Dresden 2017 – scientific programme

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AKBP: Arbeitskreis Beschleunigerphysik

AKBP 6: Poster Session

AKBP 6.5: Poster

Wednesday, March 22, 2017, 18:30–20:00, P4

Development of a cryogenic GaAs DC photo-gun for high-current applications* — •Simon Weih, Joachim Enders, Martin Espig, Yuliya Fritzsche, Neeraj Kurichiyanil, and Markus Wagner — Institut für Kernphysik, TU Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany

For high-current applications in polarized electron generation, that may be used in ERLs or for positron production at ILC, it is necessary to maximize the charge lifetime of the GaAs cathode material to ensure reasonable operation. By means of cryogenic cooling of the cathode, the local vacuum conditions around the source can be improved due to cryogenic adsorption of reactive rest gas molecules at the chamber walls. Furthermore, the cooling also allows a higher laser power deposited in the material, resulting in higher currents that can be extracted from the source. Ion-backbombardment of the cathode is expected to be reduced using electrostatic bending of the electrons behind the cathode. To measure the characteristics of such an electron source, a dedicated setup is being developed at the Photo-CATCH test facility at Darmstadt.

*supported by DFG (GRK 2128) and BMBF (05H15RDRB1)