γproduction and neutron inelastic scattering cross sections for76Ge

Recent cross-section measurements of neutron-induced reactions of importance for background estimates in0νββsearches

“…[5]. However, searches by [7] did not reveal the 2040.7 keV γ -ray line. Similarly, the work of Ref.…”

“…Mono-energetic neutrons are produced via the 7 Li(p,n) 7 Be, 3 H(p,n) 3 He, 2 H(d,n) 3 He, The well-established neutron activation technique is used. After irradiation, the samples and associated monitor foils needed for neutron fluence determination are γ -ray counted in TUNL's low-background counting facility with HPGe detectors of 55% and 60% relative efficiency.…”

Fast-neutron-induced potential background near theQvalue of neutrinoless double-βdecay ofGe76

“…A neutron energy spectrum obtained with a 16. 6 MeV deuteron beam striking a 3 cm long gas cell (see Fig. 3) pressurized to 6 atm of deuterium gas is shown in Fig.…”

“…However, the amount of background caused by neutron scattering and reaction processes involving 76 Ge and 74 Ge at energies E n >10 MeV is still poorly known. Recently, the Geel group [6] performed a 76 Ge(n,n γ) 76 Ge experiment to investigate the importance of the 69 th [7,8] excited state of 76 Ge at 3951.89 keV, that decays with an 8% branching ratio to the 5 th excited state in 76 Ge (located at 1911.07 keV) by emitting a 2040.70 keV γ ray, which could potentially mimic the 0νββ signal of interest. A partial level scheme of 76 Ge is shown in Fig.…”

“…1, indicating the decay of the 3951.89 keV state with its associated branching ratios. The work of the Geel group [6] was done with a white neutron beam focusing on neutron energies up to approximately 13 MeV. None of the decay γ rays of the 3951.89 keV state were positively identified, but upper limits of the cross section for the 2040.70 keV transition were given, ranging between approximately 1 and 5 mb.…”