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

Government Scientific Committees
Since 1960 I had often been asked to sit on scientific committees for various projects. A special committee in 1963-4 for the next Brookhaven accelerator. One for proton-proton storage rings at Fermilab in 1972. For future electron and muon experiments in 1973. I always accepted and always said what I think, but this upset some people. In 1967 I was appointed to the Board of the newly formed Universities Research Association, set up to manage the new Fermi National Accelerator laboratory, and in 1967 was Chairman of the Scientific Committee till Ed McMillan took over in 1969 when I went on leave. The last committee on which I was explicitly asked to sit, in 1973, was advising the AEC on lepton beams. I felt that with adequate funds very usable high energy electron and muon beams could be built at Fermilab, with a lower intensity than SLAC but better duty cycle; but with probably less funds than the 40 GeV upgrade for which they sought funds. It was reported to me that Burt Richter who was also on that committee made some very nasty personal remarks about me to other scientists at SLAC. I have never been asked to sit on a High Energy Physics committee again, although I, like many others have been asked my opinion. Maybe foolishly I gave it - as honestly as I could. I have, however been asked to sit on committees for which I was less qualified, such as the Health and Environmental Research Advisory Committee of the AEC and the Energy Engineering Board of the National Academy of Sciences and to chair the nuclear safety committee for the Republic of China (Taiwan).
In 1974 Francis Lowe was Chairman of a small HEPAP sub-committee to discuss future accelerator plans. There were three proposals on the table. An electron-positron collider at about 12 GeV (PEP) for SLAC, The FERMILAB “energy double” using superconducting magnets. A pair of 200+200 GeV proton rings (Isabelle) for BNL. I recommended the SLAC machine to Francis. But the US federal budget was tight and approval was delayed. In the meantime a similar DESY proposal had been funded. There was an interesting condition; the construction funds should be spent immediately to offset a recession in the German construction industry. In view of this in 1975 I changed my recommendation from the previous year. I thought the US should concentrate on matters in which we were unique. Thus we should go ahead with either the energy doubler or Isabelle. I explicitly suggested that SLAC raise their sights and aim for a 50+50 GeV electron-positron ring to produce Z and possibly W intermediate vector bosons. But they were reluctant to switch. With the experience of SPEAR behind them, both the AEC and SLAC felt that they would build the ring quickly and beat DESY. After all, SLAC had beaten DESY to the 3 GeV ring even though DESY had a head start. But this time DESY was even faster than SLAC and their higher energy ring was finished 2 years ahead of SLAC. They took the cream of the experiments. SLAC had not counted on the skill of Gus Voss. I knew Gus and had so counted. Sadly, I counted this then and now, as the crucial decision that gave the leadership in High Energy Physics to Europe, which leadership Europe has maintained ever since.
As I see the sad history, mistake after mistake followed. The proposed proton-proton collider, “Isabelle”, was funded and then canceled. Although CERN had no previous electron experience the 50+50 electron positron ring was built at CERN. SLAC tried to catch up with a fine linear collider, but this came on line only a week or so before CERN with lower intensity than CERN. They were just one week ahead of CERN on measuring the width of the Z. The width of the Z tells us the number of lepton types, known now to be limited to 3. This one week lead was not enough to raise much interest, and it made therefore less of an impact that the CEA “By Pass” which measured a high cross section a full 18 months before a better experiment at SLAC confirmed it. But the SLAC linear collider did have polarized electrons and positrons and after a few years running had an excellent measurement of sin 2_w. If one leaves out the fact that we learned a lot about how to make useful collisions in a linear collider, the cost of this measurement was high. About $200 million. But not as bad as the $900,000,000 that Argonne National Laboratory spent to replace the CEA that we had thrown away.
Finally the high energy community failed to take the proposed Supercollider as seriously as they had taken FERMILAB. Glenn Seaborg had insisted that while Fermilab was under construction, there should be no conflicting construction projects. As noted above, ths was the main reason that there was a delay in implementing electron-positron colliding beams after the first window of opportunity was missed. He had also told Congress that some smaller facilities would be shut down. Maybe at that time I should have gone to one of the major summer studies and got personally involved as I had been in Fermilab 20 years earlier. Among other things, Pief had got personally involved with the SSC as chairman of a URA committee and I did not want to risk another painful personal clash. I did point out the issue to a HEPAP subcommittee in 1987, noting that to keep to the AEC budgetary suggestions that the BNL high energy program would have to be shut down, and maybe that of SLAC or Fermilab also. In 1987 the AEC started on a course similar to that Seaborg had adopted in 1965. They declined to add a new construction project to the budget till the SSC was fully funded and asked for cut backs or closures in the existing program.
But the high energy community was not listening.. The AEC had explicitly suggested that the construction proposals for a B factory be delayed till SSC was well underway and declined to put a B factory on the budget submitted to Congress. They asked the high energy community what to cut But the community did not follow and kept following lesser agendas. I was unpopular because I recommended to HEPAP’s committee a specific suggestion of what to cut. California congressmen, whether urged by SLAC or not, pushed the construction proposal for a B factory anyway bypassing the DOE decision. In my view, this was a major contributory cause to the demise of the SSC. Of course I can count 20 things that went wrong with the SSC. Any one of them could have been overcome but congressional confidence was lost. President Clinton and Congress, in cancelling the SSC were able to say “We gave you a construction project that you asked for”.
The role of high energy physics in the Universities was maintained when Fermilab was started. Although there were leading physicists at BNL and Berkeley, much of the important work and the thinking was still done at Universities. As previously noted 40 University Presidents personally met and formed the Universities Research Association.. President Pusey took a personal interest. They started a competition for site selection, which, in my view, was a good thing. Enthusiasm for high energy physics was high in State Legislatures. Bob Wilson as Director was deeply committed to the major role of University scientists with Fermilab scientists in support. But this slowly changed. As time went on, University Presidents sent representatives instead of personally attending the meetings of the Council of Presidents. By the time the SSC was proposed the Harvard high energy physics committee went in a body to see President Bok. There was not the enthusiasm in the department as a whole as there was 20 years before. Although at our urging Derek Bok supported the SSC, many other scientists and Universities were lukewarm or opposed. For example in 1987 Glenn Seaborg asked me to introduce him to Michael Dukakis or at least his campaign staff. As noted elsewhere, he wanted to make a strong case for nuclear power. Dukakis campaign manager asked about the SSC. Glenn replied that although elementary particles was not his field (a modest remark considering his contributions) he felt it was a fundamental subject and should be supported.
But that changed for the worse 4 years later, in 1991, when the project was in deep trouble. I could not persuade either Glenn or Edward Teller to sign or cosign a letter of support for the SSC. They were content to see it go down the drain. I was not happy with the testimony given in the US Senate by the Director, Roy Schwitters, and by the distinguished high energy physicists in support It seemed to display too much arrogance and hubris. At that time, in 1991 President Neil Rudenstine of Harvard was also uninterested. Part of the change is the nature of the field. But I believe that a leading reason for the lack of University support part is that the major work is no longer done at University laboratories. Frank Pipkin and I had always insisted that our graduate students not only understand data analysis but also made a contribution to the design of the apparatus. I had contributed to the accelerator design both of the cyclotron and the CEA and so on. But more and more students are not so motivated. In the 1960s and 1970s I met students who had got PhD degrees from analysis of bubble chamber pictures, but had never looked at the accelerator or the beam line. Some of them had never looked at the bubble chamber. It has steadily got worse.

