Robert Crompton

Miller:

This is Tom Miller. It’s May 20, 2011 in Norman, Oklahoma. I’m going to be interviewing Robert W. Crompton about the Gaseous Electronics Conference. The interview will be transcribed by the Niels Bohr Library and Archives at the American Institute of Physics, and he’ll get a chance to look at the transcript and make sure it’s accurate and add anything he wants to add, and he’ll also sign a permission form so that historians can use the information in later times without attribution, without worrying about getting permissions, and the Niels Bohr Library can do whatever they want with it, put it in books, post it online, whatever.

So I want to start off by letting Bob just talk about anything he wants, but in particular how he became involved with the Gaseous Electronics Conference to begin with, if he can remember [chuckles].

Crompton:

Thank you, Tom. I think that last clause is very relevant, “if I can remember,” and I’m glad there will be an opportunity to perhaps make some amendments and additions to this transcript, because I’ve been intending to tidy my records up, and some things I think I will be able to clarify. But at the moment, since Tom’s email arrived telling me that we were going to have this talk together, I haven’t had time to check what history I can substantiate. So at any rate, I’m glad that there will be an opportunity to rectify any errors or omissions and make some additions.

Well, perhaps I’ll begin by talking about the very first GEC I attended, and Tom has very kindly dug up some records — the abstracts of those early meetings. It appears that I chaired a session in a meeting in Pittsburgh in ‘63. Now it’s not clear to me at the moment how that came about. I think probably it was my initiative to go to the GEC rather than anyone suggesting I did, but I’m not certain about that; I’ll try and find out. But that year was the first time I’d really had an opportunity to go overseas and do the conference circuit. And if I remember correctly, I had the opportunity to go to two international meetings: the International Conference of the Physics of Electronic and Atomic Collisions (ICPEAC), which was in Paris that year, and the International Conference of the Physics of Ionized Gases (ICPIG). So I went to both of those, and also in that same overseas round I went to the GEC, which in that year was in Pittsburgh. Now it is possible, since I’d been in correspondence with Art Phelps, that he may have suggested going to the conference. And records show that I chaired a session there. So that was certainly the first meeting of the GEC that I attended, and thereafter I found it the conferences series that I’ve most enjoyed going to. It wasn’t as large as the big international conferences. There’s much more of a sort of intimate feeling about these conferences: meeting with a group of people who you are much more likely to have had some contact with, a smaller group of people. That was the conference series of all of them I think that I enjoyed the most, so I went to several subsequently.

The next GEC after that was in ‘68, and the records show that I gave a plenary talk at that conference. That may well have been at the instigation of Leonard Loeb. By ‘68 I was already in Canberra. I was, in fact, in Canberra by ‘63, having moved to Canberra from the University of Adelaide in 1961, and so the ‘63 conference, which we’ve already talked about, would have taken place two years after I moved to Canberra. Now, my PhD thesis advisor was Leonard Huxley, later Sir Leonard Huxley. He had been the professor of physics at the University of Adelaide. Subsequently he took up the position of Vice Chancellor of the Australian National University in Canberra, and it was at his instigation that I moved to Canberra in ‘61. So the ’63 GEC was quite shortly after that. After 1963, Huxley actually invited Loeb to visit Canberra. He knew of his writings, of course, and so on. Whether they had met before then, I’m not certain. Anyway, Huxley invited Loeb to Canberra, and that was the beginning of a friendship that went on essentially until Loeb died.

It’s possible, and I think it’s quite likely, that Loeb suggested I give a plenary talk at the ‘68 GEC. That’s certainly after he’d been in Canberra. I’ll try and substantiate that through correspondence. I don’t know that for certain at the moment, but I think it’s highly likely that’s what happened.

As many of you who knew Leonard Loeb may know, one of his great loves was cats. He had cats at home which, when he was overseas or away from home, he missed greatly. And at the time he visited us in Canberra prior to ‘68, we had a cat and she’d just borne a litter of five kittens. One of the incidences I remember very clearly was of Loeb having dinner with us, and all of a sudden there was a sort of a roar from Leonard, saying, “Oh my God, there’s one of the kittens up my trousers!” [Chuckles] And so he loved the kittens, but he didn’t like them up his trouser legs much!

Miller:

We’re going to pause for a moment and save this file. I’ll do that every once in a while to make sure we don’t make a mistake somewhere along the line and erase everything.

