IFIC experimental seminar: "Neutron spectrometry with HENSA: from underground physics to space weather applications"

por Dr. Ariel Tarifeno Saldivia (IFIC)

lunes 4 abr. 2022 12:00 → 13:00 Europe/Madrid

1001-Primera-1-1-1 - Paterna. Seminario (Universe)

In underground facilities neutrons are produced from nuclear reactions induced by the intrinsic radioactivity of the materials in the rock and cavity walls. These radiogenic neutrons constitute a background which is a limiting factor for low counting rate experiments in astrophysics, dark matter and neutrino searches. Therefore, a proper characterization of the spectral distribution of radiogenic neutrons is required in order to properly assess or mitigate the neutron background component affecting experiments in underground facilities. On the other hand, neutrons are produced continuously as a secondary radiation from cosmic-ray interactions in the upper atmosphere of our planet. This component is the main contribution to the ambient neutron background observed at ground level or high altitudes. The measurement of cosmic-ray neutrons is connected with different fields such as environmental radioactivity, single event upsets (SEUs) in microelectronics, the physics of cosmic-rays and space weather.

In this seminar the High Efficiency Neutron Spectrometry Array (HENSA) will be presented. HENSA is a state-of-the-art detection system for neutron background spectrometry in low radioactivity facilities, such as underground laboratories, and for the measurement of secondary neutrons produced by cosmic-rays. The HENSA spectrometer has a spectral sensitivity 5-15 times larger than conventional spectrometers in a wide neutron energy range spanning from thermal up to GeV’s. For cosmic-ray neutrons, HENSA provides near real-time measurements of the neutron spectrum on a time scale of tens of minutes up to few hours, thus enabling possible applications in space weather as a neutron monitor with spectral sensitivity. Since 2019 HENSA is being used for a long-term characterization of the neutron background at the Canfranc Underground Laboratory (LSC), which includes continuous measurement in hall A and hall B (HENSA/ANAIS collaboration). Moreover, in 2020 HENSA has been used to map the cosmic-ray neutron background along the spanish territory during quiet solar conditions at the beginning of the solar cycle #25. Currently, a new version of HENSA, called HENSA++, is being developed at IFIC for space weather applications. The status of the HENSA project (www.hensaproject.org) and future perspectives will be discussed in this talk.