William J. Willis

William J. Willis (15 September 1932, Fort Smith, Arkansas – 1 November 2012, Dobbs Ferry, New York) was an American experimental particle physicist.

Biography William Willis studied physics at Yale University, where he received his bachelor's degree in 1954 and his PhD in 1958 with advisor Earle Fowler and dissertation related to the development of hydrogen bubble chambers in Ralph P. Shutt's research group. Willis was a postdoc at Brookhaven National Laboratory (BNL), where he observed weak decays of kaons and hyperons in bubble chambers. In 1961/62 he was at CERN, where he was involved in experiments on weak decays of hyperons, which confirmed the Cabibbo theory of weak interaction. In 1964 Willis joined the faculty of Yale University. The approach used in the Axial Field Spectrometer became standard for hadron colliders.

Subsequently he turned his interest to nuclear matter under extreme conditions of temperature and density: he convinced the CERN management to adapt the SPS to the acceleration of heavy ions, including lead ions, thus opening a new field, which flourished at RHIC and now also at the LHC.

From 1994 to 2010 he was assistant director of the BNL. Among other things, he supported the construction of the RHIC, which went into operation in 2000, and led the technical committee for the RHIC in the 1980s. More recently, he contributed his expertise in liquid argon detectors to the planning of neutrino experiments at Fermilab's (MicroBooNE experiment). In 1993 he was elected a member of the American Academy of Arts and Sciences.

Willis was married and had one daughter and four sons.