Low energy protons on L≤1.15 in 500 – 1500 km range Original Research Article

The results of low-energy (<1MeV) protons investigation near geomagnetic equator (L≤1.15) at different altitudes are presented. Used data from Active satellite (1989–1991, altitude 500–2500, inclination 82°, protons with energy Ep=50 – 500 keV). The proton spectra were obtained during absolute quiet period (−301.04. The characters of proton distributions with energies Ep>100 keV and Ep<100 keV are strongly different. There are features of altitude distribution connected with geomagnetic activity level: during quiet time at night hours all energy protons registered at all altitudes, at day hours the most intensive proton fluxes of were registered at 700–900 km; during disturbed time at night hours they are absent at 900–1100 km, whereas at day hours the essential high-energy proton fluxes appears only at 700 km