The Borexino detector is a large, low background liquid scintillator detector designed to reveal low energy (sub-MeV) neutrinos in real time. It was built with the goal of performing solar neutrinos spectroscopy and in particular to measure the 7Be neutrino flux from the Sun. The very low energy threshold requires extreme radiopurity of the detector. The extraordinary radiopurity achieved by Borexino, which has been further improved over the years, have made it possible to accomplish not only its primary goal but also to produce many other interesting results both within and beyond the Standard Model of particle physics.
A Borexino prototype, called the Counting Test Facility (CTF), has been built and operated in the Hall C of LNGS between 1994 and ’96. This (now dismantled) detector demonstrated the achievement of ultra-low count rates (radiopurities of the order of 10-16g/g of 238U equivalent) on the several-ton scale.
The Borexino detector have been built on the CTF experience. The detector have been completed on May 15, 2007. The first data acquisition (DAQ) run with the full detector have been started on May 16, 2007.
For more details please refer to these articles:
- “The Borexino detector at the Laboratori Nazionali del Gran Sasso” (detailed tech. description)
- “Why and how the Sun and the stars shine” (general description, scientific and historical notes)