Feb 16 – 18, 2022
US/Central timezone

Capability and Future Ideas of Polarized Beams from GaAs in DC HV Photo-guns

Feb 17, 2022, 10:30 AM


Joe Grames


The landscape of high energy particle physics experiments requiring polarized electron beams was forever changed by the introduction of the GaAs-based electron source to particle
accelerators. Introduced in the 1970’s to the SLAC accelerator, such a source was used to help establish the Standard Model. Since then DC high voltage polarized electron sources based on GaAs photocathodes were developed and operated at a number laboratories including Nagoya University, the Mainz Microtron, the MIT-Bates Laboratory, NIKHEF, Bonn University, and CEBAF at Jefferson Lab. The prospects continue, with new or upgraded polarized electron sources planned or imagined world-wide including at EIC, MESA, KEK, ILC, and CERN. In this presentation, I will begin with a brief summary of the basic requirements for constructing a DC high voltage polarized electron source and summarize demonstrated and expected performance of various facilities. Next, I will explore the evolution GaAs-source performance leading up to what we describe today as state-of-the-art. I will conclude describing prospects for performance improvement, paying special attention to capability improvements in the areas which may offer to generate higher beam intensities and with longer operating lifetimes.

Presentation materials