Scintillator plate, radiation detecting apparatus, and radiation detecting system

1. A scintillator plate comprising a substrate, a scintillator including a plurality of columnar crystals arranged above the substrate, a first protective film, and a second protective film,

wherein the first protective film chemically bonds to the plurality of columnar crystals in interfaces with the plurality of columnar crystals,

wherein the second protective film has a lower water vapor transmission rate than that of the first protective film,

wherein a film thickness of the second protective film is larger than that of the first protective film, and

wherein the substrate and the second protective film seal the scintillator and the first protective film.

2. The scintillator plate according to claim 1 ,

wherein a chemical bond in the interfaces between the first protective film and the plurality of columnar crystals is stable with respect to water, and includes at least one of a covalent bond, an ionic bond, a coordinate bond, a hydrogen bond, and a metallic bond.

3. The scintillator plate according to claim 1 , wherein the first protective film contains an oxide of at least one element selected from the group consisting of silicon, titanium, aluminum, and zirconium.

4. The scintillator plate according to claim 3 , wherein the at least one element chemically bonds to the plurality of columnar crystals via oxygen in the interfaces between the first protective film and the plurality of columnar crystals.

5. The scintillator plate according to claim 3 , wherein the first protective film further contains at least one selected from the group consisting of a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an acetoxy group, chlorine, bromine, and iodine, each of which is bonded to the element.

6. The scintillator plate according to claim 1 , wherein the first protective film covers at least an end portion of the scintillator, which is opposite to the substrate, and is arranged between the scintillator and the second protective film,

wherein the second protective film covers the first protective film and the scintillator, and

wherein a portion of not less than 20% of surfaces, which are not in contact with the substrate, of the plurality of columnar crystals is chemically bonded to the first protective film.

7. The scintillator plate according to claim 1 , wherein the plurality of columnar crystals include an outer-edge crystal formed on an outer edge of the scintillator in an orthographic projection to the surface of the substrate, and

wherein the first protective film entirely covers a portion of the outer-edge crystal, which does not face any of the plurality of columnar crystals.

8. The scintillator plate according to claim 1 , wherein a film thickness of the first protective film is not more than 100 nm.

9. The scintillator plate according to claim 1 , wherein an air gap is formed between side surfaces of adjacent columnar crystals, which are covered with the first protective film, of the plurality of columnar crystals.

10. The scintillator plate according to claim 1 , wherein a water vapor transmission rate at 40° C. 90% RH of the second protective film is 1 g/m 2 ·day (inclusive) to 10 g/m 2 ·day (inclusive).

11. The scintillator plate according to claim 1 , wherein the second protective film contains at least one of poly-p-xylylene, polyvinylidene chloride, silicon oxide, and aluminum oxide.

12. The scintillator plate according to claim 1 , further comprising a third protective film between the substrate and the scintillator,

wherein the third protective film includes a film made of the same material as that of the second protective film.

13. The scintillator plate according to claim 1 , wherein the second protective film entirely covers a portion of the substrate, which is not covered with the scintillator and the first protective film.

14. The scintillator plate according to claim 1 , wherein a spacing between side surfaces of adjacent columnar crystals of the plurality of columnar crystals is 200 nm (inclusive) to 1 μm (inclusive).

15. The scintillator plate according to claim 1 , wherein a thickness of each of the plurality of columnar crystals is 0.1 μm (inclusive) to 50 μm (inclusive).

16. The scintillator plate according to claim 1 , wherein the plurality of columnar crystals contain a halide compound.

17. The scintillator plate according to claim 16 , wherein the halide compound includes an alkali halide.

18. The scintillator plate according to claim 17 , wherein the alkali halide is represented by formula (1):

M1X1·αM2X2·βM3X3:γA1  (1),

where M1 represents at least one selected from the group consisting of lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs),

where M2 represents at least one selected from the group consisting of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), cadmium (Cd), copper (Cu), and nickel (Ni),

where M3 represents at least one selected from the group consisting of scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), aluminum (Al), gallium (Ga), and indium (In),

where X1, X2, and X3 each independently represents at least one selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I),

where Al represents at least one selected from the group consisting of Eu, Tb, In, bismuth (Bi), Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Gd, Lu, Sm, Y, thallium (Tl), Na, silver (Ag), Cu, and Mg, and

where α,β, and γ represent 0≤α<0.5, 0≤β<0.5, and 0<γ≤0.2.

19. A radiation detecting apparatus comprising:

a scintillator plate according to claim 1 ; and

a photoelectric conversion element configured to detect light converted from radiation by the scintillator.

20. A radiation detecting system comprising:

a radiation detecting apparatus according to claim 19 ; and

a signal processing unit configured to process a signal from the radiation detecting apparatus.