Neutron position detector
According to one embodiment, a neutron position detector includes a gas including a 3 He gas and an additive gas. The gas has a gas composition being set so that a total of ranges of a proton and a tritium in the gas is 2.0 to 2.7 mm. The partial pressures are in an extent surrounded by a first gas composition point of the 3 He gas of 5 atm and the additive gas of 1.6 atm, a second gas composition point of the 3 He gas of 5 atm and the additive gas of 2.3 atm, a third gas composition point of the 3 He gas of 20 atm and the additive gas of 0.6 atm, and a fourth gas composition point of the 3 He gas of 20 atm and the additive gas of 1.3 atm.
1. A neutron position detector comprising:
a tubular envelope serving as a cathode;
an anode disposed on an axis in the envelope; and
a gas including a 3 He gas and an additive gas, the gas being enclosed in the envelope,
the gas having a gas composition being set so that a total of ranges of a proton and a tritium in the gas produced by a reaction of a neutron incident into the envelope and the 3 He gas is 2.0 to 2.7 mm, the partial pressures being in an extent surrounded by a first gas composition point of the partial pressure of the 3 He gas of 5 atm and the partial pressure of the additive gas of 1.6 atm, a second gas composition point of the partial pressure of the 3 He gas of 5 atm and the partial pressure of the additive gas of 2.3 atm, a third gas composition point of the partial pressure of the 3 He gas of 20 atm and the partial pressure of the additive gas of 0.6 atm, and a fourth gas composition point of the partial pressure of the 3 He gas of 20 atm and the partial pressure of the additive gas of 1.3 atm.
2. The neutron position detector according to claim 1 , wherein
the additive gas is a CF 4 gas.
3. The neutron position detector according to claim 1 , wherein
an operation voltage applied between the envelope and the anode is 2.0 to 2.5 kV.
4. The neutron position detector according to claim 3 , wherein
an output charge from the anode is 2 to 5 pC.