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Interview of Sten von Friesen by Charles Weiner on 1971 October 22,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
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Research, mostly with cyclotrons, at Cornell University and the University of California, Berkeley; building Sweden's first cyclotron as part of the new Research Institute for Nuclear Physics in 1937, under Manne Siegbahn's directorship. Background and science interest in electron diffraction; people he met during six months spent in United States; meetings with other European cyclotron builders; characterization of Professor Siegbahn.
Maybe we can start from the beginning, in the sense of determining some of your own background in physics. I know that’s very hard to do because you can’t put everything in a capsule, but maybe we can start with the fact apparently that you were interested in science, up to the point when we’re going to pick up our story.
Well, I was born at Uppsala, as most Swedish boys, my idea was to become an engineer. We have an engineering tradition in Sweden. But the Institute of Technology was in Stockholm, and since we lived at Uppsala, my father said, “Why don’t you just try and see how you like it at the university first?” And so I took the ordinary courses of chemistry, physics and mathematics, and this meant that I had to work at the Institute of Professor Manne Siegbahn. And I got, of course, interested. I wanted to go on studying physics. Once I had seen Professor Siegbahn’s lab I didn’t want to leave it any more.
What time was this?
This was in 1928. I started on the elementary courses in physics in 1927 and then in 1928, after I had passed the examinations, I went on to do research work in X-ray spectroscopy, and I did that for about a year, and at that time, the electron diffraction had been found. And one day Manne Siegbahn said, “I think that it would be interesting for us to learn something about electron diffraction, so why don’t you try to show us in a seminar about three weeks from now what electron diffraction looks like?” So I constructed a simple electron gun with electron optics and put in a gold foil and a fluorescent screen, and it was just as simple as that. I was able to show electron diffraction rings to the seminar three weeks later, definitely the first electron diffraction rings seen in Sweden.
You had read the papers in the journals?
Yes. We now knew what that was like. This of course meant that I took up electron diffraction work, and wanted to check the de Broglie law, and I made my thesis on “precision measurements of electron wave spectra” which either was a check of the de Broglie law, or if you believe in it, it was a determination of the electronic charge and Planck’s constant. This was at the time when there was a controversy between the Robert Millikan value of the electron charge and the new value, the X-ray value, which had been found by Erik Backlin at Uppsala and J.A. Bearden in the United States. And my value came out in support of the new value. I kept on doing some work on electron diffraction, form factors and things like that Siegbahn had been promised a new institute in Stockholm, a research institute, which was called at that time the Research Institute for Physics and was a Nobel Institute at the Academy of Sciences, and this was going to be built at that time; so in 1937 he came to me and said, “I intend to have a cyclotron in my new institute, and I wonder if you’d be willing to go to the United States and find out how to build cyclotrons.” He had been in contact with his old friend Dr. Floyd Richtmyer at Cornell, and asked him about what I ought to do, and then he said that I think he ought to come first to Cornell, there Dr. Livingston has the smallest working cyclotron in the world. That would be a very good starting point. So I worked there for some months with Dr. Livingston’s people. The two young people working directly on it were Marshall Holloway and Ben Moore. And I worked with them for some months, to learn as much as possible about cyclotrons. With that background, I moved on to Berkeley.
May I ask a few questions? A number of things have, come up. When you entered the university, and your father advised you to try Uppsala, had he had any university background?
He was a professor of Scandinavian languages at the university. So it seemed to him of course that it would be, from an economical point of view, easier to study at Uppsala, for one thing, and then I thought he knew more about the university than I did, of course.
The other question, what degree steps were involved?
My first degree was filosopie magister, F.M. [master of philosophy].
Is that similar to what in Denmark is called cand. mag., the magister?
I think there are differences, and I’m not quite clear about them. After you have left school, you know, in Sweden we started in the university at the age of about 18, at that time, and then one study for this first degree for about three and a half years, and you had to have three subjects or, in my case, chemistry, physics and mathematics, and two points in each but you needed one more point for an F.M. which some people got by studying astronomy for one term, theoretical physics or something like that. In my case I studied theoretical physics, but I never appeared for an examination, because when I told Manne Siegbahn that I intended to do that, he said, “It’s more important that you have been there, than you pass that examination, so don’t spend time on that.” I was working at that time in his lab. So what I did was to take an extra point in physics, a three instead of a two, and that gave me a sufficient number of points. You need seven points for that examination. In my case two in chemistry, three in physics, two in mathematics.
On the theoretical course, did you touch on the new quantum theory?
No, not at that time.
They usually lag a good deal.
Yes. That was not given in the elementary courses in say 1928, ‘29.
What would be covered in theoretical, as differentiating from regular?
That was of course mechanics to a large extent, you know, the laws of motion and forces and such things. Well, —
That was the first degree.
That was the first degree. Then one worked for the second degree, filosopie licentiat F.L., which more or less corresponds to a normal American doctor’s degree. You work for about three years, three to four years, and you publish in international journals a number of papers. But there is no formal dissertation being defended in public the way our doctors’ thesis is being defended. But one has had to publish things which were accepted in international journals. Then there were a number of examinations on the different parts of physics. So this took me until 1933, to get this degree. After that, I started on my work in electron diffraction for my full doctor’s degree, which I got in l936. The “promohire” takes place in May only. I mean, I — we had the public discussion in December, 1935.
During this time, from 1928 on to 1935, did you have any responsibility in the university, as an assistant?
Yes. I was what was then called amanuens, which is a teaching assistant. But I was rather fortunate in not having to spend too much time on that, because I was actually, at the time teaching a course in glass blowing and metal work which was given each year to the undergraduates, and this was done in a month or two, and left much time for research work, and then of course one had as amanuens certain other responsibilities in the lab, to see that things were going — for example, I remember having to take care of a photographic darkroom and see that things were in order there. I constructed and built a magnifier, and did things like that. I taught photograph to Dr. Julian Ellis Mach who was then working with Siegbahn. Mack later became the official photographer of Alamogordo. There were tasks of different kinds in the lab which had to be done, and an amanuens was told to do such things. I don’t remember any details, but you know there are those things which have to be done. But I didn’t have much teaching responsibility during that time, I must say.
Did you find you had a knack for working with metals and glass? Did you discover that when you started the university, or had you had those kinds of skills?
No, I must say that I had never thought about how one could produce and make things from metal. I had never seen that before. I was a bit surprised to see all those things, the lathes and things, and see that you could handle even steel that way. That was new to me, but of course I had always been interested in using my hands and so I picked it up rather quickly, I think, I had passed through that course myself, and then I had of course practiced a bit. Actually after that, when I was working for my thesis, I found that I’d have to wait for a while to get some parts for my experiment, the vital parts inside my apparatus. And so I made them with my own hands to save time. This was fairly simple work, but still I knew enough to be able to go down in the shop and make a few things myself.
You say you always liked to do things with your hands — as a boy, you were a tinkerer or worked with radios?
I worked of course with radios and things like that. At that time we all built our own radios. I built my first one in 1923. I think. Which was quite early. It was at the time when to have a license for a radio receiver, it cost 40 Swedish crowns, which was quite out of the reach of course of a schoolboy at that time. So what we did was to build them all the same. But then the authorities had a stroke of genius and they lowered the course to 3.50, and everyone registered and — then of course it started to move up again.
That’s interesting about the radios, people like Merle Tuve and Ernest Lawrence did the same thing.
Oh yes, that was the natural thing to do for a boy at that time. You know, the old thing with pill boxes for coils and making condensors by gluing tinfoil on glass plates and things like that. That’s what we did. And we of course were climbing on roofs putting up aerials and all the old women were standing shaking their heads, saying, “Get off.”
