Measurements of the neutral particle spectra on Mars by MSL/RAD from 2015-11-15 to 2016-01-15

Publication date: Available online 16 June 2017 Source:Life Sciences in Space Research Author(s): Jingnan Guo, Cary Zeitlin, Robert Wimmer-Schweingruber, Donald M. Hassler, Jan Köhler, Bent Ehresmann, Stephan Böttcher, Eckart Böhm, David E. Brinza The Radiation Assessment Detector (RAD), onboard the Mars Science Laboratory (MSL) rover Curiosity, has been measuring the energetic charged and neutral particles and the radiation dose rate on the surface of Mars since the landing of the rover in August 2012. In contrast to charged particles, neutral particles (neutrons and γ-rays) are measured indirectly: the energy deposition spectra produced by neutral particles are complex convolutions of the incident particle spectra with the detector response functions. An inversion technique has been developed and applied to jointly unfold the deposited energy spectra measured in two scintillators of different types (CsI for high γ detection efficiency, and plastic for neutrons) to obtain the neutron and γ-ray spectra. This result is important for determining the biological impact of the Martian surface radiation contributed by neutrons, which interact with materials differently from the charged particles. These first in-situ measurements on Mars provide (1) an important reference for assessing the radiation-associated health risks for future manned missions to the red planet and (2) an experimental input for validating the particle transport codes used to model the radiatio...
Source: Life Sciences in Space Research - Category: Biology Source Type: research