Speaker
Dr
Mark Looper
(The Aerospace Corporation)
Description
Geant4 is a vital tool for understanding and calibrating the response of space-borne radiation sensors at The Aerospace Corporation. In the year since the last Geant4 Space Users' Workshop, we have focused on using the code to continue improving our understanding of the response, both foreground and background, of sensors aboard the Van Allen Probes and the Lunar Reconnaissance Orbiter (LRO). On the Van Allen Probes, we have tuned our model of the Relativistic Proton Spectrometer (RPS) to reproduce the observed response as closely as possible, in order to design and quantify cuts to reject contamination in the sensor’s very difficult primary measurement of penetrating energetic protons (60 MeV and up). We have also discovered a signal that is consistent with extremely energetic electrons (around 100 MeV) in the Earth’s magnetosphere, possibly from the decay of pions and muons resulting from cosmic-ray interactions with the Earth’s atmosphere, and are investigating. Also aboard the Van Allen Probes, we have completed modeling of the response of the three electron sensor heads of the Magnetic Electron Ion Spectrometers (MagEIS), and are using these to improve calibration of our measurements in the presence of penetrating and scattered background. Aboard LRO, we have continued to improve our model of background response of the Cosmic Ray Telescope for the Effects of Radiation (CRaTER), and have begun investigating the effects of varying amounts of water in the shallow lunar regolith on its observations of “albedo” protons produced at the moon by cosmic-ray interactions. We have also modeled the responses of single-element microdosimeters installed in a variety of spacecraft.
Primary author
Dr
Mark Looper
(The Aerospace Corporation)
