Physics is Fun Memoires of Richard Wilson Version of September 25th 2009

Nucleon -Nucleon (and nucleus) scattering
Returning to Oxford University in 1952, I started an extensive program of work on nucleon-nucleon scattering using the cyclotron at the Atomic Energy Research Establishment (AERE) at Harwell. At first I would park my bicycle at Christchurch and once again took the number 13 bus to Harwell main gate. It became difficult to carry equipment and in April 1953 I bought a small Austin van. One Rhodes scholar (Robert G.P. Voss) joined me as a graduate student shortly to be joined by two others - John Thresher and a year later Chris Van Zyl.. We built a simple fast neutron counter from a liquid scintillator and used it to detect neutrons scattered by hydrogen and other elements. The cyclotron, designed by Gerald (Gerry) Pickavance and John Adams, was in a pit, for shielding, with a long “escape” tunnel down which air rushed. I arranged that this be the neutron line, and in it we placed a very simple liquid hydrogen target. It was in a vacuum of course, but had no pre cooling. We would pour liquid hydrogen into it from 2 litre glass Dewars into the open top. The flow of air was adequate to ensure safety. Talking the glass Dewars from the liquefier at Oxford to Harwell was more problematic. I filled the Dewars at the liquefier, and took 4 of them in the back of my car. I had a rubber bung on each with a rubber tube going out of the window. I drove slowly and carefully to avoid bouncing. The small angle measurement was interesting (26). The cross section near zero degrees was close to that at 180 degrees, in contrast to measurements looking for earlier recoil protons in a cloud chamber Indeed, the cloud chamber measurements found a value less than the “optical theorem “which derives the imaginary part of the scattering amplitude from the total cross section. Bob Marshak was visiting us at the time. He had a model which fitted the old results but he was impressed with our new results and incorporated them into a talk he gave that night in London. He was always quick to incorporate new thinking but, alas, not careful to credit others He failed to credit us in this lecture, for example, with the comment about the optical theorem which was new to him just the day before. For me it was mainly just funny, but this failing of his which drove many scientists (mostly theorists) wild, was, I believe a reason Bob never got the full credit that he so richly deserved.
On accepting an appointment at Harvard in 1955 I continued this program at the Harvard University Cyclotron. I very soon noted one interesting facet. The Harwell machine ran 5 days a week and only 16 hours a day. The Harvard machine ran around the clock. In both cases, maintenance was done during the day. The cost of living was lower in England and salaries likewise. Yet the budget for the Harwell accelerator was double that of the Harvard cyclotron Laboratory. It is hard to be sure of the reasons why. One reason, I believe, is that a University can run things cheaper than a national laboratory. Much work is done by “slave labor” (students). But that cannot be all. MIT was not as efficient as Harvard. I think that a great deal of credit must go to the designers and operators of the Harvard machine; Ken Bainbridge, Robert (Bob) R. Wilson, and Norman F. Ramsey, who set a tone that was subsequently followed by William (Bill) Preston, Andreas (Andy) Koehler and others. The benefit and success of this organization and approach to running a laboratory became much more evident in the 1970s when the medical program began. The Laurence Radiation Laboratory at Berkeley operated and operates like a National Laboratory more than like a University department. They treated patients with tumors long before we did - Dr John Lawrence, Ernest Lawrence’s brother, was using neutrons for therapy in the 1930s - unfortunately with little success. They operated the accelerators (first the cyclotron and then the bevatron) with high energy physics funds. In addition they had about $2 million for medical research from the AEC. In total the LBL medical work cost about 10 times the 1972 budget for the Harvard cyclotron. Moreover LBL treated 1/10 the number of patients that Harvard treated. They did not know how to make it cheaper. When the high energy physics program stopped running the Berkeley accelerators, the 184 inch cyclotron and the Bevatron, the medical program at LBL shut down but the cheaper Harvard/MGH program kept going.
