TY - GEN
T1 - The Effect of Boron on Active Neutron Measurements
T2 - 2020 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2020
AU - Nowicki, Suzanne N.
AU - Festal, Sophie
AU - Czarnecki, Sean M.
AU - Gasda, Patrick J.
AU - Hardgrove, Craig J.
N1 - Funding Information:
Manuscript received December 20, 2020. We acknowledge the Dynamic Albedo of Neutrons instrument team and the broader Mars Science Laboratory team. This work was supported by the Mars Science Laboratory Participating Scientist Program, award number NNN12AA01C.
Publisher Copyright:
© 2020 IEEE
PY - 2020
Y1 - 2020
N2 - The primary objective of the Dynamic Albedo of Neutrons (DAN) experiment on board the Mars Science Laboratory (MSL) rover Curiosity is to assess the hydrogen content as the rover traverses the Martian surface. Because hydrogen is a light element, it is an efficient moderator for neutrons. The method used to estimate the hydrogen content by the DAN instrument is to measure the thermal neutron count rate emitted from the surface of the soil using a Pulsed Neutron Generator as an activation source coupled with a thermal neutron detector. However, boron has a high cross section for thermal neutron capture and can affect the thermal neutron flux measured by the DAN instrument. Recently, the MSL ChemCam instrument has shown high concentrations of B in the veins of the Murray formation and Yellowknife Bay at concentrations of 100 to 500 ppm. We show that the number of neutrons that are captured in the Martian soil increases with increasing B, resulting in reduced count rates observed by the DAN thermal neutron detector, which can lead to an overestimate of the hydrogen content.
AB - The primary objective of the Dynamic Albedo of Neutrons (DAN) experiment on board the Mars Science Laboratory (MSL) rover Curiosity is to assess the hydrogen content as the rover traverses the Martian surface. Because hydrogen is a light element, it is an efficient moderator for neutrons. The method used to estimate the hydrogen content by the DAN instrument is to measure the thermal neutron count rate emitted from the surface of the soil using a Pulsed Neutron Generator as an activation source coupled with a thermal neutron detector. However, boron has a high cross section for thermal neutron capture and can affect the thermal neutron flux measured by the DAN instrument. Recently, the MSL ChemCam instrument has shown high concentrations of B in the veins of the Murray formation and Yellowknife Bay at concentrations of 100 to 500 ppm. We show that the number of neutrons that are captured in the Martian soil increases with increasing B, resulting in reduced count rates observed by the DAN thermal neutron detector, which can lead to an overestimate of the hydrogen content.
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U2 - 10.1109/NSS/MIC42677.2020.9507973
DO - 10.1109/NSS/MIC42677.2020.9507973
M3 - Conference contribution
AN - SCOPUS:85124704127
T3 - 2020 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2020
BT - 2020 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2020
PB - Institute of Electrical and Electronics Engineers Inc.
Y2 - 31 October 2020 through 7 November 2020
ER -