Design of an electron cyclotron resonance ion source for the isotope separator and accelerator at TRIUMF

A 2.45 GHz electron cyclotron resonance ion source has been designed and bu ilt to ionize radioactive atoms and produce single charged ion beams for th e isotope separator and accelerator at TRIUMF. The source is characterized by its short axial length (8 cm) and the small pair of magnetic coils (diam =phi 26 cm) placed adjacent to the source cavity. A small diameter quartz t ube is inserted in the cavity to confine the plasma to a small volume and t o shorten total ion transient time for the exotic gaseous elements with sho rt and intermediate half life. The computer code POISSON is used to design the magnetic coils. A three-electrode extraction system simulated with the code IGUNE is used to study the beam extraction efficiency. In this article the design of the source, extraction system, and the preliminary results o n beam emittance and energy spread are presented; the results on ion transi ent time, ionization efficiency, and beam extraction efficiency are present ed in a separate article. (C) 2000 American Institute of Physics. [S0034-67 48(00)61102-4].