Development of a Compact Neutron Source for NTD and Measurement of Neutron Flux Distribution

Abstract

Neutron Transmutation Doping (NTD), which is one of the semiconductor manufacturing methods, can produce impurity semiconductor with high quality. The neutron source currently used in the NTD is a nuclear reactor, which has some problems such as to become too old for use. Hence development of a new neutron source, which enables uniform irradiation, is desired. A new Inertial Electrostatic Confinement (IEC) device with a coaxial double cylindrical structure, which is especially designed to be capable of uniform neutron irradiation, was developed. As the feature of the device, it has triple electrode structure which consists of a cylindrical grid cathode between inner and outer anodes. Neutrons are centralized in the center of the device, and uniform neutron flux is obtained there. The device achieved a neutron production rate of 1.5×106 n/s, and uniform neutron flux distribution was provided in the central hole of device. The largest size of the uniform neutron flux area was 35.2% (25 cm) of sample irradiation area in the axial direction, and 54.3% (10 cm) in the radial direction.