Earth Albedo Neutrons from 10 to 100 MeV

Energetic Neutrons Leaking from the Top of the Atmosphere

“…This results in a latitude variation at solar minimum of 15 at 19 MeV and 5 at 2 GeV. Figure 2 compares the results of the normalized calculation with the measured results of Jenkins et al,, s Preszler, Simnett, and White, 9 Eyles, Linney, and Rochester, 10 scribed above) for this solar epoch and vertical cutoff rigidity determined the normalized calculated leakage rate spectrum presented in Fig. 2, which is only 25% lower than the 4.5-GeV/e unnormalized solar-minimum spectrum presented in Fig, 1.…”

The Magnetosphere

“…_ The cosmic rays responsible for producing the source term S in (223) are extremely energetic (£'^10GeV) protons and heavier ions that have originated elsewhere in the Galaxy. Fermi, 1950, p. 230) is that a particle of charge q can arrive with momentum ρ at magnetic coordinates (τ,θ,φ) from r= 00 if (and only if) (Preszler et aL, 1972) specify omnidirectional flux of albedo neutrons at magnetic latitude 40° N, altitude 36 km. From the perspective of radiation-belt physics, however, cosmic rays are charged particles incident on the magnetopause and present in the magnetosphere with rigidities (moment per unit charge) too large to justify a kinematical analysis based on the adiabatic invariants of charged-particle motion.…”

Neutron high-energy spectra at 5 mbar near the geomagnetic equator

“…To compare In Figur e 3 we observe that for energies above 30 M eV our albedo neutron spectrum is in good agreement, with regard to general shape and slope, with the experimental results of Preszler et al [1972] as well as with the theoretical curve of Freden and White [1962]. These results show that the calculated slope for both the low-energy range and the high-energy range is in good agreement with our experimental spectra.…”