Transport and Extraction of Radioactive Ions in Superfluid Helium

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Described here are experiments on the transport under electric field and the extraction of impurities from the surface of superfluid helium. As impurities we introduced radioactive heavy ions into helium. We established an experimental method of production, transport and extraction of ions in superfluid helium by using radiation detection method. With this method we tackled with determination of extraction probability, its dependence on temperature and barrier height at the interface of liquid-vapour phases.The improvements realised were ; 1.extraction potential barrier for the positive ions has been determined for the first time and this is almost equivalent for the extraction of electrons. 2.The snowball production rate at the 215Po source has been improved by applying higher electric field on the surface of the source. 3.The extraction has become more effective by using pulsed second sound for raising locally and instantaneously the surface temperature. We attained the precise determination of probability, its temperature dependence on barrier height. Nuclear spectroscopy experiments with radioactive nuclear beams have been developed further in parallel with these.Rich variety of heavy-ion reaction products will be stopped in superfluid helium and emerge as ultra-cold (zero- energy) radioactive beams. It is expected that this novel method is applicable in the new projects planned in the world. The GSI Darmstadt is counted as one of such institutions.