US Patent No. 9,190,250

RADIATION MEASUREMENT APPARATUS


Patent No. 9,190,250
Issue Date November 17, 2015
Title Radiation Measurement Apparatus
Inventorship Toshiaki Takeuchi, Saitama (JP)
Kozo Ono, Saitama (JP)
Kuichi Kubo, Saitama (JP)
Kunio Hamaguchi, Saitama (JP)
Assignee NIHON DEMPA KOGYO CO., LTD, Tokyo (JP)

Claim of US Patent No. 9,190,250

1. A radiation measurement apparatus for measuring radiation emitted from a sample, comprising:
a first Geiger-Muller counter tube that seals an electrode within a circular pipe-shaped enclosing tube, the enclosing tube
extending in a straight line, the first Geiger-Muller counter tube being arranged along a first direction;

a second Geiger-Muller counter tube that seals an electrode within a circular pipe-shaped enclosing tube, the enclosing tube
extending in a straight line, the second Geiger-Muller counter tube being arranged in a second direction intersecting with
the first direction;

a radiation-direction calculating unit configured to compare a first detection signal and a second detection signal with one
another to calculate a direction of radiation to be emitted from the sample, the first detection signal being output from
the electrode of the first Geiger-Muller counter tube, the second detection signal being output from the electrode of the
second Geiger-Muller counter tube;

a third Geiger-Muller counter tube that seals an electrode within a circular pipe-shaped enclosing tube, the enclosing tube
extending in a straight line, the third Geiger-Muller counter tube being arranged along a third direction perpendicular to
the first direction and the second direction, wherein the radiation-direction calculating unit is configured to compare a
third detection signal, the first detection signal, and the second detection signal with one another, the third detection
signal being output from the electrode of the third Geiger-Muller counter tube;

a fourth Geiger-Muller counter tube that seals an electrode within an enclosing tube, one of an inside of the enclosing tube
and an outside of the enclosing tube being covered with a metal film, the metal film shielding beta ray; and

a computing unit,
wherein the first Geiger-Muller counter tube and the second Geiger-Muller counter tube are each configured to detect beta
ray and gamma ray to be emitted from the sample,

the fourth Geiger-Muller counter tube is configured to detect the gamma ray to be emitted from the sample, and
the computing unit is configured to compute respective amounts of the beta ray and the gamma ray based on the first detection
signal, the second detection signal, and a fourth detection signal, the fourth detection signal being output from the electrode
of the fourth Geiger-Muller counter tube.