Fabrication of neutron-converter-coated GEM for thermal neutron measurement

Since the introduction of GEM (gas electron multiplier) in 1996, it has been developed in many application areas. One of the interesting application areas is the thermal neutron measurement. Neutron converting materials such as Gd, ¹⁰B, or ⁶Li are coated, and the charged ions, which are produced from the neutron interactions in the converting material, can be measured with GEM. One of the good points to measure neutron with GEM is that GEM can be used in high neutron flux. ¹⁰B is widely used as the neutron converting material. However, it is difficult to produce the stable ¹⁰B converter foil. We use two methods to fabricate the stable B foil to measure the thermal neutron with GEM. One is to make the ¹⁰B foil with ¹⁰B compound, and the other is to produce a segmented B foil. The neutron converting foils are fabricated with two methods, and they are used for the neutron measurement.