The Neptune photoinjector

The RF photoinjector in the Neptune advanced accelerator laboratory, along with associated beam diagnostics, transport and phase-space manipulation techniques are described. This versatile injector has been designed to produce short-pulse electron beams for a variety of uses: ultra-short bunches for injection into a next-generation plasma beatwave acceleration experiment, space-charge dominated beam physics studies, plasma wake-field acceleration driver, plasma lensing, and free-electron laser microbunching techniques. The component parts of the photoinjector, the RF gun, photocathode drive laser systems, booster linac, RF system, chicane compressor, beam diagnostic systems, and control system, are discussed. The present status of photoinjector commissioning at Neptune is reviewed, and proposed experiments are detailed. (orig.)