APLE accelerator prototype cavity fabrication and low power tests

The first 5-cell, 433-MHz accelerator cavity for the APLE free electron laser experiment at Boeing has been assembled and tuned. Low power RF measurements indicate that the critical electrical parameters (Q₀, f, and β) for the accelerator and TM₁₁₀-like modes are consistent with expectations based on measurements made on an 800-MHz model cavity. The cavity is being readied for its initial vacuum bakeout, during which the constituents of the residual gas will be monitored. First application of high power RF is scheduled for late summer of 1993