Similarity laws in turbulent focus plasma with beam-beam neutron production

Abstract

The problem of scaling plasma focus devices for increased neutron output has recently been discussed by several authors. Imshennik et al. developed a similarity theiry, proceeding from the assumption that the ratio of collision mean free path to characteristic length of the device should remain constant throughout the scaling process. In the following note, it will be shown that the constancy of the Mach number to Reynolds number ratio can be argued from a kinetic treatment of the neutron production mechanism. Furthermore, the influence of turbulent resistivity will be considered throughout the similarity considerations, and for the current an equation yielding the dip due to collaps will be employed instead of using the maximum current value.