To precisely determine BBN 6Li production, the cross-section of the nuclear reaction 2H(α, γ)6Li must be directly measured within the astrophysical energy range of 30-400 keV. This measure requires an ultra-low γ-ray background in the experimental set-up. We have realized the conditions matching these very strict requirements at LUNA, the deep underground accelerator laboratory active in the INFN Gran Sasso National Laboratory (LNGS), Italy: the γ-ray spectrometer background has been reduced down to reach unmatched low levels, comparable to the good ones experienced in dedicated off-line underground ultra low γ counting rate. We present and discuss the γ-ray background reduction reached in the HpGe spectrometer, where most of the remaining γ-ray background seen in the spectra are coming from the energetic deuterons scattered in the gas target by the α beam. Thanks to the low neutron environmental background at LUNA, the effect of this weak flux of 2-3 MeV neutrons on HpGe detectors has been studied in details and the results are presented and discussed.
Ultra-sensitive γ-ray spectroscopy set-up for investigating primordial lithium problem / Gervino, G.; Gustavino, C.; Trezzi, D.; Aliotta, M.; Anders, M.; Boeltzig, A.; Bemmerer, D.; Best, A.; Broggini, C.; Bruno, C.; Caciolli, A.; Cavanna, F.; Corvisiero, P.; Davinson, T.; Depalo, R.; Dileva, A.; Elekes, Z.; Ferraro, F.; Formicola, A.; Fülöp, Zs.; Guglielmetti, A.; Gyürky, Gy.; Imbriani, G.; Junker, M.; Menegazzo, R.; Prati, P.; Scott, D. A.; Straniero, O.; Szücs, T.. - In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION A, ACCELERATORS, SPECTROMETERS, DETECTORS AND ASSOCIATED EQUIPMENT. - ISSN 0168-9002. - 824:(2016), pp. 617-619. [10.1016/j.nima.2015.11.019]
Ultra-sensitive γ-ray spectroscopy set-up for investigating primordial lithium problem
Best, A.;Dileva, A.;Imbriani, G.;
2016
Abstract
To precisely determine BBN 6Li production, the cross-section of the nuclear reaction 2H(α, γ)6Li must be directly measured within the astrophysical energy range of 30-400 keV. This measure requires an ultra-low γ-ray background in the experimental set-up. We have realized the conditions matching these very strict requirements at LUNA, the deep underground accelerator laboratory active in the INFN Gran Sasso National Laboratory (LNGS), Italy: the γ-ray spectrometer background has been reduced down to reach unmatched low levels, comparable to the good ones experienced in dedicated off-line underground ultra low γ counting rate. We present and discuss the γ-ray background reduction reached in the HpGe spectrometer, where most of the remaining γ-ray background seen in the spectra are coming from the energetic deuterons scattered in the gas target by the α beam. Thanks to the low neutron environmental background at LUNA, the effect of this weak flux of 2-3 MeV neutrons on HpGe detectors has been studied in details and the results are presented and discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
