Pulsed discharge characteristics of spherically convergent beam fusion

Summary form only given, as follows. Previous studies of spherically convergent beam fusion (SCBF) indicate that it has a potential applicable to a portable neutron source. However, some problems remain for the practical uses. Although high neutron output needs a discharge with high voltage and current, it is difficult to get a power supply with sufficient capacity. Moreover, such a discharge leads to overheating of the cathode. Recently, pulsed SCBF has been studied in order to overcome these problems and to be applied to some applications, which require pulsed neutron output, such as landmine identification. However, the pulsed discharge of SCBF has not been studied in detail. In this study, experimental results of pulsed discharge of SCBF will be presented. An experimental device is made of 45-cm diameter, 31-cm high stainless steel cylindrical chamber, in which a spherical mesh-type anode of 30-cm diameter is installed. An open spherical grid cathode of 7-cm diameter, which is made of 1.2-mm diameter stainless steel wire, is set at the center of the spherical anode. The system is maintained at a constant pressure of 1-15 mTorr by feeding deuterium gas. An electric pulse is generated by a discharge of a capacitor charged by a power supply through a high voltage transistor switch, and is added to a dc discharge with small voltage and current powered by another power supply. Pulsed discharge characteristics were measured with changing charging voltage of capacitor, gas pressure, dc discharge current, etc.