Example of gyroradii of particles with 1 MeV < E < 16 MeV during quiet geomagnetic conditions. Left: Gyroradius map in the equatorial plane. Right: Gyroradius map in the meridional plane (X = 0). The gyroradii of these particles can be as large as tens of R_E. Here, X-axis is directed toward the Sun, and Y-axis is in the equatorial plane, and Z-axis is such that the frame of reference is right-handed. The free-space energy spectrum of the simulated energetic particles is taken from Badavi et al. (2011).