Crompton:

So the records show that the next GEC meeting I went to was in ‘75 at Rolla, and apparently there were three talks there, all coauthored of course with other people. In the transcript we should say who were the coauthors of these papers^[1]. Now the next GEC after that was ‘77 at Palo Alto^[2]. In ‘77 and ‘78 I was on sabbatical leave at the University of Oklahoma at Norman, where this interview is now being recorded. On that occasion, Bob St. John and his wife Phyllis very kindly invited my wife Helen and me to go with them by car from Norman to Palo Alto where the GEC was to be held that year. That was a memorable ride, of course — it’s quite a trek from Norman across to Palo Alto. And we greatly enjoyed their company on however long it took us to do that journey, which I don’t remember. But that was a highlight for us. The conference itself, as usual, was highly enjoyable, highly informative, and the trip to and from made it particularly memorable.

The next conference the GEC abstracts show I attended was in Buffalo in 1979^[3]. I’d have to look up the record again to find out what my participation in these conferences was after that date. There was actually a conference of the GEC held in Norman, in 1980 I think^[4]. And that was, for me, the conference held, as it were, on American home ground, because we were back to the place which I’d spent a very enjoyable nine months or so in ‘77, ‘78. Again, I don’t have the record of what papers were given there, but I was obviously there because the record shows that, and we can look that up. It was in Norman, at the University of Oklahoma, that I first met Michael Morrison. Michael, along with three or four other young recruits, had just joined the Department of Physics and Astronomy which was enjoying a rebuilding phase under its new Chair, David Golden. It was David who invited me. Dick Fowler had just retired from the Chair after a long period of service, but I knew him well also because he had visited Syd Haydon at Armidale when the (now) University of New England was still a College of the University of Sydney. That meeting with Michael was the beginning of a lengthy and fruitful collaboration that resulted in several later visits of Michael and his wife Mary to Canberra, continuing after I had retired.

Miller:

I’m pretty sure 1980 was the one in Norman, because the record shows that I was chair of the session you spoke in.

Crompton:

That all fits together perfectly, doesn’t it. Yes. After that it becomes a bit more difficult, but I had intended to go to the library at the ANU before coming here. It will be easy enough to find because I think these have been recorded in the Bulletin of the American Physical Society. It should be easy to find some information there. Tom has actually supplied me with a lot of information, giving me leads to the abstracts that have been put on the Web. But that arrived only shortly before I left home to come here to Norman on this occasion, which is why we’re able to have this interview at the University of Oklahoma right now. But there were two other occasions after the Norman meeting in 1980. Just a minute, I’ll have to think about this. There looks to have been a gap — Tom, is that right? — between 1980 and …?

Miller:

I just looked on the Internet, and these are two that I found, but there may have been others.

Crompton:

I think there probably weren’t others. I think that’s probably right. And the last one that seems to be on the record is at Maui in ‘98, quite a few years after I had retired (in 1991)^[5]. That’s when the GEC went offshore. Would that be the first time it went offshore, do you think?

Miller:

I think that’s right.

Crompton:

And so that was another very interesting occasion, of course, and an opportunity to meet up with my old friends from the GEC off mainland U.S.A. It was the 51st meeting of the GEC, and I was invited to give a talk as one of the series entitled The Foundations of Gaseous Electronics. The theme I chose was Electron Swarms: A Link between Gaseous Electronics and Atomic Physics. It was now some years after my retirement in 1991, so it was my swansong as far as the GEC was concerned, and I felt very honoured to have been asked to give this talk.

Miller:

We’ll pause here again and save this file and start a new file. Now I’d like to ask some questions of Bob. At present time there’s a very large Australian contingent at the GEC: Steve Buckman from ANU, Mike Brunger from Flinders, and people from Adelaide, and this anti-matter group always shows up with positron scattering. My question is this. The natural assumption is that you had something to do with that, that they all come to the GEC meetings because of your history with the meetings, and I would like to know if that’s true, and did you recommend it? I could probably look at the record and find when Steve Buckman first came and when the others first came^[6]. But if you can say something about it?

Crompton:

Steve Buckman had a period at Boulder, I know. That’s correct, isn’t it?

Miller:

With Art Phelps?

Crompton:

Yes, he had a period at Boulder after he graduated from Flinders, and following a postdoc in Manchester with Frank Read.