That’s interesting, such an international tradition. That’s good background. What about the other people in the university. Were there many other students?
Oh yes. This was a very active group. The year when I passed through the elementary lab, that was 1927, there were with me in that group, 18 or something like that, and among us were Bengt Edlen, the well know spectroscopist, Hannes Alfven, and a number of other people who later became professors of physics in Sweden. There was Arne Sandstrom and Torsten Magnusson, who is now director of the Swedish defense research establishment, director general of that. He was Manne Siegbahn’s personal assistant.
These were your classmates.
Yes. I think about half of us sat down in occupied the different chairs in the country a few years after that. So for a while we were actually dominating Swedish physics, experimental physics.
All of them went through the same pattern you did, getting the doctorate about the same time?
Yes. Alfven was probably about a year quicker. He did not take chemistry. Edlen was slightly before me, arid so on. They were — well, Alfven never did any spectroscopy at all. He always despised spectroscopy. What he did was to play with radio again, Barkhausen-Kurtz oscillations and things like that, was what he started on. Edlen started in X-ray spectroscopy but moved over to far ultraviolet studies which Siegbahn initiated at that time. And he’s kept to it ever since. [He is still achoe (1989) explaining NASA’s spectroscopical findings] Of course, Bengt Edlin.
With great results.
With good results, yes.
That’s very interesting. The problem of the thing, with so many people coming through at once, is to find positions for them in a small country where there are relatively few chairs.
Yes, we were, I think, lucky to some extent. And then of course Siegbahn represented the new physics. You know, the old experimental physics had become a tradition more or less. People wore stiff collars, you know, and everything was done in an approved way. You mustn’t do this, you mustn’t do that, you can’t knock down walls or anything like that. When Manne Siegbahn came to Uppsala in 1923, he came from Lund. He immediately started re-arranging things to get room for his spectrographs he knocked down walls and so on. He found things in the collection of instruments which could be used for this or that, but they of course were numbered and belonged to the collection of demonstration instruments and nowhere else. I once went to him and said that I see something in there that I could well use, do you think I could take it? Then he said, “Why, what else could it be used for?” So I just took it. And the old men who were there still were extremely worried. There was always at that time a galvanometer in every lecture hall, and the galvanometer broke down in our lecture hall. And Siegbahn went up on a ladder and mended it. And the old people there were standing around saying, “You mustn’t do this, we must send it to the factory, you can’t do a thing like that.” I mean, this was the new times coming in with Siegbahn, and I think this is one of the reasons why his people were successful — and there had been a generation before us, but they had done things the old way. So we were his second generation of people at Uppsala. He came to Uppsala in 1923, and then new people had passed through and left, one generation of physicists. So he looked around to fill the positions as amanuens and assistants and so on, end then he picked us up from the elementary lab.
He sought you out?
Yes, he asked the man who was in charge of it, Bengt Beckman, who was an associate professors — Laborator, and in charge of the teaching lab — which ones would be good to pick up. So we happened to get there that way.
He was really consciously trying to build a whole school.
He was doing that. And I remember that at one time we counted that there were 23 X-ray spectrographs working at the same time one night in the building. We always worked late at night at that time and had a wonderful time. One of the boys while doing his exposures, was walking up and down in the corridor playing his violin. The acoustics were good. We stayed late and we spent very much time discussing physics together, of course, and especially with Dr. Erik Backlin, who was assistant professor. He meant very much for us all –- we could always discuss our problems with him. I mean, Siegbahn, or course, was a very nice person and he got us all the equipment, but he was very quiet and shy, and you didn’t immediate go to him with your troubles. I mean, at the same time of course that we liked him very very much, still -– he was an older man and we weren’t. So we spent most of our time learning to solve all types of problems that came up, to discuss the question of accuracy in measurements and things like that with Erik Backlin.
He was younger.
He was younger than Siegbahn.
Closely related to the research work. Would you say that he was the lab director? Supervising the work?
No, he wasn’t. He was decent at that time. But he was the natural point around which we all gathered. He meant very much to us all. He died unfortunately very early. Well, that’s the background.
Good, I’m glad I made you come back. You say Siegbahn was promised an institute in Stockholm. What do you mean, who promised?
The Swedish Academy of Sciences.
Do you know anything about how that came about?
Well, I think he must have done most of it himself. He must have convinced the government, who must, I think, have given most of the money, that it was time to take up nuclear physics in Sweden. A large part of the money came from the Wallenberg foundation. There was no nuclear physics, of course, before that, And so this was the first nuclear physics institute in Sweden.
Was it specifically to be devoted to nuclear physics?
Yes. Yes. It was.
Was that reflected in the title of it in any way?
No, it was called Forsknings institutet for Atom fysik but you know there is the confusion that nuclear physics is very often called atomic physics, atomic energy, now instead of nuclear energy and so on, but it was actually built and intended for nuclear physics.
You mention that he came to ask you to go to America in 1937. When was is institute started?
They started building in 1937. They started at about that time.
I do have in New York the memorial to Siegbahn which I’m sure covers this, but I haven’t referred to it recently so it’s not fresh in my mind.
You have got that, yes. I’m sure you must —
That will give the history of the institute.
Yes, I think it does, so you’d better check that.
This is a gap, when he talked to you about cyclotrons, a gap of about two years from the time of your doctorate. What were you doing between?
I was working. In between I was working on electron diffraction, as I told you, electron diffraction measurements, for example, questions about form factors, determined with electrons and so on. I continued work after I got my thesis. And then of course I had a good deal of teaching to do at that time. I became a decent, an assistant professor.
Immediately after your degree?
Yes. I became that— I think, before Christmas only a week or two after I had finished, after I had passed the examination.
Up until the time he talked with you about the cyclotron, you had done no work in nuclear physics?
None at all. I’d never done any work in nuclear physics, I’d always been on the outside. I have been surrounded by nuclear physics. Down here it so happened — well that doesn’t belong to this at all, but as a matter of fact when I came down here first as an associate professor, then as a full professor, they had invited Dr. Helmut Bradt from Cornell University to come here and be a professor of nuclear physics, but he died unfortunately before he could come. [He came here to look around and I showed him the new Physics building which was being built at that time.] So what I had to do was to start nuclear physics without being a nuclear physicist, and I was lucky in getting good people and we have a department of nuclear physics.
When was that?
That was — well, I started it a little before that, but say around 1947. I came here in 1946. You see —
I was going to get back to the earlier period. You mean it was as simple as that, that Siegbahn felt there was a need to have attention to nuclear physics in Sweden, an institute was necessary for it — do you have any idea whether the idea of accelerators of some kind was part of the original plan?
Oh yes, that was — the cyclotron was —
— a laboratory to contain a cyclotron was part of the plan? In other words, it was given with that in mind?
Yes. I think that was quite clear, that that was what they needed.
In the discussion with you, how did he broach the subject? Did he discuss what he wanted to do with the cyclotron?
No. Not at all. He just said, “I’d like to have a cyclotron.”
Had you heard of the cyclotron before?
Oh yes, of course I had heard of the cyclotron. Yes, yes.
But you had no —
— no, I had never seen one, of course, and had only read about it in books.
Why was it determined that you should go to the United States? There were cyclotron projects beginning in Copenhagen.
No, they started at the same time.
Jackson Laslett was the one who built it, my very old friend, we met in Berkeley. I saw him about three weeks ago when I was in Berkeley or four weeks. He’s a very old friend of mine. And there were a number of people — there was Bernard Kinsey and Harold Walk in Liverpool, Donald Hirst at Cambridge, and others. Paxton in Paris. He just left for Paris when I was in Berkeley. We had a party for him, I remember.
