Seminari INFN

The Borexino detector and the Po210 saga

by Nicola Rossi (INFN Roma)

Europe/Rome
Aula Conversi (Dipartimento di Fisica - Ed. G.Marconi)

Aula Conversi

Dipartimento di Fisica - Ed. G.Marconi

Description
According to astrophysical models, the CNO cycle is responsible of ~1% of the luminosity emitted by the Sun. The existence of this process can be proven by the detection of the neutrino flux associated to its specific nuclear reactions. Furthermore, a precision measurement of these neutrino interaction rates can solve the so-called solar abundance problem. Since May 2015, the Borexino experiment, located at LNGS (INFN) , has been improving its sensitivity to CNO neutrinos through a challenging campaign of thermal insulation and background stabilization. The basic idea of this attempt is to constrain independently the 210Bi (the most important background for such a search) to the value inferred by the 210Po rate, as they are chained to the long lived 210Pb parent. The systematic study of the space time evolution of the 210Po activity has given us a lot of interesting and unexpected lessons.