Plasma and Fusion Research

Volume 12, 1305029 (2017)

Letters

Absorbed Dose Rate in Air at the NIFS Site before the Deuterium Plasma Experiment in LHD
Yoshitaka SHIROMA, Naofumi AKATA, Hitoshi MIYAKE, Hiroshi HAYASHI, Takuya SAZE, Masahiro TANAKA and Kiyohiko NISHIMURA
National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
(Received 20 April 2017 / Accepted 22 May 2017 / Published 19 July 2017)

Abstract

The absorbed dose rate in air was measured at the National Institute for Fusion Science (NIFS) site before the deuterium plasma experiment in the Large Helical Device (LHD). A pocket survey meter was used for the measurement of 1 cm dose equivalent rates in units of μSv h−1 and these results were converted to absorbed dose rates in air (units: nGy h−1) using a conversion factor. The arithmetic mean of the absorbed dose rates in air based on 257 measurement points at NIFS site was 45 nGy h−1. The result of this study suggests that the building material and/or paving stone enhance the dose rates in air at the NIFS site.

Keywords

absorbed dose rate, environmental radiation, background measurement, deuterium plasma experiment, NIFS site

DOI: 10.1585/pfr.12.1305029

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