Usage of a capillary plate as a pre-gas-amplification device for neutron Micro-Strip Gas Chamber

A capillary plate, an assembly of the fine glass-tubes, was applied as a pre-gas-amplification device for a neutron Micro-Strip Gas Chamber (MSGC) under high-gas pressure of helium-3. The authors have developed the method to evaluate the collection efficiency of the electrons between the capillary plate and MSGC at the neutron irradiation, and evaluated it as a function of the potential between them. The detector system comprised of the capillary plate and MSGC showed the collection efficiency of 17 % maximally at the tested configuration, and achieved the effective gas gain of ∼600 at the gas pressure of 3 atm with 10% mixture of ethane with helium-3. It was confirmed that the capillary plate could be used as a pre-gas-amplification device for neutron detection at a pressurized helium-3 gas.