(from: http://en.wikipedia.org/wiki/Van_Allen_radiation_belt, 10.8.2006)
Van Allen belts by the Earth magnetic field and sunstorms
Van Allen radiation belt is a ring with energetic loaded particles (plasma). The ring encloses the whole Earth. It's coming from the Earth magnetic field which produces the ring. Generally it's understandable that the Van Allen belts are the result of the confrontation of the Earth magnetic field with the solar winds. The particles of the solar winds are trapped by the magnetosphere of the Earth.
In former times the Van Allen belts were called simply "Earth magnetic field"
[By this the fact of the radiation was covered-up by the "USA" and the "SU" to support further moon fantasy and to get further research orders].
Different Van Allen belts - polar lights
There are different Van Allen belts. They are connected with polar lights. There where the polar lights come out, particles (from sunstorms) are touching the upper atmosphere and lighten (fluorescing).
Proof of the existence of Van Allen belts in 1958 by Explorer an Pioneer satellites
The existence of a radiation belt was admitted even before the atmosphere flight and was confirmed by missions of the satellites Explorer I on 31 January 1958 and Explorer III which all were performed under leadership of Dr. James Van Allen. The radiation intensity within the Van Allen belt was recorded first be the satellites Explorer IV and Pioneer III.
The events within the Van Allen belts
The release of fluorohydrocarbons in the upper atmosphere causes a selective absorption of alpha particles in that space. A conglomeration of such (invisible) clouds are called pseudo Van Allen belts and are 1x10-9 lower than the real Van Allen belts. Recently, the NSF funded 2 competing proposals to study these belts and their effect on the amount of radiation that enters the inner atmosphere of the earth.
Energetic electrons form two distinct radiation belts, while protons form a single belt. Within these belts are particles capable of penetrating about 1 g/cm2  of shielding,(see: The Radiation Belt and Magnetosphere by Wilmot Hess (1968)
e.g., 1 millimeter of lead.
Other radiation belts
The term Van Allen Belts refers specifically to the radiation belts surrounding Earth; however, similar radiation belts have been discovered around other planets. The Sun does not support long-term radiation belts.
The extension of the Van Allen radiation belts
The Earth's atmosphere limits the belts' particles to regions above 200-1,000 km, while the belts do not extend past 7 Earth radii RE. The belts are confined to an area which extends about 65° from the celestial equator.
(see: Introduction to Geomagnetically Trapped Radiation by Martin Walt (1994)
The outer Van Allen belt (in a height of 10,000 to 65,000 km)
There is debate as to whether the outer belt was discovered by the US Explorer IV or the USSR Sputnik II/III.
The large outer radiation belt extends from an altitude of about 10,000–65,000 km and has its greatest intensity between 14,500–19,000 km.
It's admitted that the outer belt consists of plasma which is trapped by the magnetosphere of the Earth. The "Soviet" probe "Luna 1" recorded in the outer belt only a few high energetical particles.
The outer belt consists mainly of high energy (0.1-10MeV) electrons trapped by the Earth's magnetosphere.
The gyroradii for energetic protons would be large enough to bring them into contact with the Earth's atmosphere.
The electrons in the outer Van Allen belt have a high flow rate, also at the outer ridge, and electrons with a cinetic energy of over 40 keV can fall back on their normal interplanetary rate within about 100 km (a regression of a factor 1,000). This regression is a result of the solar wind.
The allocation of the outer belts with particles are different, with electrons and different ions. Most of the ions are in a form of energetic protons, but a certain part are alpha particles and O+ oxygen ions, similar to these in the ionosphere, but much more energetic. By this mixture of ions one can conclude that the loaded particles in the ring are probably coming from different sources.
The outer belt is bigger and more diffuse than the inner one. The outer belt is surrounded by a less intensive area, known as a ring stream. In the contrary to the inner belt the particles in the outer belt are fluctuating in far distances and have a lower intensity (less than 1 MeV). The intensity is rising when magnetic storms bring in fresh particles from outside of the magnetosphere. After the storm the intensity is falling again
The inner Van Allen belt
The inner Van Allen belt is extending over 1.1 to 3.3 Earth radii, and it contains a high concentration of energetic protons with energies over 100 MeV. The particles are trapped from strong magnetic fields of the area (stron compared to the outer belt).