My main work in the first 6 years at Harvard was a continuation of the Harwell program. Firstly, I had realized that the energy 95 MeV was too small to achieve polarized beams. We needed a much higher one. Although it would have been nice to go higher, Norman Ramsey explained to me that 165 MeV was possible. So that was my first task. As soon as I had accepted the appointment in January 1952 I went to Liverpool to visit their 350 MeV cyclotron where they had just extracted an external beam. Professor Le Couteur had written a theory of the extraction mechanism that enabled a better system than the one Jim Tuck and Teng had developed at Chicago. Albert Crewe built this (and then went to Chicago and Argonne National Laboratory). This we copied. A few weeks after my arrival at Harvard, in October 1955 the faculty and staff of the cyclotron agreed to the upgrade. Andy Koehler and Paul Cooper, with help over the thanksgiving holiday from the expert Dr. Mackenzie, visiting us en route from Berkeley to his home in Scotland, modified the oscillator so that it work at a more extended frequency range. In those days people did such help for free. But he did get a (free) Thanksgiving dinner with Andrée and our two children in our small apartment. My student Arthur Kuckes found a “flip chip” as a simple electronic integrator instead of a Gaussmeter, and a system to rotate it all around the magnet center. Karl Strauch and I shimmed the magnet so that a larger radius could be used. I remember cutting shims with tin shears till 10 pm on Christmas eve. Our families forgave us. Interestingly, the crudely cut shims, the regenerator and the extraction channel worked untouched till the cyclotron was shutdown 45 years later. I summarized all of this in the book "Nucleon-nucleon interactions" (Wiley-Interscience) which was later listed in the citation index as a most quoted book (68,452).
I was invited to talk about our work in many places, including Princeton. I had looked for Eugene Wigner in Princeton when I first visited in August 1950 on a special visit to Bob Hofstadter, but he was away, probably at Oak Ridge National Laboratory where he spent many summers, and it was not until about 1957, when I was 31 and Eugene was already 55, that I gave a colloquium at Princeton on my experiments on proton-proton and proton-nucleus scattering and really remember meeting Eugene. I had been warned about one facet of Eugene’s formidable reputation. This mild looking man would sit in the front row and in the question time after the lecture would, in a gentle voice, ask the most penetrating, and shattering questions showing the weaknesses in the lecturer’s arguments. I cannot remember him asking a question at that colloquium, but I was always able to answer on the later occsasions when he did. Valentine Telegdi told me that Eugene was much less gentle in Hungarian and had learned the gentle courteous behavior believing that was the way Englishmen were supposed to behave. Whether or not it was originally a pose I do not know. Suffice to say that for physicists at least the pose had become the man by the time I knew him. But then, most physicists do not speak Hungarian. It used to be said that if Eugene entered a revolving door before another person, he would always come out after him. The opposite was said of his friend John Von Neuman who would always come out first.
I talked about the nucleon-nucleon scattering at the high energy physics conferences in Rochester in 1957, in CERN in 1958 and in Kiev in 1959. I remember the Kiev meeting in particular. Godfrey Stafford of AERE described Eric Taylor’s work on measuring the depolarization parameter D. Chester Huang had just got his first results on this, and found the opposite sign! I warned Godfrey to be careful but he was not. So I got up and said that I thought the result was wrong, and we had preliminary data, which we were checking, saying so. Interestingly the AERE result agreed with calculations based upon a potential by Signell and Marshak, but our results agreed with a potential by Gammel end Thaler on Los Alamos. This dramatic difference enhanced my reputation.
In 1967 I was already fully engaged in other work, but was asked by Alex Green and Malcomb MacGregor to help in running a conference on nucleon-nucleon scattering in Florida. We wanted the best theorists so we invited Gregory Breit saying that his friend Eugene Wigner was coming, and invited Eugene saying that his friend Gregory Breit was coming. They both came. It was a stimulating conference and discussions with these great theorists were particularly fine. We wrote up the results in a useful summary (102).
