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Author Sartori, E. ♦ Panasenkov, A. ♦ Veltri, P. ♦ Serianni, G. ♦ Pasqualotto, R.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY ♦ PLASMA PHYSICS AND FUSION TECHNOLOGY ♦ BEAM CURRENTS ♦ BEAMS ♦ CALORIMETERS ♦ COPPER ♦ CURRENT DENSITY ♦ DIAGNOSTIC TECHNIQUES ♦ ELECTRON EMISSION ♦ ELECTRONS ♦ HEATING ♦ HYDROGEN ♦ ITER TOKAMAK ♦ PLASMA ♦ SECONDARY EMISSION ♦ TEST FACILITIES ♦ TUBES
Abstract In high power neutral beams for fusion, beam uniformity is an important figure of merit. Knowing the transverse power profile is essential during the initial phases of beam source operation, such as those expected for the ITER heating neutral beam (HNB) test facility. To measure it a diagnostic technique is proposed, based on the collection of secondary electrons generated by beam-surface and beam-gas interactions, by an array of positively biased collectors placed behind the calorimeter tubes. This measurement showed in the IREK test stand good proportionality to the primary beam current. To investigate the diagnostic performances in different conditions, we developed a numerical model of secondary electron emission, induced by beam particle impact on the copper tubes, and reproducing the cascade of secondary emission caused by successive electron impacts. The model is first validated against IREK measurements. It is then applied to the HNB case, to assess the locality of the measurement, the proportionality to the beam current density, and the influence of beam plasma.
ISSN 00346748
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-11-15
Publisher Place United States
Journal Review of Scientific Instruments
Volume Number 87
Issue Number 11


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