Theoretical geomagnetic effects in cosmic radiation

A brief review is given of the theory of the effect of the earth's magnetic field on cosmic radiation. The basic results of the theory are presented in graphical form, and are intended to be useful in the experimental investigation of cosmic radiation. The material presented includes curves of minimum energy of arrival, as measured in Störmer units, versus azimuth angle, for zenith angles at 10° intervals, arising from the combined Störmer and shadow cone (for all latitudes at 10° intervals), and from the main cone (at latitudes 0°, 20°, and 30°). Minimum momentum in Be V/c, and minimum energy in BeV, for protons and heavy nuclei, are given versus geomagnetic latitude for azimuths N, S, E, and W, at all zenith angles in 15° steps. Other available presentations of the basic theory are mentioned and the conversion procedures involved in the application of the theory are described.