As I look back on these years the enormous pleasure was in the interaction in those years with experimental apparatus and making decisions on how to get the job done. The preceding paragraph describes the beam extraction from the cyclotron. But then when we came to the triple scattering experiments to elucidate the details of the nucleon-nucleon interaction, I balked at rotating the apparatus, as Chamberlain and Segré had done at Berkeley, to study spin rotation in the scattering. We rotated the spins. I designed a solenoid for this. Instead of buying an AC motor and DC generator to power the magnet Andy Koehler suggested that we use the new high voltage and high current silicon diodes. The voltage would be controlled by a saturable reactor. When we assembled them and switched on, all three components failed. The magnet, built by the GE coil winding shop, to their own design, in Medford for $5,000 overheated and shorted I designed another, specifying in detail the phosphor bronze fittings to be used, to be built by Karl Brown’s firm in Palo Alto for $6,000. The rectifier, made by a small firm in Englewood NJ for $150 failed quickly. I visited them (by bus of course) during the January APS meeting in New York. But they could not get them right, so we bought some rectifiers for $400 instead of $100 from Westinghouse and put them in our own water cooled metal plate. The saturable reactor was also mis designed by the supplier for 110 volts instead of the 200 volt phase to phase that was specified. We ordered another saturable reactor off the shelf from somewhere. That all worked within six months and it gave me great satisfaction. I remember talking to Pief at the NY APS meeting about 1958. I explained to him that this system would be simpler that the motor-generator system used in his laboratory. It was also cheaper and that he should suggest it to Bob Hofstadter. “These are fighting words” was his reply. Bob preferred established and tested technology when available. But we never bought a motor-generator set at CEA and were probably the first accelerator laboratory not to do so.
I always believe in simplicity of apparatus. In my neutron proton scattering experiment at small angles (26), we filled the target with 2 liters of liquid hydrogen by pouring it in by hand from a glass Dewar. We filled the glass Dewars from the hydrogen liquefier in the Clarendon laboratory, put them in the back of my van, with windows open and a rubber hose taking the gas from the Dewars out of the window. Then we drove slowly and steadily to Harwell. The targets were in a long “escape” tunnel through which air rushed to an extractor fan. At the Harvard cyclotron laboratory I was more “sophisticated” . The target cup was now plastic film glued with epoxy. We bought the hydrogen in a large 30 liter Dewar and I built a transfer tube as I had learnt at Oxford. Liquid nitrogen, poured in by hand, surrounded the cold hydrogen. We did put a hood over the target with an extractor fan and I removed the windows at the top of the experimental area to avoid trapping of hydrogen. Of course we put up big non-smoking signs. On one occasion the ONR representative was being brought around by the director of the laboratory, Bill Preston. He was smoking. I did not notice, but Alan Cormack was there and acted quickly. There was no time to call out. Alan moved forward and quickly took the cigarette out of the approaching bureaucrat’s mouth. At the Cambridge Electron Accelerator we decided on another approach. Every hydrogen target would have a small helium liquefier attached to cool the hydrogen My targets were never more than 100ccs,. There was one concern. When we used an internal hydrogen target the ordinary plastic suffered from radiation damage. We used “H film” which is radiation resistant. But still, it would fail after 10 hours or so. On one occasion when it did fail the vacuum chamber of the accelerator was half filled with hydrogen gas. But as expected, the gas cleaned the vacuum chamber and it was pumped down again to a vacuum below 10-6 mm mercury in 20 minutes. This was far simpler than the complex target system we now have at CEBAF.
CEA
I used to go at least once a year to the American Physical Society meetings. Once, in 1968 I believe, George Chapman, Professor George Chapman from Oxford gave an invited 30 minute talk on geophysics. Jesse DuMond had come east for the meeting. George went out of his way to emphasize the spirit of cooperation among American physicists and their generosity to European colleagues who were less fortunate and were still recovering from world war II. Jesse was surprised and overwhelmed. I was not surprised because I was the recipient of such generosity and cooperation and indeed that was one of the reasons I decided to come to the USA in 1955. Alas, I had hoped for, and expected, too much.
