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Title: Intrinsic emittance reduction in transmission mode photocathodes

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4944790· OSTI ID:1469694
 [1]; ORCiD logo [1];  [1]
  1. Cornell Univ., Ithaca, NY (United States). Cornell Lab. for Accelerator-Based Sciences and Education (CLASSE)

High quantum efficiency (QE) and low emittance electron beams provided by multi-alkali photocathodes make them of great interest for next generation high brightness photoinjectors. Spicer’s three-step model well describes the photoemission process; however, some photocathode characteristics such as their thickness have not yet been completely exploited to further improve the brightness of the generated electron beams. Here, we report on the emittance and QE of a multi-alkali photocathode grown onto a glass substrate operated in transmission and reflection modes at different photon energies. We observed a 20% reduction in the intrinsic emittance from the reflection to the transmission mode operation. This observation can be explained by inelastic electron-phonon scattering during electrons’ transit towards the cathode surface. Due to this effect, we predict that thicker photocathode layers will further reduce the intrinsic emittance of electron beams generated by photocathodes operated in transmission mode.

Research Organization:
Cornell Univ., Ithaca, NY (United States)
Sponsoring Organization:
USDOE Office of Science (SC); National Science Foundation (NSF)
Grant/Contract Number:
SC0014338; SC0011643; PHY-1416318
OSTI ID:
1469694
Alternate ID(s):
OSTI ID: 1243144
Journal Information:
Applied Physics Letters, Vol. 108, Issue 12; ISSN 0003-6951
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 11 works
Citation information provided by
Web of Science

References (20)

Measurement of the tradeoff between intrinsic emittance and quantum efficiency from a NaKSb photocathode near threshold journal June 2015
Transmittance Spectra and Optical Constants of Alkali-Antimony Compounds K 3 Sb, Na 3 Sb, and Na 2 KSb journal May 1973
Bi-alkali antimonide photocathodes for high brightness accelerators journal September 2013
Raman scattering from monoalkali (Na-Sb and K-Sb), bialkali (Na-K-Sb) and multialkali (Na-K-Sb-Cs) photocathodes journal May 1992
Alkali antimonides photocathodes growth using pure metals evaporation from effusion cells
  • Cultrera, Luca; Lee, Hyeri; Bazarov, Ivan
  • Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena, Vol. 34, Issue 1 https://doi.org/10.1116/1.4936845
journal December 2015
Measurement and Control of Charged Particle Beams book January 2003
Theory of photoemission from cesium antimonide using an alpha-semiconductor model journal August 2008
Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap journal September 2014
Demonstration of cathode emittance dominated high bunch charge beams in a DC gun-based photoinjector journal March 2015
Thermal emittance and response time measurements of negative electron affinity photocathodes journal March 2008
Record high-average current from a high-brightness photoinjector journal January 2013
Photoemissive, Photoconductive, and Optical Absorption Studies of Alkali-Antimony Compounds journal October 1958
Review and demonstration of ultra-low-emittance photocathode measurements journal July 2015
Cold electron beams from cryocooled, alkali antimonide photocathodes journal November 2015
Status of the high brightness polarized electron source using transmission photocathode journal May 2011
A novel system for measurement of the transverse electron momentum distribution from photocathodes journal January 2015
Quantum efficiency and thermal emittance of metal photocathodes journal July 2009
30-kV spin-polarized transmission electron microscope with GaAs–GaAsP strained superlattice photocathode journal July 2012
Enhancement of photoemission from and postprocessing of K 2 CsSb photocathode using excimer laser journal February 2014
Effective temperature of an ultracold electron source based on near-threshold photoionization journal January 2014

Cited By (1)

Rb based alkali antimonide high quantum efficiency photocathodes for bright electron beam sources and photon detection applications journal February 2017