Effect of the insulator length on Mather-type plasma focus devices

Plasma focus devices were studied in order to identify the design parameters and logical relationships that exist among device components. A quantitative parameter has been defined as the ratio of insulator sleeve length to the radial distance between the electrodes, “Lins/(b−a)Lins/(b−a)”. It is demonstrated that the Mather-type plasma focus device, operated in the optimum regimes, has a remarkably low sensitivity to this parameter which relates the insulator length to the electrodes geometry. A modification factor for the axial velocity in different PF devices has been introduced to maintain the value of the “q” parameter within the range of zero to one.