|
Detailed Reference Information |
Paranicas, C., Ratliff, J.M., Mauk, B.H., Cohen, C. and Johnson, R.E. (2002). The ion environment near Europa and its role in surface energetics. Geophysical Research Letters 29: doi: 10.1029/2001GL014127. issn: 0094-8276. |
|
This paper gives the composition, energy spectra, and time variability of energetic ions measured just upstream of Europa. From 100 keV to 100 MeV, ion intensities vary by less than a factor of ~5 among Europa passes considered between 1997 and 2000. We use the data to estimate the radiation dose rate into Europa's surface for depths 0.01 mm -- 1 m. We find that in a critical fraction of the upper layer on Europa's trailing hemisphere, energetic electrons are the principal agent for radiolysis, and their bremsstrahlung photon products, not included in previous studies, dominate the dose below about 1 m. Because ion bombardment is more uniform across Europa's surface, the radiation dose on the leading hemisphere is dominated by the proton flux. Differences exist between this calculation and published doses based on the E4 wake pass. For instance, proton doses presented here are much greater below 1 mm. |
|
|
|
BACKGROUND DATA FILES |
|
|
Abstract |
|
|
|
|
|
Keywords
Planetology, Solar System Objects, Jovian satellites, Planetology, Fluid Planets, Magnetospheres, Magnetospheric Physics, Energetic particles, trapped |
|
Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
|
|
|