It was an exciting period in Berkeley, I remember, with everyone being dispatched.
You’re saying that in 1937 these other projects weren’t advanced enough so you could learn from them.
No. They were thinking about it.
In each case it was around 1935 when they began raising money and so forth, true that it took three or four years before anything developed. He suggested you go to the United States?
Who would pay for that?
That was paid for, I think, by the money he had for his new institute. He gave me some money, I don’t remember how much, but he just said, “When you need more just write me,” and I wrote him I think and got more money. When I got back of course I had it written down, all I had spent and so on, and had some money left and I went to him and said, “Look, here is what I spent and I have got so many dollars here,” and he said, “I won’t see it, take it away, keep it, I’m not interested.” That’s characteristic of him.
Was it clear that you were leaving your position in Uppsala to do this?
Oh yes. I was given a job there as assistant from Sept. 1st 1937.
I see, and your first assignment was to go on this trip.
No this was before I was hired.
And he had suggested Cornell University.
Yes, after having asked Richtmyer about it. Richtmyer was his old friend, of course, X-ray man, and he wrote him, said what ought I to do about this? “Send him here,” he said, “we have the world’s smallest cyclotron. And of course Livingston is a good man.”
I talked with him about this Cornell period too. Were you married at the time?
No, I’m not, have never been married. I’d be completely free to do anything I wanted.
Then you went directly to Cornell. Did you stop anywhere?
Oh yes, I think — I don’t remember, I may have gone directly to Cornell, but then I was given the opportunity to travel a good deal in the United States, and I visited a lot of places, and I had letters of recommendation from Siegbahn to all his friends, so I met very many of the people who are now in charge of physics in the United States. I went to — of course, I went to Chicago, saw Sam Allison. I went to Madison, Wisconsin, and saw Van de Graaffs. I built a Van de Graaff here when I came to Lund, not a cyclotron, and I visited of course Princeton.
Milton White was then.
Oh yes, he was there. I remember, that was funny, I came in there and there was nobody to be seen, and finally I located somebody, and then Milton White said, “Well, I saw somebody. I thought it was an insurance man so I disappeared. I was carrying a briefcase.
We ought to do something systematically about the visits because it’s of great interest to me. You were a very perceptive observer. You were looking not just for curiosity or amusement but to learn something. The things that would stand out in your mind might be very interesting things.
Well, I don’t remember too much about it.
Maybe it we did it by itinerary — first, if you can retrace your steps, where you went first, then next.
No, I’m afraid I can’t do that because that was so long ago arid I think I’ve been 15 times to the United States. They run together. But I know I traveled. I saw Kruger, I think, at Illinois, yes, and of course I went down to Pasadena to see Charlie Lauritsen. That was a Van de Graaffs again, and I went to Stanford University where I saw at that time the man I remember was David Webster, who was an X-ray man again, so that was the one I had a letter to. I went to Schenectady and saw Hull and Langmuir, I remember.
This was on general principles, nothing to do with cyclotrons.
No, this was because while you are in the United States, you ought to see this and you ought to see that, said Siegbahn. He was very generous in that respect.
How about Columbia?
Oh yes, I saw [John] Dunning at Columbia. They had a cyclotron going at that time. Yes — as far as I can remember. And I went to Rochester to see Sid Barnes. He was the man there at that time. We became very good friends.
You covered most of them. Did you get to Michigan, Ann Arbor?
Oh yes, I was in Michigan.
They had a cyclotron there.
Oh, yes. Yes.
They had Cork there and Thornton was there and they got Crane later.
Yes. I don’t remember too much about the last one.
At Chicago you saw Sam Allison — the cyclotron wan started at Harkins’ Chemistry department.
Did you come in contact with Harkins?
I met him but I don’t remember. I never got to know him, but Sam Allison I got to know and met several times afterwards too. [The meson(?) had just been formed and I saw Carl Anderson and Neddermeyer at Cal Tech and Sheet and Stevenson at Harvard.]
On this first visit, if you can separate it out from subsequent ones, when you went to the places when cyclotrons were working, was it your purpose to get their experiences and specific data they had?
Well, I don’t think I actually did that. I more wanted to get a general idea about the layout and so on, became for the cyclotron itself I got such excellent — I got blueprints and the information and so on from Donald Cooksey at Berkeley, — I saw Cooksey now again when I was there a month ago.
How is he?
He was fine. I was surprised to see it. He was extremely helpful, really spent much time on helping us all. So I remember him very, very fondly, and I got all I needed, all kinds of information from him.
The visit to Cornell, the first really planned visit, was that a long one?
That must have been on the order of two or three months or so.
What did you do?
I took part in the running of the cyclotron. You know, the little cyclotron, when you had to tune the oscillator you had wooden pliers and you squeezed the coil. The idea was, squeeze the coil, was the orders given by the man in charge. So it was done, in a very simple way, the whole thing at that time. So I just helped to run the machine, and when we had trouble of course that was very good because one could see the inside of it and one could work on filaments and things like that, replacing filaments, and on the whole getting the thing to work.
How much time was involved in getting it to work, as compared to the actual working time? At Cornell?
That’s very hard to tell. I have no recollection that we spent all our time fiddling with it. I think it behaved reasonably well at that time.
Were there any medical uses of the machine at the time?
Not that I remember.
Not any question of isotopes or —
— no, not that I remember, but I may not have thought very much about that, since my main job was to build the cyclotron. I concentrated on the machine itself.
You weren’t so much concerned with the experiments or research programs.
No. But I have a feeling that people were producing isotopes and measuring half-lifes. I have that in my memory, you know, the plotting on a plotter, getting point after point, things like that. That’s about all I remember.
Did Bethe have any contact with the cyclotron group at that time?
I didn’t see him come down, but of course Bethe and Bacher were there at the time, and they gave seminars and talks and so on, and we sneaked in to listen to some of them, but they were beyond me of course at that time — theoretical.
Which was rapidly changing, too. Wasn’t this the time when Bethe with the help of Bacher and Livingston were writing Review articles on physics — 1936, 1937. Were the articles finished by the time you came? It’s not clear to me anyway whet month you left. What month you went to Cornell?
I must have come there in March, probably early March or so. I was there probably till May and then moved on.
They were published in 1936, 1937.
Yes, but this is a later one. This is the 1946 one I have here. Yes, but they were probably — I remember them. There were two people. There was Bacher and another man.
No, but there was another theoretical physicist, fairly short man. I remember two people. I remember Bethe walking through the corridors with his hair streaming and a couple of steps behind him, two young men, that was Bacher and another man.
Rose? [I think today (1989) that his name began with B]
Possibly. I don’t remember. But they were about the same height, somewhat shorter than Bethe. Bethe was the master and they were the followers, I remember that.
It might have been Rose.
I saw Bacher now again when I was in America. I saw most of them, about a month ago.
Did you visit some of the earlier ones?
Yes, it was because I had been to Australia for a cosmic ray conference, and on my way back I picked out the places where I had people I knew, more or less.
At Cornell for those two or three months, would you say you spent practically every working day with the cyclotron?
Oh yes, all the time.
The idea was to immerse yourself in the work they were doing, to become part of the group, in order to get this experience.
Yes. That was the idea. And of course I must have taken notes about technical details and so on at that time.
This was pretty much the sum of your experience, doing that. You didn’t participate much in the department.
No, that was not part of my job.
