The SILIa-4 light-nucleus isotope spectrometer for cosmic-ray studies outside earth's atmosphere

The SILIa-4 mass spectrometer has been specially designed for satellite-borne studies of the isotopic and atomic abundances of light cosmic-ray nuclei as well as their energy spectra. This spectrometer is intended for use in identifying isotopes of hydrogen and helium nuclei in the energy range from about 50 to 200 MeV/n and in determining the atomic abundances of hydrogen, helium, lithium, and beryllium nuclei in the energy range above 50 MeV/n. The design of SILIa-4 is described along with its physical specifications, components, and mode of operation. It is noted that this spectrometer has been deployed aboard the Cosmos 557 satellite and the Salyut 4 space station.