One of the reasons for coming to Harvard was the planning for a 6 GeV electron synchrotron. My year at Stanford, and the following since of the work of Robert Hofstadter had convinced me of the simplicity of understanding physics with electrons compared to physics with protons. The leader in the planning was M. Stanley (Stan) Livingston, who as a graduate student of Ernest Lawrence had been the actual person who built the first cyclotron, under his thesis advisor’s direction, about 1928 I joined in the planning with enthusiasm and became Chairman of the Scientific Advisory Committee. I did the calculations for radiation shielding. I was particularly interested in electron scattering, and made the first calculations on how to extract an external beam, Summer 1959 was spent at Stanford trying to understand what they were planning and how we might coordinate. They were by that time planning for their 20 GeV linear accelerator and I wanted to be sure we were cooperative rather than competitive. We would have an electron beam 6 years or so before they would and although our energy would be lower, the duty cycle would be better. But cooperation was not to be. One consequence, whether of this summer work or not was that I received an offer in summer 1960 to go to Stanford as a Professor. After mulling about this a lot, I declined. I often wonder how physics would have turned out if I had gone to Stanford in 1961. Or later in 1963-4. when the opportunity recurred. I suspect that being related to Pief by marriage would have made matters difficult when the inevitable jockeying for position took place.
The enthusiasm for the CEA in the Cambridge area was large. the Harvard physics department faculty there were, in addition to myself, Professors Norman Ramsey, Frank Pipkin, Karl Strauch and Curry Street. At MIT, Louis Osborne, David Frisch, Martin Deutsch, and Irwin Pless were enthusiastic. Jerry Friedman and Henry Kendall joined the MIT faculty just before the first beam. We also had groups from neighboring Universities, Brandeis, Tufts, Northeastern, University of Massachusetts at Dartmouth and Yale university. At that epoch in High Energy Physics, the style was to have a lot of small experiments around one accelerator. Many professors each forming his own research group. The style of having one or two large spectrometers with, perhaps, several groups using them had not yet developed. One of the deep problems at the CEA was a failure to get together to build such a spectrometer. I remember late in 1961 discussing with Henry Kendall and Jerry Friedman how we might jointly build a high class, expensive spectrometer to use with the external beam and work either together, or divide the work between us. We already had a small plan for electron-proton scattering using the internal beam, using a crude spectrometer, which had its runs a few weeks later. A little later, Kendall and Friedman set a graduate student on electron-deuteron scattering with this apparatus. The graduate student thanked us both in wring in his thesis and orally at a seminar. . Neither Jerry nor Henry ever did. Unfortunately we could not seem to work together.. I had hoped that by hiring excellent research fellows I could get someone to help me build such a spectrometer. One such was Lou Hand. It was Lou that brought the electric and magnetic form factors to my attention. He was and is very bright but he wanted to actually do physics at once and not wait a few months for the CEA beam.. He realized what Lehman, Taylor and Wilson had done at Orsay and wanted to do this with deuterium at Stanford. He used my targets from the cyclotron. Recently (2008) he spontaneously told me that he was wrong and should have been more directly involved in my program for the CEA. It might have made a crucial difference. Of course I had been disappointed, but accepted Lou’s decision at the time. I was taken aback by his recent candour and still am.

This was an era of Reggae trajectories. All excited states of protons and other particles ran on a Reggae trajectory, with interesting consequences for scattering at high energies. Why not the photon? There would be exited states of the proton at higher mass. Maybe the rho or the omega mesons If so, elastic electron scattering would no longer be described by a couple of Form Factors but the cross section would increase with energy. We disproved that in the first experiment at the CEA (64). Later runs looked at form factors in a more ordinary way. Other groups looked for failures of quantum electrodynamics for this and similar reasons. The cross section for electron-positron pairs produced by high energy photons would be higher than given by the Bethe-Heitler formula. Frank Pipkin set out to measure wide angle electron-positron pairs. Jerry Friedman and Henry Kendall joined Weinstein of Northeastern in looking for wide angle muon pairs. Vernon Hughes of Yale did so also. Physicists give much more credit to the first person to have an idea or make an interesting measurement than they assign blame for an incorrect measurement. There is therefore great incentive to be the first to find a predicted effect. This may have been the general reason that all three experiments found a high cross section. But they were all wrong. This threw a shadow on all CEA work such as Frank Pipkin’s excellent photo production of vector mesons. Indeed the first reported measurements on vector meson photo production at SLAC and DESY differed somewhat from Frank’s, and were widely accepted as superior, but Frank was correct.

