Patent Number: 
Section: claims

1. A neutron beam transmission adjusting device, comprising:a neutron beam transmission unit that comprises a neutron reactant and is capable of modulating at least any one selected from the group consisting of an energy and a flux of a neutron beam transmitted through the neutron beam transmission unit,wherein the neutron beam transmission unit contains a hydrogel containing water, a polymer, and a mineral. 2. The neutron beam transmission adjusting device according to claim 1,wherein the neutron beam transmission adjusting device is used, with the neutron beam transmission adjusting device disposed between a source of the neutron beam and an irradiation target to be irradiated with the neutron beam on a path of the neutron beam, andwherein the neutron beam transmission unit is configured to perform a modulation in an accordance with a lesion site condition of the irradiation target. 3. The neutron beam transmission adjusting device according to claim 2,wherein the neutron beam transmission unit has a shape conforming to a surface of the irradiation target. 4. The neutron beam transmission adjusting device according to claim 1,wherein the neutron reactant contains at least any one selected from the group consisting of a boron atom, a lithium atom, and a gadolinium atom. 5. The neutron beam transmission adjusting device according to claim 1,wherein the neutron beam transmission unit has a thickness distribution. 6. The neutron beam transmission adjusting device according to claim 1,wherein the neutron beam transmission unit has a concentration distribution of the neutron reactant. 7. The neutron beam transmission adjusting device according to claim 1,wherein the neutron beam transmission unit is deformable. 8. A neutron beam adjusting method, comprising:when irradiating an irradiation target of a neutron beam from a source of the neutron beam with the neutron beam, disposing the neutron beam transmission adjusting device according to claim 1 between the source of the neutron beam and the irradiation target of the neutron beam on a path of the neutron beam. 9. The neutron beam adjusting method according to claim 8, further comprising:performing a modulation with the neutron beam transmission adjusting device in an accordance with a condition of the irradiation target of the neutron beam. 10. A method for producing a neutron beam transmission adjusting device, the method comprising:producing a neutron beam transmission adjusting device according to claim 1 using a three-dimensional object producing apparatus. 11. The method for producing a neutron beam transmission adjusting device according to claim 10,wherein the three-dimensional object producing apparatus is a material jetting type. 12. The method for producing a neutron beam transmission adjusting device according to claim 10,wherein producing the neutron beam transmission adjusting device using the three-dimensional object producing apparatus comprising producing the neutron beam transmission adjusting device based on object formation data corresponding to a lesion site condition of an irradiation target to be irradiated with a neutron beam. 13. The method for producing a neutron beam transmission adjusting device according to claim 12, further comprising:controlling a thickness distribution of the neutron beam transmission unit based on the object formation data. 14. The method for producing a neutron beam transmission adjusting device according to claim 12, further comprising:controlling a concentration distribution of the neutron reactant in the neutron beam transmission unit based on the object formation data. 15. A cancer treating method, comprising:using a neutron beam transmission adjusting device according to claim 1. 16. The cancer treating method according to claim 15, further comprising:when irradiating an irradiation target of a neutron beam from a source of the neutron beam with the neutron beam, disposing the neutron beam transmission adjusting device between the source of the neutron beam and the irradiation target of the neutron beam on a path of the neutron beam. 17. The cancer treating method according to claim 15, further comprising:performing a modulation using the neutron beam transmission adjusting device in an accordance with a lesion site condition of the irradiation target of the neutron beam.