Speaker
Description
Rare event search experiments require very careful simulations, in addition to accurate measurements
of ambient radiation contribution from radioactive decay and nuclear processes in the surrounding rock
components as well as from charged cosmic rays. A new underground laboratory has been set up at 555 m
(∼1.6 km water equivalent) vertical depth, with the vision of undertaking future experiments like direct dark
matter search, neutrino less double-beta decay, etc. I shall present the various measurements and simulation
of background for such underground experiments arising from penetrating charged cosmic rays, radiogenic
and cosmogenic neutrons, in addition to measurement and shielding studies of gamma background, which
in-turn shall serve as the basis of all future rare event search experiments at the underground site. I shall
also discuss about investigating the possibilities of detecting core collapse supernova (CCSN) neutrinos by
large volume liquid Xenon detectors, designed primarily for direct dark matter search. In addition to giving
rise to Coherent Elastic Neutrino Nucleus Scattering (CEνNS) interactions, CCSN neutrinos would undergo
charge current (CC) interactions with the Xenon nuclei and consequently produce neutrons inside the liquid
xenon tank. These neutrons would in turn produce nuclear recoils through multiple elastic scatterings. This
presents an extra-handle, in addition to the CEνNS interactions to detect CCSN neutrinos. I shall discuss
that careful simulation of these interactions, to finally compute the observable S1 and S2 signals, reveals
that this second channel indeed gives a dominant contribution to the total number of detected nuclear
recoil events at the high detector threshold regime. Detection of these second type of events in future large
volume detectors like LZ, DARWIN, etc., may give observational handle on the flavour composition of CCSN
neutrinos, since this second channel shall only be generated by νes while the CEνNS interactions would arise
from all flavours of neutrinos.
