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Interview of John Woodyard by Lillian Hoddeson on 1976 August 27, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/4980
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Testing klystrons at Wright Field for blind landing, at request of Wilmer L. Burrow of Massachusetts Institute of Technology; Sperry Gyroscope research contract with Stanford University, San Carlos and Garden City plants. Contact with solid state physics through use of old-fashion crystal detectors in the klystron. Bell Laboratories and other centers for research in microwaves; John Pierce and other scientists in semiconductor work. Cooperation among industrial labs and the military for war effort; doping of germanium; history of silicon detectors, Winfield Salisbury’s contribution, William P. Cook, Karl Lark-Horovitz. Sperry patent; first semiconductor amplifier designed by Woodyard but not claimed on patent; the Sperry-Texas Instruments patent suit. Work on the Manhattan Project, 1942. Joined Lark-Horovitz at Purdue University following war to continue research in electron linear accelerator. Move to Berkeley’s Radiation Laboratory; continued work on transistors. Also prominently mentioned are: William Webster Hansen, R. A. Heising, Vivian Annabelle Johnson, Jones, Guglielmo Marconi, Arthur Norbert, Russell S. Ohl, David Sloan, and Bill Wasson.
Professor Woodyard, I would like to consider our interview today as a supplement to the series of interviews that Arthur Norberg has been carrying out with you in connection with his program at the Bancroft Library. Many portions of your productive life have already been covered in detail in previous interviews which will in time be available to interested scholars. We needn’t, therefore, backtrack over this material unless the events referring specifically to our discussion today weren’t perhaps covered in sufficient details.
Norberg’s recordings were made quite a while ago and I don’t remember really what I included in them, but you’ve seen the more recent ones.
I’ve seen them and will try to guide you. As I told you last night on the telephone, I’m particularly interested in your recollections of the semiconductor research at Purdue and at Sperry during the 1940’s, and in the relationship of these developments to similar activities in the same period at other laboratories, particularly the Bell Laboratories. Just to get started today, I wonder if perhaps you could give me a general summary of your movements during the 1940’s, let’s say, from the time you left Stanford until about 1946 or 47. Where were you and what were you working on generally?
Yes, I left Stanford twice, once for a few months trip to Wright Field and M.I.T. This was just before I got my degree, and that would be about 1939. And then I came back to Stanford and finished my degree there. This trip to M.I.T. and Wright Field was for being nurse-maid to a klystron really; with which they wanted to test their new ideas in blind-landing systems at both places, M.I.T. and Wright Field, that is blind-landing of airplanes.
Who invited you to come to M.I.T.?
It was W.L. Barrow. He was a professor of Electrical Engineering at M.I.T.; I believe that Barrow also covered for Wright Field. Barrow had an experiment going at Wright Field before I got there. I had a one kilowatt 40 centimeter wavelength klystron, which was more power than anybody at M.I.T. or Wright Field had. So I worked a few months testing at Wright Field and again at the Boston Airport at M.I.T. and brought the klystron back a few months later and finished my thesis at Stanford around 1940, just about the time the War broke out. Sperry Gyroscope Company was also interested in blind—landing. It has a different name now; it’s Sperry Rand now or something like that. When they heard about the work at Stanford and the large amount of power this new klystron device provided at centimeter wavelengths, they sent off one of their representatives to Stanford and negotiated a research contract. It was the first research contract in that field that Stanford ever had. Sperry furnished Stanford with what was then a large amount of money, I think it was $15,000. So that helped us get the klystron through development up to a production stage, and eventually we moved this klystron project to a nearby town, San Carlos. I was there until sometime in 1940. And then they moved the whole operation back to Long Island, to Garden City, and I went along with it. That has nothing to do with solid state except that we did in our testing, in the late 30’s or early 40’s, have to use the old fashioned crystal detector cat’s whisker type, which Marconi used in his earlier experiments, because nothing else would work at these frequencies. You may interrupt me please because I’m rambling.
You’re doing fine. What led people back during the late 30’s, or perhaps it was even earlier, to the old crystal detector?
There’s a lot of this in Norberg’s recording but I don’t know what I said so I’ll have to answer your questions directly.
I don’t believe this specific question was answered. Was there a particular individual involved? I’ve heard that Southworth was one of the people who got the idea to go back to the cat’s whisker detector.
Well, I was a natural thing. I suppose I was the first one at Stanford that told them about it, because the old crystal detector had been forgotten. I was helping Fred Terman write books, that’s a way I worked my way through college, I was a proof reader of McGraw-Hill for Terman.
Did you think of this independently?
Well, I suggested to him when he was writing this book that he should put something in it about the volt-ampere characteristics of the crystal type of detector because that was interesting; and he said oh we can’t have any of that old historical stuff; we can’t waste space in the book.
Why did you feel it was interesting?
