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Post Info TOPIC: Radiation belt remediation
Blobrana


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Van Allen radiation belts
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Thousands of miles above Earth, a cosmic chorus is filling the heavens with a mysterious, low frequency "hiss."
That's the conclusion of scientists studying data from a set of NASA probes designed to monitor substorms - dramatic exchanges of energy among charged particles that spark the auroras at Earth's poles.
The charged particles come from the sun and get trapped in loops around our planet by Earth's magnetic field.

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Blobrana


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Radiation Protection
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New space technology, developed by scientists at the University of Strathclyde, could offer vital protection to astronauts and bring the dream of a manned mission to Mars one step closer.
A major obstacle to deep space travel is 'space weather'; Solar radiation and deadly cosmic rays which could disable a spacecraft's electronic systems and cause harm to astronauts.

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Blobrana


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Van Allen radiation belt
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Radio transmitters on Earth cause charged particles to leak out of the inner Van Allen radiation belt in space, new observations confirm.
Future satellite transmitters may take advantage of the effect, which had been predicted theoretically, to help clear the belt of charged particles from intense solar outbursts or nuclear explosions in space that could threaten satellites.

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Blobrana


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RE: Radiation belt remediation
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Title: Gyro-resonant electron acceleration at Jupiter
Authors: Richard B. Horne, Richard M. Thorne, Sarah A. Glauert, J. Douglas Menietti, Yuri Y. Shprits & Donald A. Gurnett

According to existing theory, electrons are accelerated up to ultra-relativistic energies 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. Recently, it has been shown that gyro-resonant electron acceleration by whistler-mode waves is a major, if not dominant, process for accelerating electrons inside the Earth's outer radiation zone, and has redefined our concept for producing the Van Allen radiation belts. 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 FokkerPlanck simulations, are strong enough to accelerate electrons to relativistic energies on timescales comparable to that for electron transport. Gyro-resonant acceleration is most effective between 6 and 12 jovian radii (Rj) and provides the missing step in the production of intense synchrotron radiation from Jupiter

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Blobrana


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Radio waves accelerate electrons within Jupiters magnetic field in the same way as they do on Earth, according to new research published in Nature Physics this week. The discovery overturns a theory that has held sway for more than a generation and has important implications for protecting Earth-orbiting satellites.

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Blobrana


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Just outside Earth's atmosphere, extending into space for thousands of kilometres, lurk the Van Allen radiation belts. Normally, the ionised electrons there pose a manageable danger to satellites and spacecraft. But every month or so, radiation levels can suddenly spike, generating extremely energetic streams of electrons that fry electronic circuits or damage the DNA of astronauts unlucky enough to be there.

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Blobrana


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Van Allen radiation belt
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Settling a longstanding scientific debate, Los Alamos scientists have demonstrated conclusively how electromagnetic waves accelerate ordinary electrons in the belts of radiation outside Earth's atmosphere to a state where they become "killer electrons," particles that are hazardous to satellites, spacecraft, and astronauts.
Using data from several satellites, including NASA's Polar spacecraft, Los Alamos scientists published in the July issue of Nature Physics a paper showing how interactions between electromagnetic waves and electrons are responsible for accelerating radiation-belt particles in the Van Allen radiation belts to the point they become "killers."

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Blobrana


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Radiation belt remediation
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A proposed US system to protect satellites from solar storms or high-altitude nuclear detonations could cause side-effects that lead to radio communication blackouts, according to new research. If activated, the "radiation belt remediation" (RBR) system could significantly alter the upper atmosphere, seriously disrupting high frequency (HF) radio wave transmissions and GPS navigation around the world.
The remediation system aims to protect hundreds of low earth-orbiting satellites from having their onboard electronics ruined by charged particles in unusually intense Van Allen radiation belts "pumped up" by high-altitude nuclear explosions or powerful solar storms.

The approach, which is being pursued by the US Air Force and the US Defence Advanced Research Projects Agency, involves the generation of very low frequency radio waves to flush particles from the radiation belts and dump them into the upper atmosphere over one or several days.
The scientific team from New Zealand, UK and Finland calculate that Earth's upper atmosphere could be dramatically affected by such a system, causing unusually intense HF blackouts around most of the world.

"Some planes and ships that rely on HF communications could lose radio contact, and some remote communities that also depend on HF could be isolated for as long as six to seven days, depending on the system's design and how it was operated. GPS signals between ground users and satellites would also be disrupted as they pass through the disturbed ionosphere" - Dr Mark Clilverd from British Antarctic Survey.

The disruptions result from a deluge of dumped charged particles temporarily changing the ionosphere from a "mirror" that bounces high frequency radio waves around the planet to a "sponge " that soaks them up.
The research is published in the August edition of the international journal Annales Geophysicae. The researchers suggest that policymakers need to carefully consider the implications of remediation.
If the intense radiation belts resulted from a rogue state detonating a nuclear-tipped missile in the upper atmosphere, using such remediation technology would probably be acceptable to the international community, regardless of any side effects. However, using the system to mitigate the lesser risk to satellites from charged particles injected by naturally occurring solar storms should be considered more closely. The impact of the disruption to global communications needs to be weighed carefully against the potential gains.

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