Geiger-Muller counter tube and radiation measurement apparatus

Patent metadata

Field	Value
Publication number	US-9378935-B2
Application number	US-201414558730-A
Country	US
Kind code	B2
Filing date	Dec 3, 2014
Priority date	Dec 4, 2013
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A Geiger-Muller counter tube includes a cylindrical enclosing tube, an anode electrode, a cylindrical cathode electrode, an inert gas, and a quenching gas. The cylindrical enclosing tube has a sealed space. The anode electrode is disposed inside the space and formed in a rod shape. The cylindrical cathode electrode surrounds a peripheral area of the anode electrode inside the space to have an opening. The inert gas and the quenching gas are sealed inside the space. At least one of the anode electrode and the cathode electrode includes a plurality of electrodes inside the enclosing tube.

First claim

What is claimed is:

1. A Geiger-Muller counter tube, comprising:
a cylindrical enclosing tube, having a space which is sealed;
an anode electrode, being disposed inside the space, and the anode electrode is formed in a rod shape;
a cathode electrode in a cylindrical shape, surrounding a peripheral area of the anode electrode inside the space, and the cathode electrode having an opening; and
an inert gas and a quenching gas, being sealed inside the space, wherein
at least one of the anode electrode and the cathode electrode includes a plurality of electrodes inside the enclosing tube to at least form a first radiation detecting unit and a second radiation detecting unit; and
a shielding portion that blocks β-ray by surrounding a peripheral area of the first radiation detecting unit from the outside of the enclosing tube.

2. The Geiger-Muller counter tube according to claim 1 , further comprising:
a bead, being formed of an insulator, and a through-hole is in a center of the bead, and the anode electrode passing through the through-hole to secure the bead to the anode electrode,
wherein the bead is disposed so as to be surrounded by the cathode electrode.

3. The Geiger-Muller counter tube according to claim 1 , further comprising:
a ring, being formed of an insulator, and the ring having an inside diameter smaller than a diameter of the opening of the cathode electrode, and the ring being disposed at the opening,
wherein the anode electrode passes through the inside of the inside diameter of the ring, and
the ring prevents a direct contact between the anode electrode and the cathode electrode is prevented by using the ring.

4. The Geiger-Muller counter tube according to claim 1 , wherein
the cathode electrode is formed as a winding to surround the peripheral area of the anode electrode.

5. The Geiger-Muller counter tube according to claim 1 , wherein
the cathode electrode is formed of a metal sheet in a cylindrical shape and has a side surface through which a through-hole is formed.

6. The Geiger-Muller counter tube according to claim 1 , wherein
the anode electrode includes a first anode electrode and a second anode electrode formed on a straight line,
the cathode electrode has a central axis disposed on the straight line, and
the first anode electrode and the second anode electrode are disposed apart one another at both end sides of the cathode electrode,
the first anode electrode and the cathode electrode constitute the first radiation detecting unit for detecting radiations, and
the second anode electrode and the cathode electrode constitute the second radiation detecting unit different from the first radiation detecting unit.

7. The Geiger-Muller counter tube according to claim 1 , wherein
the cathode electrode includes a first cathode electrode and a second cathode electrode,
a central axis of the first cathode electrode and a central axis of the second cathode electrode are disposed on a straight line,
the anode electrode is disposed on the straight line, and
the first cathode electrode and the second cathode electrode are disposed apart one another at both sides of the anode electrode so as to constitute the first radiation detecting unit and the second radiation detecting unit.

8. The Geiger-Muller counter tube according to claim 1 , wherein
the anode electrode includes a first anode electrode and a second anode electrode disposed on a straight line,
the cathode electrode includes a first cathode electrode and a second cathode electrode,
a central axis of the first cathode electrode and a central axis of the second cathode electrode are disposed on the straight line,
the first anode electrode and the first cathode electrode, and the second anode electrode and the second cathode electrode are disposed apart one another so as to constitute the first radiation detecting unit and the second radiation detecting unit.

9. A radiation measurement apparatus, comprising:
the Geiger-Muller counter tube according to claim 6 ;
a first high voltage circuit; and
a second high voltage circuit,
wherein the first high voltage circuit applies a voltage to the first radiation detecting unit, and
the second high voltage circuit applies a voltage to the second radiation detecting unit.

10. A radiation measurement apparatus, comprising:
the Geiger-Muller counter tube according to claim 1 ;
a calculator that receives an output of β-ray detection amount and γ-ray detection amount from the first radiation detecting unit and the second radiation detecting unit, and the calculator performing an arithmetic mean or a difference calculation; and
a position determining unit that determines a first position and a second position, the shielding portion surrounds the first radiation detecting unit at the first position, the shielding portion not surrounding the first radiation detecting unit at the second position, wherein
when the position determining unit determines that the shielding portion is at the first position, the calculator performs a difference calculation on outputs of β-ray detection amount and γ-ray detection amount received from the first radiation detecting unit and the second radiation detecting unit, and
when the position determining unit determines that the shielding portion is at the second position, the calculator performs an arithmetic mean on outputs of β-ray detection amount and γ-ray detection amount received from the first radiation detecting unit and the second radiation detecting unit.

11. A radiation measurement apparatus, comprising:
the Geiger-Muller counter tube according to claim 1 ; and
a calculator that receives outputs of β-ray detection amount and γ-ray detection amount from the first radiation detecting unit and the second radiation detecting unit to perform a difference calculation.

12. A radiation measurement apparatus, comprising:
the Geiger-Muller counter tube according to claim 1 ;
one single high voltage circuit unit that applies a predetermined high voltage between the anode electrode and the cathode electrode;
a counter, being connected to the high voltage circuit unit, and the counter counting pulse signals measured by the Geiger-Muller counter tube; and
a calculator that converts the pulse signal counted by the counter into a radiation dose.

Assignees

• Nihon Dempa Kogyo Co

Inventors

• Takeuchi Toshiaki
• Hamaguchi Kunio
• Kubo Kuichi
• Ono Kozo
• Kimura Noritoshi
• Fukushima Takaharu

Classifications

• H01J47/08 Primary

  Geiger-Müller counter tubes {(gas filling with very short deionisation times H01J17/64, H01T)} · CPC title

• G01T1/18

  with counting-tube arrangements, e.g. with Geiger counters (tubes H01J47/08; {with alarm provision G01T7/125}) · CPC title