Associated particle imaging instrumentation for future planetary surface missions

An all-digital associated particle imaging system for the 3D determination of isotopic distributions

“…We obtained gamma-ray spectra from different elemental materials including 12 C, 16 O, 28 Si, 27 Al, and 56 Fe and used these data to benchmark Monte Carlo simulations. We found generally good agreement confirming that the radiation transport code MCNP6 can be used to optimize the system and support the data analysis.…”

“…In an early proof-of-principle paper Beyerle et al 11 obtained 2D projections for different materials (water and table salt), hence showing some of the most important capabilities of this technique. Since then, API has found many uses in different areas of research and industry including detection of illicit drugs 12 , explosives 13 , special nuclear material (SNM) 14 , diamond search 15 , and space exploration 16 , among many other applications. Fast scintillators, fast electronics, and highresolution position-sensitive photomultiplier tubes have recently enabled both sub-nanosecond time resolution and submillimeter position resolution.…”

An associated particle imaging system for soil-carbon measurements

“…Note that the API technique allows for the measurement of gamma-ray spectra from selected regions in space, greatly reducing counts from unwanted events that would show up in other measurement techniques. This has proven to be useful in other areas such as the one reported by Litvak et al 13 where spectroscopic analysis is rather difficult due to high background levels coming from structural materials. The gamma spectra in Figure 5 shows several peaks which are the result of inelastic neutron scattering (INS) on the three main elements (Si, C, O), several transitions between excited states of each nuclei, and interactions of gamma rays within the detector crystal.…”