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Title: Enhanced surface flashover strength in vacuum of polymethylmethacrylate by surface modification using atmospheric-pressure dielectric barrier discharge

Polymer materials, such as polymethylmethacrylate (PMMA), are widely used as insulators in vacuum. The insulating performance of a high-voltage vacuum system is mainly limited by surface flashover of the insulators rather than bulk breakdown. Non-thermal plasmas are an efficient method to modify the chemical and physical properties of polymer material surfaces, and enhance the surface insulating performance. In this letter, an atmospheric-pressure dielectric barrier discharge is used to treat the PMMA surface to improve the surface flashover strength in vacuum. Experimental results indicate that the plasma treatment method using Ar and CF{sub 4} (10:1) as the working gas can etch the PMMA surface, introduce fluoride groups to the surface, and then alter the surface characteristics of the PMMA. The increase in the surface roughness can introduce physical traps that can capture free electrons, and the fluorination can enhance the charge capturing ability. The increase in the surface roughness and the introduction of the fluoride groups can enhance the PMMA hydrophobic ability, improve the charge capturing ability, decrease the secondary electron emission yield, increase the surface resistance, and improve the surface flashover voltage in vacuum.
Authors:
; ; ;  [1] ;  [2] ;  [1] ;  [3]
  1. Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China)
  2. (China)
  3. Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States)
Publication Date:
OSTI Identifier:
22310869
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ATMOSPHERIC PRESSURE; BREAKDOWN; CAPTURE; CARBON TETRAFLUORIDE; DIELECTRIC MATERIALS; ELECTRIC DISCHARGES; ELECTRIC POTENTIAL; ELECTRON EMISSION; ELECTRONS; FLUORIDES; FLUORINATION; MODIFICATIONS; PHYSICAL PROPERTIES; PLASMA; PMMA; ROUGHNESS; SURFACES; TRAPS