Electrostatic design and conditioning of a triple point junction shield for a –200 kV DC high voltage photogun [Electrostatic design of a triple point junction shield for a -200 kV DC high voltage photogun using COMSOL]
Abstract
Nuclear physics experiments performed at the Continuous Electron Beam Accelerator Facility (CEBAF) at the Jefferson Lab require a DC high voltage photogun to generate polarized electron beams from GaAs photocathodes. The photogun uses a tapered ceramic insulator that extends into the vacuum chamber and mechanically holds the cathode electrode. Increasing the operating voltage from nominal –130 kV to –200 kV will provide lower beam emittance, better transmission through injector apertures, and improved photocathode lifetime. This desire to increase the photogun operating voltage led to the design of a triple-point-junction shield electrode which minimizes the electric field at the delicate insulator-metal-vacuum interface and linearizes the potential across the insulator, thus reducing the risk of arcing along the ceramic insulator. Furthermore, this work describes the results obtained using COMSOL® electrostatic-field simulation software and presents the high voltage conditioning results of the upgraded –200 kV CEBAF photogun.
- Authors:
-
- Old Dominion Univ., Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Publication Date:
- Research Org.:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- OSTI Identifier:
- 1489811
- Alternate Identifier(s):
- OSTI ID: 1475477
- Report Number(s):
- JLAB-ACC-18-2842; DOE/OR/23177-4563
Journal ID: ISSN 0034-6748
- Grant/Contract Number:
- AC05-06OR23177
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Review of Scientific Instruments
- Additional Journal Information:
- Journal Volume: 89; Journal Issue: 10; Journal ID: ISSN 0034-6748
- Publisher:
- American Institute of Physics (AIP)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 47 OTHER INSTRUMENTATION
Citation Formats
Palacios-Serrano, Gabriel G., Hannon, Fay E., Hernandez-Garcia, Carlos, Poelker, Matt, and Baumgart, Helmut. Electrostatic design and conditioning of a triple point junction shield for a –200 kV DC high voltage photogun [Electrostatic design of a triple point junction shield for a -200 kV DC high voltage photogun using COMSOL]. United States: N. p., 2018.
Web. doi:10.1063/1.5048700.
Palacios-Serrano, Gabriel G., Hannon, Fay E., Hernandez-Garcia, Carlos, Poelker, Matt, & Baumgart, Helmut. Electrostatic design and conditioning of a triple point junction shield for a –200 kV DC high voltage photogun [Electrostatic design of a triple point junction shield for a -200 kV DC high voltage photogun using COMSOL]. United States. https://doi.org/10.1063/1.5048700
Palacios-Serrano, Gabriel G., Hannon, Fay E., Hernandez-Garcia, Carlos, Poelker, Matt, and Baumgart, Helmut. Wed .
"Electrostatic design and conditioning of a triple point junction shield for a –200 kV DC high voltage photogun [Electrostatic design of a triple point junction shield for a -200 kV DC high voltage photogun using COMSOL]". United States. https://doi.org/10.1063/1.5048700. https://www.osti.gov/servlets/purl/1489811.
@article{osti_1489811,
title = {Electrostatic design and conditioning of a triple point junction shield for a –200 kV DC high voltage photogun [Electrostatic design of a triple point junction shield for a -200 kV DC high voltage photogun using COMSOL]},
author = {Palacios-Serrano, Gabriel G. and Hannon, Fay E. and Hernandez-Garcia, Carlos and Poelker, Matt and Baumgart, Helmut},
abstractNote = {Nuclear physics experiments performed at the Continuous Electron Beam Accelerator Facility (CEBAF) at the Jefferson Lab require a DC high voltage photogun to generate polarized electron beams from GaAs photocathodes. The photogun uses a tapered ceramic insulator that extends into the vacuum chamber and mechanically holds the cathode electrode. Increasing the operating voltage from nominal –130 kV to –200 kV will provide lower beam emittance, better transmission through injector apertures, and improved photocathode lifetime. This desire to increase the photogun operating voltage led to the design of a triple-point-junction shield electrode which minimizes the electric field at the delicate insulator-metal-vacuum interface and linearizes the potential across the insulator, thus reducing the risk of arcing along the ceramic insulator. Furthermore, this work describes the results obtained using COMSOL® electrostatic-field simulation software and presents the high voltage conditioning results of the upgraded –200 kV CEBAF photogun.},
doi = {10.1063/1.5048700},
journal = {Review of Scientific Instruments},
number = 10,
volume = 89,
place = {United States},
year = {Wed Oct 03 00:00:00 EDT 2018},
month = {Wed Oct 03 00:00:00 EDT 2018}
}
Web of Science
Figures / Tables:
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Figures / Tables found in this record: