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Title: Low secondary electron yield engineered surface for electron cloud mitigation

Secondary electron yield (SEY or δ) limits the performance of a number of devices. Particularly, in high-energy charged particle accelerators, the beam-induced electron multipacting is one of the main sources of electron cloud (e-cloud) build up on the beam path; in radio frequency wave guides, the electron multipacting limits their lifetime and causes power loss; and in detectors, the secondary electrons define the signal background and reduce the sensitivity. The best solution would be a material with a low SEY coating and for many applications δ < 1 would be sufficient. We report on an alternative surface preparation to the ones that are currently advocated. Three commonly used materials in accelerator vacuum chambers (stainless steel, copper, and aluminium) were laser processed to create a highly regular surface topography. It is shown that this treatment reduces the SEY of the copper, aluminium, and stainless steel from δ{sub max} of 1.90, 2.55, and 2.25 to 1.12, 1.45, and 1.12, respectively. The δ{sub max} further reduced to 0.76–0.78 for all three treated metals after bombardment with 500 eV electrons to a dose between 3.5 × 10{sup −3} and 2.0 × 10{sup −2} C·mm{sup −2}.
Authors:
; ;  [1] ; ; ;  [2]
  1. ASTeC, STFC Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom)
  2. School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom)
Publication Date:
OSTI Identifier:
22395457
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 23; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM; CHARGED PARTICLES; COPPER; ELECTRONS; EV RANGE; IRRADIATION; LASER RADIATION; LIFETIME; MATHEMATICAL SOLUTIONS; MITIGATION; PHYSICAL RADIATION EFFECTS; POWER LOSSES; RADIOWAVE RADIATION; SENSITIVITY; STAINLESS STEELS; SURFACES