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Title: Performance of large electron energy filter in large volume plasma device

This paper describes an in-house designed large Electron Energy Filter (EEF) utilized in the Large Volume Plasma Device (LVPD) [S. K. Mattoo, V. P. Anita, L. M. Awasthi, and G. Ravi, Rev. Sci. Instrum. 72, 3864 (2001)] to secure objectives of (a) removing the presence of remnant primary ionizing energetic electrons and the non-thermal electrons, (b) introducing a radial gradient in plasma electron temperature without greatly affecting the radial profile of plasma density, and (c) providing a control on the scale length of gradient in electron temperature. A set of 19 independent coils of EEF make a variable aspect ratio, rectangular solenoid producing a magnetic field (B{sub x}) of 100 G along its axis and transverse to the ambient axial field (B{sub z} ∼ 6.2 G) of LVPD, when all its coils are used. Outside the EEF, magnetic field reduces rapidly to 1 G at a distance of 20 cm from the center of the solenoid on either side of target and source plasma. The EEF divides LVPD plasma into three distinct regions of source, EEF and target plasma. We report that the target plasma (n{sub e} ∼ 2 × 10{sup 11} cm{sup −3} and T{sub e} ∼ 2 eV) has no detectable energetic electronsmore » and the radial gradients in its electron temperature can be established with scale length between 50 and 600 cm by controlling EEF magnetic field. Our observations reveal that the role of the EEF magnetic field is manifested by the energy dependence of transverse electron transport and enhanced transport caused by the plasma turbulence in the EEF plasma.« less
Authors:
; ; ; ; ;  [1] ;  [1] ;  [2]
  1. Institute for Plasma Research, Gandhinagar 382 428, Gujarat (India)
  2. (Korea, Republic of)
Publication Date:
OSTI Identifier:
22254969
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ASPECT RATIO; ELECTRON TEMPERATURE; ENERGY DEPENDENCE; FILTERS; MAGNETIC FIELDS; PERFORMANCE; PLASMA DENSITY; SOLENOIDS; TAIL ELECTRONS