Time has made these unpleasant incidents of 1965-1975 more understandable to me if not acceptable. Everyone has his priorities, and for Pief the first priority was SLAC and supporting the scientists he had hired. Of course I knew this at the time, but it was over ten years before I come to terms with this simple fact, and became willing to talk with Pief and visit him again. Andrée and I went to his retirement party in, I believe, 1989. In 2008 I was present at the special symposium at Stanford where Pief’s extraordinary career was being celebrated. But in view of the history above, I had a great problem when Pief asked me in 1991 why we had not tried to make a synchrotron radiation facility out of CEA. Of course we had, but Pief’s desire to have the synchrotron radiation facility at SLAC prevented it at the time, because NSF were only willing to allocate $500k and SLAC wanted that limited sum. Since he was instrumental in getting our proposal for conversion to a dedicated synchrotron radiation facility turned down, I was upset at his reopening the old wound. A year or so later he opened another old wound. He was musing on how to keep high energy physics in the universities. I rudely and abruptly said that it was too late. If he had been interested in keeping high energy physics in the universities in 1964, matters would be very different. I commented that as the leader in the field, he could rightly accept the credit for a lot of the correct decisions and also take the credit for a lot of actual experiments that had been done in high energy physics but he should also accept some blame for things which had gone wrong. Pief was silent.

