Variations of dose rate observed by MSL/RAD in transit to Mars
Abstract
Aims: To predict the cruise radiation environment related to future human missions to Mars, the correlation between solar modulation potential and the dose rate measured by the Radiation Assessment Detector (RAD) has been analyzed and empirical models have been employed to quantify this correlation. Methods: The instrument RAD, onboard Mars Science Laboratory's (MSL) rover Curiosity, measures a broad spectrum of energetic particles along with the radiation dose rate during the 253-day cruise phase as well as on the surface of Mars. With these first ever measurements inside a spacecraft from Earth to Mars, RAD observed the impulsive enhancement of dose rate during solar particle events as well as a gradual evolution of the galactic cosmic ray (GCR) induced radiation dose rate due to the modulation of the primary GCR flux by the solar magnetic field, which correlates with long-term solar activities and heliospheric rotation. Results: We analyzed the dependence of the dose rate measured by RAD on solar modulation potentials and estimated the dose rate and dose equivalent under different solar modulation conditions. These estimations help us to have approximate predictions of the cruise radiation environment, such as the accumulated dose equivalent associated with future human missions to Mars. Conclusions: The predicted dose equivalent rate during solar maximum conditions could be as low as one-fourth of the current RAD cruise measurement. However, future measurements during solar maximum and minimum periods are essential to validate our estimations.
Keywords
Cite
@article{arxiv.1503.06631,
title = {Variations of dose rate observed by MSL/RAD in transit to Mars},
author = {Jingnan Guo and Cary Zeitlin and Robert F. Wimmer-Schweingruber and Donald M. Hassler and Arik Posner and Bernd Heber and Jan Köhler and Scot Rafkin and Bent Ehresmann and Jan K. Appel and Eckart Böhm and Stephan Böttcher and Sönke Burmeister and David E. Brinza and Henning Lohf and Cesar Martin and Günther Reitz},
journal= {arXiv preprint arXiv:1503.06631},
year = {2015}
}
Comments
6 pages, 4 figures