TY - JOUR
T1 - Optimization of the secondary electron yield of laser-structured copper surfaces at room and cryogenic temperature
AU - Calatroni, Sergio
AU - Garcia-Tabares Valdivieso, Elisa
AU - Perez Fontenla, Ana Teresa
AU - Taborelli, Mauro
AU - Neupert, Holger
AU - Himmerlich, Marcel
AU - Chiggiato, Paolo
AU - Bajek, David
AU - Wackerow, Stefan
AU - Abdolvand, Amin
N1 - Funding Information:
The laser structuring at the University of Dundee was conducted under the aegis of grants and financial support from the Science and Technology Facilities Council (Grant No. ST/P00086X/1) and CERN (Collaboration Agreement KN3362).
Publisher Copyright:
© 2020 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/" Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
PY - 2020/3
Y1 - 2020/3
N2 - Electron cloud (e-cloud) mitigation is an essential requirement for proton circular accelerators in order to guarantee beam stability at a high intensity and limit the heat load on cryogenic sections. Laser-engineered surface structuring is considered a credible process to reduce the secondary electron yield (SEY) of the surfaces facing the beam, thus suppressing the e-cloud phenomenon within the high luminosity upgrade of the LHC collider at CERN (HL-LHC). In this study, the SEY of Cu samples with different oxidation states, obtained either through laser treatment in air or in different gas atmospheres or via thermal annealing, has been measured at room and cryogenic temperatures and correlated with the surface composition measured by X-ray photoelectron spectroscopy. It was observed that samples treated in nitrogen display the lowest and more stable SEY values, correlated with the lower surface oxidation. In addition, the surface oxide layer of air-treated samples charges upon electron exposure at a low temperature, leading to fluctuations in the SEY.
AB - Electron cloud (e-cloud) mitigation is an essential requirement for proton circular accelerators in order to guarantee beam stability at a high intensity and limit the heat load on cryogenic sections. Laser-engineered surface structuring is considered a credible process to reduce the secondary electron yield (SEY) of the surfaces facing the beam, thus suppressing the e-cloud phenomenon within the high luminosity upgrade of the LHC collider at CERN (HL-LHC). In this study, the SEY of Cu samples with different oxidation states, obtained either through laser treatment in air or in different gas atmospheres or via thermal annealing, has been measured at room and cryogenic temperatures and correlated with the surface composition measured by X-ray photoelectron spectroscopy. It was observed that samples treated in nitrogen display the lowest and more stable SEY values, correlated with the lower surface oxidation. In addition, the surface oxide layer of air-treated samples charges upon electron exposure at a low temperature, leading to fluctuations in the SEY.
UR - http://www.scopus.com/inward/record.url?scp=85082752393&partnerID=8YFLogxK
U2 - 10.1103/PhysRevAccelBeams.23.033101
DO - 10.1103/PhysRevAccelBeams.23.033101
M3 - Article
AN - SCOPUS:85082752393
SN - 2469-9888
VL - 23
JO - Physical Review Accelerators and Beams
JF - Physical Review Accelerators and Beams
IS - 3
M1 - 033101
ER -