Parity Violation experiments
I remember going to Professor EA. Milne’s lectures on Vector and Tensor Calculus in summer 1945 when a student. He discussed parity and said that all known physical laws conserve parity”. I remember Hans Halban in 1953 or so asking Vicky Weisskopf, visiting at the time, whether it was worthwhile looking at the angular distribution of the beta rays from a cold nucleus using the apparatus developed by Nicholas Kurti and collaborators. The answer was “No. Because parity is conserved”. So when in 1946 Yang and Lee suggested that it is NOT conserved in weak interactions I knew what to think. It is noteworthy that my friends Ernie Ambler and Ralph Hudson, two of Nicholas Kurti’s graduate students at Oxford, understood quickly and when Ms. Wu of Columbia suggested they search for it, they already had the apparatus. In my view most American scientists credit Ms. Wu with that measurement and fail to give Ambler and Hudson the credit that they deserve. But I did not force my way in on others experiments at that time but waited for an opportunity to do some myself.
When the cyclotron upgrade was finished we included an experiment on time reversal in the program. But then matters opened up in 1970. I was interested, as were others, in the “Intermediate Vector Boson”, now the W and the Z. How could one see them? I calculated two methods. One is to use a muon beam from pion decay at Fermilab, a procedure which suggested itself followed the parity violation experiment of Jerry Friedman and Valentine Telegdi in 1956. The muons at Fermilab were automatically longitudinally polarized. After our initial experiments on muon scattering I proposed to use the longtitudinally polarized muon beams .for studies of parity violation. But that proposal was rejected and the experiments were done in CERN in the late 1980s. While traveling back from a meeting in Washington with Herman Feshbach he suggested to me another experiment. He proposed that I look for parity violation in a reaction with which I was very familiar N + P -> d + ( but with looking for the polarization of the gamma ray. He thought that there might be an asymmetry as large as 2 x 10-6. That would be easy to find. I scoured possible reactors. By this time I knew I would have to travel to find an accelerator or reactor that I wanted. MIT. I discussed the possibility with reactor physicists and engineers at Watertown Arsena, at NASA in Ohio and at Brookhaven and finally at the National Bureau of Standards (NBS) in Gaithersburg, MD. We started at NBS and succeeded in demonstrating parity violation on neutron capture in cadmium but NBS. were not at the time amenable to the necessary liquid hydrogen target in the reactor. At Norman Ramsey’s suggestion I visited the Institute Laüe Langevin (ILL) in Grenoble where they had just installed a polarized neutron beam. I changed the idea of the experiment to look for the asymmetry of the gamma ray in capture of polarized neutrons - not quite the inverse of Feshbach’s and simpler theoretically as it turned out. Using these neutrons from the ILL reactors we found parity violation in deuterium, chlorine, and strontium but in neutron-proton capture we only able to place an upper limit of 5 x 10^-8 - 50 times smaller than suggested by Feshbach, and smaller than had (erroneously) been found in USSR by Lobashov and collaborators but in agreement with what is now expected from the modern theory. I still think it is an interesting experiment and reaction. Professor Puppi of Italy had a triangle in 1955 of three weak interactions. Leptons on leptons, leptons on hadrons and hadrons on hadrons. The first two have been extensively studied, and in particular weak neutral currents have been found in each. It would be nice to confirm that these apply quantitatively to nucleons on nucleons also.
In 1970 one of the experiments I wanted to do was the study of parity violation in either electron scattering or muon scattering. My attempts to do so at SLAC (electrons) and muons (Fermilab) were described in an earlier section. But like many people, once one has an idea one cannot let go. So in 1980 this interest metamorphosed into parity violation in electron scattering from carbon at the small Bates linear electron accelerator in Middletown, MA. More recently our techniques have been used at CEBAF at Jefferson National Laboratory (JLAB), )in Newport News, VA. This addresses various aspects of the weak interaction and is now addressing the contribution of strange quarks to the proton structure (716, 791, 886, 887, 905). One reason that I still remain emotionally committed to this experiment is of course my failure to be able to participate in the first of these at SLAC in 1975.
ln all, I have worked and done experiments at a large number of accelerators and reactors as shown in the following list:
Nuclear Reactors
British Experimental Pile (BEPO) (Harwell)