Well I’m just interested in everything that’s interesting. I don’t know why. It was a big thing, I used those detectors in some of my radio operator experience. I worked my way through college by being a radio operator on a tug boat or on freighters or at stations in Alaska or things like that. And some of these ships or land stations had equipment that was so old fashioned that I had a spark gap transmitter and a crystal detector. Crystal detectors were just about going out by the time I first came in, but I knew about them and I knew that they worked and I knew that I heard a station a thousand miles away on just headphones and crystal detector and no amplifier. It can be done at the right time of night under the right conditions. So it was the natural thing to do.
This was around ‘37 or ‘38?
Well, this covers a large time span because I started my commercial radio experience in ‘27 and my amateur radio experience while I was still in high school, oh about ‘21 or ‘20 or something like that.
But then you went back while you were working on the book with Terman?
Well I was just thinking back and said, “Well you left out part of radio!” See, this was Terman’s big radio engineering book and it was supposed to cover all of radio. And I was a little bit more than a proof reader; I filled in sections of his book and things like that with his permission. It was a good source of income when I was a student.
Were you aware of the work that was being carried out at the Holmdel Laboratory of Bell Telephone at that time?
I knew about the place. I am not sure when Holmdel was started as a lab, do you have any figure? I don’t know whether it was going as a lab in 1940, was it?
Let’s see, they were first on West Street in New York and the radio people were at Cliffwood. Then at a certain point they were all moved to Holmdel, New Jersey. I don’t remember the exact date but it was sometime during the ‘30s. They were working on microwave detections.
I wasn’t particularly aware of that, but I’ve heard of it.
Among the people there, for example, were Harold Friis and Russel Ohl…
I had a long court appearance with Heising.
In the 1950’s, on the Sperry Patent, which got into court.
I will want to ask you some questions about that; that’s on the doping of germanium?
Yes, and R.A. Heising is a very good source if he is still alive. He’s in his 90’s I suppose and he had a very good memory the last time I saw him. He was the star of this court.
Others at Holmdel then included Southworth, and Lloyd Espenshied.
I particularly remember Heising, I didn’t know Heising personally until later. I had heard about him because his name was a byword in radio. For example, the early radio telephone transmitters, the broadcast stations and ham radio, whenever it was telephone, used the Heising modulation system. So I knew who he was. He was a great name and all of a sudden we were together in a hotel. It was a big thrill.
Last night on the telephone you mentioned that in the period of the ‘40s the chief thing was to find suitable diodes.
The chief thing was really to find transmitters and that would be either a klystron or a magnetron. The British furnished their new type of magnetron, which really led the way for transmitter to develop into pulse transmitters instead of CW Doppler transmitters. But the klystron was what influenced the line of development of the receivers; that was the local oscillator for the superheterodyne. But then there was one thing missing and that was the detector or frequency changer that changed it up from ten centimeter frequencies down to 30 megacycles. They say megahertz nowadays. Then from there on, it was pretty much well known how to handle things. The crystal detector frequency changer combination had the lowest noise; it was always the noise background that was the problem. So that’s the way they ended up.
When you say “they” are you speaking generally about the whole country?
And Britain. It was done differently in Germany.
Could you list for me, for my own information, the leading centers in that period?
Well let’s see. There was the so-called radiation lab at M.I.T.; there was I forget what they called it, at Harvard right near by the countermeasure system. You see, at M.I.T., they were developing radar and then over there at Harvard they were developing ways of wrecking it. Terman headed that and I forgot who headed radar. Somebody who later went on to Caltech. There is a book about that; I have a copy. Sort of like the Symthe report on the atomic energy development, right after the war life as much as could be talked about. Then there was of course several army labs. There was Bell Labs; that was also a big one. And there was Westinghouse and GE. I visited all those places, in that period. Yes, I visited them regularly on business.
About how often?
Just as often as necessary. Sometimes from weekly to months or a year. There was the army research lab. I can’t remember the name of that place but it was in New Jersey. I don’t think Wright Field did any actual research in microwaves although they were doing research in Systems. They weren’t researching on Solid State that’s why I had to go to Wright Field just before the war started.
What about the University of Pennsylvania?
Pennsylvania was in the wartime semiconductor research too; we used to get some materials from them and some of the research was done at the commercial labs. We got all of our silicon and germanium, at first it was germanium principally, we got that from a well-known chemical company whose name escapes me at the moment.
Was it Dupont?
No, they were not quite yet in it then. They made our first silicon I expect but before that we worked with germanium. Mostly it was germanium because it was easier to melt and purify. Oh, Eagel Pitcher, that’s a well known metallurgical company; it’s been going for 50 years or more. They did research on germanium. And one of their high up officers, vice president or something, he actually did the research with his own hands, was killed by fumes from a germanium furnace when he was doping with arsenic in a hydrogen furnace. That made AsH3 which is a deadly poison; he got a whiff of that and died.
I’d like to go back to our discussion of the visits that you made. Was it very common for individuals from one of these laboratories to share their information?
Very common. And during the War we could do things that would be totally impossible except in wartime because they’re not going to share any of their company secrets. I was continually amazed by how Bell Labs would tell us about their secret processes.
During the war?
You were coming from Sperry. Were you briefed about what you could or couldn’t talk about? Or was everything free?