Miller:

What about the others, like the people from Flinders and Adelaide? Do you think as a couple of you started going to the meetings others started going? Like Mike Brunger is now the GEC representative to DAMOP, so he serves on the DAMOP Executive Committee as the GEC representative. So somehow the Australians have moved in. [Chuckles]

Crompton:

Yes. Actually it’s fairly incestuous, all that, because I think the strong connection now between ANU and Adelaide in this field (actually it’s now mostly with Flinders, I think) comes in through Steve Buckman. The tie-up with the GEC meetings initially may be due to my early connections. I don’t want to take unjustified credit, but I think that’s probably true. But what I’m going to do when I get home is to substantiate that by talking to Steve, because he’ll know. I do know that when I recruited Steve to my group at the ANU, that was because I’d met him at the 1981 ICPEAC conference in Gatlinburg while he was at Boulder. He was giving a poster. Mike Brunger’s connection is certainly via Steve Buckman. So it was a sort of ancestral progression, I guess: Huxley, then me, and then finally Steve, bringing in the Flinders lot. So that’s roughly how it all stitches together, I think. And while we are on scientific genealogies, it is interesting that this line of gaseous electronic connections stretches right back unbroken to J. S. Townsend, undoubtedly one, if not the, founder of the subject. Huxley was Townsend’s student, I was Huxley’s, one of his first after he came to Adelaide to take the Elder Chair at the University of Adelaide in 1949. I was very fortunate to have had a brief meeting with Townsend in 1953 shortly before he died, being introduced to him by Huxley, of course. I have his autograph on one of my earliest papers, and it’s a prized possession.

Miller:

I wanted to ask another question. Nowadays there’s a huge Japanese contingent at the GEC, and often we meet — like in Maui and in Paris — we meet with the Japanese ICRP, which is their version of the Gaseous Electronics Conference. I had noticed at meetings you have Japanese friends and talk a lot to them, and I wondered whether you have anything to do with the fact that there is a large Japanese contingent at these meetings? Or it just that Australia is closer to Japan than it is to the U.S.?

Crompton:

I’d very much like to know the answer to that myself. It’s possible I can get a lead on that, too, Tom. In those earlier years there began to be a very useful connection between the people in gaseous electronics in Australia and those in Japan because we actually held three so-called Australia-Japan Workshops on Gaseous Electronics. Now those were small meetings. I think there were probably contingents of about 15 physicists from either side — 15 from Japan roughly, and the same number from Australia. We had our first meeting in Sydney, and then the second meeting in Japan near Tokyo (not actually at Tokyo but in a resort nearby), and the third meeting back again in Australia. Now certainly there was an increasingly strong connection between Australian and Japanese physicists in gaseous electronics as a result of that. Whether that had any connection really with an increasing attendance at the GEC I just don’t know. But it was a group of people in those early days that all knew each other pretty well, so you never know what talking about this and that may have led to. But certainly I can’t claim any direct connection to that.

Miller:

The other thing I’m very interested in is your friendship with Leonard Loeb, because I remember seeing Loeb at early meetings, and he was very nattily dressed, very proper, and almost always he would get up at the end of somebody’s talk and give a very critical remark. I Don’t think I ever heard him say, “That was a wonderful talk.” [Chuckles] And so I was afraid of him; I was afraid to talk to him. You know, I was a student, a low-level person. And it was only through Bob that I finally actually stayed at his house and met him, met his family. And he was a wonderful guy, very interesting, and I’m wondering how you became friends with him. Apparently you weren’t afraid of him. [Chuckles]

Crompton:

No, well I always had an extremely warm relation with him, and it must be remembered that that started quite late in the piece when he was an older man. I think you have to say he was an elderly man by this time. And so he had mellowed a lot, as I understand it, from those early days of the fierce controversy between his group and the U.K. physicists led perhaps by Llewellyn-Jones, [chuckles] who were firm protagonists of Townsend’s way of looking at things. Leonard Loeb firmly believed that the streamer theory was the correct explanation. He was then teaming up with another English group in Liverpool who were also subscribers to the streamer theory. And because of those strongly held views, there was quite a lot of animosity. Leonard Loeb wasn’t afraid to state his opinions [chuckles], which were often very firmly held and hard to shake.

But as a result of Loeb coming to us in Canberra, we became very firm friends. And also with Charlotte, of whom Helen and I were very fond. She was a lovely person. And more recently we’ve known their daughter [Valery Loeb] quite well too, and I saw her in California quite recently when I went to visit Rob Varney. Rob Varney I think was then 100 and in very poor health, but nevertheless that was a delightful occasion. The daughter’s name is Valerie, and Valerie and Leon Fisher and I went across to see Rob Varney. Unfortunately he’s just died, within the last month or so. But I was very glad to see him. I’d known him for many years as well, delightful gentleman, and had seen him in Innsbrook when he was visiting Hanspeter Helm. So there’s a strong connection there as well.