The CEA had put priority into helping a large bubble chamber to get going. This was to be a collaborative effort with Irwin Pless of MIT in charge of construction and Karl Strauch and Curry Street at Harvard and others with analysis capabilities. As a result the bubble chamber had priority in the machine and assembly shops at CEA since 1959. But it was only ready for test in summer 1965. July 4th 1965 was the real disaster. Norman Ramsey and I were, with our students, beginning electron scattering experiments with the just completed apparatus in the external electron beam. The bubble chamber was being cooled down for the first time, at long last! I remember Norman and I idly calculated the size of an explosion if something went wrong!. We went home at 2 am. At 4.33 am the beryllium window failed, pouring 300 liters of liquid hydrogen into the vacuum system and then onto the floor. The fire burnt 6 hard working scientists from the waist up. Fortunately the Boston area had previous experience with large scale burns from a night club fire some years before , in which emergency exit doors were locked. The fire also set off safety seals on the tanks of propane and the burning gas added to the conflagration. The roof literally fell in on one of the young scientists - an MIT undergraduate - and he died a few days later. It also destroyed the electron scattering apparatus. We had a two year delay in the electron scattering program and DESY caught up and overtook us. I remember being called at 6 am by the graduate student Bill Shlaer who was running the cyclotron that night looking for proton bremsstrahlung. He kept on running, but eventually shut down at fire department request. Five minutes after he rung off I called back. “Please secure the 2 liquid hydrogen Dewars outside the cyclotron next to the CEA.”
Bob Budnitz also called. He was awoken by the sound of fire engines at 4.47 am, and went to investigate. He found firemen trying to enter CEA through the emergency exit on Gorham Street. The firemen would not let him near there. “There is radiation” . And the firemen went on trying to open the door with axes. “But I have a key of the door”. Still they would not let him near until Louis Osborne came and said “I am an MIT Professor and I know about the radiation.” He was allowed in. I assume that everyone who reads this will agree that emergency plans should be practiced. Less obvious is the that they should be integrated as far as possible for various accidents. For example both evacuation for a nuclear power accident, which we hope will be infrequent or never, is similar to evacuation when there is an overturned freight car with toxic chemicals. The less frequent possibility can be exercised by the frequent possibility of other accidents if the plans are integrated. I had only just got to bed and probably wrongly decided at that time to go on sleeping. In the morning after a few hours sleep I got to the laboratory at 8 am. I took administrative action for which I doubted that I had authority. I called the families of everyone who had been taken to hospital and told them that Harvard would pay for the expenses of anyone visiting their loved ones. Fortunately that unauthorized promise was confirmed later by the administrators. I organized blood donations at the hospitals (MGH and Cambridge City Hospital)..

Then began a series of meetings to decide what had happened and what do. If the accident had been in the UK the death of the MIT student would have forced an inquest. What follows therefore is only an informal statement of what happened. I count four major mistakes.

(1) The beam entry window of the bubble chamber was thin and deliberately of low Z material, beryllium. It is known to be brittle as machined . It can be made less brittle by annealing. Apparently this was known to the manufacturers at the time but not to me and not to the responsible MIT professor (Professor Irwin Pless) or Professor Stan Livingston the lab director.
(2) There were two windows: from the liquid hydrogen to the vacuum and from the vacuum to the outside world. It was assumed that if the inner one broke, the spilled hydrogen would be rapidly pumped and leave the outer window intact. Yet an experiment by the same group in a liquid propane bubble chamber at BNL had found that the breaking of the inner window would break the outer one - probably by a projectile. Indeed, Professor Street, our Harvard colleague informed us, that he Professor Street, had reported on this at a meeting in CERN.
