Scintillator structure and method of evaluating scintillator
A scintillator structure includes a scintillator and a reflecting material that covers the scintillator. Here, the scintillator includes a resin and a phosphor, and a phosphor particle perimeter indicating a normalized length of an interface between the phosphor and the resin in a cross-sectional image of the scintillator is smaller than 6.25.
1. A scintillator structure comprising:
a scintillator; and
a reflecting material that covers the scintillator,
wherein the scintillator includes a resin and a phosphor, and
wherein a phosphor particle perimeter indicating a normalized length of an interface between the phosphor and the resin in a cross-sectional image of the scintillator is smaller than 6.25.
2. The scintillator structure according to claim 1 ,
wherein the phosphor particle perimeter is measured through following steps 1 to 5:
(step 1) obtaining an observation surface of a cell by a polishing machine;
(step 2) obtaining a secondary electron image of the observation surface,
(condition 1) scanning electron microscope,
(condition 2) resolution of image: 1920×1200, and
(condition 3) magnification: 500 times;
(step 3) binarizing the secondary electron image;
(step 4) correcting the binarized image; and
(step 5) calculating the phosphor particle perimeter,
(condition 4) calculation formula
phosphor particle perimeter=number of pixels of interface/pixel size×100 (μm 2 )/total area (μm 2 ),
(condition 5) viewing angle: 1.04 mm×0.65 mm, and
(condition 6) area threshold when calculating the length of the interface: 3 (μm 2 ).
3. The scintillator structure according to claim 1 ,
wherein the phosphor particle perimeter is 2.48 or more and less than 6.25.
4. The scintillator structure according to claim 1 ,
wherein a density of the scintillator is 4.3 g/cm 3 or more and 5.0 g/cm 3 or less.
5. The scintillator structure according to claim 1 ,
wherein the phosphor includes gadolinium oxysulfide containing a luminescent element.
6. The scintillator structure according to claim 5 ,
wherein the resin is an epoxy resin.
7. A method of evaluating a scintillator including a resin and a phosphor, the method comprising a step of evaluating performance of the scintillator based on a correlation between a phosphor particle perimeter indicating a normalized length of an interface between the phosphor and the resin in a cross-sectional image of the scintillator and a luminous output of the scintillator.
8. The method of evaluating the scintillator according to claim 7 ,
wherein the correlation is a negative correlation.