Recent progress in cryogenic techniques applied to pulsed ion beam generation and target ablation experiments

The authors are still continuing their efforts to apply cryogenic techniques to pulsed ion beam generation and target ablation experiments with such ion beams. In this article, the most recent progress and the most interesting results in this field are described. One of their experiments is to produce pulsed ion beams with a cryogenic anode diode. They used N/sub 2/O ice as the ion source to get medium mass ion beams. The anode was cooled with a cryogenic cooler. A pulsed power machine (PICA-3) at Yokohama was used to produce ion beams. The diode characteristics were measured together with the ion beam characteristics. A biased ion collector, the Thomson parabola track detector, was used to measure the time of flight of the beams and the beam energy and species. The beam divergence angle was estimated with a multi-pinhole camera with the time integrated track detector. This divergence angle was compared with the case of the light ion beams, and the future direction was discussed for the development of the medium mass pulsed ion beams as one of the ICF beam candidates. Their other experiment irradiated cryogenic targets with pulsed ion beams.