(3) The intention was to have a long vacuum beam pipe from the outer window to the accelerator so that even if the outer window failed there would be less chance of a failure to the outside. Because of haste in getting the test ready, the beam pipe was not ready and instead of delaying the test 2 days, a piece of wood was clamped with C clamps to the outside of the window. As the hydrogen escaped the window, it fell to the floor and ignited. Tom Collins, Associate Director of CEA estimated that 30 liters out of an inventory of 60 liters burnt rapidly, within a second. I confirmed his calculation. This was not formally an explosion, because there was no shock wave, but the pressure went up enough to lift the roof which it was in fact designed to do.
(4) The MIT members of the management committee all had insisted that Professor Pless should have complete authority over the bubble chamber engineering. Harvard would have no authority and they insisted that Stanley Livingston and his staff did not. Stan Livingston and the Harvard members of the committee, including myself as Chairman, had acquiesced in this. If it was a problem it would be an MIT problem. I was wrong. The newspapers made it very clear. It was at the CEA on Harvard property and it was a Harvard explosion. I had failed my responsibility.
I do not think I would have made any of mistakes 1 to 3 myself and therefore feel little responsibility. But I felt, and feel, deeply my responsibility for mistake 4. It has influenced my opinion on such matters as nuclear power safety. But the three MIT members of the management committee did not learn. When Professor Pless proposed rebuilding the bubble chamber with an identical management structure, and in the identical location, Stan Livingston balked. He wanted to have the ultimate responsibility with a proper safety committee to exercise it. Stan morosely expressed his concern to me. “I feel I am destroying the CEA.” I reassured Stan. All three of the Harvard members of the committee agreed with him. So Professor Pless proposed to move the bubble chamber to Argonne National Laboratory. In order for that to happen, the AEC had to find the funds, a part of which came from cutting our (Harvard) budget by about $80,000 at a time we needed it. Worse still the bubble chamber never operated at Argonne National Laboratory or anywhere else. But there was further fall out. The theorist Victor (Vicky) Weisskopf had deliberately got himself on the CEA management committee to support a continuation of the old administrative structure. Although I had admired and respected Vicky for his marvelous work in explaining difficult concepts in physics, and had sought his judgment on many matters up till that time, I never again trusted his judgment. I found it difficult even to ask him about theoretical matters which were unrelated to this engineering and safety matter. As noted later, he failed to support us on our colliding beam proposals and both privately and as first Chairman of the AEC’s High Energy Advisory Panel (HEPAP) he preferred SLAC. Whether this was the reason or not, Vicky told Andrée some five years later that I was just a trouble maker.
In the recovery from the accident and subsequent fire several of us had to spend many months completely rebuilding. First and foremost were the physical casualties. The death of the MIT undergraduate and the five scientists burned from the waist up were the most important. But a non physical casualty was the cooperation between Harvard and MIT. MIT Professors began to put all the blame on Stan Livingston - one of their own.. “He is the stupidest person on two legs” was a rude, and absolutely incorrect, comment by one MIT Professor, not normally known for such unpleasant thoughts. Indeed, he had not made much of a mark as a nuclear or high energy physicist. His major contribution in the basic physics itself was being a co-author with Hans Bethe of one of a famous trilogy of review papers in Reviews of Modern Physics in 1938. But he did have a good instinct for accelerators and both the physics and the engineering thereof. In addition to the first cyclotron at Berkeley he had built cyclotrons at Cornell, and MIT. He had contributed to, and had been a director of the very successful Brookhaven cosmotron, and was one of the three inventors of strong focusing, together with the theorists Ernie Courant.. Stan had assembled a first rate team. I had helped a little in this, particularly in recruiting a couple of Britons - Ewan Patterson and Ron Little. Tom Collins, who had been working on a mass spectrometer with Ken Bainbridge, went on to be Deputy Director of Fermilab But regretfully it was clear to me that if CEA was to have a future as a joint Harvard-MIT facility, another director was needed. I discussed this extensively with Curry Street and Norman Ramsey at Harvard. Stan resigned. After some searches Karl Strauch agreed to be director. Alas, this willingness to give up research for an administrative duty was not enough.
