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Title: Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap

Abstract

A new high voltage photoemission gun has been constructed at Cornell University which features a segmented insulator and a movable anode, allowing the cathode-anode gap to be adjusted. In this work, we describe the gun's overall mechanical and high voltage design, the surface preparation of components, as well as the clean construction methods. We present high voltage conditioning data using a 50 mm cathode-anode gap, in which the conditioning voltage exceeds 500 kV, as well as at smaller gaps. Finally, we present simulated emittance results obtained from a genetic optimization scheme using voltage values based on the conditioning data. These results indicate that for charges up to 100 pC, a 30 mm gap at 400 kV has equal or smaller 100% emittance than a 50 mm gap at 450 kV, and also a smaller core emittance, when placed as the source for the Cornell energy recovery linac photoinjector with bunch length constrained to be <3 ps rms. For 100 pC up to 0.5 nC charges, the 50 mm gap has larger core emittance than the 30 mm gap, but conversely smaller 100% emittance.

Authors:
; ; ; ; ;  [1]
  1. Cornell Laboratory for Accelerator-Based Sciences and Education, Cornell University, Ithaca, New York 14853 (United States)
Publication Date:
OSTI Identifier:
22314447
Resource Type:
Journal Article
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 85; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0034-6748
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ANODES; BEAM EMITTANCE; CATHODES; ELECTRIC POTENTIAL; ELECTRON GUNS; ENERGY RECOVERY; LINEAR ACCELERATORS; OPTIMIZATION; PHOTOELECTRON SPECTROSCOPY; PHOTOEMISSION; SIMULATION

Citation Formats

Maxson, Jared, Bazarov, Ivan, Dunham, Bruce, Dobbins, John, Liu, Xianghong, and Smolenski, Karl. Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap. United States: N. p., 2014. Web. doi:10.1063/1.4895641.
Maxson, Jared, Bazarov, Ivan, Dunham, Bruce, Dobbins, John, Liu, Xianghong, & Smolenski, Karl. Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap. United States. doi:10.1063/1.4895641.
Maxson, Jared, Bazarov, Ivan, Dunham, Bruce, Dobbins, John, Liu, Xianghong, and Smolenski, Karl. Mon . "Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap". United States. doi:10.1063/1.4895641.
@article{osti_22314447,
title = {Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap},
author = {Maxson, Jared and Bazarov, Ivan and Dunham, Bruce and Dobbins, John and Liu, Xianghong and Smolenski, Karl},
abstractNote = {A new high voltage photoemission gun has been constructed at Cornell University which features a segmented insulator and a movable anode, allowing the cathode-anode gap to be adjusted. In this work, we describe the gun's overall mechanical and high voltage design, the surface preparation of components, as well as the clean construction methods. We present high voltage conditioning data using a 50 mm cathode-anode gap, in which the conditioning voltage exceeds 500 kV, as well as at smaller gaps. Finally, we present simulated emittance results obtained from a genetic optimization scheme using voltage values based on the conditioning data. These results indicate that for charges up to 100 pC, a 30 mm gap at 400 kV has equal or smaller 100% emittance than a 50 mm gap at 450 kV, and also a smaller core emittance, when placed as the source for the Cornell energy recovery linac photoinjector with bunch length constrained to be <3 ps rms. For 100 pC up to 0.5 nC charges, the 50 mm gap has larger core emittance than the 30 mm gap, but conversely smaller 100% emittance.},
doi = {10.1063/1.4895641},
journal = {Review of Scientific Instruments},
issn = {0034-6748},
number = 9,
volume = 85,
place = {United States},
year = {2014},
month = {9}
}