The Increase in the Primary Cosmic-Ray Intensity at High Latitudes, and the Non-Existence of a Detectable Permanent Solar Magnetic Field

Abstract

The primary cosmic-ray intensity at Churchill, Manitoba (geomagnetic latitude 69\ifmmode^\circ\else\textdegree\fi{} N) has been compared directly with that at Swarthmore, Pennsylvania (geomagnetic latitude 52\ifmmode^\circ\else\textdegree\fi{} N). The measurements, obtained with identical vertical quadruplecoincidence counter trains, have revealed an increase at the more northern station caused by the presence in the primary radiation of particles having energies below that which would have been permitted had the sun's magnetic field been effective to the extent previously assumed. The ratio of intensities is $\frac{{I}_{T}(0,69\ifmmode^\circ\else\textdegree\fi{})}{{I}_{T}(0,52\ifmmode^\circ\else\textdegree\fi{})}=1.46$. Intensity vs. altitude curves were obtained with several different thicknesses of absorber interposed in the counter trains.