Progress in the study and construction of the TESLA test facility injector

A 500 MeV, 1.3 GHz superconducting linear accelerator is being studied and built to serve as a test facility for the TESLA linear collider project. The phase 1 injector, having an energy of 8-14 MeV and an intensity of 8 mA with a high duty cycle (800 microseconds, 10 Hz repetition rate), consists of a 250 keV electron gun, a 216.7 MHz subharmonic buncher and a superconducting capture cavity at the main linac frequency. The main characteristics (intensity, position, emittance, bunch length, energy spread) are to be measured using different techniques. A particular effort will be made on the use of optical transition radiation (OTR) for the determination of the transverse beam emittance as well as the bunch length. The injector, involving, the participation of three French laboratories (LAL, CEA/DAPNIA, IPN), will be tested partly in France (Orsay-Saclay) and then completely at DESY (Hamburg)