Solar cycle changes in inner-zone protons

Abstract

Calculations on time dependence of the inner Van Allen belt proton population show that large changes of the population up to a factor of 50 will take place during the solar cycle. The effect is most pronounced for the region of B‐L space corresponding to minimum altitudes of 300–700 km. Because protons of different energies respond to the changing solar cycle at different rates, the proton energy spectrums will change with time also.

Radiation belts in the region of the South-Atlantic magnetic anomaly

“…The appropriate results are shown in Figure 9 for the time x Energy,MeV interval of October-November, 1963. In the region of the artificial radiation belt (L~< 1.7) at energy E ~> 2 MeV, the electron spectrum does not contradict, within the experimental errors, the spectrum expected from the decay of the fission fragments soon after the explosion (CARTER et al, 1959). A similar result follows from WEST et al…”

Summary of Particle Populations in the Magnetosphere

“…They showed that only part of the changes were adiabatic. At low altitudes the solar cycle effect predicted by Blanchard and Hess (1964) finally has become evident. Nakano and Heckman (1968) have reported the 63 MeV protons with minimum altitudes between 220 and 375 km decreased a factor of 2 between mid 1966 and late 1967 after remaining constant for the previous 3-1/2 yr.…”

Time serial analysis of the induced LEO environment within the ISS 6A

“…The proton environment is then proportional, in steady state, to the source (neutron albedo) and the population lifetime (atmospheric interaction) as shown by Blanchard and Hess (1964). The interpolation procedure we will implement assumes a steady state solution to the population kinetic equations as the product of the albedo neutron source and the particle population lifetimes that are proportional to the product of neutron monitor count rate and solar radio output at the 10.7 cm wavelength related to atmospheric heating resulting in expansion.…”