Internal bremsstrahlung of $\beta$ decay of atomic ${}_{16}{}^{35}\mathrm{S}$

We calculate the energy spectra and the branching ratio of the internal bremsstrahlung (IB) of the ${\beta }^{-}$ decay of atomic ${}_{16}{}^{35}\mathrm{S}$. We show that the theoretical spectrum of the IB, calculated within the standard model and QED, fits well the experimental spectra, measured by M. S. Powar and M. Singh [J. Phys. G: Nucl. Part. Phys. 2, 43 (1976)] and by A. Singh and A. S. Dhaliwal [Appl. Radiat. Isot. 94, 44 (2014)] for the photon energy regions $0.025\le \omega \le 0.150\mathrm{MeV}$ and $0.001\le \omega \le 0.100\mathrm{MeV}$, respectively.

Figure 1

The photon energy spectrum of the QED internal bremsstrahlung for the photon energy region ${\omega }_{\min }=0.001\le \omega \le {\omega }_{\max }=E_0-m_e=0.16718\mathrm{MeV}$ with the account for the daughter ion recoil (left). The difference $\Delta S$ between the photon energy spectra, calculated with and without the daughter ion recoil (right). The theoretical curve (left) is compared with the experimental data by Powar and Singh [16], who measured the photon energy spectrum for the photon energies ${\omega }_{\min }=0.025\le \omega \le {\omega }_{\max }=0.150\mathrm{MeV}$ [black (dark) triangles], and by Singh and Dhaliwal [20], who measured the photon energy spectrum for the photon energies ${\omega }_{\min }=0.001\le \omega \le {\omega }_{\max }=0.100\mathrm{MeV}$ [green (light) triangles].