Recent progress of intense pulsed ion-beam driven fusion studies at Nagaoka

Very tightly-focused ion beam was obtained by “Plasma Focus Diode” (PFD), yielding focusing diameter of ~360 μm, and power density of ~ 0.1 TW/cm² at the beam energy of ~1.5 MeV. Enhanced energy deposition was observed in the interaction with aluminium target with the enhancement ratio of ~1.5. In comparison of the experimental data with 1-D hydrocode simulation, good agreement is obtained between them. Versatile inductive voltage adder, "VIVA-I", has been successfully developed, which has the pulse-power output of 4 MV, 80 kA, 65 ns. Furthermore, systematic studies are carried out on high frequency response of various saturable cores (ferrite and amorphous) for applications to pulse-power technology. Cylindrical, magnetically insulated ion diode was sucessfully developed, which has the actual cathode rather than virtual cathode to stabilize electric field. Highly repetitive, discharge-pumped, XeCl excimer laser is developed with subsonic gas flow by using Ludwieg charge tube. Time-resolved spectroscopic measurement is developed on anode plasma of several ion diodes as well as target plasma.