Assess the Feasibility of Using a Compact Gamma-Ray and Neutron Spectrometer with a CLYC Scintillator to Measure the Elemental Composition of a Small Body

The contractor will assess the feasibility of using a compact Gamma-Ray and Neutron Spectrometer (GRNS) with a CLYC scintillator to measure the elemental composition of a small body. The measurements would be made from a spacecraft flying in formation with the asteroid. The objective of this study is to estimate the sensitivity of the measurements to target elements (major- and radio-elements), which could be used to infer the presence of platinum group metals. This work supports planning for the Company’s deep space observation mission of a near-Earth asteroid by performing the following tasks:

1)      Generate model compositions for use in nuclear spectroscopy simulations for candidate asteroid spectral types.

2)      Model the surface leakage spectrum of radiation produced by the decay of natural radioelements and secondary particles produced by the interaction of cosmic rays with the asteroid. The following steps are required for each model composition:
a.       Selection of mission-relevant input parameters, including the modulation of galactic cosmic rays
b.      Problem setup, simulation, reduction/interpretation of output data

3)      Estimate the response of the sensor to gamma rays and neutrons as a function of spacecraft distance and hold time. This requires the following steps:
a.       Model the instrument geometry and materials
b.      Propagate the surface leakage radiation to the spacecraft
c.       Generate the response of the instrument to the incident radiation from the asteroid
d.      Generate random samples of the data, accounting for accumulation time and a simple model of spacecraft backgrounds
e.       Estimate uncertainties for analyses of target elements as a function of distance and accumulation time4)      Deliverable: A report presenting the results of the calculations, their interpretation, and recommendations for how to deploy the spectrometer on a NEA mission. The report will include an assessment of hold times and feasible altitudes. Supplementary electronic data files containing composition tables and samples of reduced spectra from simulations will accompany the report when necessary to support findings. Simulation input/output files and processing/modeling software will not be delivered as part of this contract.