a New Injector for Polarized Electrons at Elsa

A pulsed 50 kV inverted gun of polarized electrons, optimized for a reliable operation for future experiments at the stretcher ring ELSA, was set into operation. Due to operation in space charge limitation a current of 100 mA in a rectangular 1μs long electron puls is produced. Using a Be-InGaAs/Be-AlGaAs superlattice photocathode P = 80 % and QE = 0.2 % could be obtained. The performance of the gun, the transfer line and the results of first measurements are described in this report.