link source : Mysterious ‘electron stash’ found hidden among Van Allen belts ... a distinct, long-lasting ring of high-energy electrons had never before been seen by any prior instrument in space or on Earth. The findings suggest that the Van Allen Belts somehow capture and store energetic electrons in a circular path around our home planet, perhaps in much the same way as a cyclotron can capture and store charged particles here on Earth. ... Approfondimenti:
qui"Particle Energies in Nature
How does nature compare?
0.03 ev
The energy of a molecule of oxygen or nitrogen in the air we breathe. It moves as fast as a speeding bullet, but is still rather low on the scale of energies.
0.5 eV
An atom or molecule at the temperature of the Sun's surface.
0.67 ev
The energy needed by a proton or neutron to escape the Earth's gravity.
1000 - 15,000 ev
Typical energy of an electron in the polar aurora.
40,000 ev
Energy required by an electron to penetrate a thin-wall Geiger counter like that of Explorer 1.
50,000 ev
Typical energy of an ion in the ring current.
Hold it!
We need bigger units:
1,000 ev = 1 kev (kilo-electron-volt, pronounced kay-ee-vee)
1,000,000 ev = 1 Mev (mega-electron volt or em-ee-vee)
1,000,000,000 ev = 1 Gev (giga-electron-volt or gee-ee-vee)
1.4 Mev The energy of electrons from radioactive potassium, a major source of the Earth's internal heat.
4.2 Mev The energy of alpha particles from radioactive uranium 238, another source of the Earth's heat (and of its helium as well--see positive ions, history).
10-100 Mev Typical proton energies in the inner radiation belt.10-15,000 Mev Range of energies in solar outbursts (see Sun).
1-100,000,000,000 Gev Range of energies among cosmic ray ions.
However as their energy goes up, their intensity goes way down, so that ions at the high energy end are quite rare.
To be sure, sometimes even bigger units are needed:
1,000 Gev = 1 Tev (Tera-electron-volt)
1,000,000 Gev = 1 Pev (Peta-electron volt)
1,000,000,000 Gev = 1 Eev (Exa-electron-volt)
The Pierre Auger Cosmic Ray Observatory in Argentina has observed particles whose energy was estimated to be around 57 Eev and up"[/i]