Preface

I first visited Harvard University and its cyclotron in January 1951. I had met Professor Norman Ramsey the week before in the New York subway (Broadway line) on the way from the American Physical Society meeting in Columbia University. The director of the laboratory, "Tex" Holt invited me to the department lunch. But not until 1954 did I seriously think about working there. I accepted a position as Assistant Professor starting in summer 1955. I had been working at a cyclotron of 150 Mev at AERE, Harwell, and had already thought about the line of research that I wanted to pursue, of which the first step was to upgrade the energy of the Harvard cyclotron and to extract the proton beam. The other Professors and the cyclotron staff readily agreed and helped with the conversion. Andy Koehler modified the oscillator, aided by a fortunate visit from Professor Mackenzie, and Professor Strauch and myself shimmed the magnet and built the regenerative extraction system. Then began eight years of active physics research. It was a happy time. The physics department and the University administration were very supportive. We were not competing with each other but with the task of unraveling the secrets of nature as best as we could.

I had expected that by 1970 the cyclotron would close and all effort be transferred to particle physics at the local Cambridge Electron Accelerator. But the medical program, started by Bill Preston and Andy Koehler, was already showing promise, and was encouraged by the persistence and dedication of Andy.

In the following pages I tell the story of the cyclotrons at Harvard as best as I can. The physics experiments themselves are well described elsewhere - in the original papers in journals such as Physical Review, and also in a little book I wrote in 1963, The Nucleon-Nucleon Interaction. As often happens in fundamental physics few, if any, of the experiments are important now; science has moved on and absorbed the information. But the medical work has more lasting implications. Although Harvard/MGH were not the first to treat patients with proton beams, we have treated more than any other facility and for a long time treated more than all others put together. This gave the physicians and surgeons solid data and experience to show the advantages of this treatment modality. The list of proton medical facilities in the world tells the story.

This does not fully describe the unique environment at the cyclotron. Even after the major program of nucleon-nucleon and nucleon-light nucleus scattering was finished, experiments continued. The list of publications shows that Professors from neighboring Universities brought their students and almost as many theses were presented to other Universities as were presented to the Harvard faculty. As exemplified by some of the talks in the 50th anniversary symposium, they were universally appreciative of the welcome they received at the cyclotron laboratory. This continued with the physicians and those coming for radiation damage studies.

Indeed, the cyclotron was a happy place to work. I tried to visit once a week - usually over a sandwich lunch. There was an extraordinary rapport with the physicians at MGH. This made for an efficient operation. This efficiency was often misunderstood by others who tried to replicate the medical treatments. The cyclotron laboratory was a place to make friendships. Friendships which have lasted all one's life even though the cyclotron itself has been dismantled and the site razed.

Richard Wilson

February 2004