Low Background Physics at the Laboratori Nazionali del Gran Sasso (LNGS)

LNGS is just one of four INFN (Istituto Nazionale di Fisica Nucleare - National Institute of Nuclear Physics). It is the largest underground laboratory in the world for experiments in particle physics, particle astrophysics and nuclear astrophysics. It is used as a worldwide facility by scientists, presently ~750 in number, from 22 different countries, working on about 15 different experiments in their different phases.

LNGS is located between the towns of L'Aquila and Teramo, about 120 km from Rome, Italy.

The underground facilities are located on a side of the ten km long freeway tunnel crossing the Gran Sasso Mountain. They consist of three large experimental halls, each about 100 m long, 20 m wide, and 18 m high and service tunnels, for a total volume of about 180,000 m³.

The average 1400 m rock coverage gives a reduction factor of one million in the cosmic ray flux, moreover, the neutron flux is thousand times less than on the surface, thanks to the small Urananium and Thorium content in the dolomite rocks of the mountain.

Main research topics of interest to us include: neutrino physics with neutrinos naturally produced in Sun, searching for the MAJORANA mass in neutrinoless double beta decay, direct dark matter searches and nuclear reactions of astrophysical interest.

LNGS is the home to an ultralow background detector called NRL-1. This detector was developed by the Max Planck Institute (MPIK) under cooperative agreement with the Naval Research Laboratory (NRL). The detector and shield were assembled to operate at LNGS in Italy in 2005. Important calibrations still are needed before the detector can be considered fully functional, but the preliminary assessment of its performance show that background rate is slightly lower than its predecessor, the GEMPI-1 on which its design is based. The NRL-1 is similar in size (2.3 kg germanium) and efficiency to the GEMPI-1. Both detectors were fabricated by Canberra in Olen, Belgium, based on a design and materials chosen by MPIK.

We have the unique opportunity to access this detector - the lowest background germanium detector in the world. We will use this detector as well as those listed on the Kimballton page to perform material assay for experiments such as MAJORANA (0νββ) and DEAP/CLEAN (dark matter/solar neutrino searches).