Activities observed in iridium after neutron bombardment. Remarks on a paper by H. H. Hennies and A. Flammersfeld
Recently Hennies and Flanunersfeld (Naturwissenschaften, 47: 11(1960)) reported ths observation of a new 47-sec activity produced by irradiating Ir powder with slowed-down neutrons. The activity was tentatively assigned to Ir/ sup 194//sup m/. Beta activities, previously ascribed to Ir/sup 192//sup m/, were reassigned to Ir/sup 194//sup m/. A repetition of the experiment on the bombardment of Ir/sup 193/ with slow neutrons (Phys. Rev. Lettens, 3: 4S(1959)) confirmed the previous conclusions and ruled out a 47-sec period in Ir/sup 192/ or Ir/sup 19 / 4>s. It was suggested that the Hennies and Flammersfeld results may be partly ascribed to a Rh impurity and partly to the effect of fast neutrons. (J.S.R.)
77Ir194m, ein neues Kern-Isomer mit T1/2=47 sec Halbwertszeit
Spectroscopically pure Ir powder was irradiated with slow neutrons from deuteron bombardment of Be/sup 9/ at 1 Mev for 10 sec to 1 min. The beta spectrum was measured with a plastic scintillator and, after irradiation, was photographed by a pulse spectrograph. Along with the short-lived beta compenent the 19-hr Ir/sup 194/ decay to Pt/sup 194/ was observed. The new activity was assigned to Pt/sup 194m/ It is certain that the 130-kev gamma line is the unconverted isomer process to Ir/sup 194/ since this gamma quantum doesn't coincide with the beta particle. (T.R.H.)
DECAY SCHEME OF 2:1 hr $sup 178$Ta
tron branching to stable Hf/sup 178/. The methods of preparing and parifying the Ta/sup 178/are discussed, and the method of deducing the decay scheme is described. (J.R.D.)