Albedo trajectories for protons of 0.5, 1.0, 1.5, and 2.0 Bev in the earth's dipole and quadrupole magnetic field were computed. The zenithal, azimuthal, latitude, and magnetic rigidity effects were studied. The quadrupole induces an asymmetry which seems only to be important near the geomagnetic equator. Shadow cones were obtained for one point of incidence.

• Received 6 December 1955

DOI:https://doi.org/10.1103/PhysRev.101.1821