Low Energy Neutrino Spectroscopy

The direct measurement of the low-energy flux of primary p-p neutrinos has been a goal in understanding energy generation in the Sun and neutrino properties for several decades. The very high backgrounds at low energies have precluded the use of single-signature solar neutrino detectors. A detector that employs a delayed coincidence on an 176Yb target offers the promise of being able to detect the p-p neutrinos in a real-time detector in the presence of large backgrounds. The Low Energy Neutrino Spectroscopy (LENS) collaboration is pursuing the development of a large neutrino detector employing 20-40 tons of Yb dissolved in liquid scintillator. Significant advances have been made in realizing a liquid scintillator with all of the requisite properties with the development of carboxylate scintillators. The LENS collaboration is currently developing pulse-shape analysis of the fast delayed-coincidence scintillator signal, establishing a low-background test facility at Gran Sasso to assess detector backgrounds, and developing prototype detectors. The development work and future plans for LENS will be presented.