PTB製線標準場での線組織吸収線量率の測定評価

Measurement evaluation of -rays tissue absorbed dose rate in -ray reference fields made by PTB

清水 滋; 根本 久*; 梶本 与一; 立部 洋介; 高橋 拓士*

Shimizu, Shigeru; Nemoto, Hisashi*; Kajimoto, Yoichi; Tatebe, Yosuke; Takahashi, Hiroshi*

われわれは、ドイツ連邦物理工学研究所(PTB)で研究開発されISO6980-1(2006)のSeries 1に対応する線組織吸収線量率の標準場を、2010年2月に原子力機構(JAEA)の放射線標準施設棟に整備した。本標準場の線組織吸収線量率をPTB製の外挿電離箱を用いて測定評価を行い、PTBの標準値との比較により、両者はよく一致した。本発表では、これらの評価結果及び比較結果を述べるとともに、標準場利用時の線組織吸収線量率への、試験環境の空気密度の影響の補正方法について述べる。

We were researched and developed in German federal physical engineering laboratory (PTB) and established the standard field of the ray tissue absorbed dose rate corresponding to Series 1 of ISO6980-1(2006) to the Facility of Radiation Standard of Japan Atomic Energy Agency (JAEA) in February, 2010. We measured ray tissue absorbed dose rate of this standard field using an extrapolation ionization chamber made in PTB. By the comparison between this result and standard value of PTB, both agreed well. In this announcement, we speak these evaluation results and comparison result. In addition, we speak that the ray tissue absorbed dose rate at the time of the standard field use comes under a big influence by a change of the air density of the examination environment.