National Bureau of Standards (NBS) (now LIST)

MIT Nuclear Engineering Dept., Cambridge MA USA

HIBA Brookhaven National Laboratory

Institute Laüe Langevin (ILL), Grenoble , France

Power Reactor at Bugey, France (CEA)

(Proton) Cyclotrons
Rochester, NY(240 Mev)

Harwell, (AERE) (160 Mev)

Harvard University, (160 Mev)
Electron Synchrotrons
Oxford (100 Mev)

Cambridge Electron Accelerator (CEA) (6 GeV)

Continuous Electron Beam Accelerator Facility (CEBAF)
Proton Synchrotrons
Cosmotron, BNL (3Gev)

Alternating Gradient Synchrotron (AGS) (30 GeV)

Fermilab (350 GeV)
Linear Electron Accelerators
Mark II Stanford (45 Mev)

Bates (MIT) (500 MeV)

Colliding Beam facilities
CEA (e+/e- 3 GeV)

Cornell Electron Storage Ring (CESR) (e+/e- 5 GeV)

CERN (18 GeV)(P Pbar)
To the owners and operators of these facilities I give my thanks. Without them I would have been unsuccessful and even bored!
Medical Experiments and Treatments
In 1970 when CEA was collapsing, I had three worries. The first I have just described: how to maintain my high energy physics interest, particularly that in colliding beams, the second was how to keep the CEA alive - at that time for synchrotron radiation studies, and thirdly how to keep the exciting medical program at the cyclotron going. I succeeded in the last, which was for me personally the third priority. I referred earlier to the Harvard cyclotron. After I had stopped experiments personally in 1961, I had watched the work of others with approval, but had taken no specific action. But it was still under the purview of the high energy and nuclear physics committee of which I was still chairman. In the years 1969 to 1971 I watched it carefully in my semi-administrative capacity. I described this in my book “A Short History of the Harvard Cyclotrons” (870). Andy Koehler and Bill Preston had encouraged the use of protons from the Harvard University Cyclotron for "radio surgery" by Dr Ray Kjellberg of the neurosurgery department of MGH. On the closure of the ONR/AEC contract for the cyclotron operation, there was an issue of who was to pay. I spent 2 hours with Dean Ebert of the Medical school trying to persuade his faculty to take it over, with Harvard physics department faculty and staff in the background if something went wrong. No luck. So we were about to shut down the cyclotron when I was invited to meet Herman Suit who was thinking of coming to MGH as head of their department of radiation medicine. A major attraction was the existence of the cyclotron. So I stuck my neck out, exceeded my authority, and stated that Harvard would keep it going. It was one of the best things I ever did. Bill and I persuaded the physics department to keep it operational for medical treatment, collecting use charges from the Massachusetts General Hospital. Andy Koehler insisted on taking only half a salary for his full time work. But we all knew this could not, and should not, last for long.
We were helped by John Lawrence M.D. (Ernest Lawrence’s brother) from Berkeley. AEC Chairman Glenn Seaborg had negotiated an exchange with the USSR and John Lawrence took a 3 man team to Russia to study proton therapy. He chose Andy Koehler as his third man. Then a return visit came. By now Herman and Ray had got many others interested and Andree and I arranged a party in our garden of about 30 people to meet the visiting Russian trio of three people. The 30 were mostly physicians and surgeons from Massachusetts General Hospital but included Paul Martin, the physics Department Chairman. Paul told me afterwards that this convinced him that we had made the right decision. The AEC had assigned an interpreter to the visiting 3 person (1 woman, 2 men) team but it was very soon clear that the interpreter was out of his depth. So I got the excellent Russian teacher from the Newton High School to come. He saved the day.
Although MGH paid for treatments and collected patient fees we tried to get some general research funding. The obvious place was AEC which had a medical program as a part of its’ charter. But AEC were spending $2 million a year at Lawrence Berkeley Laboratory (LB:L) for medical funds from the AEC biology program. They said “NO! in no uncertain terms. We found a little money from NSF from a new program, “Research Appropriate for National Needs (RANN)”. But Andy’s efficiency, which I knew so well, made the difference. In 1975 for example, we had about 1/10 the budget of LBL and treated 10 times the number of patients! LBL inefficiency was their doom. The accelerator was paid for by the high energy physics program and when the cyclotron and Bevatron shut down, so did their medical program.
