Gamma-ray attenuator and gamma-ray shield for gamma-ray spectroscopy
The present disclosure provides a gamma-ray attenuator and a gamma-ray shield for use in gamma-ray spectroscopy. The gamma-ray attenuator is a sleeve comprising a wall, a distal end, and a proximal end. The distal end of the sleeve is closed, and the proximal end of the sleeve forms an opening. A copper insert, a tin insert and a tungsten insert are installed in the sleeve such that the copper insert is adjacent to the distal end and the tungsten insert is closest to the proximal end. The sleeve is comprised of one or more materials that do not substantially attenuate gamma-rays. The open end of the sleeve fits over a tungsten safe that is operable to hold a radionuclide sample. When fitted together, a gamma-ray attenuator and a safe comprise a gamma-ray shield.
1. A gamma-ray shield comprising:
a radiation safe comprising a wall, a distal end, a proximal end and a well, wherein the proximal end forming an opening to the well, the well extending along an axial direction of the radiation safe to the distal end of the radiation safe, and the distal end of the radiation safe being closed; and
a gamma-ray attenuator operable to receive the radiation safe, wherein the gamma-ray attenuator comprises
a sleeve having a wall, a distal end, and a proximal end, wherein the distal end being closed and the proximal end forming an opening;
a copper insert operable to be installed within the opening, wherein the copper insert has a substantially uniform thickness, measured along an axial direction of the sleeve;
a tin insert substantially abutting the copper insert on a side of the copper insert opposite the sleeve, wherein the tin insert has a substantially uniform thickness, measured along an axial direction of the sleeve;
a tungsten insert substantially abutting the tin insert, wherein the tungsten insert has a substantially uniform thickness or a thickness that is thinner at an edge than at a midpoint, measured along an axial direction of the sleeve;
wherein the copper insert, the tin insert, and the tungsten insert each have at least one through hole formed therethrough and are operable to be aligned with each other.
2. The gamma-ray shield as recited in claim 1 , wherein:
the copper insert has a thickness of about 0.9 millimeters to about 1.1 millimeters, and the through hole(s) have a total diameter of about 1 millimeter to about 2 millimeters;
the tin insert has a thickness of about 1.0 millimeter to about 1.7 millimeters, and the through hole(s) have a total diameter of about 1 millimeter to about 2 millimeters; and
the tungsten insert has a thickness of about 0.9 millimeters to about 1.1 millimeters, and the through hole(s) have a total diameter of about 1 millimeter to about 2 millimeters.
3. The gamma-ray shield as recited in claim 2 , wherein:
the copper insert has a thickness of about 0.95 millimeters to about 1.05 millimeters, and the through hole(s) have a total diameter of about 1 millimeter to about 2 millimeters;
the tin insert has a thickness of about 1.5 to about 1.6 millimeters, and the through hole(s) have a total diameter of about 1 millimeter to about 2 millimeters;
the tungsten insert has a thickness of about 0.95 to about 1.05 millimeters, and the through hole(s) have a total diameter of about 1 millimeter to about 2 millimeters.
4. The gamma-ray shield as recited in claim 2 , wherein:
the copper insert has a thickness of about 1.0 millimeter, and the through hole(s) have a total diameter of about 1 millimeter to about 2 millimeters;
the tin insert has a thickness of about 1.55 millimeters, and the through hole(s) have a total diameter of about 1 millimeter to about 2 millimeters; and
the tungsten insert has a thickness of about 1.0 millimeter, and the through hole(s) have a total diameter of about 1 millimeter to about 2 millimeters.
5. The gamma-ray shield as recited in claim 2 , wherein the through hole(s) for each insert has a total diameter of about 1.2 millimeters to about 1.6 millimeters.
6. The gamma-ray shield as recited in claim 1 , wherein the wall of the sleeve has a height of about 4 millimeters to about 16 millimeters measured in the axial direction of the sleeve and/or the wall of the sleeve has a thickness of about 0.5 millimeters to about 5.0 millimeters.
7. The gamma-ray shield as recited in claim 1 , wherein a diameter of each insert is equal to the inner diameter of the sleeve or greater than the inner diameter of the sleeve by about 0.5 millimeters.
8. The gamma-ray shield as recited in claim 1 , wherein the diameter of each insert is about 20 millimeters.
9. The gamma-ray shield as recited in claim 1 , wherein the sleeve is a rubber.
10. The gamma-ray shield as recited in claim 1 , wherein the closed distal end of the sleeve is integrally formed with the wall.
11. The gamma-ray shield as recited in claim 1 , wherein one or more of the copper insert, the tin insert, or the tungsten insert is removable from the sleeve.
12. The gamma-ray shield as recited in claim 1 , wherein the closed distal end of the radiation safe has a thickness of about 0.9 millimeters to about 1.1 millimeters.
13. The gamma-ray shield as recited in claim 12 , wherein the closed distal end of the radiation safe has an average thickness of about 0.9 millimeters.
14. The gamma-ray shield as recited in claim 12 , wherein the closed distal end of the radiation safe has a thickness, measured at the midpoint, of about 1 millimeter.
15. The gamma-ray shield as recited in claim 1 , wherein the closed distal end of the radiation safe is integrally formed with the wall of the radiation safe.
16. The gamma-ray shield as recited in claim 1 , wherein the wall of the radiation safe has a thickness of about 2 millimeters to about 3 millimeters.
17. The gamma-ray shield as recited in claim 1 , wherein the radiation safe is comprised of pure tungsten.
18. The gamma-ray shield as recited in claim 1 , wherein an inner diameter of the radiation safe is about 10 millimeters to about 20 millimeters and the wall of the radiation safe has a height, measured in the axial direction of the radiation safe, of about 30 millimeters to about 40 millimeters.
19. The gamma-ray shield as recited in claim 18 , wherein an inner diameter of the radiation safe is about 15 millimeters and the wall of the radiation safe has a height, measured in the axial direction of the radiation safe, of about 35 millimeters.
20. A system comprising:
a gamma-ray shield as recited in claim 1 ; and
a gamma spectroscopy detector;
wherein the gamma-ray shield is positioned at a distance of about 10 centimeters from the detector's surface, either measured from the distal end of the gamma-ray attenuator and the through holes of the copper, tin and tungsten inserts are aligned with the detector or measured from the distal end of the radiation safe; and
wherein the container in the well of the radiation safe comprises a composition comprising a radionuclide.