Dense high-speed scintillator material of low afterglow
The invention relates to an inorganic scintillator material of formula Lu (2−y) Y (y−z−x) Ce x M z Si (1−v) M′ v O 5 , in which: M represents a divalent alkaline earth metal and M′ represents a trivalent metal, (z+v) being greater than or equal to 0.0001 and less than or equal to 0.2; z being greater than or equal to 0 and less than or equal to 0.2; v being greater than or equal to 0 and less than or equal to 0.2; x being greater than or equal to 0.0001 and less than 0.1; and y ranging from (x+z) to 1. In particular, this material may equip scintillation detectors for applications in industry, for the medical field (scanners) and/or for detection in oil drilling. The presence of Ca in the crystal reduces the afterglow, while stopping power for high-energy radiation remains high.
1. A method for preparing a single-crystal scintillator material comprising Lu, Si, O, and M or M′ in which M represents a divalent alkaline earth metal ion and M′ represents a trivalent metal, the method comprising:
growing the single crystal according to the Czochralski method.
2. The method according to claim 1 , wherein the single-crystal scintillator material comprises Y.
3. The method according to claim 1 , wherein M or M′ substantially reduces the afterglow.
4. The method according to claim 1 , wherein M is present and M is at least one selected from the group consisting of Ca, Mg, and Sr.
5. The method according to claim 1 , wherein M′ is present and M′ is at least one selected from the group consisting of Al, Ga, and In.
6. The method according to claim 1 , wherein M is introduced in said scintillator material for substituting for a trivalent rare-earth ion, or M′ is introduced in said scintillator material for substituting for a tetravalent silicon atom.
7. The method according to claim 1 , wherein the single-crystal scintillator material has a formula of:
Lu (2−y) Y (y−z−x) Ce x M z Si (1−v) M′ v O 5 ,
wherein:
(z+v) is greater than or equal to 0.0001 and less than or equal to 0.2;
z is greater than 0 and less than or equal to 0.2;
v is greater than or equal to 0 and less than or equal to 0.2;
x is greater than or equal to 0.0001 and less than 0.1; and
y is from (x+z) to 1.
8. The method according to claim 7 , wherein (z+v) is greater than or equal to 0.0002.
9. The method according to claim 7 , wherein (z+v) is less than or equal to 0.05.
10. The method according to claim 7 , wherein (z+v) is less than or equal to 0.01.
11. The method according to claim 7 , wherein (z+v) is less than 0.001.
12. The method according to claim 7 , wherein x is greater than 0.0001 and less than 0.001.
13. The method according to claim 1 , wherein an atomic ratio of a sum of M and M′ to O ranges from 0.00002 to 0.04.
14. A method, comprising:
performing a medical scan with a scintillator system comprising a scintillation detector comprising an inorganic scintillator material comprising Lu, Si, O, and M or M′ in which M represents a divalent alkaline earth metal ion and M′ represents a trivalent metal.
15. The method of claim 14 , wherein the scintillation detector is a component of a computed tomography scanner.
16. The method of claim 15 , wherein the computed tomography scanner is coupled to a positron emission tomography scanner.
17. The method of claim 14 , wherein M or M′ substantially reduces the afterglow from cerium ion emission between about 350 nm and 450 nm.
18. The method of claim 14 , wherein the scintillation material is a single-crystal material which is grown in the presence of M or M′ in the melt or the scintillation material is a single-crystal material which is grown by the Czochralski method in the presence of M or M′ in the melt.
19. The method of claim 14 , wherein the scintillator system is a continuous acquisition scintillator system.
20. The method of claim 14 , wherein the scintillator system is a positron emission tomography system having time of flight measurement and optionally emission tomography.