I am currently working with Dr. Craig Hardgrove on development and/or characterization of a variety of nuclear spectroscopy instruments including SINGR, LunaH-Maps’ Mini-NS, MiniPNG, and various CLYC scintillator detectors. My responsibilities consist of developing techniques using active neutron sample analysis with DT generators and dual scintillator detectors such as CLYC. Our testing is done in collaboration with both NASA Goddard Space Flight Center (GSFC) and Los Alamos National Labs (LANL). I have been debugging and characterizing electronic systems for use with CLYC pulse-shape discrimination algorithms, in collaboration with RMD Inc. and ASU’s EEE dept.
The SIngle-scintillator Neutron and Gamma Ray spectrometer (SINGR) can be used on future rovers or landers where the mission science goals include characterization of the hydrogen content, the depth distribution of hydrogen, and the bulk geochemistry of a planetary surface.
Publications in prep:
- Working Title: Pulsed Neutron Investigations of Planetary Surfaces using a Single Detector System: Field Experiments and Data
Gamma-ray and neutron spectrometers (GRNS) can be used to determine the hydrogen content and elemental abundances within the top ~tens of cms of planetary surfaces. Through the added use of a D-T (Deuterium-Tritium) pulsed neutron generator (PNG) GRNS can more rapidly characterize a planet’s surface material; this makes active GRNS useful for roving and landed missions. The SIngle-scintillator Neutron and Gamma Ray spectrometer (SINGR) instrument was characterized for use with both passive and active techniques on a rover/lander scale. Active GRNS measurements were performed with SINGR at the NASA Goddard Space Flight Center (GSFC) Goddard Geophysical and Astronomical Observatory (GGAO) outdoor test site to interrogate geologically relevant materials (Mars, the Moon, Titan) and to demonstrate the capability of a dual-use scintillator to provide neutron and gamma-ray spectroscopy using a PNG. By running the neutron generator in a pulsed mode (250 – 1000 Hz), GRNS responses can be studied both during and between pulses. We successfully constructed neutron die-away curves (i.e. bulk hydrogen abundance with depth distribution) as well as gamma-ray spectra (i.e. Fe, Si, Al, O, K, Th abundances). We investigated planetary analog materials such as basalt (volcanic, extrusive), granite (crustal, intrusive, high Th & K), polyethylene (ice, water, hydrated material simulant), and organic (milorganite fertilizer) for our measurements; we also acquired neutron die-away data for low to high amounts of H. These experiments contribute to a better understanding of instruments that will be useful for landed missions to Mars, the Moon, Titan, and other planetary bodies.
- Working Title: Pulsed Neutron Investigations of Planetary Surfaces: Simulations and Sensitivity
Information about the elemental composition of a planetary surface can be determined through the use of nuclear instrumentation, such as neutron spectrometers (NS) and gamma-ray spectrometers (GRS). The overall goal of this research is to develop and characterize dual instrument gamma-ray and neutron spectrometers (GRNS) for detecting neutrons and gamma-rays to measure planetary surface composition. This paper explores the possible uses of a variety of gamma-ray and neutron spectrometers, via simulations using MCNP 6.1, for a variety of different landed planetary scenarios on Mars, Titan, and the Moon.