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Title: Simultaneous measurement of ion and electron temperatures in the scrape-off layer of a small tokamak

Abstract

This article describes a system composed of an electrostatic ion probe associated with an electronic circuit designed and constructed to be used in the scrape-off layer of the TBR-1 tokamak for simultaneous measurements of local electron and ion temperatures. The electronic circuit is discussed. Details of the mechanical structure and dimensions of the probe can be found in another article (Rev. Sci. Instrum. {bold 57}, 2205 (1986)). The circuit is composed of a sweep generator followed by an amplifier. The sweep time can be varied from 50 {mu}s to 50 ms and the probe voltage amplitude from 0 to 200 V. The circuit supplies a maximum current of 250 mA, is short-circuit protected, and provides cable capacitance neutralization. The ion current is detected by a current transformer sensitive to currents as low as 20 {mu}A. The total probe current is measured by the voltage drop in a resistor inserted in the circuit. The system has been tested in the TBR-1 boundary plasma and showed good performance with a time resolution better than 500 {mu}s. The obtained results showed that, for TBR-1 boundary plasma, the ion temperature is about two times the electron temperature.

Authors:
;  [1]
  1. Instituto de Fisica, Universidade de Sao Paulo, C.P. 20516, 01498 Sao Paulo, SP (Brazil)
Publication Date:
OSTI Identifier:
5216987
Resource Type:
Journal Article
Journal Name:
Review of Scientific Instruments; (United States)
Additional Journal Information:
Journal Volume: 62:11; Journal ID: ISSN 0034-6748
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ION PROBES; DESIGN; LANGMUIR PROBE; PLASMA DIAGNOSTICS; TOKAMAK DEVICES; ELECTRON TEMPERATURE; ELECTRONIC CIRCUITS; ION TEMPERATURE; CLOSED PLASMA DEVICES; ELECTRIC PROBES; PROBES; THERMONUCLEAR DEVICES; 700102* - Fusion Energy- Plasma Research- Diagnostics

Citation Formats

da Silva, R P, and Nascimento, I C. Simultaneous measurement of ion and electron temperatures in the scrape-off layer of a small tokamak. United States: N. p., 1991. Web. doi:10.1063/1.1142203.
da Silva, R P, & Nascimento, I C. Simultaneous measurement of ion and electron temperatures in the scrape-off layer of a small tokamak. United States. doi:10.1063/1.1142203.
da Silva, R P, and Nascimento, I C. Fri . "Simultaneous measurement of ion and electron temperatures in the scrape-off layer of a small tokamak". United States. doi:10.1063/1.1142203.
@article{osti_5216987,
title = {Simultaneous measurement of ion and electron temperatures in the scrape-off layer of a small tokamak},
author = {da Silva, R P and Nascimento, I C},
abstractNote = {This article describes a system composed of an electrostatic ion probe associated with an electronic circuit designed and constructed to be used in the scrape-off layer of the TBR-1 tokamak for simultaneous measurements of local electron and ion temperatures. The electronic circuit is discussed. Details of the mechanical structure and dimensions of the probe can be found in another article (Rev. Sci. Instrum. {bold 57}, 2205 (1986)). The circuit is composed of a sweep generator followed by an amplifier. The sweep time can be varied from 50 {mu}s to 50 ms and the probe voltage amplitude from 0 to 200 V. The circuit supplies a maximum current of 250 mA, is short-circuit protected, and provides cable capacitance neutralization. The ion current is detected by a current transformer sensitive to currents as low as 20 {mu}A. The total probe current is measured by the voltage drop in a resistor inserted in the circuit. The system has been tested in the TBR-1 boundary plasma and showed good performance with a time resolution better than 500 {mu}s. The obtained results showed that, for TBR-1 boundary plasma, the ion temperature is about two times the electron temperature.},
doi = {10.1063/1.1142203},
journal = {Review of Scientific Instruments; (United States)},
issn = {0034-6748},
number = ,
volume = 62:11,
place = {United States},
year = {1991},
month = {11}
}