Optimized Design of Sub-kilo Joule Dense Plasma Focus and Measurement of Neutron Yield

Abstract

This paper specifically talks about optimized design strategy of sub-kilo Joule Dense plasma focus (PF) fusion device in a full-fledged systematic manner. Recently, there are many pulsed power groups working in design and development of various PF devices in the range of sub-kilo joule energy. Few of them are publishing with the optimized operating parameters for the maximum neutron yield. Most of them, talks about the estimation of PF parameters based on traditional high voltage break down mechanisms in vacuum, plasma pinch behavior and neutron generation, which are optimized for higher energy level (few kJ to MJ) PF devices. It has been very tricky and iterative way to achieve maximum neutron yield for a sub kJ PF device. A conceptual design strategy is presented for estimation of four critical PF tube parameters. These four parameters are: Anode radius, cathode radius, effective anode length and insulator length. This is very important to know these parameters, in advance of actual fabrication and plasma pinch experiments. A 400 J PF device is designed and operated at 20 kV with the help of above design strategy in single go. Maximum neutron yield is measured 50% higher with wide range of deuterium gas pressure (6–12 mbar) among sub kJ PF devices. A detailed design strategy, experimental pulsed power system development, neutron measurement and results are discussed.