Hydrogels for isotopic neutron emitters and antineutrino detection and related detection systems and methods

1. A hydrogel comprising:

water, a gadolinium compound, and a scintillation compound in a polymer matrix of the hydrogel, the scintillation compound comprising:

strontium diiodide, fac-tris(2-phenylpyridine)iridium (Ir(ppy)3), a quinine compound, or combinations thereof; or

2-(4-biphenylyl)-5 phenyl-1,3,4-oxadiazole (PBD), 2-(4-tert-butylphenyl)-5-(4-phenylphenyl)-1,3,4-oxadiazole (b-PBD), 2,5-diphenyl oxazole (PPO), 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP), or combinations thereof.

2. The hydrogel of claim 1 , wherein the gadolinium compound and the scintillation compound are homogeneously dispersed in the water and the polymer matrix.

3. The hydrogel of claim 1 , wherein the gadolinium compound comprises diethylenetriaminepentaacetic acid gadolinium(III) ((Gd-DTPA).xH 2 O), gadolinium(III) nitrate (Gd(NO 3 ) 3 .6H 2 O), gadolinium(III) sulfate (Gd 2 (SO 4 ) 3 ), terbium-doped gadolinium oxysulfide (Gd 2 O 2 S:Tb 3+ ), terbium-doped gadolinium oxide (Gd 2 O 3 :Tb 3+ ), gadolinium tris-tetra-methyl-heptanedionate, or combinations thereof.

4. The hydrogel of claim 1 , wherein the scintillation compound comprises strontium diiodide and the gadolinium compound comprises Gd-DTPA.xH 2 O.

5. The hydrogel of claim 1 , wherein the scintillation compound comprises Ir(ppy) 3 and the gadolinium compound comprises Gd-DTPA.xH 2 O.

6. The hydrogel of claim 1 , wherein the scintillation compound comprises 2-(4-biphenylyl)-5 phenyl-1,3,4-oxadiazole (PBD), 2-(4-tert-butylphenyl)-5-(4-phenylphenyl)-1,3,4-oxadiazole (b-PBD), 2,5-diphenyl oxazole (PPO), 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP), or combinations thereof and the gadolinium compound comprises Gd-DTPA.xH 2 O.

7. The hydrogel of claim 1 , wherein the scintillation compound comprises 2-(4-biphenylyl)-5 phenyl-1,3,4-oxadiazole (PBD), 2-(4-tert-butylphenyl)-5-(4-phenylphenyl)-1,3,4-oxadiazole (b-PBD), 2,5-diphenyl oxazole (PPO), 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP), or combinations thereof and the gadolinium compound comprises Gd 2 O 3 :Tb 3+ .

8. The hydrogel of claim 1 , wherein:

the polymer matrix comprises polyacrylamide;

the gadolinium compound comprises diethylenetriaminepentaacetic acid gadolinium(III) or Gd 2 O 3 :Tb 3+ ; and

the scintillation compound comprises strontium diiodide homogeneously dispersed in polyacrylamide.

9. The hydrogel of claim 1 , wherein:

the polymer matrix comprises polyacrylamide;

the gadolinium compound comprises diethylenetriaminepentaacetic acid gadolinium(III) or Gd 2 O 3 :Tb 3+ ; and

the scintillation compound comprises 2-(4-biphenylyl)-5 phenyl-1,3,4-oxadiazole (PBD), 2-(4-tert-butylphenyl)-5-(4-phenylphenyl)-1,3,4-oxadiazole (butyl-PBD), 2,5-diphenyl oxazole (PPO), 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP), or combinations thereof homogeneously dispersed in polyacrylamide.

10. The hydrogel of claim 1 , wherein the hydrogel is rigid and substantially maintains its shape.

11. A detection system comprising:

an enclosure, at least one photomultiplier tube, and a hydrogel in proximity to the at least one photomultiplier tube, the hydrogel of the detection system configured to detect neutron or antineutrino radiation, the hydrogel comprising:

water, a gadolinium compound, and a scintillation compound homogeneously dispersed in a polymer matrix, the scintillation compound comprising:

strontium diiodide, fac-tris(2-phenylpyridine)iridium (Ir(ppy)3), a quinine compound, or combinations thereof; or

2-(4-biphenylyl)-5 phenyl-1,3,4-oxadiazole (PBD), 2-(4-tert-butylphenyl)-5-(4-phenylphenyl)-1,3,4-oxadiazole (b-PBD), 2,5-diphenyl oxazole (PPO), 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP), or combinations thereof.

12. The detection system of claim 11 , wherein the detection system has an active volume of about 1 m 3 or less.

13. A method of detecting radiation emitting from an article, comprising:

interacting neutrons or antineutrinos emitted from an article with a hydrogel of a detection system, the hydrogel comprising:

water, a gadolinium compound, and a scintillation compound homogeneously dispersed in a polymer matrix, the scintillation compound comprising:

strontium diiodide, fac-tris(2-phenylpyridine)iridium (Ir(ppy) 3 ), a quinine compound, or combinations thereof; or

2-(4-biphenylyl)-5 phenyl-1,3,4-oxadiazole (PBD), 2-(4-tert-butylphenyl)-5-(4-phenylphenyl)-1,3,4-oxadiazole (b-PBD), 2,5-diphenyl oxazole (PPO), 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP), or combinations thereof; and

detecting the neutrons or antineutrinos.