On July 17, 1940, F. Wheeler Loomis, Head of the Department of Physics at the University of Illinois, received a letter from Donald W. Kerst. The latter, a young physicist who had only begun working at the University of Illinois the prior year, penned to Loomis:

Monday afternoon the electron accelerator started to work. It was its first trial with the new glass doughnut and the new pole pieces. By evening the intensity of the X-rays produced when the electrons strike the target was up to about the effect of 10 millicuries of radium gamma rays (radium at target distance) according to the callibration on the electron-scope.[1]

Soon to be known as the “betatron,” Kerst’s induction electron accelerator was an innovation on which his colleagues had cast a shadow of doubt. Loomis, who was on leave from the university during World War II for government-related work in the Radiations Laboratory at MIT, later admitted to Dean Melvin L. Enger, “This changes his project from an off-chance one to the most promising and original ones that has ever occurred in the department…it is capable of bringing as much renown to our department as the cyclotron did to Berkeley.”[2] A few years later, the betatron would be hailed as “the most important development of a decade.”[3] Indeed, the impact of this “atom smasher” would prove to be far-reaching, holding the attention of the world as it made its appearance on the horizons of medical science and atomic research. Continue reading ““A Very Bold and Original Device”: Donald Kerst and the Betatron” →