Solar Magnetic Moment and Diurnal Variation in Intensity of Cosmic Radiation

Abstract

The effect of the earth's magnetic field upon the orbits of primary cosmic-ray particles is computed in detail for the special case of those particles arriving vertically anywhere on the earth's surface. A procedure is evolved for taking this deflection in conjunction with the previous deflection in the magnetic field of the sun, and thereby calculating for any given cosmic-ray energy spectrum an expected diurnal variation in total cosmic-ray intensity. Examples of this procedure are given for an inverse power spectrum applied to two different magnitudes of the solar magnetic moment. The sample calculations are made for several latitudes of observation, and the expected diurnal variation is then studied as a function of the solar magnetic moment and of the energy spectrum. The phase of the variation is found to be very sensitive to the solar moment, and so it is hoped that a successful experimental determination of the diurnal variation will settle the question of the existence and magnitude of a permanent solar magnetic moment.