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.)
Zur Isomerie des Ir194
The 47-sec isomer of Ir194 reported by Hennies and Flammersfeld was ascribed by other workers to impurities. A repeat of the experiment using BR- 1 reactor neutrons gave results in very good agreement with Hennies and Flammersfeld. A study of the same reaction using enriched Ir191 and Ir193showed no short-lived activity other than well established ones. It was concluded that the 47-sec activity should be ascribed to Rh. It was established that the 0.05 sec Ir194m is the only isomer excited by neutron capture in the half-life period considered.
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