CsI(T1) scintillator crystal including antiomy and other multi valance cations to reduce afterglow, and a radiation detection apparatus including the scintillation crystal
A scintillation crystal can include a cesium halide that is co-doped with thallium and another element. In an embodiment, the scintillation crystal can include CsX:Tl, Me, where X represents a halogen, and Me represents a Group 5A element. In a particular embodiment, the scintillation crystal may have a cesium iodide host material, a first dopant including a thallium cation, and a second dopant including an antimony cation.
1. A scintillator crystal comprising:
a cesium iodide host material;
a first dopant comprising thallium;
a second dopant comprising antimony, wherein the scintillator crystal comprises between 1×10 −7 mol % and 1×10 −2 mol % antimony; and
a third dopant comprising bismuth, wherein the scintillator crystal has a reduced afterglow.
2. The scintillator crystal of claim 1 , wherein a molar concentration of the first dopant is less than 10%.
3. The scintillator crystal of claim 1 , wherein the second dopant comprises trivalent antimony.
4. The scintillator crystal of claim 1 , wherein the scintillator crystal comprises less than 1×10 −3 mol % antimony and wherein the scintillator crystal has a light output intensity of less than 0.4% at 100 ms after exposure to an X-ray irradiation, relative to a light output intensity measured during the X-ray irradiation.
5. The scintillator crystal of claim 1 , wherein the scintillator crystal comprises less than 1×10 −3 mol % antimony and wherein the scintillator crystal has a light output intensity of less than 0.3% at 500 ms after exposure to an X-ray irradiation, relative to a light output intensity measured during the X-ray irradiation.
6. The scintillator crystal of claim 1 , wherein the scintillator crystal contains more than 1×10 −6 mol % of a second codopant capable of existing in more than one oxidation state within the crystal matrix.
7. The scintillator crystal of claim 1 , wherein a concentration of the second dopant in the scintillator crystal is greater than zero and no greater than 0.003 mol %.
8. The scintillator crystal of claim 1 , wherein the second dopant comprises pentavalent antimony and the third dopant comprises pentavalent bismuth.
9. A scintillator crystal comprising:
a cesium iodide host material;
a first dopant comprising thallium;
a second dopant comprising a group VA element, wherein the scintillator crystal comprises no greater than 0.1 mol %; of the second dopant; and
a third dopant comprising bismuth.
10. The scintillator crystal of claim 9 , wherein the group VA element is at least partially in its 3+ oxidation state.
11. The scintillator crystal of claim 9 , wherein the second dopant comprises pentavalent antimony.
12. The scintillator crystal of claim 9 , wherein the scintillator crystal comprises at least 3×10 −4 mol % antimony.
13. The scintillator crystal of claim 9 , wherein the scintillator crystal comprises less than 1×10 −3 mol % antimony and wherein the scintillator crystal has a light output intensity of less than 0.5% at 100 ms after exposure to an X-ray irradiation, relative to a light output intensity measured during the X-ray irradiation.
14. The scintillator crystal of claim 9 , wherein the scintillator crystal comprises less than 1×10 −3 mol % antimony and wherein the scintillator crystal has a light output intensity of less than 0.2% at 500 ms after exposure to an X-ray irradiation, relative to a light output intensity measured during the X-ray irradiation.
15. The scintillator crystal of claim 9 , wherein the scintillator crystal contains more than 1×10 −6 mol % of the second co-dopant capable of existing in more than one oxidation state within the crystal matrix.
16. The scintillator crystal of claim 9 , wherein the scintillator crystal comprises no greater than 0.003 mol % of the second dopant.
17. A scintillator crystal formed by a growth process, comprising:
providing a cesium iodide host material;
doping with thallium, wherein a molar concentration of said thallium is less than 10%;
codoping with antimony, wherein a concentration of the second dopant in the melt is greater than zero and no greater than 0.01 mol %; and
codoping with bismuth to produce a scintillator crystal with a reduced afterglow.
18. The scintillator crystal formed by the growth process of claim 17 , wherein the growth process is a Bridgman growth process.
19. The scintillator crystal formed by the growth process of claim 17 , wherein the formed scintillator crystal comprises between 1×10 −7 mol % and 1×10 −2 mol % antimony.
20. The scintillator crystal formed by the growth process of claim 17 , wherein the formed scintillator crystal comprises no greater than 0.003 mol % antimony.