And your status was that of a visitor who presented himself with recommendations of course, your way was paid, and you were just welcomed there as a working visitor.
Yes. I was very well treated of course by everyone, by also — a man who was very kind to me, he was Freddie Hirsch, Jr., you remember him. He was there at that time, I don’t know it he’s still alive — he has been very ill for a long time with rickettsia(?) or something, and he moved to Pasadena many years ago because of that — but he was an X-ray man too. But he was very kind me, married to a Swede, I remember. And then — well, I may be mixing up different years, but I remember him, and then of course Richtmyer was very kind to his friend’s student, too.
Well, it must have been a good time of the year to be there too.
It was very interesting, It was a bit cold, it was snow – and steam (?) on for a few hours in the morning.
Then the next stop on your circuit was, to go directly to Berkeley, or did you make stops on your way out?
I’m afraid I don’t remember, but it’s very likely that I made stops on my way out, so that I went from Cornell up to Madison probably, say, Chicago, Rochester, Madison, that seems —
Rochester you would have hit first. Those were much shorter stays?
Those were for some days or a week or so.
Of all of those in between stops including Princeton, Columbia, Michigan, Chicago, Illinois, Rochester, did you get the feeling of any differences in these groups, or were they pretty much organized along the same lines doing the same kinds of things?
I think they were. I remember the group where I felt perhaps most at home was the group at Madison with Herb and Kerst. That was a very friendly group. They were all friendly, but I remember especially those days, and I must have been back there again in 1947, so I mix them up a bit too, but even the first time I got very much impressed by the Van de Graaff that Herb had then and the work that was going on.
Siegbahn had definitely decided on a cyclotron.
He had not considered other accelerators, either instead of or in addition to a cyclotron?
I never heard him talk of that. And what he had done, when I came back, he had ordered the magnet for the cyclotron, and this was I must say rather an unsuitable one. It was built by the ASEA company, and they are experts in building magnets, and they built the best possible magnet, but that doesn’t mean the best possible cyclotron magnet. It was almost impossible to get at things inside this very very compact magnet. That gave me a good deal of trouble.
I’d like to get to those details later. It’s interesting what you tell me about Madison and the group there, and you finally got to Berkeley. What time of year was that?
That must have been in the early summer.
How long did you stay in Berkeley?
It must have been three months, because I think I got back probably around the 1st of September.
So the whole visit was about six months?
Something like that. I don’t remember quite clearly. But I remember that when I got back, the building was not quite finished. The building in Stockholm, because there was no glass in the windows, and I woke up — I lived on the top floor of the institute, and when I woke up, then was a bird sitting on my bed above my head.
Was the bird indoors or were you outdoors?
No, I was indoors, without any windows, and there was a small bird just jumping around the head of my bed misbehaving, because then were no window panes.
I’m surprised the building had even gone that far.
Yes, I think they must have started on the building before I left.
In Berkeley, I’d like to know as much detail as you can remember about your experiences there. As you mentioned earlier, so many people who were assumed to be working in different parts of the world as so it’s interesting to get the atmosphere there, what was going on, what these people were like, what they did, what you did.
Well, I was assigned to MacMillan’s group. There were two groups. There was the F.N.D. Kurie (Of the Kurie plots) group and the MacMillan group, and I was with the MacMillan group, taking part in what was going on. The people were the people who were running the machine, those two teams.
How many people were in each team?
As I remember, then must have been three or four people on each team who were running the machine at each time. I mean, one day one team had to run it, another day the other team. And I remember that at one time, when I was at work, Cooksey came and said, “I want you now. You’ll have to give him to me,” and he took me up to see the Sequaias. At a time when I ought to have been working.
It was good for you.
Well, yes. And then I remember that it quite often happened of course that the oscillator tubes broke down, and I remember especially once when we drove down to Redwood City to Charlie(?) Litton, who was the man who, at the time, made the tubes for the cyclotron, and we went down then in two cars. It must have been on a Sunday or something like the that, there were two cars, I don’t remember MacMillan but he must have been there. Then was Jackson Laslett, there was Reginald Richardson, I think Cooksey was with us too, and we had a wonderful time, of course.
Again, you came there and presented yourself with letters of recommendation. Who received you first?
Donald Cooksey. Well, he was — Donald Cooksey was away, but he had left word, the first day I could stay in his bedroom, so I was put in Donald Cooksey’s bedroom when I came in, and the next day he came back, and then I moved, and I lived — I think I stayed at — oh yes, I know, I stayed in a private house, when also Nahmias stayed. You’ve heard of Nahmias, a French speaking Turk [who didn’t like America with rattlesnakes and poison ivy]. We stayed there in a small house, somewhere to the north of the lab, in one of the streets, I’ve forgotten the name of the street, but it was some ten blocks northwest of the lab, not on the hill but down at the, where the hill more or less starts, you see, about what it —
— he was there as well?
He was there at that time, yes, and there was a spare room. His landlady had a spare room. And he also was very kind to me [he said he needed to see a European], and we used to go out on Sundays, he and Lorenzo Emo. The Italian Count, right? They had a Buick that they had paid $25 for, and in this Buick we went out on Sundays, went for trips to different parks. There was a famous trip into the desert where we had a lot of trouble, because we were going to some kind of swimming pool on the edge of the desert, and there you had to park. The swimming was free but you had to pay 50 cents for parking, that was the income of the man, and I remember Nahmias saying that, “This car isn’t worth 50 cents, let’s put it outside.” We put it outside and went in, and we decided against bathing because then were too many people and too little water, so we just walked through and walked up the small hill and came back, and when we came back the car didn’t start, because the man — well, this is such a long story — but what happened was that we tried to start the car, and we did this by having people push us along the road, up one hill, and we tried to start it by running down the next hill, and then somebody pushed us up the next hill, and they got very nervous, because they said, “We are in the desert and this is rather dangerous.” I said, “Then is a car every five minutes, it can’t be terribly dangerous.” Well, they were very very worried, and finally Lorenzo looked inside the car and saw that the man had removed the distributor head to prevent us from using it. So Lorenzo said, “You are much too angry to be allowed to handle this. Nahmias this takes diplomacy. So I’ll handle this, and you keep quiet.” We went in and Lorenzo said to the man, “We are extremely thankful to you for taking care of our oar so that people won’t steal it, and we’d be very happy to give you a dollar for that.” Then there was the crucial moment when the man’s hand moved to his trousers pocket and came out with the distributor head. We got back, and both of them were extremely excited. We hadn’t had anything to eat, and they were hungry, and we stopped somewhere and went in to have something to eat, and there they started in some way a quarrel with some Italians who were standing there. Where were we?
You were telling about the quarrel in the restaurant.
Yes, they had a quarrel in a small restaurant with some Italians, and we had to get out very quickly. Then we had to buy gas, and he found a gas station which was owned by a French Canadian and Emo and I could not speak French with him, but Nahmias could and got some comic papers which were advertising something and he said, “This is really a friendly man, this is a French Canadian and something quite different from the Californians.” Then finally we got home, and then that night Nahmias and I were invited to Professor Leonard Loeb’s for dinner, and Nahmias told the whole story again, and when we came out, we found that he had got a ticket. He had been parked in the wrong place. This was a really bad day for them. This story became very famous. I told it on my way down to Redwood City on that occasion, and I have heard it retold again many many years afterwards, this story. They ended by saying that the worst thing of all, “Was to have this damned Swede laughing at us all the time.” Well, this doesn’t — we were all there for the same reason, yes.
When you came, you mentioned, Cooksey provided you with this nice reception. Then what was the next thing? It would be interesting to me to sort of take you through your routine there. Did you tour? Did they introduce you to people? Did they put you to work right away?