Before we could rebuild our external beam scattering apparatus, Dr Brasse of DESY repeated our internal target experiment on electron scattering with an almost identical technique. He found an absolute value of the electron scattering a cross section about 20% to 30% less than we had found. If we had been able to maintain our lead, we could have corrected it ourselves as so many scientists in history have been able to do. I note that in this field, for example, that the first elastic electron scattering cross sections from SLAC that were presented at a conference were 10-20% high - corrected by the time they appeared in Physical Review Letters a year later. Our mistake came from a very obscure fault that I found later. The Faraday cup that measured the intensity of the gamma rays from the bremsstrahlung as electrons struck the target was filled with pure helium to avoid electron recombination on impurities such as oxygen. But the helium not only leaked out, but the hole must have been a small one and the air molecules could not get back in to replace the helium and there was a partial vacuum. Our gauge read zero when it should have read minus 1/4 atmosphere. At that time I and others were just testing our scattering equipment, less sophisticated than I would have had if we had succeeded in a collaboration, in the external electron beam. But we had to rebuild everything, with less enthusiasm. Most groups took up to 18 months to rebuild their apparatus. My stalwart students quickly rebuilt the electron scattering detectors and we took data scattering electrons from the external beam off both hydrogen and deuterium on May 6th 1966,, only ten months later. The notes say it was at a four momentum transfer, of q² = 7 inverse Fermi-squared or 0.3 (GeV/c)^-2,
Just after the explosion, Sam Ting, then an Assistant Professor at Columbia University, asked me whether we would consider favorably a proposal from him to measure wide angle electron pairs. Of course, I said: “ you are welcome to propose it, and of course we would consider it. But we have three groups who want to repeat their measurements with extra checks.” I believe I went as far as to say that we needed another one like a hole in our heads! I thought that the CEA group would want to give the other experimenters a chance to correct what I thought was an error. I suggested to him that he propose the experiment to DESY. They had a shortage of experienced scientists, and moreover he could get started 6 months or more before it could be possible at CEA even if accepted. This he did. I still believe it was good advice for him, but maybe not for us at CEA. After experiments restarted Weinstein, less Friedman and Kendall who had abandoned CEA for SLAC, and Pipkin repeated their experiments on wide angle electron or muon pairs with extra checks. Their results never got published. Jimmy Walker at Harvard made precise total photon (mostly pair production) cross sections at high energy which agreed with theory. That unfortunate chapter was closed.
Another facet of CEA organization aroused criticism. MIT and more particularly Harvard, was and is, restrictive in bestowing the title Professor. It was restricted to those who taught and went through the formal promotion procedure. Bill Preston, hired as Director of the Cyclotron became Department Chairman and then Director of the Physics laboratories. But he was only a Senior Lecturer. In the CEA, only Stan Livingston, who was already a Professor at MIT had that title. The rest of the CEA staff were senior research associates. But they had as much a promise of tenure as Professors at SLAC, who did not teach and whose appointment depended on the contract. Harvard did make a promise of finding them positions if the CEA contract ceased as it did in 1993. As a practical matter, we encouraged those who wanted to carry out research on physics to get an appointment with Harvard or MIT physics departments and used CEA appointments for those primarily interested in accelerator physics, although research groups were mixed. Burt Richter explicitly told me, and no doubt he told others, that he was recommending people not to come to CEA for that reason. I found this peculiar. Since then other young scientists have complained to me that Pief, when director of SLAC had asked them to decide between working on the physics and engineering of the accelerator physics or carrying out experiments with the beams provided. The excellent accelerator physicists, Euan Patterson, and John Rees who went to SLAC never became Professors. Only Herman Winnick did, working on synchrotron radiation. But the use of the title, Professor to apply to non Professing scientists is becoming increasingly common. Basically, in supporting this restrictive policy I, and Harvard physics department, lost out. Perhaps the present policy of appointing “Professors of the Practice” in Engineering and Public Policy departments would solve this problem.
