The Laboratory for Underground Nuclear Astrophysics (LUNA) is a nuclear astrophysics experiment running at the INFN Gran Sasso National Laboratories (LNGS).
Aim of the experiment is the direct measurement of the cross sections regarding the fundamental thermonuclear fusion reactions for stellar nucleosyinthesis (below or near the Gamow peak, at a few tens of keV).
The experiment is located deep underground to reduce of few orders of magnitude the environmental background due to the contributions of the cosmic radiation.
To achieve this purpose, two high current electrostatic accelerators have been installed in the LNGS: first a 50 kV machine (LUNA I, 1992-2001) and then a 400 kV machine (LUNA II, 2000 - today). Two different beam lines are devoted to solid and gas target experiments, respectively, both equipped with high energy resolution and high efficiency radiation detectors.
The future of LUNA involves the installation of a new higher voltage machine, in the MV range. A new 3.5 MV accelerator providing high intensity hydrogen, helium and carbon beams will be devoted to the study of nuclear reactions that take place at higher temperatures.
