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Title: Photoemission characterization of N-polar III-nitride photocathodes as candidate bright electron beam sources for accelerator applications

We report on the growth and characterization of a new class of photocathode structures for use as electron sources to produce high brightness electron beams for accelerator applications. The sources are realized using III-nitride materials and are designed to leverage the strong polarization field, which is characteristic of this class of materials when grown in their wurtzite crystal structure, to produce a negative electron affinity condition without the use of Cs, possibly allowing these materials to be operated in radio frequency guns. A Quantum Efficiency (QE) of about [Formula: see text] and an emitted electrons’ Mean Transverse Energy (MTE) of about 100 meV are measured at a wavelength of 265 nm. In a vacuum level of [Formula: see text] Torr, the QE does not decrease after more than 24 h of continuous operation. The lowest MTE of about 50 meV is measured at 300 nm along with a QE of [Formula: see text]. Surface characterizations reveal a possible contribution to the MTE from surface morphology, calling for more detailed studies.

 
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NSF-PAR ID:
10364227
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
American Institute of Physics
Date Published:
Journal Name:
Journal of Applied Physics
Volume:
131
Issue:
12
ISSN:
0021-8979
Page Range / eLocation ID:
Article No. 124902
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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