DBR-Photocathodes: A source for high-intense polarized electron beams
Eric Riehn (KPH Mainz)

The demand for highly polarized electron beams at currents far above 100 microamperes strongly increased during the last years. A new type of photo cathode with an integrated distributed Bragg reflector has been investigated with respect to parameters such as polarization (P), quantum yield (QY), lifetime and manageability. The thermal durability is also a very important parameter towards the aim of producing the desired currents and therefore has been examined extensively. Time resolved P and QY measurements with a resolution of better than two picoseconds revealed that the common understanding of electron motion in semiconductors is invalid for the increasingly used class of super lattice structures.