Speaker
Description
Highly spin-polarized electron bunches with polarization degrees of nearly 90% may be generated by photo-emission from semiconductor superlattice structures. I will discuss the cathode lifetime phenomena which limit the integrated electron fluence from the photocathode and hence the operational lifetime of a source. Fluences of 1000 Coulomb per square centimeter are possible. Whereas this can be sufficient for some of the applications presently discussed, another limitation of polarized electron generation is the fact that charge accumulation on the surface ("surface photovoltage") may limit the fluence within a single bunch at nanosecond timescales. This may cause challenges for machines which need highly charged bunches of Nanocoulombs with a low emittance.
