Fabrication of a scintillator material of elpasolite type
The present disclosure relates to a process for fabricating a crystalline scintillator material with a structure of elpasolite type of theoretical composition A 2 BC (1-y) M y X (6-y) wherein: A is chosen from among Cs, Rb, K, Na, B is chosen from among Li, K, Na, C is chosen from among the rare earths, Al, Ga, M is chosen from among the alkaline earths, X is chosen from among F, Cl, Br, I, y representing the atomic fraction of substitution of C by M and being in the range extending from 0 to 0.05, comprising its crystallization by cooling from a melt bath comprising r moles of A and s moles of B, the melt bath in contact with the material containing A and B in such a way that 2s/r is above 1. The process shows an improved fabrication yield. Moreover, the crystals obtained can have compositions closer to stoichiometry and have improved scintillation properties.
1. A detector, comprising a scintillator including a crystalline scintillator material, wherein the crystalline scintillator material includes a compound A a B b C c M m X x , wherein:
A comprises Cs, Rb, K, Na, or a combination thereof;
B comprises Li, K, or Na, A being different from B;
C comprises a rare earth element, Al, or Ga;
M comprises an alkaline earth element; and
X comprises a halogen,
a, b, c, m, and x represent respective atomic fractions of A, B, C, M, and X, and a sum of a, b, c, and m is 4,
1.7≤a≤2.3;
0.8≤b≤1.2;
0.85≤c≤1.1;
0≤m≤0.05;
5.05≤x≤6.9;
a 2b/a ratio is in a range from 0.97 to 1.4.
2. The detector of claim 1 , wherein m>0, and wherein M includes Ca, Mg, Sr, Ba, or a combination thereof.
3. The detector of claim 1 , wherein C comprises at least one activating rare earth element including Ce, Pr, Eu, Tb, or Nd, wherein a ratio of an atomic fraction of the at least one activating rare earth element to a sum of c and m is above 0.00001 and below or equal to 0.1.
4. The detector of claim 1 , wherein B comprises Li.
5. The detector of claim 1 , wherein B is Li.
6. The detector of claim 1 , wherein A comprises Cs, B comprises Li, and X comprises Cl or Br.
7. The detector of claim 1 , wherein A comprises Cs, B comprises Li, C comprises La, and X comprises Br.
8. The detector of claim 1 , wherein A comprises Cs, B comprises Li, C comprises Y, and X comprises Cl.
9. The detector of claim 1 , wherein A is Cs, B is Li, C is a mixture of Y and Ce, and X is Cl.
10. The detector of claim 9 , wherein m>0, and wherein M is Sr.
11. The detector of claim 1 , wherein A is Cs, B is Li, C is a mixture of La and Ce, and X includes Br, Cl, or a combination thereof.
12. The detector of claim 1 , wherein A is Cs, B is Li, C is a mixture of La and Ce, and X is Br.
13. The detector of claim 1 , wherein A is Cs, B is Li, C is a mixture of La and Ce, and X is a mixture of Br and Cl.
14. The detector of claim 1 , wherein A is Cs, B is Li, C is a mixture of La, Y, and Ce, and X is Cl.
15. The detector of claim 1 , wherein A is Cs, B is a mixture of Li and Na, C is a mixture of Y and Ce, and X is Cl.
16. The detector of claim 1 , wherein A is Cs, B is Li, C is a mixture of Y and Ce, and X is F.
17. The detector of claim 1 , wherein A is Cs, B is Li, C is a mixture of La and Ce, and X includes Br, Cl, or a combination thereof.
18. The detector of claim 1 , wherein the 2 b/a ratio is in the range from 1.1 to 1.4.
19. The detector of claim 1 , further comprising a photomultiplier tube, a photodiode, a silicon photomultiplier, or an avalanche photodiode.
20. The detector of claim 1 , wherein the crystalline scintillator material has a scintillation energy resolution below 6%, measured with a source of 137 Cs gamma rays of 12keV.