The Design and Construction of a Small Cyclotron

Abstract

A small cyclotron is under construction at Houghton College. It utilizes a water cooled electromagnet with 15.2 cm pole faces that produces a maximum field of approximately 1.1 T with a 3.8 cm gap. The vacuum pump consists of a rotary forepump, a diffusion pump and a liquid nitrogen cold trap. The chamber consists of a brass ring with eight ports: one for evacuating the chamber, one for introducing gas, two viewports, two feedthroughs, an ion gauge, and the Faraday collector. It is sealed with two aluminum discs with Viton o-ring seals. The ‘dee’ electrodes are constructed from copper, with the dummy dee at ground potential and a true dee supplied with a radiofrequency signal by a function generator and an RF power amplifier. The expected energy for deuterons is 0.15 MeV, and 0.08 MeV for Helium nuclei. The immediate objective is to accelerate Helium nuclei to test the machine, and the ultimate is to accelerate deuterons to produce neutrons for inelastic scattering experiments.