Results of a High Altitude Cosmic-Ray Survey Near the Magnetic Equator

Abstract

Electroscope and Geiger counter observations have been taken with free balloons at geomagnetic latitudes of 3°, 17°, and 25°N. The most important results are as follows: (1) The Geiger counter technique with a single counter will give results very close to those obtained with the electroscope and of comparable accuracy. (2) Vertical coincidence measurements give rise to markedly different values for the relative amounts of incident energy at various latitudes, as compared with the electroscope or single counter data. (3) Within the experimental error, no difference was obtained between the vertical coincidence curves at 3° and 17°, and thus no new energy lies in the primary energy spectrum between the limits of 17 and 15 Bev. (4) This is direct evidence for a banded structure in the primary cosmic-ray spectrum. (5) Flights made with triple and quadruple coincidences, and also with counters arranged to record showers, showed that showers do not significantly affect the vertical coincidence measurements.