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Title: Beam Tests of Diamond-Like Carbon Coating for Mitigation of Electron Cloud

Abstract

Electron cloud beam instabilities are an important consideration in virtually all high-energy particle accelerators and could pose a formidable challenge to forthcoming high-intensity accelerator upgrades. Our results evaluate the efficacy of a diamond-like carbon (DLC) coating for the mitigation of electron in the Fermilab Main Injector. The interior surface of the beampipe conditions in response to electron bombardment from the electron cloud and we track the change in electron cloud flux over time in the DLC coated beampipe and uncoated stainless steel beampipe. The electron flux is measured by retarding field analyzers placed in a field-free region of the Main Injector. We find the DLC coating reduces the electron cloud signal to roughly 2\% of that measured in the uncoated stainless steel beampipe.

Authors:
ORCiD logo [1]; ORCiD logo [1];  [2];  [1]; ORCiD logo [1]
  1. Fermilab
  2. KEK, Tsukuba
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1423251
Report Number(s):
FERMILAB-CONF-17-581-APC
1627467
DOE Contract Number:
AC02-07CH11359
Resource Type:
Conference
Resource Relation:
Conference: 8th International Particle Accelerator Conference, Copenhagen, Denmark, 05/14-05/19/2017
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS

Citation Formats

Eldred, Jeffrey, Backfish, Michael, Kato, Shigeki, Tan, Cheng-Yang, and Zwaska, Robert. Beam Tests of Diamond-Like Carbon Coating for Mitigation of Electron Cloud. United States: N. p., 2017. Web. doi:10.18429/JACoW-IPAC2017-THPVA031.
Eldred, Jeffrey, Backfish, Michael, Kato, Shigeki, Tan, Cheng-Yang, & Zwaska, Robert. Beam Tests of Diamond-Like Carbon Coating for Mitigation of Electron Cloud. United States. doi:10.18429/JACoW-IPAC2017-THPVA031.
Eldred, Jeffrey, Backfish, Michael, Kato, Shigeki, Tan, Cheng-Yang, and Zwaska, Robert. Mon . "Beam Tests of Diamond-Like Carbon Coating for Mitigation of Electron Cloud". United States. doi:10.18429/JACoW-IPAC2017-THPVA031. https://www.osti.gov/servlets/purl/1423251.
@article{osti_1423251,
title = {Beam Tests of Diamond-Like Carbon Coating for Mitigation of Electron Cloud},
author = {Eldred, Jeffrey and Backfish, Michael and Kato, Shigeki and Tan, Cheng-Yang and Zwaska, Robert},
abstractNote = {Electron cloud beam instabilities are an important consideration in virtually all high-energy particle accelerators and could pose a formidable challenge to forthcoming high-intensity accelerator upgrades. Our results evaluate the efficacy of a diamond-like carbon (DLC) coating for the mitigation of electron in the Fermilab Main Injector. The interior surface of the beampipe conditions in response to electron bombardment from the electron cloud and we track the change in electron cloud flux over time in the DLC coated beampipe and uncoated stainless steel beampipe. The electron flux is measured by retarding field analyzers placed in a field-free region of the Main Injector. We find the DLC coating reduces the electron cloud signal to roughly 2\% of that measured in the uncoated stainless steel beampipe.},
doi = {10.18429/JACoW-IPAC2017-THPVA031},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon May 01 00:00:00 EDT 2017},
month = {Mon May 01 00:00:00 EDT 2017}
}

Conference:
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  • In order to mitigate the electron cloud instability in an intense positron ring, an electron clearing electrode with a very thin structure has been developed. The electrode was tested with a positron beam of the KEKB B-factory (KEKB). A drastic reduction in the electron density around the beam was demonstrated in a wiggler magnet with a dipole-type magnetic field of 0.78 T. The clearing electrode was then applied to a copper beam pipe with antechambers assuming an application of the electrode to a wiggler section in the Super KEKB. The beam pipe was installed at a magnetic-free region in themore » ring and tested with beam. No extra heating of the electrodes and feed-throughs were observed. A reduction in the electron density reasonable in a magnetic-free region was also obtained.« less
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