GAMMA-RAY MEASUREMENT DEVICE AND GAMMA-RAY MEASUREMENT METHOD
Provided are a gamma-ray measurement device and a gamma-ray measurement method which perform a gamma-ray measurement of simple and inexpensive structure in a mixed field of neutrons and gamma-rays. A gamma-ray measurement device is used in a method for measuring the dose in the same place when using a lead filter and when not using the filter, and obtaining a gamma dose from a difference. The gamma-ray measurement device includes a first detector which is made up of the lead filter for shielding gamma-rays and a glass dosimeter disposed in the center of the filter, and a second detector that is made up of only the glass dosimeter.
1 . A gamma-ray measurement device comprising:
a first detector which is disposed around a radiation dosimeter that is the same as a radiation dosimeter constituting a second detector used together, and is formed of lead or lead alloy, wherein the first detector is made up of a filter in which the thickness is determined such that an attenuation of neutrons and a correction factor of gamma-rays are within an allowable range in the measurement of gamma rays.
2 . The gamma-ray measurement device according to claim 1 , wherein the thickness of the filter is 2 cm or less and 1 cm or more in terms of pure lead.
3 . The gamma-ray measurement device according to claim 1 , wherein the filter further is a substantially hollow spherical body or a substantially cylindrical body having a uniform thickness in which a glass dosimeter is disposed in a center.
4 . The gamma-ray measurement device according to claim 3 , further comprising:
a support member configured to support the glass dosimeter at a predetermined position therein.
5 . A gamma-ray measurement method comprising:
placing the first detector of the gamma-ray measurement device according to claim 1 , and the second detector made up of the same radiation dosimeter as the radiation dosimeter used in the first detector in a mixed field of neutrons and gamma-ray; and
thereafter, determining the dose of gamma-rays based on the remaining dose as the attenuation of the dose of gamma-rays, by subtracting the dose measured by the radiation dosimeter of the first detector from the dose measured by the radiation dosimeter of the second detector.
6 . The gamma-ray measurement device according to claim 2 , wherein the filter further is a substantially hollow spherical body or a substantially cylindrical body having a uniform thickness in which a glass dosimeter is disposed in a center.
7 . The gamma-ray measurement device according to claim 6 , further comprising:
a support member configured to support the glass dosimeter at a predetermined position therein.