Physics of high-intensity nanosecond electron source: Charge limit phenomenon in GaAs photocathodes
- 1 May 1996
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 79 (9) , 7318-7323
- https://doi.org/10.1063/1.361448
Abstract
GaAs negative electron affinity cathodes are used as high‐intensity, short‐time electron source at the Stanford Linear Accelerator Center. When the cathodes are illuminated with high‐intensity laser pulses draw peak currents that are extremely high, typically of tens of Amperes. Because of the high currents, some nonlinear effects are present. Very noticeable is the so‐called charge limit (CL) effect, which consists of a limit on the total charge in each pulse; that is, the total bunch charge stops increasing as the light pulse intensity increases. The CL effect is directly related to a photovoltage built up in the surface as a consequence of the photoelectrons coming from the bulk. We discuss possible ways to minimize the formation of the surface photovoltage.This publication has 4 references indexed in Scilit:
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