Evaluation of the effect of anode groove pitch to ion beam focusibility on spherical plasma focus diode

To evaluate the effect of anode plasma ununiformity on LIB focusibility, we have developed a new PIC simulation code. Inducing anode grooves in the code, we have represented the anode plasma ununiformity. On the experiment conditions, groove pitch ∼ 2.2 mm and groove width= 1.0 mm, simulation results is in good agreement with the those of the experiments. At the groove pitch= 2.4 mm, local divergence was very small, although focus length was very long. Therefore, we have recognized that the focusibility of SPFD would be determined by the z-deflection angle rather than the local divergence angle. To get higher power density on focus point, it may be effective to modify the anode curvature.