Recent results of laser induced electron emission from a ferroelectric cathode in the CLIC dc test setup

For the first time a ferroelectric cathode has been tested in an accelerator-like structure. In the CLIC dc test stand electron pulses with ns duration and with charges up to 2.5 nC were generated by laser light using 308, 266 and 213 nm wavelength. Electron emission has been investigated as a function of the extraction voltage, the laser energy density, and for one particular material for two different prepoling conditions. The results show that the amount of emitted charge is influenced by the ferroelectric state of the sample; laser illumination and simultaneously electrically switching the materials polarization enhances emission. Two long term tests at a laser repetition rate of 10 Hz prove the reliability of ferroelectric cathode material up to more than 2x106 pulses. (orig.)