Scintillator, scintillator panel, radiation detector and method of manufacturing scintillator
According to one embodiment, a scintillator includes a first layer provided on a surface of a substrate and including thallium activated cesium iodide; and a second layer provided on the first layer and including thallium activated cesium iodide. The second layer includes crystals having a [001] orientation partially diverted from a direction perpendicular to the surface of the substrate. Half width at half maximum of a frequency distribution curve of an angle between the direction perpendicular to the surface of the substrate and the [001] orientation, which is obtained by measuring the angle using EBSD method, is 2.4 degree or less.
1. A scintillator, comprising:
a first layer provided on a surface of a substrate and including thallium activated cesium iodide; and
a second layer provided on the first layer and including thallium activated cesium iodide, the second layer including crystals having a [001] orientation partially diverted from a direction perpendicular to the surface of the substrate,
wherein half width at half maximum of a frequency distribution curve of an angle between the direction perpendicular to the surface of the substrate and the [001] orientation, which is obtained by measuring the angle using EBSD method, is 2.4 degree or less.
2. The scintillator according to claim 1 , wherein a thallium concentration in the first layer is higher than a thallium concentration in the second layer.
3. The scintillator according to claim 1 , wherein a thallium concentration in the first layer is 3 wt % or less.
4. The scintillator according to claim 1 , wherein a thallium concentration in the first layer is 2 wt % or less.
5. The scintillator according to claim 1 , wherein a thallium concentration in the first layer is 1.5 wt % or less.
6. The scintillator according to claim 1 , wherein the first layer has a thickness of 3 μm or less.
7. The scintillator according to claim 1 , wherein the second layer includes a plurality of columnar crystals.
8. A scintillator panel, comprising:
a substrate being transmissive for radiation; and
a scintillator provided on the substrate,
wherein:
the scintillator comprises:
a first layer provided on a surface of the substrate and including thallium activated cesium iodide, and
a second layer provided on the first layer and including thallium activated cesium iodide, the second layer including crystals having a [001] orientation partially diverted from a direction perpendicular to the surface of the substrate; and
half width at half maximum of a frequency distribution curve of an angle between the direction perpendicular to the surface of the substrate and the [001] orientation, which is obtained by measuring the angle using EBSD method, is 2.4 degree or less.
9. The scintillator panel according to claim 8 , wherein a thallium concentration in the first layer is higher than a thallium concentration in the second layer.
10. The scintillator panel according to claim 8 , wherein a thallium concentration in the first layer is 3 wt % or less.
11. The scintillator panel according to claim 8 , wherein a thallium concentration in the first layer is 2 wt % or less.
12. The scintillator panel according to claim 8 , wherein a thallium concentration in the first layer is 1.5 wt % or less.
13. The scintillator panel according to claim 8 , wherein the first layer has a thickness of 3 μm or less.
14. A radiation detector, comprising:
a substrate including a plurality of photoelectric conversion elements; and
the scintillator according to claim 1 , the scintillator being provided on a region of the substrate, and the plurality of photoelectric conversion elements being provided in the region.
15. A radiation detector, comprising:
a substrate including a plurality of photoelectric conversion elements; and
the scintillator panel according to claim 8 , the scintillator panel being provided on a region of the substrate, and the plurality of photoelectric conversion elements being provided in the region.