A Moon-borne electromagnetic calorimeter

Abstract

We discuss an electromagnetic sampling calorimeter for the detection of very high energy gamma-rays on the Moon, which is based on the use of scintillating cylinders and plates imbedded in the lunar soil. The use of lunar soil as a calorimeter radiator reduces the weight of the material to be transported to the Moon and minimises environmental impact. Plastic scintillator bars inserted into the regolith about 1.5 m are the active elements of this instrument: at the surface, each bar is terminated by a plastic scintillator plate to veto high energy charge particles. The readout system for the scintillator bars and plates are based on recently developed single photon solid state detectors (Silicon Photomultiplier, SiPM), extremely compact, sturdy and sensitive devices suited for detecting small light pulses in a space experiment. The performance of a regolith-scintillator calorimeter is evaluated and the relevant parameters are optimised using a GEANT4 simulation.

Removing the dose background from radioactive sources from active dose rate measurements in the Lunar Lander Neutron & Dosimetry (LND) experiment on Chang'E 4

“…In fact, the composition of the lunar soil and concrete is not exactly the same (especially for water content), so the scattering effect on the neutrons and gamma rays is also different. The Monte Carlo program was used to simulate the lunar soil [12] and concrete [7,8], using the very much simplified geometry as shown in figure 7. We use the neutron (gamma) spectrum of PuO 2 for concrete and lunar soil simulation.…”

Spaceborne Experiments

“…For this reason space scientists are considering experiments where the medium where the particle interactions take place is separated from the detector, similarly to what happens for ground based Cherenkov Telescopes, under water or under ice neutrino detectors or Extremely Energetic Cosmic Rays detector arrays, where Cerenkov and fluorescence light produced in the atmosphere, water or ice, respectively, is measured using photon detectors. In the case of these space experiments the medium could be the atmosphere [85,86], the Moon surface [87] or the magnetosphere [88]: extremely large sensitivities to rare events can be reached by using our whole planet, the Earth, or its satellite, the Moon, as detecting media observable from space borne detectors, collecting emitted light or radio waves by using suitable instrumentation. Discussing these projects is outside the scope of this chapter, however it is interesting to note here a pattern of development which might in the future drive the development of space borne particle experiments devoted to extremely rare events.…”