Patent Number: 
Section: claims

1. A radiation detector comprising:a photoelectric conversion substrate converting light to an electrical signal; anda scintillator layer being in contact with the photoelectric conversion substrate and converting externally incident radiation to light,the scintillator layer being made of a phosphor containing Tl as an activator in CsI, which is a halide, a concentration of the activator in the phosphor being 1.6 mass %±0.4 mass %, a concentration distribution of the activator in an in-plane direction being within ±15%, and a concentration distribution of the activator in a film thickness direction being within ±15%. 2. The radiation detector according to claim 1, wherein in the scintillator layer, the concentration distribution of the activator in the in-plane direction is ±15% or less in a region of a unit film thickness of 200 nm or less and the concentration distribution of the activator in the film thickness direction is ±15% or less in the region of the unit film thickness of 200 nm or less. 3. The radiation detector according to claim 1, wherein the scintillator layer has a columnar crystal structure. 4. A method for manufacturing a radiation detector including a photoelectric conversion substrate converting light to an electrical signal and a scintillator layer being in contact with the photoelectric conversion substrate and converting externally incident radiation to light,the scintillator layer being made of a phosphor containing Tl as an activator in CsI, which is a halide,the method comprising:forming the scintillator layer by a vapor phase growth technique using a material source of CsI and Tl, a concentration of the activator in the phosphor being 1.6 mass %±0.4 mass %, a concentration distribution of the activator in an in-plane direction being within ±15, and a concentration distribution of the activator in a film thickness direction being within ±15%. 5. A scintillator panel comprising:a support substrate transmissive to radiation; anda scintillator layer being in contact with the support substrate and converting externally incident radiation to light,the scintillator layer being made of a phosphor containing Tl as an activator in CsI, which is a halide, a concentration of the activator in the phosphor being 1.6 mass %±0.4 mass %, a concentration distribution of the activator in an in-plane direction being within ±15%, and a concentration distribution of the activator in a film thickness direction being within ±15%. 6. The scintillator panel according to claim 5, wherein in the scintillator layer, the concentration distribution of the activator in the in-plane direction is ±15% or less in a region of a unit film thickness of 200 nm or less and the concentration distribution of the activator in the film thickness direction is ±15% or less in the region of the unit film thickness of 200 nm or less. 7. The scintillator panel according to claim 5, wherein the scintillator layer has a columnar crystal structure. 8. The scintillator panel according to claim 5, wherein the support substrate is formed from a material composed primarily of a light element rather than a transition metal element. 9. A method for manufacturing a scintillator panel including a support substrate transmissive to radiation and a scintillator layer being in contact with the support substrate and converting externally incident radiation to light,the scintillator layer being made of a phosphor containing Tl as an activator in CsI, which is a halide,the method comprising:forming the scintillator layer by a vapor phase growth technique using a material source of CsI and Tl, a concentration of the activator in the phosphor is 1.6 mass %±0.4 mass %, a concentration distribution of the activator in an in-plane direction and a film thickness direction being within ±15%, and a concentration distribution of the activator in a film thickness direction being within ±15%.