No, it was all a need-to-know basis. If the higher ups decided that you needed to know something for your own work then there was no trouble there; the road was all paved for you. You didn’t even know what went on; you just talked to a certain man. He would say well, you talk to so and so, at the end of the day maybe. These visits were not very far, so you were usually there and home the same day. Once in a while you had to stay in a hotel. I attended a monthly conference in Manhattan on the whole project. I think it was run by the Army because there was a lot of army brass there. It was on the Empire State Building; it wasn’t quite the top floor, but it was pretty near.
Tell me more about that.
It was one or two floors from where that airplane crashed into the Empire State Building during the War and killed a bunch of people.
About how many of you would meet?
Oh there would be about 25 or 30 there from M.I.T., and Sperry, and the Army, and Bell Labs, and Westinghouse, and General Electric, and so on.
What were the subjects of the meetings?
Various troubles that the different laboratories were having with their material or their processing or their circuit development.
Were they one day conferences? Were talks given? Were they mainly open discussion?
They were one day conferences. There were talks and papers; some of those papers are still in existence.
Do you think that I might find those in federal records, army records?
Right after the war, they released lots of these wartime reports that were declassified and sent a bunch of them to the University of California, maybe to several of the big universities. There was an enormous file somewhere here in the basement of the library or something for a long time, I don’t know whether they threw them away yet or what. Norberg might know something about it.
I will ask him.
There was that set of books there on the shelf, a 28 volume set. One is loaned out to somebody. That’s the only complete set on one shelf I’ve ever seen. The libraries don’t shelve them that way. So if there’s anything in there, well a lot of your questions would be answered if you just sat down and read through the 28 volumes. You know of the existence of that set?
I think out of it now. They made a lot of money out of that set. It’s obsolete now except for history. I am in the process of dismantling my library and so I occasionally run across it and I’ll make a point now of not throwing it out and actively keeping my eyes open for it if it will do you any good.
It would be very useful.
Even several weeks or a few months from now?
Certainly. And it might also be useful to call Arthur Norberg and ask him what would be the most logical place for you to deposit these valuable books or papers when you come across them.
I’ve given him a lot of them already; there’s a big stack as a result of this patent suit between Sperry and Texas Instruments. That’s the one I testified in. I was called in; I had long since left Sperry and I had no loyalty to them anymore. I was called back years later in this suit and so I stayed in Dallas for something like ten days.
Let’s talk about that doping of germanium work now while we’re on it. This is as good a time as any. That was in the middle of your period at Sperry, sometime in ‘42 or so?
I was there from ‘40 to ‘45, not counting the time I was working on their money at Stanford.
That was later on?
That was before the war; it was just before Pearl Harbor.
What exactly went on in that work? How did you come to it? What was the nature of it?
Well, like I said, one of the big problems in radar was this crystal detector. And several labs were working it. I don’t remember all of them: G.E., Purdue, Westinghouse, Bell Labs, Sperry and some others. First they started out using silicon because germanium wasn’t known about. Silicon and galena and a few others that Marconi had used were tried out for microwaves. Oh yes, General Radio Company was doing quite a bit on this too.
Now this is before the war?
This is just before the war and also the first year of the war. We were still playing around with silicon and taking just the silicon that you could buy commercially and pounding it up and getting a little chip out and doing just about like Marconi.
You say they chose silicon because everybody knew about it from Marconi’s days?
Yes, that was in Morecroft’s big book which was the radio engineering book pre Termin.
When did that come out?
The first edition came out around 1910 or something like that.
And silicon is described in that book?
Yes, a lot of them are; silicon is mentioned. I have a copy of that book that one of my grad students found in a used bookstore in Berkeley. And it turns out to be Luis Alverez’s copy when he was a high school kid. I have a copy of a course that I studied when I was a kid too. It was the book and silicon and galena and all the others, about a dozen or more of them, are in that book.
But when did people generally begin to consider silicon as the best?
Well there was a cycle there. We had to use very primitive methods with silicon, about like Marconi did, but we could get some radar working with it. There was a lot of noise and so on. But we knew for our measurements that a much better detector could be made, because this one had a lot of so-called excess noise that isn’t there by thermodynamics. And so after these crude silicon detectors, somebody looked through the Handbook of Chemistry and Physics and I think it was a man at M.I.T., he was out here working with Lawrence long before that — I’ll think of his name, Winfield Salisbury, he’s that type of a person.
What did he do?
He was looking to see what was particular about silicon that made it a good detector. People had various theories as to why it worked and he thought, well maybe thermocouples will rectify. And so he looked in the thermoelectrical coefficient table and in the chemical tables and sure enough silicon was a great number 500 or something and a little further down, “well germanium! Oh that’s 2,500! We’ll try that; that might be better!” So they tried it and it was better, but it turned out that wasn’t the way it worked at all, that was just making the right discovery for the wrong reason.
Why was germanium better? It gave more signal and less noise and was a better conductor and various reasons. You could write a book on that.
About when did this happen?
Oh early in ‘42 or late in ‘41; it’s in my notebooks. Because Russell Ohl at the Holmdel of Bell Laboratories — you never heard of him?
