Alex Schenck's memories of Ken Crowe

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Kenneth M. Crowe played a crucial role in my professional life. I first got to know him in the spring of 1969 when, as a post doc, I came to Berkeley as a member of the particle physics group of the University of Washington (Prof. R.W. Williams) to perform in collaboration with Ken a high precision determination of the magnetic moment of the positive muon at the 184 inch cyclotron. After the experiment was set up and commissioned, only D.L. Williams (the Ph.D. student from the U.of W.) and I remained in Berkeley to collect the data, now coming in much closer contact with Ken, who saw to it that the experiment continued smoothly and all possible obstacles were solved.

During this time it occured to me that the implanted muons should behave like protons in the same environment, e.g. by showing spin relaxation phenomena corresponding to those studied by the NMR technique. This was tested by stopping muons in a strong paramagnetic solution and -- eureka! -- the muons relaxed as expected. It also became immediately clear that the implanted muons, via muonium formation, were subject to chemical reactions just like atomic hydrogen. From the beginning, Ken supported, encouraged and contributed to these studies with much and never ending enthusiasm, providing extra beam time and even organizing suitable targets like, as I remember vividly, a huge single crystal of gypsum. He also arranged meetings with the big shots in solid state physics at UC Berkeley at that time.

This was the beginning of what later was called µSR spectroscopy in Berkeley and became in later years an important research tool in solid state physics and chemistry at the so-called meson factories (SIN, LAMPF and TRIUMF), as well as at other laboratories in England and Japan, all inspired by the work started in Berkeley. My involvement in these early studies also paved the way for my later career at ETH Zürich and SIN (now PSI) and would not have been possible without Ken‘s generous support and permission to "misuse" some of the allocated beam time for these exploratory measurements.

Whoever worked with Ken sooner or later would be invited (or rather conscripted) to serve as a crew member on his sailing boat when a race was up to take place. I had the pleasure only once in the summer of 1973 and it was a remarkable experience. That time there were only three persons on the boat: Ken as the skipper, myself and Heinz Graf, a Ph.D. student from the University of Zürich. The competion was fierce, the wind blew strongly and Heinz and I were rather ignorant of sailing. At a certain moment Ken was yelling to Heinz: "Enough, enough!" which meant to loosen the rope to the jib, but Heinz was instead pulling the rope tighter and tighter and we nearly tipped over. Another participating boat accused Ken of some unfair manoeuvre in getting in its way with the result that a trial was to take place a few days later at the fashionable Yacht Club in Sausalito. Heinz and I were called to be witnesses. Our testimony must have been quite contradictory and Ken lost the case. But it ended in a very amiable mood as Ken was inviting us for a drink at the bar of the Yacht Club, an unforgettable experience, like so many others in the course of many later years.

Alexander Schenck
Untersiggenthal, Switzerland
21. Feb. 2012