Borexino: A real time liquid scintillator detector for low energy solar neutrino study

TL;DR

Borexino is a highly sensitive liquid scintillator detector designed for real-time detection of low energy solar neutrinos, achieving unprecedented radiopurity levels to study the solar neutrino problem.

Contribution

This paper reviews the design, technology, and capabilities of Borexino, a novel detector enabling real-time low energy solar neutrino measurements with high radiopurity.

Findings

Achieved radiopurity levels of 10^{-16} g/g for U/Th.

Successfully detected monoenergetic $^7Be$ solar neutrinos.

Demonstrated the detector's capability for low energy neutrino studies.

Abstract

Borexino is a large unsegmented calorimeter featuring 300 tons of liquid scintillator, contained in a 8.5 meter nylon vessel, viewed by 2200 PMTs. The main goal of Borexino is the study, in real time, of low energy solar neutrinos, and in particular, the monoenergetic neutrinos coming from $^7Be$, which is one of the missing links on the solar neutrino problem. The achievement of high radiopurity level, in the order of $10^{-16} g/g$ of U/Th equivalent, necessary to the detection of the low energy component of the solar neutrino flux, was proved in the Borexino prototype: the Counting Test Facility. The detector is located underground in the Laboratori Nazionali del Gran Sasso in the center of Italy at 3500 meter water equivalent depth. In this paper the science and technology of Borexino are reviewed and its main capabilities are presented.