Computer Designed 805 MHz Proton Linac Cavities

Abstract

A numerical mesh calculation which computes the fields and frequency for a resonantcavity has been developed. Fields for any cavity which has cylindrical symmetry, and for which the magnetic field has only a θ component, can be computed. The program has been used on the IBM 7094 to study 805 MHz protonlinaccavities. These design studies have shown that cavities having curved walls and triangular drift tubes give improved performance. Calculated values of ``shunt impedance'' per unit length ZT 2 for such cavities range from 32.4 MΩ/m at β=v/c=0.45 to 53.0 MΩ/m at β=1. Experimental measurements have verified the calculations.