Ultra-sensitive in-beam gamma-ray spectroscopy for nuclear astrophysics   at LUNA
  Ultra-sensitive in-beam gamma-ray spectroscopy studies for nuclear astrophysics are performed at the LUNA (Laboratory for Underground Nuclear Astrophysics) 400 kV accelerator, deep underground in Italy's Gran Sasso laboratory. By virtue of a specially constructed passive shield, the laboratory gamma-ray background for E_\gamma < 3 MeV at LUNA has been reduced to levels comparable to those experienced in dedicated offline underground gamma-counting setups. The gamma-ray background induced by an incident alpha-beam has been studied. The data are used to evaluate the feasibility of sensitive in-beam experiments at LUNA and, by extension, at similar proposed facilities. 
A. Caciolli, L. Agostino, D. Bemmerer, R. Bonetti, C. Broggini, F.   Confortola, P. Corvisiero, H. Costantini, Z. Elekes, A....