Theory of Measurement of Collision Kerma in Photon Beams with an Ionization Chamber

• Shiragai Akihiro

  Division of Physics, National Institute of Radiological Sciences

抄録

Despite the accepted limitation to the determination of exposure for photons of energies higher than a few MeV, it is shown that the collision kerma for a suitable material or the exposure is a measurable quantity which is useful to describe the high-energy photon field. These quantities are measured at a point in free space or inside a material different from air by using ionization chambers, which have small gas cavities, calibrated in terms of exposure, air kerma or absorbed dose in the cavity gas for photons of a specified quality. As for measurements of collision kerma in soft tissue, the correction factor for attenuation and scatter in the wall and buildup cap of the chamber when exposed in air to the calibration photons or user’s beams may be experimentally determined if the chamber wall and buildup cap are of tissue-equivalent materials.

収録刊行物

• Japanese Journal of Applied Physics

  Japanese Journal of Applied Physics 29 (6), 1227-1229, 1990

  社団法人応用物理学会

キーワード

• measurement of collision kerma
• measurement of exposure
• high-energy photon
• radiation dosimetry
• ionization chamber
• theoretical study

詳細情報

• CRID: 1571980077294299392
• NII論文ID: 110003901952
• NII書誌ID: AA10457675
• 本文言語コード: en
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