Radiation detector to determine a depth of interaction and method of using the same
A radiation detector can include a logic element configured to determine a depth of interaction based on a decay time corresponding to a radiation event and a constituent concentration profile of a radiation-sensing member. In another aspect, a method of detecting radiation can include determining a depth of interaction based on a decay time corresponding to a radiation event and a constituent concentration profile of a radiation-sensing member. The radiation detector and method can be useful in applications where depth of interaction is significant. The radiation-sensing member may include a variety of different materials, and is particularly well suited for alkali metal halides.
1. A radiation detector comprising:
a logic element configured to:
determine a depth of interaction based on a monotonic decay time corresponding to a radiation event and a constituent concentration profile of a first radiation-sensing member,
wherein the radiation sensing member comprises a material having a general formula of:
A y B (1-y) X:Ac, wherein:
A represents an alkali metal;
B represents an alkali metal different from A or a combination of alkali metals, wherein each alkali metal within the combination is different from A;
Ac is an activator;
X includes a halogen; and
0< y< 1.
2. The radiation detector of claim 1 , further comprising the first radiation-sensing member.
3. The radiation detector of claim 1 , wherein the logic element comprises a processor, a field programmable gate array, or an application-specific integrated circuit.
4. The radiation detector of claim 1 , further comprising a solid-state photosensor.
5. The radiation detector of claim 1 , wherein the constituent concentration changes monotonically along a length of the first radiation-sensing member.
6. A method of detecting radiation using a radiation detector, the method comprising:
determining a depth of interaction based on a decay time corresponding to a radiation event and a constituent concentration profile of a first radiation-sensing member, wherein the first radiation-sensing member comprises a material having a general formula of:
A y B (1-y) X:Ac, wherein:
A represents an alkali metal;
B represents an alkali metal different from A or a combination of alkali metals, wherein each alkali metal within the combination is different from A;
Ac is an activator;
X includes a halogen; and
0<y<1.
7. The method of claim 6 , further comprising receiving an electronic pulse corresponding to the radiation event, and determining the decay time from the electronic pulse.
8. The method of claim 7 , wherein the constituent concentration changes monotonically along a length of the first radiation-sensing member.
9. The method of claim 8 , wherein the length of the first radiation-sensing member extends from a surface closer to a radiation-receiving end of the first radiation sensing member to an opposite surface of the first radiation-sensing member closer to a photosensor.
10. The method of claim 8 , wherein the length is at least 4 mm.
11. The method of claim 8 , wherein the length is at least 11 mm.
12. The method of claim 8 , wherein the length is at least 74 mm.
13. The method of claim 8 , wherein the length is at least 101 mm.
14. The method of claim 6 , wherein A is Li, B is Na, Ac is Tl, and X is I.
15. The method of claim 6 , wherein 0<y<0.08.
16. The method of claim 6 , wherein 0<y<0.025.
17. The method of claim 6 , further comprising an array of radiation-sensing members, including the first radiation-sensing member.
18. A dual-mode radiation detector comprising:
radiation-sensing members of the dual mode detector, each having:
a radiation-receiving end and a photosensor end opposite the radiation-receiving end;
a length extending between the radiation-receiving end and the photosensor end; and
a constituent concentration gradient along the length of the radiation-sensing member; and
a photosensor optically coupled to the radiation-sensing members,
wherein the radiation detector does not have a phoswich configuration for the radiation-sensing members,
wherein the at least one of the radiation-sensing members comprises a material having a general formula of:
A y B (1-y) X:Ac, wherein:
A represents an alkali metal;
B represents an alkali metal different from A or a combination of alkali metals, wherein each alkali metal within the combination is different from A;
Ac is an activator;
X includes a halogen; and
0<y<1, and
wherein the radiation detector is configured to determine a depth of interaction based on a decay time corresponding to a radiation event and the constituent concentration gradient of the at least one of the radiation sensing members.
19. The dual-mode radiation detector of claim 18 , wherein for each radiation-receiving member, the length of the radiation-sensing member is substantially perpendicular to a surface along the radiation-receiving end of the radiation-receiving member or a surface along the photosensor end of the radiation-receiving member.