Galactic Cosmic Ray Anisotropies in the Energy Range 10¹¹ – 10¹⁴eV.

Abstract

Abstract A review is presented of the evidence for anisotropies of galactic origin in the charged cosmic ray particle intensity at median primary energies of detection in the range 10 11 – 10 14 eV. It concerns the period from 1958, when the first substantial long-term observations at energies of solar and sidereal modulation near 10 11 eV commenced underground, until 1984, by which time results were available from a number of years of accurate observations with detectors of small air showers at energies near 10 14 eV, too high for complicating effects of solar origin to be present. There is evidence for the existence of both unidirectional and bidirectional galactic anisotropies over the whole energy range. Tentative descriptive models are discussed in relation to advances both in solar and sidereal analytical techniques and in the ability of experimenters to account for and exploit the modulating influence of the heliomagnetosphere at the lower energies of detection.