Ohl went through a series of experiments in the mid ‘30s, or maybe it was the late ‘3Os and just tested about 300 or so materials.
People did that even back in the Marconi days. No rhyme or reason but they just mostly tested the natural minerals. One of them was iron pyrites; it’s a fairly good one. Galena was the most sensitive but you had to have very light contact, so it was easily destroyed by vibration.
But your contact was with the M.I.T. people, so you heard about it from them?
Yes. There was a lot of weekend commuting. One of our men, W. W. Hanson, who was my professor at Stanford, who has left there by now: every weekend he was commuting back and forth between M.I.T. and Sperry. He was working for Sperry but I guess Sperry and M.I.T. were sharing his salary. And he brought this Winfield Salisbury story back. Now it may have happened some other way.
So the story came to you from M.I.T. on the first germanium —.
Yes. So we got some dealer in rare chemicals and sure enough we found somebody that had some, what was supposed to be, germanium. Maybe it was 99% or 98%. And we knew that we could melt it, because we knew it’s melting point. We couldn’t melt the silicon because of the facilities we had there; it’s melting point is up above the melting point of quartz crucibles, which is the natural thing to use. Actually you can melt in quartz crucibles and a little later on Bell Labs did, but it’s pretty hard to do. So we could melt it and purify it and saw it up with a hand saw and all that stuff, and that developed the process of casting flat plates which could be broken up into little chips. And it made good detectors. We were all excited about it and went into production on it.
This is the germanium?
Germanium and silicon; just about the end of the war we went back to silicon again and I guess we made millions of them, literally we were always experimenting with what it was that made it good or bad. In other words, we knew it was impurities but we couldn’t test which impurities were good until we got it purer first. So in 1942, or nearly ‘42, that was a large part of my work — research in the hydrogen furnace on methods of purifying it, so that we could deliberately add the right ones. And everybody else was doing it too, of course, Bell Labs and I don’t know who all probably Purdue.
Who chose that?
Well, as soon as we found out about germanium, we called in all the others and said hey you ought to try germanium. Maybe somebody else found out even before we did.
So this was something that was assigned to you by Hanson?
Well by my boss and Hanson too.
Who was your boss?
My nominal boss was Bill Cook. I don’t know if he was one of the vice presidents of research, anyway he was the head of the radar research. He had a degree from Columbia which he never collected.
William P. Cook. He finished all of his Ph.D. except for writing the thesis, and then he got a nice job. And then he always figured well, I’ll write it, but he never got around to it. Everybody called him Dr. Cook. He did a thesis at Columbia on mechanical losses in vibrating iron when it was magnetized. The Q, he told me, went up to infinity as soon as they turned the magnetic field on this steel wire. But of course it wasn’t. He did a very interesting thesis and he was silly for not collecting it. But of course he was making so much money then he couldn’t even take a month off just to write it. You’ve heard of cases like that. Anyway that was my official boss.
Alright so then you were making all of this germanium and exploring why it was better or worse than other materials.
I ordered about 50 grams or something like that and pretty soon it was all used up. Then we ordered 2,000 grams that was the entire world sample of metallic germanium. And we had to repeat that order. The first order was five times the price of gold, and then the second time we ordered it why it was way down because they got big enough orders so that they worked over a lot of tailings. A lot of things get cheaper the more the supply and demand works and germanium did that.
So what happened then in your work?
Well then a large part of my work consisted of making test samples, cutting them up into chips, mounting them in one of their little microwaves holders, you still see them around they look like the semiconductor, well, they still make them in that same form — 3cm wave guides and fit them in that and then test their static characteristics with an oscilloscope.
What lead to your patent? That —
Well, testing on the oscilloscope, I found some germanium just having a full hand characteristic like a rectifier; it had negative resistance in the forward direction, so I knew it would amplify. See we didn’t have any semiconductor solid state amplifiers then. There was a negative resistance out in the reverse direction. But that was very slow, so everybody knew it was just a thermal effect and it wouldn’t be any good for a thousand megaton and then I knew that this one must be electronic, because you couldn’t see any time lag on the 60 cycle sweep. So I built an oscillator with it. I knew if it was an amplifier, it would oscillate, and that was the easiest way of proving that it was an amplifier. So I put one of these little cat’s whisker cartridges into a radio frequency circuit and sure enough it oscillated. So it was after the first semiconductor amplifier, unless Marconi did it and didn’t know it, way back then. So I wrote this in my notebook that this interesting fact was published as a Sperry report which got circulated in all the labs. And in this same report was the description for purifying the germanium which made this phenomenon. But I was mostly interested in this negative resistance amplifier, and I put that in my notebook too. My notebook had descriptions of how to purify germanium by melting it in graphite crucibles, which had some purifying effect on the germanium that casting it into thin wafers without sawing so that they could be cut up into little chips. And then doping, I guess I made the first highest purity germanium before any of the other labs did by this process. It was up in the three ohm 30 centimeter region, which isn’t quite intrinsic but it’s getting there. We knew there would be such a thing as intrinsic silicon germanium; there was enough solid state theory known then although it was pretty crude to know there was n type and p type and intrinsic and all those words, at least we had the ideas. We used n type and p type; I don’t remember whether we used intrinsic or not, but I realized right away that this three ohm-centimeter piece that I made must be up in the parts per million or per billion and so I broke the news to Purdue. Lark-Horovitz was a great visitor to Sperry; something like weekly. So I showed him this, I guess that was the way it was. And he said, Oh you’ve probably made the highest purity chemical ever made.
