Patent Number: 
Section: claims

1. A radiation detector, comprising:radiation detection element arrays in which a plurality of radiation detection elements detecting a radiation generated from a radiation source are arranged in a first direction and a second direction orthogonal to the first direction;collimator plates that are arranged along the first direction on the radiation source side of the radiation detection element arrays to remove scattered radiations; andcollimator plate support members that have grooves supporting the collimator plate and are arranged along the second direction between the radiation detection elements;wherein a width between radiation detection elements where the collimator plate support members are arranged is wider than a width between radiation detection elements where the collimator plate support members are not arranged. 2. The radiation detector according to claim 1,wherein there are even numbers of the collimator plate support members, and they are provided in symmetric positions on the basis of the central position in the first direction. 3. The radiation detector according to claim 1,wherein the radiation detection elements are composed of scintillator elements for generating a visible light when a radiation is incident as well as light detection elements for outputting an electrical signal when the visible light is incident,reflectors for reflecting the visible light are provided between the scintillator elements, andthe collimator plate support members are composed of the same material as the reflectors. 4. An X-ray CT apparatus, comprising:the radiation source; the radiation detector according to claim 1, that is disposed opposite to the radiation source to detect a radiation transmitted through an object; a rotating disk that is equipped with the radiation source and the radiation detector and rotating around the object; and image reconstruction device for reconstructing a tomographic image of the object based on a transmitted radiation amount detected by the radiation detector from multiple angles; and an image display device for displaying the tomographic image reconstructed by the image reconstruction device. 5. The X-ray CT apparatus according to claim 4,wherein the X-ray CT apparatus has a predetermined maximum slice thickness for image reconstruction, and wherein a position where collimator plate support members of the radiation detector are arranged is a joint position of the maximum slice thickness. 6. The radiation detector according to claim 1,wherein the collimator plate support members include an epoxy resin.