It's admitted that the protons with energies of over 50 MeV in lower heights in the lower belts are the result of a collapse of the beta collapse of the cosmic radiation neutrons. As a source of the protons with low energy the proton diffusion is admitted because there are changes within the magnetic field during the geomagnetic storms.
Tascione, Thomas F. (1994). Introduction to the Space Environment, 2nd. Ed.. Malabar, Florida USA: Krieger Publishing CO.. ISBN 0-89464-044-5.
The effects of the Van Allen belts [on the atmosphere flight]
[The effects on the atmosphere ships can be the following ones]:
Solar cells, integrated circuits and sensors can be damaged by the radiation. In 1962 the Van Allen belts could temporarily extend. This was caused by a nuclear explosion in the height ("Starfish Prime test").
The "Starfish Prime test" contained a firing of an atomic bomb on 9th July 1962 in a height of 400 km over Johnston Island over the Pacific as a part of the "Operation Dominic".
By the atomic bomb firing in the high atmosphere and the extension of the Van Allen belts some satellites became out of function.
Magnetic storms damage the electronic components of atmosphere ships sometimes.
The satellites become more and more little and have more an more electronics, and by digitalization and electronic data and circuits satellites are more and more vulnerable against the radiation. By this the entering ions can have high radiation like the force of the circuits. Electronic devices on satellites have to be shielded against the radiation for a reliable functioning. The Hubble space telescope often switches off his sensors when passing through a region with high radiation, as other satellites, too.
A satellite with 3mm strong aluminium shield gets about 2,500 rem (25 Sv) per year.
(see: Ptak, Andy (1997). Ask an Astrophysicist. NASA GSFC. Retrieved on 2006-06-11)
According to Van Allen there is hardly any health damage for astronauts by passing the Van Allen belts because the belts are quickly passed. [...]
[But the high radioactive radiation on the moon itself which has no protective atmosphere is concealed by Wikipedia].
The Van Allen belts and why they exist [diverse theories]
Generally it's understandable that the Van Allen belts are the result of the confrontation of the Earth magnetic field with the solar winds. The particles of the solar winds are trapped by the magnetosphere of the Earth. The trapped particles are rejected from the regions with stronger magnetic fields, so magnetic lines of magnetic flux can be seen. By this certain particles are flowing between the poles back and forth where the magnetic field is rising.
The gap between the inner and the outer Van Allen belt is caused by the waves in Very Low Frequency VLF. They spread the particles in an edge angle (angle between the magnetic field and the particle speed). At the end the particles are lost in the atmosphere. So, solar outbreaks can close the gab, but then they disappear after a few days again.
There was admitted that the radio waves were cause by the troubles in the radiation belts. But latest studies of James Green from NASA from Goddard Space Flight Center are comparing the map of the light activity (collected data of the atmosphere ship "Micro Lab 1") with the data of the radio waves in the gap of the radiation belt (collected data of atmosphere ship IMAGE). The comparison results the conclusion that in reality the radio waves are generated by the lights within the Earth atmosphere. The radio waves collide with the ionosphere in a right angle and pass the ionosphere in high areas only where the low end with the gap is approaching the higher atmosphere. These results are always in discussion yet within the scientific debate.
Once the "Soviets" blamed the "USA" having caused the inner belt as a result of nuclear tests in Nevada. The "USA" also blamed the "USSR" having caused the outer belt by nuclear tests. But it's not sure how particles of such tests could leave the atmosphere and could reach the heights of the radiation belts. At the same time it's not clear why the belts have not been weakened since the ban of nuclear tests. Thomas Gold indicated that the outer belt could be a remnant of the aurora, at the other side Dr. Alex Dessler indicated that the belt would be a result of volcanic activity.
Another sight explains that the belt could be considered as an electron stream which is fed by solar winds. With the positive protons and the negative electrons the area between the belts is considered as a flowing stream which is "flowing away" again. It's also said that the belt would be the drive for the aurora, the drive for the lights and for many other electronic effects.
To remove the belts [and this is dangerous - different theories)
The belts are a risk for artificial satellites, and they are a medium risk for humans, too. A protection shield is difficult and costs a lot.
There is the idea of Robert L. Forward - called "Hi-Volt" - to reduce the belts to 1 % of their natural level within a year. The proposal contains to bring high electronic linen into a high Earth orbit,