You know, the place was quite small — that little wooden building, you remember. So we just went down there and we — I was told about what things were. I was introduced to people, Absersold and Abelson, and Livingood was there and of course Kurie and Kamen, I remember, and well, there were a lot of people. I just got in there and everything was natural, I was one of the people there. It worked very nice. And of course Ernest Lawrence came down and discussed things with us. [I was invited to Lawrence Berkeley Laboratory 50th Anniversary in 1981 as one of the old boys, “He was here even before Lofgren, you know.”] They opened the Golden Gate Bridge while I was there and Ernest Lawrence took me across on the first possible day. One day, you know Lawrence had a communication system with loudspeakers and microphones between his office and the lab — one day we were standing there discussing something that he had decided and we said that this is foolish and so on, this isn’t good at all, I wonder why he’s done that — and then suddenly we heard a voice that said, “I’ll tell you, boys, it wasn’t as dumb as all that, because —”
Two way communication?
Yes. And then I decided never to have anything like that in any lab of mine.
Terrible feeling. Van Friesen: I mean, he was very friendly, but we were a little bit worried.
How much time at that time did he spend with the machine?
As far as I can remember, only shorter periods. He came down each day probably for 20 minutes or something like that. He was obviously very busy finding money for expansions and things like that.
Which one were you working with, was this already the 60?
This was the 57 inch, I think, if I remember rightly.
They had a 37 and a 60, something like that. This would have been what he was interested in.
I may be mistaken. This was the one with the magnet, General Electric magnet, an open magnet which they had got from the Navy somewhere. That will tell you which one it was, but you can see that from the time also. I’ve forgotten how many inches there were. But then we were all scrubbing the dees and doing all kinds of work like that and looking for leaks.
Was it operating when you first came?
Yes. It was operating. It had been operating for quite some time.
At that moment?
Oh yes, as far as I can remember, it was.
In this case did you have anything to do with the experimental end of it or was it pretty much the same as —?
— it was much the same. My job was to find out how to build the cyclotron and how to run it, so I mostly looked at the technical details, and as I said, I spent much time with Cooksey who told me about different details and gave me blueprints of the different things. Which were needed. Another thing happened which hasn’t got much to do with this, but almost immediately when I came I was told that Professor Raymond T. Birge wanted to see me in his office. I went up to Birge and Birge said, “I have been reading your thesis.” He had a large sheet of paper filled with very small writing, lots of calculation, and “It’s all wrong,” he said, “because I have re-calculated it all and I’ve found that the limits of error you’ve given are much too wide. If you do it correctly, you’ll find that it ought to be this instead.” [I might mention that my value with its limits of error covers the modern value. His limits were much too small.] Then I said, “But I have experience of this experiment. I’ve added something for the systematic errors and the uncertainties which I feel are there.” But he told me, “You can’t do that, you must do it this way.” Well, I was a bit soared of Birge from then on. I felt I was right, but he was so completely certain that I was wrong that I avoided him for the rest of my stay there.
Would you ordinarily have had much to do with him anyway?
Nothing at all, I think.
He was chairman of the department.
And the department was physically separated from the —
Yes, it was.
Did he ever come to the laboratory?
Not that I can remember. The only time that I remember seeing him was when I went to see him in his office.
Did you get any glimpse of Oppenheimer during this period?
No. No, I don’t remember having seen him then.
Who else? You mentioned a large number of people there. These were the regulars, Livingood, Kurie, Kamen who came in, Lawrence himself and Emo. Earlier you had mentioned —
— Laslett was there.
He was part of the regular crew, yes. Then you mentioned people like Paxton.
Paxton was there, of course, but he was very shortly going to Paris when I came.
In his case, was it clear when you came that he was getting ready to go?
Oh yea, I think it was. I can’t have been there very long when we went down to a fish restaurant somewhere in Berkeley and had a party for him. I can’t have been there probably for more than a week or two.
I remember letters asking about arrangements with Joliot for Paxton and also with the Rockefeller Foundation to put up the money, actually.
Yes. You see, this is so long ago, I may well be mistaken about dates. I haven’t got any memory at all actually for time. Time is something that I can never judge.
This is all holding together quite nicely. By the way, did you preserve any of the notes or letters?
Oh yes, I must have — must have a good deal of that. I haven’t looked at it for a long long time. [Unfortunately I have moved many times and cannot find those papers. 1989]
As an historian, I’d like to read that whole thing there, and emphasize the importance of preserving this and making it available for the future, because you may think, well, it’s not significant, but I think it is, the kind of documentation that makes all of this come to life. If people forget about it it gets scattered and lost, and that’s a shame, so if you come to the point of needing any help or advice on that, let me give you some pointers and suggestions of what could be done. In this case, did you again as in Cornell work every day?
Oh yes, I spent all ray time in the lab, of course.
When you were assigned to a group, you were sort of an extra member of the group, as they already had the group personnel made up.
I suppose so, but I think that towards the end I was more of a regular member of a group, so that somebody else could go away.
Did you have specific responsibility within it?
No, I think we were — of course, the “captain” told each one what he had to do, in every special situation, and mine was MacMillan.
How did he function as a captain? That’s a term you’re using, they didn’t use that term?
Oh, they called it at that time the crew “captains”, Kurie and MacMillan.
Yes. I remember them calling them that at that time.
Were there any other titles?
No, not that I can remember.
Today they have a chaplain. What about [Luis] Alvarez at the time?
He was there of course too.
As another group?
I have not the feeling that he was in any group. He was Alvarez already then, I think — I mean, an important kind of person. He scared me almost to death, when he asked me about the magnet that we were going to have, and this had been — the gap could be varied in our magnet, and I gave him the power. Let me see. When he asked me about what field we could reach, I gave him the field with the smallest gap. When he asked what gap we could have, I gave him the largest gap, and he very quickly calculated that this didn’t fit, this was impossible, and he said, “You are wrong,” and he looked at me with his blue eyes, and I had to explain to him, what the situation was. But I mean he was already then a very forceful personality.
Oh yes, I spent some very nice time with him now in Berkeley. I have known him of course since l937 and we soon became friends. [Later on when he got the Nobel Prize in 1968 I was on the Committee and gave the talk for him at the ceremony, describing his work.]
Your day to day contact then was with your group — at the same time with this other group?
Oh yes, with all the people rushing out to eat somewhere and so on. I know that Jackson Laslett had his meals at some Chinese restaurant which was the cheapest place in town, and I went with him once or twice, but I felt that it was maybe a little too cheap for me.
Or for Swedish tastes anyway.
Well, yes. That I remember. Well, I don’t remember any other — there must have been other people.
I’m curious about the two groups. Would they be working simultaneously?
No, I think those were the ones who were just running the machine, so that one group had one day, something like that, next day somebody else was in charge of running the machine. This was the technical side of it which had to be taken care of.
The group that wasn’t running the machine, what would they be doing?
They were obviously working on their experiments, preparing experiments and so on.
Did you do part of that too?
No, I don’t think I did. I don’t remember. My free time must have been spent collecting information about the machine, about the technical side, in the workshop with Cooksey, looking at how things were being made, things like that.
Were there ever any meetings, group discussions where you could sit down, not necessarily as formal as a colloquium or seminar, but where you’d discuss the problems of the group?
I don’t remember that we were sitting down in any office or anything at that time. Later on when I have been working there I have been invited to take part in their meetings on research policy. I think the discussions were carried on, on the floor, around the machine.
When did you determine that you’d learned enough and it was time to go back?
