Photocathode source for studying two-dimensional fluid phenomena with magnetized electron columns

Magnetized electron columns are a valuable experimental tool used to study two-dimensional (2D) fluid phenomena. Traditionally, the electrons have bee n generated with thermionic sources, typically limiting the initial electro n distribution to one filled circle and thereby restricting the range of ac cessible fluid phenomena. Here, we describe a new electron source based on a cesium antimonide photocathode that can generate more complicated initial electron distributions. Experiments so far have focused on the stability o f 2D vortex patterns. (C) 1999 American Institute of Physics. [S0034-6748(9 9)02612-X].