But yes, it’s true that Loeb and I became firm friends. It was easy to bury those earlier days of antagonism because by the time I got to know him he was an older man, and I was able to steer clear of streamers! [Laughs] He seemed to have a high opinion of our work, from what I could make out. We took him to the lab, of course. So he really was very generous to me in what he did for me. And as I say, it’s quite likely that he was the person who suggested I give a plenary talk at the ‘68 GEC. I can’t be certain of that, but I’m pretty sure that’s how it came about.

Miller:

I’m going to pause this again to save this file, to make sure we don’t make any mistakes. Bob, one question we’ve been asking everybody we interview is: how have you seen the Gaseous Electronics Conference change over time? I know I have, and if you can contribute… I don’t want to bias you by telling you my thoughts [chuckles], but if you can say a word?

Crompton:

Yes, to some extent from my point of view I guess they became a little less of direct interest to me. In those early days, there was a mixture of arcs and sparks, as well as —. Well I guess our kind of work only just squeaked through the gate at the Gaseous Electronics Conferences — I think because my interest was in carrying out swarm experiments whose specific aim was to determine electron atom and molecule collision cross-sections, and that formed a fairly minor part of those conferences in the early days. Perhaps I ought to correct that to say that, to get a paper into ICPEAC (as opposed to the GEC), which was the obvious place to present work on swarm experiments aimed at providing information on collision cross-sections was extremely difficult in those days. This was because the ICPEAC community didn’t really believe that anyone could get accurate information about collision cross-sections from swarm experiments. And that of course was entirely understandable, because in those early days there was no way to do it until I think Art Phelps and his group pioneered extraction of cross sections from swarm experiments using computers to do it. In the early days all one could use were so-called mean free path theories, which gave very approximate results for cross sections. So it really wasn’t until one solved the Boltzmann equation, using a computer, to unravel what you measure by diffusion and drift experiments. So it probably wasn’t surprising in those early days that one had quite a difficulty persuading people in ICPEAC to take a paper on cross-section derived from swarm experiments. That’s just a little aside I thought I’d put in.

Miller:

Because that certainly wasn’t true at GEC. The GEC welcomed swarm experiments.

Crompton:

Yes it did. It was different with the GED because they came in from a different perspective. What I also want to add, actually, more as a sequel to what we’ve been talking about, is that there was a conference of ICPEAC in Kalamazoo in 2009, and I think it was their 50th year — not their 50th conference, but their 50th year. And so they had invited a lot of the old buffers to come to the conference, whether they were actual contributors to the current meeting or not — some of them were, some of them weren’t. I was one of the ones who wasn’t, but I went just because I was invited to join this crowd of people who had been associated with the conferences in the early years. And among those whom I particularly remember — well there were three, actually. There was Felix Smith and Eddy Gerjuoy and Ben Bederson. So it was a real thrill to be on stage with those three who I’ve known for a very long time. Tom and I have just been talking about Eddy Gerjuoy, and wondering how at age 90+ he can possible look as he does and remain so active in his field. I’ve just been looking at a YouTube recording of a lecture he’s just given^[7]. I don’t know exactly where that was, but it was Eddy Gerjuoy unchanged from when I first knew him years ago. Absolutely amazing. So all his hair is there, and what’s more, it’s not tinted I’m sure!

Miller:

Let me add — again, I said I didn’t want to bias you — but when I was at SRI, GEC did a lot of gas laser work. They were trying to figure out how to get different wavelengths and so forth. Of course it’s all driven by funding and where the funding went. But what happened is I think those people started going to their own meetings, and now I see the conferences much more heavily plasma, and plasma processing in particular. But the nice thing about the conference, and Chun Lin is one who is responsible for this they have always felt that they needed the fundamental people there. They give the fundamental people sessions, even though those sessions are a small fraction of the meeting. It’s nice they still feel they want those people, and they encourage them to come. Chun Lin used to call you, asking you to come and submit a paper.

Crompton:

That’s an interesting fact, isn’t it. In fact the amount of collision data that one requires to do any sort of reasonable computation on the characteristics of electrical discharge is huge. And when some of these cross-sections are very unknown, results can be wild. So it’s quite true that it does play a very important part in gaseous electronics. I guess my comment would simply be that it’s a bit hard to know where some of this work fits. Is it in a conference on atomic collisions, or is it in a conference on gaseous electronics? And in fact it has a place in both.

Miller:

I think, unless we think of some more questions later, that will terminate the interview. Thank you, Bob.

Crompton:

Thank you very much, Tom.