Neutron detector using lithiated glass-scintillating particle composite

• US 7,582,880 B2
• Filed: 03/20/2003
• Issued: 09/01/2009
• Est. Priority Date: 03/20/2002
• Status: Expired due to Fees

• Current Assignee: Neutron Sciences, Inc., Oak Ridge Associated Universities, UT-Battelle LLC
• Original Assignee: Neutron Sciences, Inc.
• Inventors: Stephan, Andrew C., Im, Hee-Jung, Dai, Sheng, Wallace, Steven
• Primary Examiner(s): Porta; David P
• Assistant Examiner(s): Baker; David S
• Application Number:
  US10/393,300
• Publication Number:
  US 20030178574A1
• Time in Patent Office: 2,357 Days
• Field of Search: 250/390.01, 250/390.12, 250/370.05, 250/484.5, 250/487.1, 250/484.2, 250/483.1, 250/486.1, 250/390.11, 250/390.1, 250/484.4, 252/301.4 R, 252/646
• US Class Current: 250/390.11
• CPC Class Codes: G01T 3/06 with scintillation detectors

Abstract

A neutron detector composed of a matrix of scintillating particles imbedded in a lithiated glass is disclosed. The neutron detector detects the neutrons by absorbing the neutron in the lithium-6 isotope which has been enriched from the natural isotopic ratio to a commercial ninety five percent. The utility of the detector is optimized by suitably selecting scintillating particle sizes in the range of the alpha and the triton. Nominal particle sizes are in the range of five to twenty five microns depending upon the specific scintillating particle selected.

Claims

1. A neutron detecting material comprising:

a matrix material fabricated from a sol-gel precursor to glass having a volumetrically high loading of a neutron absorbing material, said neutron absorbing material yielding at least one of an electron, a proton, a triton, an alpha particle and a fission fragment when said neutron absorbing material absorbs a neutron; and

a scintillating material in particulate form and embedded in said matrix material to form a heterogeneous composition, said scintillating material being provided to scintillate when traversed by said at least one of an electron, a proton, a triton, an alpha particle and a fission fragment, said scintillating material being configured such that said matrix material surrounding particulates of said scintillating material is dimensioned such that charged particles emitted from said matrix material enter said scintillating material.

2. The neutron detecting material of claim 1 wherein said neutron absorbing material includes at least one element selected from the group consisting of Li-6, B-10, Gd, U-233, U-234, U-235, U-236, U-238, Np-237, Pu-239, Pu-240, Th-232 and Am-241.

3. The neutron detecting material of claim 1 wherein said neutron absorbing material is selected from the group consisting of at least silver, rhodium, gold, indium, and dysprosium.

4. The neutron detecting material of claim 1 wherein said neutron absorbing material is in particulate form, individual particles of said neutron absorbing material defining a size within the range of from approximately five microns to approximately twenty-five microns.

5. The neutron detecting material of claim 1 wherein said scintillating material is selected from the group consisting of at least cerium-activated calcium sulfide, europium-activated calcium sulfide, bismuth germanate, cerium-activated yttrium oxide, cerium-activated yttrium aluminum perovskite, cerium-activated yttrium aluminum garnet, cerium-activated lutetium oxyorthosilicate, cerium-activated yttrium silicate, europium-activated calcium fluoride, gallium-activated zinc oxide, thallium-activated cesium iodide, europium-activated lanthanum oxysulfide, manganese-lead-activated calcium silicate, europium-activated gadolinium oxysulfide, europium-activated indium borate, polystyrene doped with PPO (2,5-diphenyloxazole) as a primary flour and POPOP (1,4-bis(5-phenyloxazol-2-l) benzene) as a secondary flour.

6. The neutron detecting material of claim 5 wherein said scintillation material is in particulate form, individual particles of said neutron absorbing material defining a size within the range of from approximately five microns to approximately twenty-five microns, whereby charged particles originating within said matrix material are transmitted into and captured within said scintillation material particles.

7. The neutron detecting material of claim 1 defining a film disposed on a surface viewable by an optical emission detecting element to image neutrons.

8. The neutron detecting material of claim 1 being disposable on an optically clear disk placed in optical communication with a detector.

9. The neutron detecting material of claim 1 in communication with at least one detector element sensitive to scintillation light, whereby said detector element produces an electrical signal upon detection of scintillation light resulting from neutron absorption by said neutron absorbing material.

10. The neutron detecting material of claim 9 wherein said detector element is selected from the group consisting of a photomultiplier, a silicon photodiode, a charge coupled device, an amorphous silicon screen, a microchannel plate, a channeltron and an avalanche photodiode.

11. The neutron detecting material of claim 9 wherein a plurality of said detector elements is provided for rapidly accumulating data from a chamber utilized for observing temporal dynamics between a pulsed deuterium-tritium source of neutrons and a response recorded from said plurality of detector elements.

12. The neutron detecting material of claim 9 wherein said at least one detector element includes first and second planar arrays of optical fibers, said first array and said second array being disposed orthogonally with respect to each other, said first and second arrays being spaced apart a distance such that optical pulses within said neutron detecting material couple into at least one fiber in each of said first and second arrays, whereby a position of a neutron absorption in an x-y plane in yielded.

13. The neutron detecting material of claim 12 wherein each of said first and second arrays is defined by a plurality of spaced apart fibers, wherein space between said fibers is filled with a lithiated glass containing scintillation material.