Ultracold electron sources

Ultra-cold plasmas with electron temps. of .apprx.10 K can be created by photo-ionization just above threshold of a cloud of laser-cooled atoms. Recently it was shown 7 by GPT particle tracking simulations that an ultra-cold plasma has an enormous potential as a pulsed bright electron source. Here we discuss these results in the framework of normalized 6D brightness, which allows us to make a proper comparison both with the performance of pulsed, radio-frequency photo-emission sources and with the performance of continuous, needle-like field-emission sources. In addn. we speculate on the possibility of using ultra-cold plasmas to realize quantum degenerate electron beams, constituting the ultimate limit in electron beam brightness