for a picnic. When I retired from MIT, they gave me a big retirement party, and the gift I got was a wind surfer -- I guess you'd call it "seilbrett" in Norwegian. I haven't really mastered it yet, unfortunately. But I'm working on it. Have you ever tried that? It's very difficult. I mean, I do water skiing on one ski, with a rope around my heel, for instance, so I have a fairly good balance, but boy, this is a difficult thing to do.

Vaagen:

You spoke about family and your wife, and now that they have been in this country for 32 years, is it so that the whole family finds this international experience a rewarding one?

Enge:

Well, my wife is still a Norwegian citizen, but if I should pass away, I'm sure she would stay here. My oldest son is an anthropologist, and the two youngest ones are in electrical engineering, one is a professor at Worcester Polytech, and the other one is a manager at a computer company, so we have been very lucky in raising our children. It may have been hard originally to leave Norway for my wife, but for me, it was the thing to do, and she went along with it. She is completely acclimatized to this country, has very good friends here. One thing I should have mentioned, of course, as a token of gratitude is to your University of Bergen for making me an honorary doctor. In addition to the Bonner Prize it was one of the highpoints in my career.

Vaagen:

Thank you very much. OK, that's it.