Applicability study on existing dosimetry systems to high-power Bremsstrahlung irradiation

既存吸収線量計システムの高出力制動放射線への適用性

Mehta, K.*; 小嶋 拓治; 須永 博美

Mehta, K.*; Kojima, Takuji; Sunaga, Hiromi

既存線量計システムの高出力制動放射線への適用性を線量相互比較を通して調べた。5MeV電子加速器から得た高出力制動放射線を用いて数種の線量計をファントム中で4-12kGy照射した。線量計には、3種のアラニン線量計と3種の液体化学線量計(硫酸セリウム,重クロム酸及びエタノールクロロベンゼン)及びグルタミン線量計を用いた。制動放射線に対する線量応答については、Co-60線の校正曲線から線量値を決定した。いずれの線量計も3線量レベルの値は3%以内でよく一致し、高出力制動放射線にも応用できることが示された。

Applicability of the existing dosimetry systems to high-power Bremsstrahlung irradiation was investigated through a dose intercomparison study, where several dosimeters were irradiated in the dose range 4-12 kGy in identical polyethylene phantoms in a Bremsstrahlung beam obtained from a 5-MeV electron accelerator. Included in the study were alanine dosimeters molded by three different binders, three types of liquid dosimeters:ceric-cerous, dichromate and ethanol-chlorobenzen (ECB), and glutamine powder. The dosimeter responses for Bremsstrahlung radiation were analyzed at the issuing laboratories, and the dose values determined using calibration based on cobalt-60 -ray irradiation. Dose values for all the three dose levels for all dosimetry systems were in good agreement of better than 3%. The results of the study demonstrate that these existing dosimetry systems have a potential for application to high-power Bremsstrahlung irradiation.