Was he a consultant for Sperry?
No he wasn’t a consultant for Sperry, that’s not the right way to say it. He was the man in charge of the project at Purdue. He had a lot of people working there, young physicists and he spent most of his time wandering around picking up ideas at M.I.T., Sperry, G.E. and all these places. He had a real good knowledge of chemistry for a physicist.
I have two questions before we leave this. First, just a general question. You referred to the words n-type and p-type. Were you and your collaborators fairly well informed about the quantum theory of solids as described in some of the new texts?
The quantum theory of solids wasn’t very well worked out by then, but everybody knew they were quantum.
There was some important new books on metals such as Mott and Jones and/or Mott and Gurney.
Those books didn’t do us much good because they didn’t say anything that applied to semiconductors hardly. They were mostly about metals as far as I know. Later on everybody in solid state was researching on silicon.
Wilson model of semiconductors came out in 1931.
I didn’t even realize that the word semiconductor existed before 1940. It probably did but you see I wasn’t in that part of physics, I was in electronics.
I think the theory was fairly well developed but they couldn’t go any further because they didn’t have the materials. It wasn’t until during and after the War that they had the materials to work with and go on.
Well Purdue could have been working on solid-state physics when the War started and that’s the reason they got this contract.
My guess is that there were a few people at Purdue working in solid-state since way back ten years before the war and so Lark-Horovitz saw his chance there. You said you made the first semiconductor amplifier.
So far as I know, yes.
How did this relate to the development of the transistor after the war?
Well, I stopped in the middle of the story; I didn’t tell you. When I developed this thing that everybody was trying to do, purify germanium, and proved that it was high purity by measuring its high resistivity, then the Patent Department of Sperry — you know you turn in your notebooks and they search through them first for some ideas. Their Patent Engineer followed us from Stanford there and —.
Do you remember his name?
Well, I will in a minute. Anyway he wrote up a rough draft of an application and brought it around for me. In the same part of the book this semiconductor amplifier was described; and it’s really just something that came up in testing this high purity stuff. What happened was that sometimes we’d get n-type material and sometimes p-type, and so I cut out a little chip that had n on one side and p on the other and soldered that down to the ground end of the sample. And then I put a cat’s whisker back and forth on a micro-manipulator and moved it along there and left it on the oscilloscope. I still only got a diode as far as the external world is concerned: two terminals soldered onto a large contact with a little point contact. Anyway, I put the contact down right on what I thought was the junction between n and p, see when on one side you would have n type and you would get a curve that way and on the other side you would have p type and get a reverse curve. And I thought, well what would happen if I put it down right between them. I got this funny thing with a negative resistance. Well you remember the first real transistors that Bell Labs built; they were called point contact, they had two points and one large connection. And later they eliminated the points and used two junctions, grown junctions at first. And so I probably had a hybrid of that; it wasn’t a point contact or a junction; it was a point hyphen junction transistor. And one of the terminals was floating.
Did you take a patent?
That was described in the description, you know how a patent looks? They have a description and a lot of blabber and then the claims and drawings and description. And this negative resistance thing was mentioned, that I proved that it amplified, in this patent in the description. And then when Bill Wasson brought around the rough draft, I said “Hey, you left out the most interesting part.” Now, if I was paying my money to patent this, I’d patent this solid state amplifier. I don’t know if I used the word solid-state. Yah I guess I did, anyway the semiconductor amplifier. And he said, “Oh, I don’t know how it works”, I said well neither do I but you know as well as I do that you don’t have to understand how something works to patent it. And he said, I wasn’t going to make any money out of the patent so I didn’t argue.
So did it appear?
It appeared in the patent but it didn’t appear in the claims. If he had written a claim that said “I claim a semiconductor amplifier containing a p—n junction”, then it would have read on the real junction transistor. So I’ve often wondered how Sperry felt. Well he did anyway, he knew what I said maybe it didn’t get to the higher ups but Sperry would have made millions of dollars instead of just a quarter of a million or so out of it. So that patent was in application form for years and years and finally got issued and then finally, after the War was well over, it got that different companies, R.C.A., Texas Instruments and a lot of others, started making transistors. And the companies were using the method of purifying and doping germanium, which was claimed in this patent. And so that went on for a few years and finally around 1950, the patent was issued in ‘46 I guess, Sperry said to R.C.A. well you’re not paying us royalties and you’re using this patent. So R.C.A. took out a royalty contract for three quarters of a cent for transistors to Sperry and that made them 2 or 3 hundred thousand dollars. And then Sperry came across. By any other violator you had to either go after them or they know you don’t mean it. And the first one will stop paying. So they took on Texas Instruments next, and T.I. was big then. And T.I. instead of working on royalty basis they decided to fight in court so that’s when I spent this time in Dallas in the ‘50s. And the last I heard was that it was found by the judge, there was no jury just a judge, that wasn’t enough of an invention to be a patent. In other words, the patent was invalid, and then of course it was appealed and appealed. After the first deposition in court, why then after that there are only just testing the appeals are not tested then and with new evidence, they just re-judge on the old evidence, so I was through. And the last I heard was that Sperry lost it and I don’t know whether they are still going or not.