It was about 1965 that a Professor from Cornell, whose name now escapes me, proposed to use synchrotron radiation. We discussed this in the management group. I suggested, and others agreed, that we should of course run the accelerator for him but any capital equipment or building he would have to provide or help to get extra AEC funding.. Stan Livingston was forward looking and inclined to do more. In retrospect I think Stan was right and I was wrong. So Ed Purcell persuaded Ed Land of Polaroid to produce $50,000 for a special building and some experiments were conducted in this special buillding, including some by Harvard Assistant Professor Paul Horowitz. The CEA finally closed in 1973. What should be done with it? “We” at CEA, Harvard and MIT, primarily Herman Winnick, prepared an excellent proposal for continuing the facility for synchrotron radiation. There was no hope of getting AEC to fund this, because of Seaborg’s commitment to Congress to close CEA and the But NSF agreed to provide $500,000 for synchrotron radiation which would be adequate to keep a facility going. Bill Paul of the Department of Applied Sciences would be director. Again SLAC wanted a storage ring although it was and still is my view that they were less prepared for it. Again there was a competition and NSF set up a committee to decide. I heard through the grape vine that the NSF committee were dubious about the commitment of the Harvard faculty. I had other fish to fry and was not personally interested but I hated to see a good project go down the drain. So I proposed to the physics department that we formally tell NSF that if the facility were approved that we would emphasize an interest in using synchrotron radiation in our forthcoming search for a “low energy” (solid state) tenure appointment. But the physics department Chairman, Paul Martin, was against this, and we failed to make such a statement. I believe it was merely a “New England reticence”. In contrast, SLAC only had an assistant Professor in the Stanford physics department who tated his interest. He promptly went on leave. That turned out not to matter, because Herman Winnick went to SLAC as CEA collapsed. I do not know the details but am inclined to attribute to Herman the fact that everything worked well at the Stanford Synchrotron Radiation Laboratory.. As noted earlier, he was made a Professor which would not have happened at CEA. At that time Pief could usually get what he wanted and although he said to the committee recommending government funding, in my presence, that CEA should get a facility after the SLAC ring was funded, no one took this seriously. That, of course, is usual. People usually only take the first item on a list seriously.
I proposed first to the physics department, and then in a personal letter to Harvard President Derek Bok, that we leave the CEA ring and equipment in place until the relevant funding agencies “come to their senses”. In retrospect “coming to their senses” would only have taken a couple of years. But the physics department was uninterested and Karl Strauch, the Director, not unnaturally, wanted a clean end and I was busy on other matters. David Monckton, a member of the committee told me many years later, that he was unaware at first of the importance of synchrotron radiation and the committee discussion educated him. Two years later he proposed a small synchrotron radiation facility for Brookhaven which was funded. Later he was fingered to run the Argonne National Laboratory 7 GeV facility. This facility, finished 25 years after CEA, was not appreciably bigger or better, although it did have an “undulator”, as proposed by Hans Motz in 1950, and other improvements. These would, no doubt have been installed at CEA if we had been funded because they were all in our proposal! The ANL facility cost $900,000,000 whereas we threw away a similar facility that cost 100 times less when built. In retrospect I think that the failure to keep the CEA alive for synchrotron radiation was a far more serious issue than my failure to get a storage ring in Cambridge. Even 7 years later there were more users of synchrotron radiation in the “Greater Cambridge” area than anywhere else. It was not only a Harvard failure, but in view of the large sum for the Argonne facility it was a national failure. But it had less impact on me personally than the other failures at that time..
Gerhard (Gerry) Fisher, John Rees and Ewan Patterson went on to build the Stanford colliding beam, Gus Voss went to build PETRA at DESY and then to synchrotron radiation. As of 2009 he unfortunately has gone completely blind. Bill Jones (electrical engineer) became an undergraduate lab instructor first at Harvard and then MIT before he died at age 90.. I lost track of Ron Little. But Ken Robinson was the big loss to the physics community. He never did any physics again and died, probably after excessive drinking, unknown and unnoticed in a California apartment.