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Title: Space charge distributions in insulating polymers: A new non-contacting way of measurement

A new technique for the determination of space charge profiles in insulating polymers is proposed. Based on the evolution of an existing thermal wave technique called Focused Laser Intensity Modulation Method ((F)LIMM), it allows non-contact measurements on thin films exhibiting an internal charge to be studied. An electrostatic model taking into account the new sample-cell geometry proposed was first developed. It has been shown, in particular, that it was theoretically possible to calculate the internal charge from experimental measurements while allowing an evaluation of the air layer appearing between the sample and the electrode when non-contact measurements are performed. These predictions were confirmed by an experimental implementation for two thin polymer samples (25 μm-polyvinylidenefluoride and 50 μm-polytetrafluoroethylene (PTFE)) used as tests. In these cases, minimum air-layer thickness was determined with an accuracy of 3% and 20%, respectively, depending on the signal-to-noise ratio during the experimental procedure. In order to illustrate the reachable possibilities of this technique, 2D and 3D cartographies of a negative space charge implanted by electron beam within the PTFE test sample were depicted: like in conventional (F)LIMM, a multidimensional representation of a selectively implanted charge remains possible at a few microns depth, but using a non-contacting waymore » of measurement.« less
Authors:
; ;  [1] ;  [2] ;  [3]
  1. Université de Toulouse, UPS, LAPLACE, 118 route de Narbonne, F-31062 Toulouse (France)
  2. (France)
  3. Université de Pau et des Pays de l’Adour, SIAME, IPRA, 2 avenue du Président Pierre Angot, F-64053 Pau (France)
Publication Date:
OSTI Identifier:
22392461
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 86; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ELECTRON BEAMS; LASERS; LAYERS; MODULATION; SIGNAL-TO-NOISE RATIO; SPACE CHARGE; TEFLON; THIN FILMS