skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Validations of calibration-free measurements of electron temperature using double-pass Thomson scattering diagnostics from theoretical and experimental aspects

Abstract

This paper evaluates the accuracy of electron temperature measurements and relative transmissivities of double-pass Thomson scattering diagnostics. The electron temperature (T{sub e}) is obtained from the ratio of signals from a double-pass scattering system, then relative transmissivities are calculated from the measured T{sub e} and intensity of the signals. How accurate the values are depends on the electron temperature (T{sub e}) and scattering angle (θ), and therefore the accuracy of the values was evaluated experimentally using the Large Helical Device (LHD) and the Tokyo spherical tokamak-2 (TST-2). Analyzing the data from the TST-2 indicates that a high T{sub e} and a large scattering angle (θ) yield accurate values. Indeed, the errors for scattering angle θ = 135° are approximately half of those for θ = 115°. The method of determining the T{sub e} in a wide T{sub e} range spanning over two orders of magnitude (0.01–1.5 keV) was validated using the experimental results of the LHD and TST-2. A simple method to provide relative transmissivities, which include inputs from collection optics, vacuum window, optical fibers, and polychromators, is also presented. The relative errors were less than approximately 10%. Numerical simulations also indicate that the T{sub e} measurements are valid undermore » harsh radiation conditions. This method to obtain T{sub e} can be considered for the design of Thomson scattering systems where there is high-performance plasma that generates harsh radiation environments.« less

Authors:
; ; ; ;  [1]; ; ; ;  [2]; ; ;  [3]
  1. National Institutes for Quantum and Radiological Science and Technology, 801-1 Mukoyama, Naka 311-0193 (Japan)
  2. National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan)
  3. Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561 (Japan)
Publication Date:
OSTI Identifier:
22597625
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 87; Journal Issue: 9; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ACCURACY; APPROXIMATIONS; CALIBRATION; COMPUTERIZED SIMULATION; ELECTRON TEMPERATURE; ELECTRONS; ERRORS; KEV RANGE 01-10; LHD DEVICE; OPTICAL FIBERS; PLASMA; SIGNALS; SPHERICAL CONFIGURATION; TEMPERATURE MEASUREMENT; THOMSON SCATTERING; TOKAMAK DEVICES; VALIDATION; WINDOWS

Citation Formats

Tojo, H., E-mail: tojo.hiroshi@qst.go.jp, Hiratsuka, J., Yatsuka, E., Hatae, T., Itami, K., Yamada, I., Yasuhara, R., Funaba, H., Hayashi, H., Ejiri, A., Togashi, H., and Takase, Y.. Validations of calibration-free measurements of electron temperature using double-pass Thomson scattering diagnostics from theoretical and experimental aspects. United States: N. p., 2016. Web. doi:10.1063/1.4961476.
Tojo, H., E-mail: tojo.hiroshi@qst.go.jp, Hiratsuka, J., Yatsuka, E., Hatae, T., Itami, K., Yamada, I., Yasuhara, R., Funaba, H., Hayashi, H., Ejiri, A., Togashi, H., & Takase, Y.. Validations of calibration-free measurements of electron temperature using double-pass Thomson scattering diagnostics from theoretical and experimental aspects. United States. doi:10.1063/1.4961476.
Tojo, H., E-mail: tojo.hiroshi@qst.go.jp, Hiratsuka, J., Yatsuka, E., Hatae, T., Itami, K., Yamada, I., Yasuhara, R., Funaba, H., Hayashi, H., Ejiri, A., Togashi, H., and Takase, Y.. Thu . "Validations of calibration-free measurements of electron temperature using double-pass Thomson scattering diagnostics from theoretical and experimental aspects". United States. doi:10.1063/1.4961476.
@article{osti_22597625,
title = {Validations of calibration-free measurements of electron temperature using double-pass Thomson scattering diagnostics from theoretical and experimental aspects},
author = {Tojo, H., E-mail: tojo.hiroshi@qst.go.jp and Hiratsuka, J. and Yatsuka, E. and Hatae, T. and Itami, K. and Yamada, I. and Yasuhara, R. and Funaba, H. and Hayashi, H. and Ejiri, A. and Togashi, H. and Takase, Y.},
abstractNote = {This paper evaluates the accuracy of electron temperature measurements and relative transmissivities of double-pass Thomson scattering diagnostics. The electron temperature (T{sub e}) is obtained from the ratio of signals from a double-pass scattering system, then relative transmissivities are calculated from the measured T{sub e} and intensity of the signals. How accurate the values are depends on the electron temperature (T{sub e}) and scattering angle (θ), and therefore the accuracy of the values was evaluated experimentally using the Large Helical Device (LHD) and the Tokyo spherical tokamak-2 (TST-2). Analyzing the data from the TST-2 indicates that a high T{sub e} and a large scattering angle (θ) yield accurate values. Indeed, the errors for scattering angle θ = 135° are approximately half of those for θ = 115°. The method of determining the T{sub e} in a wide T{sub e} range spanning over two orders of magnitude (0.01–1.5 keV) was validated using the experimental results of the LHD and TST-2. A simple method to provide relative transmissivities, which include inputs from collection optics, vacuum window, optical fibers, and polychromators, is also presented. The relative errors were less than approximately 10%. Numerical simulations also indicate that the T{sub e} measurements are valid under harsh radiation conditions. This method to obtain T{sub e} can be considered for the design of Thomson scattering systems where there is high-performance plasma that generates harsh radiation environments.},
doi = {10.1063/1.4961476},
journal = {Review of Scientific Instruments},
number = 9,
volume = 87,
place = {United States},
year = {Thu Sep 15 00:00:00 EDT 2016},
month = {Thu Sep 15 00:00:00 EDT 2016}
}