Thermal Emittance Measurements Of A Cesium Potassium Antimonide Photocathode

Thermal emittance measurements of a CsK(2)Sb photocathode at several laser wavelengths are presented. The emittance is obtained with a solenoid scan technique using a high voltage dc photoemission gun. The thermal emittance is 0.56 +/- 0.03 mm mrad/mm(rms) at 532 nm wavelength. The results are compared with a simple photoemission model and found to be in a good agreement. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3596450]