LITHIUM-CONTAINING SCINTILLATORS FOR THERMAL NEUTRON, FAST NEUTRON, AND GAMMA DETECTION

• US 20150028217A1
• Filed: 04/15/2014
• Published: 01/29/2015
• Est. Priority Date: 07/26/2013
• Status: Active Grant

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Inventors: Zaitseva, Natalia P., Carman, M. Leslie, Faust, Michelle A., Glenn, Andrew M., Martinez, H. Paul, Payne, Stephen A.
• Granted Patent: US 9,274,237 B2
• Time in Patent Office: Days
• US Class Current: 250/361.R
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1011 Condensed systems
• CPC Class Codes: C09K 2211/1018 Heterocyclic compounds
• CPC Class Codes: G01T 1/2042 Composition for liquid scintillation systems
• CPC Class Codes: G01T 3/06 with scintillation detectors
• CPC Class Codes: G21K 4/00 Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens photographic processes using X-ray intensifiers G03C5/17; discharge tubes comprising luminescent screens H01J1/62; cathode ray tubes for X-ray conversion with optical output H01J31/50

Abstract

In one embodiment, a scintillator includes a scintillator material; a primary fluor, and a Li-containing compound, where the Li-containing compound is soluble in the primary fluor, and where the scintillator exhibits an optical response signature for thermal neutrons that is different than an optical response signature for fast neutrons and gamma rays.

Claims

1. A thermal neutron capture reagent, comprising:

a lithium-containing compound selected from a group consisting of;

Li-3-phenylsalicylate, Li-3,5-di-tert-butylsalicylate, Li-acetylsalicylic acid, and combinations thereof,

wherein the lithium-containing compound is soluble in a fluor,

wherein the thermal neutron capture reagent exhibits an optical response signature for thermal neutrons.

2. A scintillator, comprising:

a scintillator material;

a primary fluor; and

a Li-containing compound,

wherein the Li-containing compound is soluble in the primary fluor,

wherein the scintillator exhibits an optical response signature for thermal neutrons that is different than an optical response signature for fast neutrons and gamma rays.

3. The scintillator as recited in claim 2, wherein Li-containing compound is a Li-salt of a carboxylic acid.

4. The scintillator as recited in claim 2, wherein the Li-containing compound is selected from a group consisting of:

Li-3-phenylsalicylate, Li-3,5-di-tert-butylsalicylate, Li-acetylsalicylic acid, and combinations thereof.

5. The scintillator as recited in claim 2, wherein the scintillator material is optically transparent.

6. The scintillator as recited in claim 2, wherein the primary fluor is 2,5-diphenyloxazole (PPO).

7. The scintillator as recited in claim 2, further comprising a coordinating solvent, wherein the Li-containing compound is soluble in the coordinating solvent.

8. The scintillator as recited in claim 7, wherein the coordinating solvent is selected from a group consisting of:

acetone, methanol, and dimethoxyethane.

9. The scintillator as recited in claim 2, further comprising a secondary fluor, wherein the secondary fluor has a longer wavelength than the primary fluor.

10. The scintillator as recited in claim 9, wherein the secondary fluor is present in an amount of less than 2 wt %.

11. The scintillator as recited in claim 9, wherein the secondary fluor is selected from a group consisting of:

9,10-diphenylanthracene and p-bis-(o-methylstyryl)-benzene.

12. The scintillator as recited in claim 2, wherein the scintillator material comprises a polymer matrix.

13. The scintillator as recited in claim 12, wherein the polymer matrix includes one or more aromatic groups.

14. The scintillator as recited in claim 12, wherein the polymer matrix is selected from a group consisting of:

polystyrene, polyvinyltoluene, and poly(methylmethacrylate).

15. The scintillator as recited in claim 12, wherein the polymer matrix comprises at least one of an initiator and a cross-linker.

16. The scintillator as recited in claim 2, wherein the scintillator material comprises a liquid scintillator material.

17. The scintillator as recited in claim 16, wherein the liquid scintillator material includes one or more aromatic groups.

18. The scintillator as recited in claim 16, wherein the liquid scintillator material includes a xylene-based liquid.

19. A system comprising:

the scintillator of claim 2; and

a photodetector for detecting the response of the scintillator to at least one or neutron and gamma ray irradiation.

20. A method for fabricating a scintillator, the method comprising:

forming a precursor mixture; and

heating the precursor mixture until a polymerization process is complete,

wherein the precursor mixture comprises;

a monomer;

one or more fluors;

a coordinating solvent; and

a Li-containing compound selected from a group consisting of;

Li-3-phenylsalicylate, Li—

Li-3,5-di-tert-butylsalicylate, Li-acetylsalicylic acid, and combinations thereof,

wherein the Li-containing compound is soluble in at least one of the one or more fluors.