First tests at injector for the s-Band Test Facility at DESY

The s-Band Test Facility currently under construction at DESY requires 2 μs long macropulses with 8 ns, 16 ns or 24 ns interbunch spacing at an average current of 300 mA in each case and a maximum repetition frequency of 50 Hz. The injector design is based on a conventional scheme using a pulsed thermionic gun, two subharmonic bunchers (125 MHz and 500 MHz) and two travelling wave bunchers (β=0.6 and β=0.95). Together with a high power gunpulser and adequate triggering, the gun is expected to generate a 2 μs long train of pulses with less than 2.5 ns FWHM-pulsewidth and a peak current of up to 6 A. The first 50 cm of the injector beamline equipped with a wall current monitor, a button type position monitor and a Faraday-cup at the end were built up in order to commission the gun and its pulser. First results of the gun and pulser operation are presented and compared with calculated performance