Decay Scheme ofSn113

Abstract

The electron capture decay of ${\mathrm{Sn}}^{113}$ has been investigated using scintillation detectors and coincidence circuitry. Decay was found to occur to the 650- and 393-kev states of ${\mathrm{In}}^{113}$ with branching ratios of (1.8±0.1)% and (98.2±0.1)%, respectively. The 650-kev state decayed by the emission of a 255-kev gamma ray to the 393-kev state. No evidence was found for the existence of a 648-kev crossover transition. An upper limit for the intensity of this transition was placed as 0.1% of that of the 255-kev transition. The orbital electron capture ratio to the 648-kev state was determined to be $\left(\frac{P_{\mathrm{LMN}}\dots }{P_K}\right)<\mathrm{}0.19\mathrm{}$. From this value, a minimum decay energy to the 648-kev state was assigned as 150 kev. It was determined that transitions to the 393-kev state of ${\mathrm{In}}^{113}$ were first forbidden by considering $log\mathrm{ft}$ values; this is consistent with a spin and parity of ½+ or $\frac{3}{2}+$ for the ground state of ${\mathrm{Sn}}^{113}$. The 648-kev state was assigned a spin and parity of ½ or $\frac{3}{2}-$ on the basis of possible $log\mathrm{ft}$ values and the absence of the 648-kev crossover transition.