Apparatus for preparing medical radioisotopes

Patent metadata

Field	Value
Publication number	US-10867715-B2
Application number	US-201515526699-A
Country	US
Kind code	B2
Filing date	Nov 17, 2015
Priority date	Nov 17, 2014
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

Apparatus for radioisotope production includes housing, a plurality of target disks inside the housing and a curved windows positioned convex inward toward the disks. During operation, coolant flows though the housing across the disks and windows while electron beams passes through the window and the disks. The window temperature increases, rising the fastest in the middle of the window where the electron beam hits the window. A flat window would buckle because the center would deform during thermal expansion against the relatively unaffected periphery, but the curved window shape allows the window to endure high thermal and mechanical stress created by a combination of heating from the electron beam(s) and elevated pressure from coolant on the inside of the window. Such a window may be used for applications in which a pressurized coolant acts on only one side of the window.

First claim

The invention claimed is:

1. An apparatus for radioisotope production comprising:
a housing;
a target holder positioned inside the housing and configured to hold one or more targets in the housing for radioisotope production;
at least one curved window coupled to the housing and positioned adjacent to the target holder, the at least one curved window having a convex curved surface oriented facing into the housing toward the target holder, the at least one curved window operable to transmit radiation from outside the housing into the target holder for irradiation of one or more targets held by the target holder within the housing to produce a radioisotope from the one or more targets;
wherein the target holder comprises a coolant inflow portion operable to receive a coolant flowing through the housing during radioisotope production so that the coolant removes heat from one or more targets held by the target holder and so that the coolant removes heat from the at least one curved window;
wherein the target holder comprises a coolant outflow portion operable to outlet coolant from the target holder after the coolant passes over and removes heat from the one or more targets and the at least one curved window; and
wherein the at least one curved window comprises two curved windows coupled to the housing and positioned on opposite sides of the target holder, the two curved windows each having a convex curved surface oriented facing toward the target holder from opposite sides of the target holder, the two curved windows operable to transmit radiation from two different directions into the target holder for irradiation of the one or more targets from two different directions at the same time.

2. The apparatus of claim 1 , wherein the convex surface of the at least one curved window has a partially spherical curvature.

3. The apparatus of claim 1 , wherein the at least one curved window has a concave surface opposite from the convex surface.

4. The apparatus of claim 1 , wherein the housing and target holder are arranged to provide a coolant from a channel between the convex surface of the curved window and an adjacent surface of a target held by the target holder inside the housing, such that the curved window is cooled by coolant flowing over the convex surface inside the housing.

5. The apparatus of claim 1 , wherein the convex surface of the at least one curved window projects inwardly into a coolant flow path within the housing to cause increased heat transfer from the curved window to the coolant.

6. The apparatus of claim 1 , wherein the target holder is configured to hold a plurality of targets inside the target holder.

7. The apparatus of claim 6 , wherein the target holder is configured to hold a plurality of disk-shaped targets inside the target holder with the disk-shaped targets oriented substantially parallel to one another and spaced apart from one another to provide coolant flow paths between the targets.

8. The apparatus of claim 7 , wherein the target holder comprises fins configured to hold the plurality of disk-shaped targets and configured to permit coolant flow between the fins and between the targets.

9. The apparatus of claim 1 , wherein the target holder is configured to hold a plurality of packed spherical targets.

10. The apparatus of claim 1 , wherein the target holder is configured to hold a single target that comprises a plurality of coolant flow channels passing through the single target.

11. The apparatus of claim 1 , further comprising one or more targets comprising molybdenum mounted in the target holder.

12. The apparatus of claim 1 , further comprising one or more targets comprising Mo-100 mounted in the target holder.

13. The apparatus of claim 1 , further comprising a first electron beam source positioned to deliver a first electron beam at the at least one curved window, such that the first electron beam passes through the at least one curved window and then through at least one target inside the target holder.

14. The apparatus of claim 13 , further comprising a second electron beam source positioned to deliver a second electron beam at a second curved window of the apparatus, such that the second electron beam passes through the second curved window and then through the at least one target inside the target holder.

15. The apparatus of claim 1 , wherein the at least one curved window comprises an elemental metal or metal alloy.

16. The apparatus of claim 1 , wherein the at least one curved window comprise a metal alloy selected from a precipitation hardened INCONEL alloy, an alloy of aluminum and beryllium, steel, a refractory metal alloy, an alloy of molybdenum and rhenium, an austenitic alloy, a martensitic-ferritic alloy, and an alloy of titanium and zirconium and molybdenum (TZM).

17. The apparatus of claim 1 , wherein the at least one curved window comprises elemental aluminum.

18. The apparatus of claim 1 , further comprising a cooling system coupled to the housing and configured to conduct coolant through the housing and the target holder.

19. The apparatus of claim 18 , wherein the coolant comprises helium gas.

20. An apparatus for radioisotope production comprising:
a housing;
a target holder positioned inside the housing and configured to hold one or more targets in the housing for radioisotope production;
at least one curved window coupled to the housing and positioned adjacent to the target holder, the at least one curved window having a convex curved surface oriented facing into the housing toward the target holder, the at least one curved window operable to transmit radiation from outside the housing into the target holder for irradiation of one or more targets held by the target holder within the housing to produce a radioisotope from the one or more targets;
wherein the target holder comprises a coolant inflow portion operable to receive a coolant flowing through the housing during radioisotope production so that the coolant removes heat from one or more targets held by the target holder and so that the coolant removes heat from the at least one curved window; and
wherein the target holder comprises a coolant outflow portion operable to outlet coolant from the target holder after the coolant passes over and removes heat from the one or more targets and the at least one curved window;
the apparatus further comprising a first electron beam source positioned to deliver a first electron beam at the at least one curved window, such that the first electron beam passes through the at least one curved window and then through at least one target inside the target holder; and
the apparatus further comprising a second electron beam source positioned to deliver a second electron beam at a second curved window of the apparatus, such that the second electron beam passes through the second curved window and then through the at least one target inside the target holder.

Assignees

• Los Alamos Nat Security Llc
• Triad Nat Security Llc

Inventors

• Woloshun Keith A
• Olivas Eric R
• Dale Gregory E

Classifications

• G21G1/10 Primary

  by bombardment with electrically charged particles (irradiation devices G21K5/00) · CPC title

• H05H2006/002

  Windows · CPC title

• G21K5/08

  Holders for targets or for other objects to be irradiated · CPC title

• H05H6/00

  Targets for producing nuclear reactions (supports for targets or objects to be irradiated G21K5/08 {; preparation of tritium C01B4/00; targets, e.g. pellets for fusion reactions by laser or charged particles beam injection H05H1/22}) · CPC title

• G21G1/001 Primary

  Recovery of specific isotopes from irradiated targets · CPC title