Low energy cosmic ray ions observed in the Skylab experiment.

In one of the Skylab experiments, a stack of plastic detectors was used to record low energy nuclei that could provide information on the origin of cosmic rays and the earth's radiation belt. The stack consisting of 32 sheets of Lexan polycarbonate detectors was exposed for 73 days. To make them sensitive to carbon, nitrogen, oxygen, and similar nuclei, the sheets were exposed to UV radiation with subsequent etching with a 6.25 NKOH solution. The charges were resolved by measuring the track parameters. The particle fluxes obtained were found to be much higher than those expected from the known spectra of cosmic rays and particles of the Van Allen belts. The anomalously high fluxes are attributed to low-energy partly ionized atoms that are further accelerated in the earth's magnetosphere.