Radiation background and dose estimates for future X-ray observations in the Jovian magnetosphere

The Jovian magnetosphere is the most luminous system at soft X-ray wave lengths in our solar system, and hence X-ray observations can provide significant information on the Jovian magnetospheric dynamics. During X-ray observations in the Jovian magnetosphere, however, penetrating particles can hit the detector, resulting in the background noise and radiation damage. Here we consider an X-ray telescope instrument (0.3–2 keV) on board a future Jovian magnetospheric spacecraft and estimate the count rates and dose rates by the high-energy particles for the design of the instrument. Based on Monte-Carlo simulations with Geant4 codes, we confirmed that good signal-to-noise ratio (0.5–500) and negligible dose rate (<0.1krad/year) can be accomplished during observations in the lobe (i.e., the region where magnetic field lines are open), which would be achieved by the high-inclination orbit of the spacecraft.

► An X-ray instrument for the future Jovian magnetospheric mission is considered.
► The effects of the magnetospheric radiation environment are examined.
► It is found that the observations in the lobe region are feasible.