The Effects of Space Charge on Buncher Types for the ATLAS Positive Ion Injector

Abstract

Bunching is the act of converting a continuous beam of ions into a pulsed beam. In ATLAS, the heavy-ion accelerator at Argonne National Labs, a four-harmonic buncher at low energy is currently employed for this purpose; other configurations are indeed available and in use at other facilities. I worked under Dr. Richard Pardo of the Physics division at Argonne in an effort to estimate the efficiency of different bunching systems for one of the ion sources in ATLAS. In order to familiarize the reader with necessary theory and terminology, this paper attempts to explain the basics of accelerator physics, including the reason and method of bunching, before describing the project. Simulations from two computer modeling programs were used to compare three arrangements of bunchers for the ion source, and then experimental data was taken to test for qualitative agreement.