Peter Kammel's memories of Ken Crowe

In the early eighties Ken and his group joined forces with our European collaboration working on Muon-Catalyzed Fusion at Paul Scherrer Institute in Switzerland. It was a historic moment in this field, which has is origin’s in Luis Alvarez' discovery of the process at the Bevelac and Dave Jackson’s seminal papers. A new resonance mechanism had been discovered enhancing the expected yield to more than 100 fusions per muon. The next experimental step was the systematic study of the most promising deuterium-tritium mixtures. Ken had recently finished his tritium experiment at LAMPF, and had the unique scientific stature, the connections to Los Alamos and the technical capabilities to mount such an experiment in Switzerland.

I had just finished my PhD. thesis, based on an important, albeit serendipitous discovery in related [math]\displaystyle{ dd }[/math] fusion, and, as a fresh postdoc, was deeply involved in developing this program. Needless to say, this project naturally attracted Ken’s strongest interests. The effort was very competitive at the international level. It potential high-impact attracted lots of speculations, where rigorous and critical people with the experience of Ken were required to distinguish science from wishful thinking. And it needed subtle experimental techniques, including the risk involved with handling significant quantities of tritium.

The ensuing joint experiments were a highlight in my career, but most importantly established a close relationship to Ken, which would last and guide me through the rest of his and my life. I am writing these lines as faculty at the University of Washington in Seattle. It was largely Ken’s trust and mentoring that brought me from my native Vienna to UC Berkeley, followed by the University of Illinois and now Washington.

Returning to our early encounters, I was most impressed how a famous Berkeley professor was willing to fight in the trenches to make an experiment happen, and how he shared and instilled young students and postdocs with this desire. Unlike the European style, there was no hierarchical difference between a young student and a senior professor, once the student had earned Ken’s respect. But, as echoed by many colleagues on this page, earning his respect one had to, which could be a somewhat painful and rattling process until you reached the level at Ken’s expectations. But once that was achieved the student could count on support, mentoring and encouragement, which at times even generated bolder ideas exceeding your own aspirations before talking to Ken.

In our own career, we often wondered about Ken’s magic to nourish so many of us to find our own way in science and life. Even, if he did not always agree with our direction. I think, one aspect was his firm believe and respect in personal freedom. Ken was well known for his opinions, and he could argue forcefully. But in the end, he was convinced that every student must find and define his own path, and it was the responsibility of the advisor to encourage, not interfere with this development. He had the greatness of personality to let his students or postdocs run new initiatives, never demanding priority, rather encouraging and pushing them to new responsibilities with great sympathy and understanding. As regards his methods towards this end, he did not believe that success in science is easy. It has to be earned by hard work, disappointments, followed by inspiring rewards. I still remember when I was questioning his judgment when he gave an unduly difficult experimental task to a young student. He explained, that he is aware of the challenge, but if it really is too hard, the student has to come back and ask for help, that will make him grow up. But Ken did not demand anything from others, which he did not demand from himself; he was a risk taker, adventurer and entrepreneur. I vividly remember his role at the inception of the Crystal Barrel experiment. At this time the approval of the new project was in jeopardy, as both European and US funding agencies were expecting the first step from the other side. Ken's determination, negotiating skills and willingness to take on risky and initially underfunded hardware projects were instrumental to bringing this experiment to life and making it one of the most successful experiments of LEAR at CERN and his career. It very significantly contributed to the search for exotic QCD states. Ken’s group was responsible for its main tracking detector and many analyses. He spend several happy years with his wife Penny living across the French border at CERN during this time.

I worked as a postdoc in Ken’s group in Berkeley in 1985 and then returned as a research scientist from 1994-2000, where I worked closely with Ken in directing his group, after he retired from UC Berkeley. Our joint research covered a wide spectrum, from Muon-Catalyzed Fusion, to QCD studies with the Crystal Barrel experiments and finally high precision muon lifetime measurements of positive muons and negative muon capture in hydrogen. These latest experiments are just being finalized and they return to some roots Ken planted with his pioneering experiments at Berkeley. But he did much more than that, he defined the field of Medium Energy Physics and seeded a rich field of science.

Ken loved his family. Some of his favorite moments were Monday cafeteria lunches where he could report about the adventures he had over the weekend, fixing houses or sailboats for his children. With a combination of family and hardware he was in his elements. He and Penny were very close to my family, so let me end with a picture of Ken playing a duet with my daughter Laura in his famous self designed Richmond house.

Peter Kammel
Seattle
March 4, 2012