New Material Systems for Neutron Dosimetry

New Material Systems for Neutron Dosimetry

E. C. Frey1, P. N. First2, Z. Jiang2, and T.M. Orlando1,2
1School of Chemistry & Biochemistry, 2School of Physics, Georgia Institute of Technology

 

Summary: Radiation remains one of the most challenging obstacles towards sustained human presence on non-terrestrial bodies. Given the trajectory of human space exploration in the upcoming decades, there is much potential application for robust dosimeters that can be incorporated into spacesuit designs at varying locations to measure cumulative, tissue-specific dose. With this in mind it was proposed to investigate novel 2D material systems as a technological model for low-power, lightweight, and real-time radiation detectors [1]. Our initial effort hopes to utilize graphene’s unique conductivity and boron-10’s (10B) unique ability to “capture” neutrons to develop a resistance-based neutron detector. Neutrons are generated as secondaries from high-energy cosmic ray impacts (Figure 1) and pose a unique health risk to astronauts. As such, exposure should be quantified and limited. If our prototype holds for biologically-relevant neutron energy spectra (Figure 2), it would complement current radiation monitoring systems and offer a flexible dosimetry scaffolding conducive to spacesuit integration.

Image depicting a cosmic ray incident to a planetary surface

Figure 1. A cosmic ray incident to a planetary surface creates neutron secondaries of varying energies [2].

Graph of Double Stranded Breaks (DSB) per Gray of absorbed dose per cell over a range of incident neutron energies

Figure 2. Double Stranded Breaks (DSB) per Gray of absorbed dose per cell over a range of incident neutron energies [3]. Peak damage occurs around neutron energies of 0.35 MeV and 20 MeV. Locations indicate measurement depth in human torso. 

 

 

Acknowledgements:  This project was carried out as part of REVEALS, which was directly supported by the NASA Solar System Exploration Research Virtual Institute cooperative, agreement no. NNH16ZDA001N.

 

References: 

(1)          Orlando, T. M.; Jones, B.; Paty, C.; Schaible, M. J.; Reynolds, J. R.; First, P. N.; Robinson, S. K.; La Saponara, V.; Beltran, E. Catalyst: Radiation Effects on Volatiles and Exploration of Asteroids and the Lunar Surface. Chem 2018, 4 (1), 8–12.

(2)         S. Kraft et al., "Development and Characterization of Large La-Halide Gamma-Ray Scintillators for Future Planetary Missions," 2006 IEEE Nuclear Science Symposium Conference Record, San Diego, CA, 2006, pp. 3798-3804.

(3)         Baiocco, G. et al.,“The origin of neutron biological effectiveness as a function of energy,” Nature, 2016, pp. 1–14.