PROBLEM TO BE SOLVED: To stabilize the detecting property of a radiation detector regardless of inclination, movement, deformation and the like of a collimator plate.SOLUTION: A radiation ray absorbing member wider than the board thickness of a collimator plate is provided on the radiation ray incoming side and the radiation ray emission side of the collimator plate. In this configuration, a path of the primary X-ray which can enter a radiation ray detecting element is determined by the position of the radiation ray absorbing member. Therefore, even if the installation accuracy of the collimator plate is low and the collimator plate moves or deforms, the path of the primary X-ray which can enter the radiation ray detecting element does not change. As a result, the detecting property of the radiation detector can be stabilized.COPYRIGHT: (C)2014,JPO&INPIT【課題】コリメータ板の傾斜・移動・変形等によらず、放射線検出器の検出特性を安定させる。【解決手段】コリメータ板の放射線入射側および放射線出射側に、コリメータ板の板厚より幅広の放射線吸収部材を設ける。このような構成によれば、放射線検出素子に入射可能な1次X線の経路が放射線吸収部材の位置によって決まる。そのため、コリメータ板の設置精度が悪かったり、コリメータ板が移動・変形したりしても、放射線検出素子に入射可能な1次X線の経路が変わらない。その結果、放射線検出器の検出特性を安定させることができる。【選択図】図12