Are you aware of anybody else who essentially, as you did, invented the transistor before the Bardeen-Brattain team did?
Well, that’s a matter of definition. You see, I didn’t know how it worked. And Shockley, Bardeen and Brattain and others, they did the theory first and they said, aha if we do so and so why then it should amplify and make a three therminal amplifier. And so that didn’t read on Sperry’s Patent because the amplifier wasn’t in the claim. So you can say I built the first transistor, but I don’t know whether I invented it or not; it depends on your definition of invent.
Let’s move on to your period in the Lark-Horovitz group at Purdue.
That happened quite a bit later.
When was it, June ‘45 to December ‘45?
My notebook has a big gap from June ‘42 to September ‘42 when I was working on the Manhattan Project on consultation; I got dragged off of radar and moved out here to California for the summer which I liked; that’s where I came from. Anyway, I went back in the fall and I took up where I left off in my notebook.
What did you do out here?
Well, I worked on secret stuff for the Manhattan Project. You know what the Manhattan Project is?
Yes. But there’s no bombs in Berkeley. I was in Berkeley but this was the same project. It was all over the country; Chicago, Stanford, Berkeley and Los Alamos.
I mean what aspect of the bomb were you focusing on out here in Berkeley?
Well Berkeley, I can mention anything that’s in the Symthe report.
Were you working with Lawrence?
I was working with Lawrence, separating uranium. And that’s about as far as I can go without mentioning something that hasn’t been declassified, just because nobody has ever heard of it.
Well it’s beside the main theme that I’m trying to trace in this interview.
Well then in late ‘42 I continued on in the same germanium research for a while and there was a lot of interchange back and forth between Purdue and Sperry. And there were several developments as the War went along, somebody discovered how to make high back voltage junction diodes.
Who was that?
I don’t remember; it wasn’t Sperry; it could have been either Purdue or G.E. G.E. did a lot of work; somebody at G.E. developed a bonded germanium point contact, which really had a p-n junction in it. It developed by a pulse if a high current per micro second welded it on — a welded contact, that’s what they called it, which did also have negative resistance, but it wasn’t negative static resistance, it was a negative resistance at the intermediate frequency; looking in there you could see at 30 megacycles you could see a negative instrumental resistance. And so that reduced the loss; I don’t think it actually made a gain; it wasn’t really doing the thing that the transistor was to do later. Those names will all come back to me if I can find some old reports, if I haven’t thrown them out. I gave a lot of stuff to Arthur Norberg and some of them may be in there. If you see anything from Sperry, I gave him some stuff from Sperry because Hanson was mentioned, he was also interested in Hanson.
Let’s see, we’re in about ‘43 or ‘44, on the semiconductor.
After that, I don’t know whether it was ‘43 or whenever, probably around ‘43, I got out of the semiconductor research and development and more directly into radar. I was making a lot of tests with airplane for targets for the Doppler System. Sperry pushed the Doppler System because of Hanson and the two were sort of complimentary. The pulse system tells you the distance to the plane, very directly and simply with no computer. The Doppler tells you how fast the plane is moving radially with respect to you so it depends on what you want. Most work on radar was pulse radar. Now they are using some of both. And I got back on Doppler radar testings and spent quite a bit of time on each. In New Jersey they say that you should send the planes out over the ocean and back again, measuring the noise level essentially. We try and get more distance out of our radar.
Were you interacting pretty closely with Bell Laboratories in semiconductor work too?
Yes, and in the radar.
I’d like to just list the names of some people whom you might have interacted with, and if you did, I’d be interested in your recollections. Did you interact with Dean Wooldridge at all?
I don’t remember him.
John Pierce, did you interact with him at all?
Yes, with regard to klystrons. He invented a cathode that was a kind of a focusing cathode. I think that was during Wartime. He also made some discoveries about the maximum current that a beam of electrons can carry before it goes unstable and we read all that.
You interacted through letters and papers, not in person?
Well, I’m sure I talked to him. After the war, I remember showing him around the Rad Lab. There was one big magnet; that was the 184 inch a great big thing that’s bigger than a house, weighs 4,000 tons or so. It’s about 100 feet from end to end. I remember him going in, that was in building 6 up there. You probably haven’t been up there. It filled the whole building. I went in the front door with John Pierce. I was often the man that showed around the visiting dignitaries, I knew something about each one of them. Anyway he opened the door and said Jesus Christ! And I said “Yes, we call it the Jesus Christ entrance, that’s what everybody says.” (Laughter)
Do you remember MacNair?
I don’t remember him.
It’s just a name.
Jewett, who was down in Washington at that time?
