Engineering tool for trapped proton flux anisotropy evaluation.

Area of Science:

• Space physics
• Plasma physics
• Astrophysics

Background:

• High-energy trapped proton fluxes exhibit strong anisotropy at low altitudes.
• Earth's atmospheric density significantly influences proton flux, causing steep pitch-angle distributions and East-West effects.
• The East-West effect is attributed to the finite gyration radius of protons.

Purpose of the Study:

• To develop a software package, ANISO, for evaluating averaged energy spectra of trapped proton unidirectional fluxes.
• To deduce angular-dependent proton flux spectra from omnidirectional flux data for specific spacecraft orbits and attitudes.
• To incorporate established models for pitch-angle distributions into the flux calculations.

Main Methods:

• Development of the ANISO software package.
• Utilizing the AP-8 omnidirectional flux model as a basis.
• Incorporating the Armstrong et al. (1990) model and a model based on Badhwar and Konradi (1990) for pitch-angle distributions.

Main Results:

• The ANISO software enables the calculation of anisotropic proton flux spectra.
• The model accounts for the influence of atmospheric density on proton flux characteristics.
• The software provides averaged energy spectra for unidirectional proton fluxes.

Conclusions:

• The ANISO package is a valuable tool for understanding and predicting high-energy proton environments around Earth.
• Accurate modeling of proton anisotropy is crucial for spacecraft design and mission planning.
• The software enhances the analysis of trapped proton fluxes by considering orbital and attitude-dependent factors.