That had been decided, because that was when the building had been put up and I had somewhere to sit down and make my designs for the machine. I had a drawing table. I had two rooms on top of the building, and in one of them I made my drawings and designs for the machine, and then we started to build things in our workshop. The first thing, one of the first things, we built was a couple of tubes, oscillator tubes, and those were home made in those days quite often. They were for 25 kilowatts each and they were pumped with a molecular pump [which I also designed with a capacity of 72 liters/sec. Two of them were built in the shop. One for the tubes, one for the cyclotron.], and this was a bit interesting, for a man who had never designed an electron tube before, to start out building one for 25 kilowatts too — the pair for 25 kilowatts each. But they worked, and worked for a long time. So we had all kinds of interesting experiences.
You know, as I often say, a physicist must be educated to do the things he cannot do, does not know how to do. Our whole life consists of doing things that we cannot do, quite often things that nobody has done before. So we need quite a different type of training, of course, from people who learn to make shoes or anything like that. This is something which is also quite important when it comes to decide how the education of physicists should be done. In the present time, Swedish higher education has been changed a great deal. They want to shorten the time for the doctor’s degrees and so on, and they have made the new doctor’s degree consists to a large extent of reading books and so on, and some experiments must be done of course, but it’s said by the politicians that when the professor gives somebody an experiment to do, he ought to know that it’s going to work. This is something that is quite different from what it ought to be, because it’s not interesting to do anything when you know what the outcome is going to be. This did not belong in this connection.
Well, it’s interesting in connection with the experiences in Berkeley and Stockholm — a different approach.
Yes, it is, and I think that is the best approach. If you want to train people to be able to do research of an original kind, and to tackle new problems.
Something about the problems — when you came back, was there any need to educate another group of people? You were sent to learn and you did learn and came back prepared. Then how did you communicate this to others? You can’t build a cyclotron by yourself.
I had two people helping me, one of them young, — Astrom was a young electrical engineer, Bjorn Astrom. He died a couple of years ago. Also Hugo Atterling, the men who is now in charge of the cyclotrons in Stockholm. Those were the two who helped me during that time, but it was very much — it was done by a very small group. And then, as you may know, I got the beam out of the machine on the 13th of October, 1939, and on the 14th I had to leave because of the trouble between Finland and Russia was coming, so I was called up and sent to the Finnish border at the Arctic Circle, and I never came back to my cyclotron.
I know the letter that you sent to Lawrence. Let’s get the timing of this — when did you return? What was the date, approximate date? I’m trying to get a feeling of how long it took to get the beam.
I got the beam –- I must have got back, as I said, about the 1st of September, 1939, and I brought the beam out on the 13th of October, 1939. At the same time, I had a lot of trouble with the vacuum, because the ring for the vacuum chamber was cast, and was very porous, and I had very much trouble with that one. [An interesting fact is that we had two bids from different companies and I recommended one of them but Siegbahn chose the cheaper one.]
Did you have difficulty in getting skilled help to make individual parts?
No, not at all. I mean, we never have difficulties in Sweden in that respect. We had quite good men working for us in the shop.
Did you contract any work out, on the outside?
Well, the magnet, of count, but we made pretty much all the rest of it ourselves.
Was there a problem of getting materials to the proper standards?
No. I don’t remember any such difficulties. Of course, we re-designed the whole thing according to the metric system and so on. We didn’t copy anything from those drawings that we got. We made new drawings, and changed some things, and we had all the time while we were building, we were having meetings in different parts of Europe — the people who were building cyclotrons. We had meetings at Cambridge, Liverpool, we had meetings in Stockholm, in Copenhagen and so on. We were having a very fine time together, paid by the cyclotrons.
That’s very interesting, the fact that on an informal basis the people who were directly concerned with the building —
— we just traveled.
How did this start, was there a plan?
No, I think this came very natural, that somebody wrote and said, “What about the ion sources, what are you going to do about ion sources? Don’t you think we ought to meet and discuss this?” Then we wrote between us and we came together somewhere to discuss such details.
In this case it would have been, you from Stockholm — anyone else?
From Copenhagen, would it be [Otto] Frisch?
Frisch and Laslett.
You might run down the list, for curiosity — Paxton from Paris?
We never saw Paxton, I think, in these discussions. But Donald Hirst, as I said, in Cambridge, and Kinsey, Liverpool, Bernard Kinsey.
Did you know Walke?
Walke, oh yes, he was with us — he got killed, you remember.
Yes, in a cyclotron accident.
Oh yes. He came to the Stockholm meeting. We had one meeting in Stockholm, I remember, where Walke and Kinsey and Frisch and Hoffer-Jensen came from Denmark and — well, Laslett, of course —
How many meetings were there?
Hard to say, probably about four or so. I think.
It’s fascinating to me, the group converging. What would the nature be, someone presenting a paper?
No, this was very very informal. We just met, sat down around a table, telling each other our experiences, and somebody said, “But what do you do about the filaments? They warp in the magnetic field,” and things like that, and we made small sketches and showed the way we did things. This was very very informal, you know. Physicists are very direct — I mean, we don’t, we are not very fond of formal discussions and things like that. We never organize things, we just get going trying to do things. At least we did at that time.
It still survives. Do you recall places other than Stockholm where meetings were held?
Yes, we were in Copenhagen and in Cambridge, England, I remember, and I don’t remember if the — if we had a formal meeting in Liverpool or not, but I remember we were in Liverpool at one time, and met there.
With Chadwick and Kinsey.
Yes. Yes, I had a glass of port with Chadwick in his home, I remember, that time.
He’d only been there a few years.
That was also the year, when you got back, that Rutherford died. Do you recall any discussions? Was there any concern about the Cavendish, about which way it would go?
I don’t remember anything about that. No, that I don’t remember at all.
Then you said there was social activity connected with these meetings, just because you knew one another and enjoyed —?
Yes, we just took the opportunity to show our friends around. I remember taking people to Skansen in Stockholm, and things like that. I remember that when they came up from Copenhagen, of course Frisch didn’t get up early enough, so they took the train away out to some switching yard while he was still shaving, — things like that happened. [We had to find him.]
Frisch had been somewhere, that when the cyclotron people in Copenhagen would come up to Stockholm, that their Swedish colleagues had a name for them – I’m sure I’m not pronouncing it right: Karn-gubbaina
Yes. It means “old men, old guys”, something like that.
What was the origin of that?
I have no idea. It’s just that somebody —
Do you recall the term was used?
No, but it seems quite natural. You see, this is the fun, really, because Karngubbe is a very robust man, old man who is in good health and so on is called a Karngubbe. So this is actually — that has got something to do with it..It’s a double meaning. (Karna = nucleus)
The other question, a number of questions, but on the cyclotron itself, was there any problem of funds and wondering whether you could afford a certain design step?
No, I don’t remember that. We were of course very careful not to spend too much money, but Siegbahn always, he handled that entirely. So I never had to worry about that. I told him about it and then he said yes. How he got his money, what he did, I don’t know at all. He is a very quiet man. Have you met him?
He’s a very nice man. He’s still — he was born in 1886 but he is still going strong and takes an interest in physics and so on.
Where is he?
He’s at Stockholm at the Nobel Institute. Yes, he lives there.
I’m making a point, looking at my calendar, to see if I can get there. It might be worth doing. Bookkeeping, you didn’t have to worry about accounts, things like that.
No. No, not at all. I remember I made some estimates of what the whole thing had cost, but Siegbahn was not at all interested, in knowing that. You see, it was all very much mixed up in the building of — the erecting of the building and so on. So I don’t think he kept it apart very carefully. I don’t think even he wanted to keep it apart. This was the whole project, the building and the machine and all that was just one thing.
