We postulate that what determines neutron yield from discharges in a deuterium-filled plasma focus apparatus is the amount of energy passed from the capacitor bank to the individual deuterons participating in the pinch. We study plasma focus discharges within the framework of the snow plow model and write down an expression for the energy passed from the capacitor bank to the particles forming the pinch. Provided the shape of the plasma focus apparatus is fixed, this expression turns out to depend on only two dimensionless parameters comprising the electric and geometric features of the system altogether. We found that the energy per particle at pinching has a unique maximum value as a function of these dimensionless parameters, so that a criterion for optimizing plasma focus performance (i.e. neutron yield) results.We use the current formalism to evaluate the performance of a collection of practical plasma focus systems of various sizes and shapes. Finally, we indicate some modifications—obtained within the framework of the snow plow model—to be introduced in a number of practical systems under examination in order to improve their performance.
Development of plasma targets for interaction experiments at Tokyo Institute of Technology