Measuring Neutrons and Gamma Rays on Mars --- The Mars Science Laboratory Radiation Assessment Detector MSL/RAD

The Mars Science Laboratory (MSL) missions Radiation Assessment Detector (RAD) will measure the radiation environment on the Martian surface. One of the difficult measurements is that of the neutral radiation component consisting of neutrons and gamma rays. Different from Earth, this neutral component contributes substantially to the total dose on the planetary surface, principally because the Martian atmosphere is so thin. The RAD instrument is capable of measuring neutral particles through a combination of sensitive anticoincidence and organic and anorganic scintillator materials. Figure 1 shows a schematic view of RAD and explains its basic functions. In this work, we will explain how RAD will measure the neutral particle radiation on Mars and compare with calibration results.