Ponente
Abstract
Neutron background in underground facilities is a limiting factor in many rare event experiments because of the large penetrability of neutrons and the possibility of inducing background signals in the detection system. On the other hand, ground-based characterization of background neutrons is connected with different fields such as environmental radioactivity, single event upsets (SEUs) in microelectronics, thunderstorm correlated particle bursts, cosmic-rays and space weather.
In this work, the High Efficiency Neutron Spectrometry Array (HENSA) is introduced. The HENSA detector is based on the Bonner's spheres principle. The current version of HENSA consists of an array of ten He-3 tubes, each one embedded in different materials including HDPE moderators, cadmium shieldings and lead neutron converters. The system has a sensitivity for background neutrons from thermal up to GeV’s. For ground-based measurements, the HENSA detector is able to provide near real-time estimations of the neutron background spectrum on a time scale of few hours due to the its relatively high neutron efficiency (5-10x higher than standard Bonner spheres arrays). HENSA was formerly developed for measurements of background neutrons in underground facilities. The detector has been already used for the first characterization of the neutron background in the Canfranc underground laboratory (LSC), in the context of the CUNA project, and for characterization of the Felsenkeller shallow underground laboratory in Germany. Most recently, HENSA has been upgraded and used for ground-based measurements in Barcelona city at sea level. Currently, HENSA detector is running for an improved characterization of the background at Hall A in LSC. The status and perspectives with HENSA detector are presented. The expected outcomes from the latest measurement campaigns with HENSA are discussed.
