Gyro-resonant electron acceleration at Jupiter

According to existing theory, electrons are accelerated up to ultra-relativistic energies(1) inside Jupiter's magnetic field by betatron and Fermi processes as a result of radial diffusion towards the planet and conservation of the first two adiabatic invariants(2-4). Recently, it has been shown that gyro-resonant electron acceleration by whistler-mode waves(5,6) is a major, if not dominant(7), process for accelerating electrons inside the Earth's outer radiation zone, and has redefined our concept for producing the Van Allen radiation belts(8). Here, we present a survey of data from the Galileo spacecraft at Jupiter, which shows that intense whistler-mode waves are observed outside the orbit of the moon Io and, using Fokker-Planck simulations, are strong enough to accelerate electrons to relativistic energies on timescales comparable to that for electron transport. Gyroresonant acceleration is most effective between 6 and 12 jovian radii (R-j) and provides the missing step in the production of intense synchrotron radiation from Jupiter(1,9).


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Authors: Horne, Richard B. ORCIDORCID record for Richard B. Horne, Thorne, Richard M., Glauert, Sarah A. ORCIDORCID record for Sarah A. Glauert, Menietti, J. Douglas, Shprits, Yuri Y., Gurnett, Donald A.

On this site: Richard Horne, Sarah Glauert
1 January, 2008
Nature Physics / 4
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