Decay of Cs^134m

Abstract

The decay of the isomeric state of Cs¹³⁴ was studied. The decay half-timeT _1/2=2·93±0·05 hours was determined. From measurements carried out by means of a spectrometer with short lens, scintillation measurements and chemical separations, the non-existence of the weak decayβ of this state was proved, contrary to statements found previously in the literature (maximum possible intensity 0·02%, compared to the value of ∼1% found in the literature). The spectrum of conversion electrons was measured by a double-focusing spectrometer, and the following transition energies were determined: 127·3±0·3 keV (E3) and 138·4±0·4 keV (M4) (K:L:M+N is 92 ∶ 100 ∶ 27 for the 127·3 keV transition, and 206 ∶ 100 ∶ 31 for the 138·4 keV transition). The conversion coefficient of the 127 keV transition was measured, resulting in a value ofα _k =2·55±±0·4. The ratio of transition intensities isI ₁₃₈ ∶I ₁₂₇=5·7 ∶ 1000.