 Creutz encountered several members of the faculty at the University of Wisconsin , including Julian Mack , <unk> Rollefson , Raymond Herb , Eugene Wigner and Gregory Breit . Mack gave Creutz a research project to do in his junior year . Creutz remained at Wisconsin as a graduate student after receiving his Bachelor of Science ( <unk> ) degree in 1936 , working for Herb upgrading the <unk> Van de <unk> generator from 300 to 600 keV . With this done , the question became what to do with it , and Breit suggested that it had previously been observed that high @-@ energy gamma rays were produced when lithium was bombarded with protons at 440 keV . Creutz therefore wrote his 1939 Doctor of Philosophy ( Ph.D. ) thesis on <unk> <unk> of <unk> by <unk> , under Breit 's supervision . Creutz married <unk> Rollefson , a mathematics student at Wisconsin , and the sister of <unk> Rollefson , on September 13 , 1937 . The couple had three children , two sons , Michael and Carl , and a daughter , Ann Jo . 