I assume by the time the cyclotron was finished the building was fully complete.
Oh yes, it was.
Was anything else going on in the building at the time?
Oh yes, there must have been other things going on. They had Dr. Sigvard Erlund, the man in Vienna, you know, the director general of the International Atomic Energy Agency. He was one of the people who came from Uppsala to the Nobel Institute. The people who came were Siegbahn, I myself, Alfven, Torsten Magnusson, and Sigvard Erlund. He built at that time a neutron generator, high voltage set, where he accelerated deuterons to get neutrons and he made some measurements and did some neutron physics. At that time, that I remember. And Alfven had some ideas. He was working trying to build a betatron, but it didn’t work. He had the idea obviously but he didn’t. I remember during that time of course he was working out his ideas about the hydromagnetic waves and those things, about the origin of the solar system and so on. We used to go for long walks on Sundays and he tried it out on me, his new ideas. I heard very much about it, and I didn’t understand very much, but now and then of course I said, “Yes, but,” and then he (a very, very intelligent person) said, “You’re right, you’re right, I hadn’t thought of that.” So he thought I had seen something there. In most cases it was just that I felt I had to say something.
To keep the conversation going —
— yes, isn’t it, because this was very new and of course his ideas were very original and new, and he loved to talk about it and tried to explain it. That was a very interesting part of my stay there, of course.
During this period, was there any pressure that you felt on completing the machine? Was there some kind of time table where it was felt, “Let’s get this thing —”
— no, I don’t remember anything like that, but then of course personally I was very worried when I couldn’t get a vacuum because of this leaky ring, and that — I remember telling Siegbahn that I thought we ought to buy a new ring [this was a delicate thing since we had chosen that ring.], which we could easily get. It was a cast brass ring. But he didn’t want to do that. If that was because he felt that it would delay the thing, or that he couldn’t afford to pay for it, I don’t know. But I feel now that it would have been a good thing to throw it out, buy a new one. It would have saved some time. I had, of course, the feeling that it took a very long time while I was doing it. But looking at it afterwards, I feel it wasn’t so bad, as you just said.
No, it’s relatively good. If you had a chart of, from initiation to completion, it’s one of the shortest on record.
Getting back to the actual work on it, you mentioned yourself and two people who were with you. Was that the whole group of the whole period?
Yes, as far as I can remember. Well, some people came and visited us and worked for a month or two.
Much the same as you had done at Cornell and Berkeley?
Where did they come from?
Well, that was actually Professor Minhagen from Lund he came up, just because he was interested and spent a couple of months. He’s here now as professor. He is a spectroscopist. At that time he took some interest in nuclear physics. But there may have been others, but I don’t think anybody came with the intention to build a machine, but I know that I acted as some kind of consultant to a machine in Belgium. I wrote — oh yes, when was it? Liege? They were going to build one. I wrote a report telling them what one ought to do when building a cyclotron.
How about the British? [Marcus] Oliphant? Did he visit?
Well, it was a trip. Another question this reminds me of — the — I discovered that the funding for the Copenhagen cyclotron, was because of its possible application to biological problems, was the basis of the funding of it. Do you recall any discussions of that?
No, I don’t remember.
Interestingly enough, when Bohr was planning a high tension laboratory, he — 1935 — he talks of discussing with the people in Stockholm who had experience. I couldn’t make this out, to whom he was referring. No other high tension work so called going on at the time that you know of?
No, not that I remember, but you know in Stockholm there was Gustat Ising who was the first one to suggest the linear accelerator.
I had a feeling it was on medical questions.
That’s the only one I can remember. He hadn’t the technical facilities to build the linear accelerator. He tried to but he didn’t succeed. But he had the idea. He was one of the men with “high collars”.
Yes, he was a much earlier generation.
Yes, he belonged to that stiff generation. He was a nice man all the same.
Another question about contact with groups leads me to Berkeley again. Did you have continuing correspondence? I’ve seen some letters.
Oh yes. We must have written letters. I must have asked questions, written to Cooksey about this and that.
That kept up during the period as well.
You were getting to the point where war was coming, but before then, I wanted to ask about the general situation in Stockholm in terms of physics. It was Siegbahn’s interest in nuclear physics that brought about this institute. You mentioned what was going on by the time you left. What about Lise Meitner when she came? Did she work at his institute?
Yes, that’s true.
Maybe you could explain her position there. Was she working with other people or pretty much by herself?
She was pretty much by herself. She had an assistant, a man working with her, Norling — what was his first name? He died, too, very nice man, Norling. Then she had Mats-Helde. He helped her for a time as some kind of assistant, and he felt that she was a very determined lady and he said that he always felt, every time he was on his way out there he felt something, in the pit of his stomach — well, he was a bit scared of her. But I think she was very nice to me. She worked with the counters and so on, with radioactive sources and things. I don’t think she got them from us but she probably got them from — I think she must have used also natural radioactivity sources and so on.
I think she got some of the cyclotron sources that, the thing was perhaps she got — the same ones that Hevesy got.
Yes, that sounds quite likely.
I think they shared them. What about Siegbahn himself? Did he really get into nuclear physics?
No. No, he didn’t.
That’s the impression I had and that interests me because here he designed this for the field.
Yes, but he started other people doing it, just the same as I have done no nuclear physics, and I’ve built up an institute of nuclear physics and high energy physics. Just because I had to do it. But no, he didn’t. What he was doing at that time personally, and was very much interested in was that he built an electron microscope. He designed it himself, got it going, and I remember that the man who helped him was Torsten Magnusson, and they worked on it. Magnusson worked during the day, and Siegbahn usually came there at night working on it. Then they corresponded by notes, putting notes on the microscope. I remember Torsten Magnusson said “The vacuum is very bad,” and signed it “TM.” To him –- Manne Siegbahn wrote, “The vacuum is good enough, M.S.” And then I had built, for the cyclotron, the first vacuum meter, a combined Pirani and ionization meter, that we had seen in this country, as far as I know, and I had that, and Torsten Magnusson said to Siegbahn, “Let’s go down to von Friesen and get his meter and see what the vacuum is,” and Siegbahn said, “No. It’s good.” So one day Siegbahn went away, went abroad or something, and Torsten Magnusson said, “Come here now and let’s measure the vacuum.” We measured the vacuum, and it wasn’t any good. It was bad. Then when Siegbahn came back, Torsten Magnusson told him about this and Siegbahn said, “Oh, that’s interesting, tell von Friesen that he makes one for us too.” Facts, he doesn’t dispute facts, Siegbahn is like that — all right. So I built one for him too.
But your main duties, of course, you had no responsibilities except to the cyclotron project.
None at all, no.
How would that have affected your career in the long run? Would this have been a proper continuing position? It’s not the same as a —
No, it wouldn’t. I would have had to get out, of course. I got out in a very good way, I think, in a way, because more or less stoking a cyclotron is not my idea of doing physics in the long run. I mean, it’s very easy to build it, but to be responsible for the daily routine, that wouldn’t at all appeal to me. That’s also why I built a Van de Graaff here, not a cyclotron, because a Van de Graaff can be run with very little trouble by the physicists themselves. I mean, nobody more or less has to spend all his time keeping it going or anything like that. So when I came in 1947 to Berkley, and I met Ernest Lawrence, Lawrence said, “Now you have come to learn, of course you are going to build a cyclotron,” and I said, “No, I don’t think so. I don’t feel like it. I’m building a Van de Graaff,” and he got very annoyed, of course. I said, “I think we have got enough cyclotrons in Sweden,” and he said, “There can never be too many cyclotrons.” But I explained to him that with our limited resources, a Van de Graaff would be much easier to handle.