Shockley, I remember. I remember him because he was at Stanford before me and I probably talked to him.
You don’t remember any specific exchanges?
The people that I actually shared information with were probably people I wouldn’t remember now without looking at old progress reports.
Brattain, Pearson, Bardeen, Sceff —.
I may have talked with Sceff. He might have been one of the old timers; you see Bell Labs really didn’t get serious about this until they discovered that they had invented the transistor.
In the period June ‘45 to December ‘45, you worked in the Purdue semiconductor group.
I’d forgotten the exact months but yes, I guess so. As long as you stick with semiconductors, there is a whole lot of work; in between we spent testing there noise but I wasn’t in that very much. I wouldn’t know about it without looking in my notebook.
Perhaps later we can look at that. How did you happen to become a member of the Lark-Horovitz group?
Oh the war was over, and Sperry was stopping their research mostly and so I was fired so to speak. In other words, I was free again; I couldn’t quit while the war was going on. And Lark—Horovitz was trying to build up the physics department. He knew that Purdue would be interested in stuff that I’d been working on and I wanted to work on a linen accelerator like the SLACK. I’d worked with Hansen, who got into this stuff, that way at Stanford. His idea there was to make high voltage electrons before the war started. That was all stopped by the war. I had in mind to go back to some college and help build an electron linear accelerator; that’s what SLAG is. And I knew that I could do that at Purdue because Lark-Horovitz was interested in it too and other people there were, so I signed on as an assistant professor or something like that at Purdue. I don’t know what the records show.
So you applied there.
I didn’t really have to apply. Purdue just said, why don’t you come around and work for us.
That was done essentially, through your direct interactions with Lark-Horovitz during the Wartime?
Yes. And why they made me an offer and I didn’t like Lafayette. But Stanford didn’t make me an offer, so I went there. When did you say it was from, July 1945?
I have the dates June ‘45 to December ‘45.
I remember whenever it was that the A bomb was dropped; that was practically the end of the war and to me the war was over so we started making plans to leave. I guess that would be the middle of ‘45, wouldn’t it? Well, maybe we knew about it before. I guess the end of the war was getting over. Oh yes, Germany had already collapsed you see, they collapsed in ‘44 or something like that and then we had to finish up with Japan. We never used any A bomb on Germany of course because it wasn’t ready yet. Well yes, so I started making plans before to leave I guess in June to December.
How did the atmosphere at Purdue compare to that in the various other labs that you had worked in previously — Sperry, Stanford, and in particular M.I.T.?
Well, it wasn’t as interesting because if they did what I wanted to do they would be getting into a new field that would take quite a while. I made some designs for carrier resonators that were later used at Stanford. Those are not the ones actually used but they are what was later developed by Hansen into the form they used. I used the standing wave approach and Hansen decided the traveling wave approach was better; there are still arguments about it. There was the beginnings of an accelerator lab, but no actual electrons or vacuum systems yet.
So that’s essentially what you did at Purdue after the war; accelerator research.
I think I still talked to the people there about solid—state research too. I would be interested in those discussions. Vivian Johnson at Purdue who was in that solid-state research, I remember that name. She continued on in that for years after the war because I kept seeing Physical Review papers and so on by her. If you find the name Vivian Johnson why that will be Purdue. I don’t know whether she is still at Purdue. She must have been younger because I was older than just about everybody. I worked my way through college, and if you went right straight through for a doctors degree, you can get a bachelor’s at 22 and a doctor at 25. So I was like 35 because I only went to school about half time; I worked at the canneries every summer; I worked my way through college mostly as a radio operator on chips and canneries. My degree was actually assigned to this in 1940, although I was all through with it in ‘39 and that would make me 36 years old or something like that.
On the phone last night, you mentioned that there was some half dozen or so physicists in this group during the war.
Yes, but I don’t know all the names. I might know them if you read them off; I probably would in the case of the Purdue group because I talked to them a lot.
I see, and after the war who were some of the people you worked with? You mentioned one lady Johnson.
She was a solid state physicist, yes, I think her degree must have been in that. She was in it during the war too. I just remember her name because she was a woman and in those days I wasn’t married and I was looking for a blond with a Ph.D. I always told people that when they asked me why I wasn’t married.
I could, I presume read about that research in government reports.
Oh yes, quarterly reports. There were thousands of those that were sent to Calif. and other universities, they must be available someplace. You could find some maybe in the basement. They probably are at Richmond Field station if they exist, there are filing cabinets full of those and the Purdue report is probably in them. Maybe they have microfilmed all those things. As I dismantle my library I will run into some of the old Purdue reports I’m sure. You read off a list of Bell Labs names, now if you could read off a list of Purdue names I could give you more information.
Unfortunately I don’t have a list with me today, I will try to find a list and add it to the transcript when it comes back. In the meantime, I wonder if you could tell me a little bit about Lark-Horovitz himself. You’ve already told me that he did a lot of traveling and collecting of ideas. Did he work in the laboratory much?
