The Lunar OutpOst Neutron Spectrometer (LOONS)

We present a new detector concept, the Lunar OutpOst Neutron Spectrometer (LOONS), designed for the measurement of energetic (~0.4–150 MeV) neutrons of solar, terrestrial and lunar origin, as part of a low-Moon orbit or lunar-lander opportunity. Neutrons represent an important space radiation component for multiple aspects. They are produced in the interactions of cosmic rays (CRs) with the Earth’s atmosphere and spacecraft materials, posing a considerable hazard for satellite electronics and air/spacecraft crews. The detection and monitoring of neutrons originated in the CR collisions with the lunar surface is particularly important for near-future manned missions to the Moon, since they constitute a significant component of the lunar radiation environment and, at the same time, they can be used to probe the crust composition (e.g., water content). Finally, the measurement of neutrons produced in solar flares provides a unique opportunity to investigate particle acceleration mechanisms at the Sun, complementing the observations based on γ-rays and charged CR components. LOONS is based on state-of-the-art techniques for neutron detection using segmented organic scintillators coupled to silicon photomultipliers (SiPMs), and subsequently processed with modern ASICs. In this work we describe the detector development and performance, and the future plans to integrate a flight-ready instrument.