Let me tell you what else I would like to talk about, and then you must be the judge of your own time and your own schedule, whether to take a break or what, but I would like to talk about the effect of the war, the effect you pointed out before, of having to suspend work on the cyclotron. And then to talk about the subsequent history, the very fact that you mention now that by 1947 you could say that here were enough cyclotrons in Sweden — just to fill in that part of the story. So there are two questions, one, the effect of the war and how it affected your work on the machine, and the subsequent history of that cyclotron and the proliferation that apparently occurred after that. Shall we continue? That’s up to you. I raised it now, those are the two major things that are still on my mind.
Oh yes, let’s get it over with. What happened is that some other people, after I left, Dr. Sandstrom was in charge for a while, I know, and as far as I know. I don’t know too much about it. They pushed the beam in again, which annoyed me a bit, and made internal in radiations. I had taken much trouble to get it out. They obviously found that it was a bit tricky, and so they put samples inside the cyclotron. But I have no firsthand experience of what happened. You’d better get that from other sources. I know that I felt a little bit sad when I felt that they hadn’t kept it out.
Then your — they were your immediate successors?
Yes, as far as I know.
There was no period when work on the machine was suspended?
There can’t have been very much… Where were we?
I was asking about the succession.
Yes. I’m afraid I have very little to tell you there.
There was no suspension. Did you know in advance that you’d be leaving?
No. This came in a telegram just from the army.
You were in the reserve?
No, I was just as everybody else. We have of course conscription here, and I had just got a telegram to report immediately to Boden in the north, and I was sent up to the border, the line there, and there I stayed until sometime in January, and then they organized some kind of, physicist’s work, as physicists for the army and air force, and I came back to Stockholm to work for the air force — that is, for something which preceded our defense research establishment here, and I worked for them. But that meant mostly working for the air force here, and I spent about five years doing that type of work. [For some months I worked for the Navy. We lost a submarine in a German mine field in Swedish waters and I needed a group of physicists that found it.]
Throughout the entire war.
Yes. I never got back to any physics at the Nobel Institute.
But the machine itself —
— was there.
And people were immediately assigned to it. And you’re saying, if I want to get further information on what it was used for and the subsequent history of it, then I have to go elsewhere.
Yes, you’d probably ask Dr. Atterling, who is now in charge of the machines at Stockholm, Forsknings instutet for Atom Fysik. [Now Manne Siegbahn instutet, 1989.]
That raises another question about your statement that in l946 there were other cyclotrons in Stockholm. Where did they get built?
1947. No, I didn’t say that. I don’t know when they started to build the bigger cyclotron in Stockholm. That must have been after that time.
Yes, I have documentation on that.
Yes, and then they built one at Uppsala, you know. At the TSV [The Svedberg] Institute at the Department of Physical Chemistry at Uppsala.
When was that?
As I said, I don’t remember times. You can get that easily. Helge Tyren built that. But I felt that I must probably in 1947 have heard about those plans, because I felt that I didn’t want to build a cyclotron here.
I think that basic story is — rather complete, on the cyclotron and how you got involved. I’m very much interested in what you were saying about your own career, that in your subsequent career you followed some of these same traditions that developed an institute or institutional forms in connection with something that wasn’t directly concerned with your own research, because it was necessary and because you knew how to do it. How do you separate that from your own research? Is it possible to develop those kinds of facilities and at the same time do your own research?
Well, of course, it’s very hard to do much research, but when I came down to Lund and when it was decided that we had to start some kind of nuclear physics work here, we knew that to build a Van de Graaff [I designed it and it worked for 25 years.] would take a good deal of time. And so we decided to start work with nuclear emulsions using cosmic radiation as the energy source of course for nuclear physics, for elementary particle physics. And so we invited Cecil Powell and C.M.G. Lattes, and also LePrince-Ringuet, gave lectures and gave us advice, and I went over to Bristol to look at the technique and spent some time in Bristol, and then we started here around probably 1947, 1948 to work with nuclear emulsions, and that has been my main interest since then. My department here is working on the primary cosmic radiation with nuclear emulsions. What we did at that time was to study mesons and we measured the K-meson masses by photometric methods which we had worked out. And we published at that time something like a dozen or so masses of individual K mesons which we had measured with an accuracy of about plus, minus 4 percent. Nobody took any notice of it or believed us.
We are very glad now when people know what the masses are, to see that all our masses are within our given limits, are correct, and our mean value is also very close to the true value. But we were beaten by the big machines, because once we had this worked out and going and we really could do this, they started to produce K mesons in the bevatron and there they could produce large numbers and have bending magnets and things like that and do it so much better. Then we had to switch over and do something else, so we could use our methods to study the charge spectrum of the primary cosmic radiation. Some work was started by Dr. Kristiansson and Dr. Waldeskug. This has been kept up and nowadays we work very much on that. And also recently they have been able to make mass spectra. They have separated for example Carbon 12 and Carbon 13 in cosmic radiation, which is very important, and this will be kept up. But this is the type of work in which my heart has been all the time, while I have designed machinery and (?) –- you see, first we built up our nuclear physics department here, and then we had to find money to run it you know, you can always get buildings and equipment for something that’s new, but it’s always very hard to persuade the authorities that you need as much money to run it and keep it going and do something with it.
So there had been ideas here about having an engineering faculty at Lund going for a long time, and I felt that this would be a good thing, and so I had told that and it was known that I was interested. Then the government decided that they needed more engineers trained, and they wanted to have an institute of technology down here, and I was asked to be one of the members of a committee to build this, and so I took care of the physics part. There is a department of technical physics in this engineering faculty, and we have arranged it so that we have a common physics department, and that meant that we got buildings and people and equipment, and this works in such a way that on the undergraduate level they’re completely separate. Some become pilosopie magister, and some become engineers, and there’s a branch which is called technical physics. But then, once they have those degrees, in their doctor’s work they can go to any professor they want and take a doctor’s degree. You can’t see any difference between the work done by the scientists and the technical physicists, and what kind of doctor’s degree they get depends upon what their first degree is.
Actually in this way we have a very large and happy physics department here, with a lot of different activities. And I had to plan this, to plan the buildings, to plan the equipment and so on, and then I have been involved in a lot of committees in Stockholm. I’ve been on the Research Councils, both the Atomic Research Council and the National Science Research Council, also in something which is called Fakultets beredningen. We have one chancellor of the universities, for all the universities, and he is not a university man, he is a government man, and he has certain committees, and I was on — for several years working on their Council on Natural Sciences. Things like that make it rather hard to do any reasonable research work. I try to keep my nose above the water. And I’m going to retire on the 1st of July, at the earliest possible moment, to get back into doing research work, because we have a very good arrangement here, that a retired/professor has a right to have a room and a lab at the Institute, and he can get some money from research councils and probably some from the university. So it will be like being reborn, to step out of this on the 1st of July. It’s not —
— you may end up with more administrative work.
I’ll try to get out of it. It’s not my duty to do anything of that kind.
Not a duty but an obligation of, in the sense that, you recognize that you can do it.
Well, I feel that would be wrong for an old man to do things like that. It ought to be done by the ones who are going to suffer from it. [May 1989: Today at an age of 82 I work every day in the laboratory on a new computerized nuclear hack photometer to be used on tracks from the collision of very energetic particles producing a plasma of quarks and gluons(?). And I am very happy.]