The various details of the cyclotron program were important and some members of the physics department distrusted Andy and myself and wanted to worry personally about every detail. When the cyclotron operation was run by Bill Preston that presented no problem and when he retired in 1975 Bill persuaded the Dean of FAS to form a management committee, separated from the Physics Department.. I was appointed the first Chairman of that committee reporting directly to the Dean of the faculty, and remained a member of the cyclotron operating committee till closure in 2002. I believe that it was in 1978 that a most important incident occurred. I had just, at 8 am central time, just gone on shift at our Fermilab muon experiment. I got a call from Herman Suit. He was concerned about the treatments that Dr Ray Kjellberg planned that day at the cyclotron. Ray was treating artero-venous malformations where an artery comes close to a vein in the head and capillaries go from one to another and cause trouble. Ray was treating in one “fraction” (all the dose at one time) instead of spreading the dose (fractionating it) over several sessions. Herman felt that this might be OK with targets of 5 mm diameter or less but Ray was treating lesions 2 cm diameter. This was a long standing disagreement. What should I do? I called the cyclotron and discussed with Andy Koehler who asked me to cope. I asked a graduate student to take my shift on the experiment and spent the next 2 hours on the phone. I called Dr Charles (Charlie) Sanders then head of MGH. “Two of your physicians are quarreling on my turf.” I said. “I have asked Andy not to turn on the cyclotron till I get instructions from someone higher than both of them - and that is you” Charlie Sanders agreed that this was a good administrative position. He asked me my views on the quarrel. I told him the scientific situation and the political situation. Eventually Herman withdrew his opposition that day when Charles Sanders agreed to set up an MGH committee to make recommendations on future treatments. It was that power to be independent of both parties that enabled the cyclotron to be much more effective that UC Berkeley in patient treatment. After this incident I made sure that the Harvard University insurance would cover actions by the Harvard Cyclotron staff, and the Harvard lawyers (who knew the MGH lawyers) made a formal (one sided in favor of Harvard) legal agreement. Harvard cyclotron staff would have the right to stop any treatment they thought improper but MGH would take all legal responsibility. I also checked that everyone at the cyclotron was covered by medical malpractice insurance under the blanket Harvard contract. This led to many years of comparative peace between Herman and Ray and very productive work in helping patients..
When the cyclotron finally shut down, and the treatments shifted to a new, specially built cyclotron at MGH, it had treated as many patients (9,119) with heavy charged particles as all other facilities in the world put together (229, 342, 388, 396). But that shut down was not the end. The new MGH machine now treats at a rate three times as high as did the Harvard cyclotron in its last, most productive, years. That and the increase in the number of places doing the same treatments is a satisfying sign of our success. From 1973 to 2002 Herman Suit, head of the Radiation Medicine Department at Massachusetts General Hospital, asked me to be Chairman of the Advisory Committee of the Radiation Medicine Department at Massachusetts General Hospital, which oversaw construction of a replacement for the Harvard cyclotron. I am still (in 2008) a member of that committee. The hospital is a very different environment than the University. The undoubted success of proton therapy has led to a flood of patients. The Radiation Medicine Department receives about $35 million, mostly in patient fees (mostly paid by insurance) and $18 million in expenses, leaving a good surplus for capital and other hospital departments. But the physicians who make the decisions clearly have little or no concept of the way a technical project can be stimulated and operated and I fear that the lead in these matters that Harvard/MGH will disappear. In retrospect many people have said that the medical work was one of my most important achievements. But then all I had to do was to support Andreas (Andy) Koehler. The achievement of Andy, with my help, is more than the success of the cyclotron at MGH. It is the success of the 20 or so other proton therapy accelerators throughout the world.