Investigation of heavy cosmic-ray nuclei by solid-state track detectors on orbiting platforms

Results are presented from investigations of Fe-group nuclei in galactic and solar cosmic rays in the energy ranges 30–210 MeV/n and 7–210 MeV/n in various phases of the solar cycles. Spectra of Fe particles have been obtained with high energy resolution as a result of exposing PLATAN chambers, made up of layers of a polyethyelene terephthalate solid-state track detector, for between one and three years on the Salyut-6, Salyut-7, and Mir space stations, orbiting at an inclination of 51.6° to the plane of the equator and at an altitude of 350–400 km. Measurements were made of the energy spectra of Fe particles from a unique event, the series of solar flares of September 29 and October 19–29, 1989, which is the most powerful of those recorded and measured over the entire history of cosmic ray research. A modern model of particle penetration inside the Earth’s magnetosphere, developed at the Institute of Nuclear Physics at Moscow State University, is used to compare the measured spectrum with measurements made using the solid-state track detector in the HIIS experiment on the LDEF station, and with extramagnetospheric measurements made using electronic equipment on the IMP-8 satellite and the Galileo space station. It is shown that the solid-state track detector technique has advantages for obtaining the characteristics of the energy spectrum.