Radiation and the Magnetic Field

[SargeRho]

So, I'm in an ongoing discussion about Earth's magnetic field, and what it protects us against.

From my understanding, it deflects protons, electrons, their antiparticles, ions, and some cosmic rays, of which some end up in the van allen radiation belts. But it has next to no effect on gamma rays, x-rays, and any other part of the electromagnetic spectrum, so, it protects us against some cosmic rays, as well as the solar wind and CMEs, but not against solar flares themselves.

The person I'm arguing with is insisting that the van allen belts stop the EM-radiation from solar flares. I can't find anything that supports that claim.

[kerbiloid]

Magnetic field can't stop electromagnetic radiation, as they don't interact with each other.

But it protects our ozone layer from the solar wind (i.e. those charged particles), while the ozone layer protects us from UV and X-rays.

[K^2]

Other way around. Van Allen belts are formed due to solar wind getting trapped in Earth's magnetic field. And yes, as kerbiloid pointed out, it's particle radiation, not EM radiation, since EM radiation isn't affected by mag fields.

[GeneralVeers]

The Earth's magnetic field protects us from anything that carries an electrical charge. Por ejemplo, solar wind. But it doesn't stop electrically-neutral radiation.

What's going on is this: within a magnetic field, charged particles follow curved paths. If the magnetic field is even (i.e. the "field lines" are parallel) the charged particles will scribe perfect circles. When the magnetic field lines aren't parallel, the charged particles tend to curve in directions that take them wherever the magnetic field is weaker.

Some fun things that happen as a result: the Earth's magnetic flux is weakest at the poles. We get auroras because more charged particles get through the Earth's magnetic field at those points. Also, the "magnetic bottle" you hear about in science fiction isn't fictional. If you shape a magnetic field so it's weakest in the middle, charged particles (such as plasma) will concentrate in that middle section and can be contained. Then you've got the Van Allen radiation belts: the Earth's magnetic field is something of a magnetic bottle that tends to concentrate charged particles it captures. The Van Allen belts aren't extremely deadly (some of the Apollo missions passed right through them), but they can give an astronaut a fatal radiation dose in a few months, and they are really hard on electronics.

[SargeRho]

Thanks, @GeneralVeers, @K^2, and @kerbiloid, that answers my question! Thread can be locked, then.