1. Field of the Invention
The present invention relates to a scintillator, a material that emits light when excited by radiation. More particularly, the present invention relates to a scintillator crystal functionally capable of guiding light emitted from the scintillator to photodetectors. The present invention also relates to a radiation detector using a scintillator crystal.
2. Description of the Related Art
In a X-ray CT (computed tomography) apparatus to be employed in a clinical site, X-rays transmitted through a subject are received by scintillators and lights emitted from the scintillators are detected by photodetectors. The photodetectors are arranged in two-dimensional array and the scintillators are separated by partitions so as not to give rise to any crosstalk of light. The partitions are desirably formed as thin as possible from the viewpoint of not contributing the partitions to a detection of X-rays and preventing the spatial resolution of the X-ray CT apparatus from degrading.
For example, Japanese Patent Application Laid-Open No. 2008-145335 discloses a technique of forming a scintillator array by bonding together a large number of scintillator crystals by means of adhesive, subsequently etching the adhesive and filling the voids produced as a result of the etching with titanium oxide powder as partition material. According to the cited patent literature, the partitions as thin as about 1 μm can be formed.
However, while the technique disclosed in Japanese Patent Application Laid-Open No. 2008-145335 can produce thin partitions, it cannot eliminate the presence of partitions. Also, from the viewpoint of manufacturing steps, the disclosed technique requires a large number of steps including a step of cutting a scintillator and a step of bonding scintillators to form the partitions.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.