THE USE OF A RADIOACTIVE BEAM OF FISSION-PRODUCTS FOR TDPAC EXPERIMENTS

In order to use a wide variety of radioactive nuclei as probes in mate rial research, an on-line isotope separator (ISOL) for fission product s has been utilized to produce and accelerate short-lived nuclei suita ble for TDPAC experiments. The 140Cs isotope (T1/2 = 63.7 s) from ISOL has been implanted into YBaCuO compounds to investigate the hyperfine field around a Ba atom. The Ba-140-La-140 source of 3 x 10(4) decays/ s is obtained for TDPAC experiments on the 329-487 keV gamma-gamma cas cade in Ce-140. Another candidate was examined to use the 345-94 keV c ascade in the 91Rb (T1/2 = 59 s) decay. The angular correlation coeffi cients, however, unfortunately turned out to be fairly small. A tentat ive result of the g-factor measurement has been given. The details of the present method have been described with emphasis on the applicatio n to material research.