Plasma and Fusion Research

Volume 16, 2405062 (2021)

Regular Articles

Detection of Ammonia and Deuterated Hydrocarbons in Exhaust Gas by Infrared Absorption Spectroscopy during Wall Conditioning
Masahiro TANAKA1,2), Hiromi KATO1), Naoyuki SUZUKI1) and Hiroki CHIMURA1)
1)
National Institute for Fusion Science, National Institutes of Natural Sciences, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
2)
The Graduate University for Advanced Studies, SOKENDAI, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
(Received 14 November 2020 / Accepted 25 February 2021 / Published 21 April 2021)

Abstract

To detect ammonia and deuterated hydrocarbons in exhaust gas from the Large Helical Device (LHD), infrared absorption spectrometry, FTIR with a long optical path gas cell, was applied. Ammonia (NH3) and deuterated hydrocarbons (CxHyDz) could be detected during the first operations of wall baking at 368 K and the D2 glow discharge conducted after vacuum vessel closure. The concentration of ammonia increased with increasing baking temperature, and deuterated ammonia was not detected. Thus, the ammonia, which likely originated from sweat of workers produced during vacuum vessel maintenance activities, was released from the vacuum vessel wall. Hydrocarbons were likely produced by chemical sputtering of carbon tiles and were deuterated by a hydrogen isotope exchange reaction due to D2 glow discharge, while H2O was released from the vacuum vessel during wall baking. It was confirmed that ammonia and various types of deuterated hydrocarbons could be measured discriminately by an FTIR spectroscopy system using a long optical path gas cell.

Keywords

exhaust gas monitoring, ammonia, deuterated hydrocarbons, infrared absorption spectroscopy, FTIR, large fusion test device

DOI: 10.1585/pfr.16.2405062

Full Text

PDF format (790Kbytes) PDF Download

References

  • [1] M. Osakabe et al., Fusion Sci. Technol. 72, 199 (2017).
  • [2] M. Osakabe et al., IEEE Trans. Plasma Sci. 46, 2324 (2018).
  • [3] D. Neuwirth et al., Plasma Phys. Control. Fusion 54, 085008 (2012).
  • [4] M. Oberkofler et al., J. Nucl. Mater. 438, S258 (2013).
  • [5] V. Rohde et al., J. Nucl. Mater. 463, 672 (2015).
  • [6] A. Drenik et al., Fusion Eng. Des. 124, 239 (2017).
  • [7] A. Drenik et al., Nucl. Fusion 59, 046010 (2019).
  • [8] S. Grünhagen et al., Fusion Sci. Technol. 60, 931 (2011).
  • [9] U. Kruezi et al., Rev. Sci. Instrum. 83, 10D728 (2012).
  • [10] S. Grünhagen Romanelli et al., Phys. Scr. T159, 014068 (2014).
  • [11] S.G. Romanelli et al., Fusion Sci. Technol. 71, 467 (2017).
  • [12] A. Drenik et al., Phys. Scr. T170, 014021 (2017).
  • [13] M. Tanaka et al., Fusion Eng. Des. 127, 275 (2018).
  • [14] M. Tanaka et al., J. Radioanal. Nucl. Chem. 318, 877 (2018).
  • [15] M. Tanaka et al., Fusion Sci. Technol. 76, 475 (2020).
  • [16] M. Tanaka et al., Plasma Fusion Res. 15, 1405062 (2020).
  • [17] M. Tanaka et al., J. Nucl. Sci. Technol. 52, 1297 (2020).
  • [18] M. Tanaka et al., Plasma Fusion Res. 15, 2405008 (2020).
  • [19] Perkin Elmer Frontier catalogue (2011).
  • [20] H.W. Thompson, Tables of wavenumbers for the calibration of infra-red spectrometers (BUTTER WORTHS, London, 1961).
  • [21] T. Shimanouchi, Tables of molecular vibrational frequencies consolidated volume I, Nat. Stand. Ref. Data Ser., Nat. Bur. Stand. (U.S.), 39 (1972).
  • [22] H. Nakamura et al., Fusion Eng. Des. 70, 163 (2004).