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Title: Improved Ion Resistance for III-V Photocathodes in High Current Guns

Abstract

The two photocathode test systems were modified, baked and recommissioned. The first system was dedicated to ion studies and the second to electron stimulated recovery (ESR) work. The demonstration system for the electron beam rejuvenation was set up, tested and demonstrated to one of the SSRL team (Dr. Kirby) during a site visit. The requisite subsystems were transferred to SSRL, installed and photoemission studies conducted on activated surfaces following electron beam exposure. Little surface chemistry change was detected in the photoemission spectra following the ESR process. The yield mapping system for the ion (and later, the electron beam rejuvenation) studies was implemented and use made routine. Ion species and flux measurements were performed for H, He, Ne, Ar, Kr and Xe ions at energies of 0.5, 1.0 and 2.0 kV. Gas induced photoyield measurements followed each ion exposure measurement. These data permit the extraction of photoyield induced change per ion (by species) at the measured energies. Electron beam induced rejuvenation was first demonstrated in the second chamber with primary electron beam energy and dependency investigations following. A Hiden quadrupole mass spectrometer for the electron stimulated desorption (ESD) measurements was procured. The UHV test systems needed for subsequent measurements were configured,more » baked, commissioned and utilized for their intended purposes. Measurements characterizing the desorption products from the ESD process and secondary electron (SE) yield at the surfaces of negative electron affinity GaAs photocathodes have been performed. One US Utility Patent was granted covering the ESR process.« less

Authors:
Publication Date:
Research Org.:
Saxet Surface Science
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1054880
Report Number(s):
DOE/SC/0002268
DOE Contract Number:  
SC0002268
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ERL, Photocathode, injector, nuclear physics, NEA, electron source, GaAs, decay, rejuvenation, Cs, Li, emission profile, accelerator

Citation Formats

Mulhollan, Gregory, A. Improved Ion Resistance for III-V Photocathodes in High Current Guns. United States: N. p., 2012. Web. doi:10.2172/1054880.
Mulhollan, Gregory, A. Improved Ion Resistance for III-V Photocathodes in High Current Guns. United States. doi:10.2172/1054880.
Mulhollan, Gregory, A. Fri . "Improved Ion Resistance for III-V Photocathodes in High Current Guns". United States. doi:10.2172/1054880. https://www.osti.gov/servlets/purl/1054880.
@article{osti_1054880,
title = {Improved Ion Resistance for III-V Photocathodes in High Current Guns},
author = {Mulhollan, Gregory, A.},
abstractNote = {The two photocathode test systems were modified, baked and recommissioned. The first system was dedicated to ion studies and the second to electron stimulated recovery (ESR) work. The demonstration system for the electron beam rejuvenation was set up, tested and demonstrated to one of the SSRL team (Dr. Kirby) during a site visit. The requisite subsystems were transferred to SSRL, installed and photoemission studies conducted on activated surfaces following electron beam exposure. Little surface chemistry change was detected in the photoemission spectra following the ESR process. The yield mapping system for the ion (and later, the electron beam rejuvenation) studies was implemented and use made routine. Ion species and flux measurements were performed for H, He, Ne, Ar, Kr and Xe ions at energies of 0.5, 1.0 and 2.0 kV. Gas induced photoyield measurements followed each ion exposure measurement. These data permit the extraction of photoyield induced change per ion (by species) at the measured energies. Electron beam induced rejuvenation was first demonstrated in the second chamber with primary electron beam energy and dependency investigations following. A Hiden quadrupole mass spectrometer for the electron stimulated desorption (ESD) measurements was procured. The UHV test systems needed for subsequent measurements were configured, baked, commissioned and utilized for their intended purposes. Measurements characterizing the desorption products from the ESD process and secondary electron (SE) yield at the surfaces of negative electron affinity GaAs photocathodes have been performed. One US Utility Patent was granted covering the ESR process.},
doi = {10.2172/1054880},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2012},
month = {11}
}