Measurement of the ${}^{76}\mathrm{Ge}(n,\gamma )$ cross section at the n_TOF facility at CERN

The ${}^{76}\mathrm{Ge}(n,\gamma )$ reaction has been measured at the n_TOF facility at CERN via the time-of-flight technique. Neutron capture cross sections on ${}^{76}\mathrm{Ge}$ are of interest to a variety of low-background experiments, such as neutrinoless double $\beta$ decay searches, and to nuclear astrophysics. We have determined resonance capture kernels up to 52 keV neutron energy and used the new data to calculate Maxwellian-averaged neutron capture cross sections for $k_{\mathrm{B}}T$ values of 5 to 100 keV.

Figure 1

Nucleosynthesis path of the $s$ process going along the stability valley. Solid boxes represent stable isotopes. Neutron captures are marked by purple lines and $\beta$ decays by green (${\beta }^{-}$) and red (${\beta }^{+}$) lines. There is only a marginal reaction flow to ${}^{76}\mathrm{Ge}$ via ${}^{75}\mathrm{Ge}(n,\gamma )$.

Figure 2

Plot of the weighted ${}^{76}\mathrm{Ge}$ spectrum compared with empty sample holder and ambient background.

Figure 3

(a)–(c) Examples for some sammy fits of the experimental capture yield.

Figure 4

${}^{76}\mathrm{Ge}$ neutron capture cross section reconstructed from sammy resonance fits in this work compared with ENDF/B-VIII [14].