High gradient acceleration in a 17 GHz photocathode RF gun

The physics and technological issues of high gradient particle acceleration at 17 GHz are examined. A RF gun with a 1 1/2 cell cavity and a design peak accelerating gradient of about 250 MV/m has been built. The beam parameters, when operating with a photoemission cathode, are: output energy 2 MeV, normalized emittance 0.47π mm·mrad, energy spread 0.18%, bunch charge 0.1 nC, and bunch length 0.47 ps. The goal is to study particle acceleration at high field gradients for potential applications in next generation linear colliders and to generate high quality electron beams for compact free electron lasers. The experimental setup and status are described. copyright 1995 American Institute of Physics