When he was younger. But I think by this time he was mostly — well he was chairman of the Physics Department and I think that occupied most of his time outside of Wartime, that is before Wartime started. He must have had graduate students but I, oh yes some of these Wartime semiconductor projects were I’m sure done by his graduate students at Purdue. They were working on a degree and some of them stayed there. Some were faculty I know that so you can see that he did research through his graduate students. That’s the way a lot of professors here do their research. He had me out to his home a couple of times, he was a great music lover, opera, and he had a whole side of his wall covered with records. In those days there were no tapes. He had more records than I have books in my library. And I think we would play bridge.
Did he do less traveling around after the war than he did during the war?
Oh yes, well I’m assuming he did, I mean generally was it. Well he went to all of the physical society meetings of course, there were a lot of them and everybody did that in those days. In those days, the university paid your way if you went to deliver a paper and sometimes even if you didn’t.
Were you asked not to share your information, or were you briefed about what you should or shouldn’t do after the war? During the war you told me everything was exchanged freely.
Not freely to the public, but freely among the people that needed to know. So even after the war you still didn’t talk about anything unless you knew it had been declassified. And you kept getting in every mail stacks of reports that are stamped declassified.
Were you aware of the developments that were going on at Bell that were leading up to transistor?
Those didn’t happen until just after the war and my connection with Bell Labs stopped at the end of the war.
But while you were at Purdue you interacted with Bell: It was just in that period when they set up the big new solid state program under Shockley and Morgan.
I think I visited Bell Labs before the war, I don’t remember visiting them at all. Then you couldn’t find out much until they were ready to publish it in a scientific paper. I did hear that somebody at Bell Labs had a solid state amplifier before it was announced, wherever it was announced. I didn’t picture it as what it actually turned out to be.
Do you remember where you heard that?
Through Dave Sloan. Norberg has a big file on him too. Sloan worked at Westinghouse during this same period. Westinghouse was working on counter measures fuse, because Sloan had invented a triode that would put out lots and lots of C.W. power and so he went back there. I think it was Westinghouse, I could be wrong. It might have been G.E., but we’ll call it Westinghouse. So he was back in the war too, but he was connected more with the Harvard counter measure screw; and Westinghouse was connected with both.
Was anything like the work of Bell that led to the transistor going on in the Lark-Horovitz group in the mid ‘40s?
You mean anybody there who was thinking in terms of a three terminal amplifier?
Well, I don’t know, because if they did they didn’t tell me. You see it’s been alleged that the Lark—Horovitz group was only something like a month behind the Bell Labs Solid State group in the development of the transistor, but I’m not sure if this is true or not and it would be very interesting to find out.
Do you think Vivian Johnson would know?
Well she would be a good person to ask if any.
What caused you to move on from Purdue?
Oh because I got an offer from Berkeley Rad Lab up here. I found out that I could come back and work at the radiation lab instead of the University of Stanford, I thought of going back to Stanford after the war but I didn’t see any openings there.
You were here in Berkeley when the news of the transistor as announced? How did you feel when you received this news?
Oh I said that’s fine, but it won’t help me with my work at the Pad Lab because we were trying to build a billion volts there.
But you had come so close; you had actually built one.
I realized then that what I had built was a hybrid between a point and a junction type.
Did you feel scooped?
Well I wasn’t very much interested in it I guess, because by then I was only interested in how you go from a million volts to a billion volts. Of course, when the first transistor came out the general public wasn’t aware that it was about to revolutionize radio. I remember seeing my first pocket transistor radio. You know you had these little ones about the size of a computer or smaller. And as soon as I saw that — well already there were such things as computers, the first generation computer was about48 or something like that, the great big vacuum tube thing. And as soon as I saw this transistor radio I said, oh I can get rid of my slide rule; I turned out to be right.
But you must have been aware of the almost inevitable applications of the transistor, because you were so closely involved in the same work in the earlier period.
The first Bell Labs thing with two points wasn’t very impressive because everybody knew that point contacts where what they were trying to get away from. When Philco or somebody invented a method of making the points not side by side where they got bum geometry and spreading currents, but on opposite sides of a thin piece of germanium, (you know that piece of germanium, a little chip) and etch it electrically almost half way through on each side and left a thousand of an inch or something there and then put their point down. Then they got a better transistor and I liked that and I said, well we’re getting somewhere, maybe this thing will be practical after all. You know it’s like the automobile. The first one, everybody said “Well, it will never replace the horse.”
And you never went back to that kind of work?
Well, I had students doing it after I got on the faculty just for something to do. You know a student always wants master thesis or a doctor’s thesis and so there is a thesis copy here somewhere, a master’s thesis. By deliberately using one point and one junction, we got a grown junction diode and we used the micromanipulator and moved the point along and found that sure enough it does have this. In the M.I.T. book they call this phenomenon of the forward negative resistance, which I discovered, the “photo-diode”, because that’s sensitive to light, which I found out too by turning the little emission on and off. In a bright light, the negative resistance disappears. Anyway I had a student do a master’s thesis on that and pretty much verified what I guessed during the war.
Well, this has been extremely interesting and helpful and I guess this is a good time to break. I want to thank you and I hope to see some of your books.