A Study of the Diurnal Time Variations of the High Energy Cosmic Radiation

Abstract

Observations of the diurnal time dependence of the high energy primary cosmic ray intensity have been made at Wellington, N.Z. (geographic latitude 41°S, geomagnetic latitude 45.5°S, altitude 130 metres) during the period August 1955 to August 1956 by the recording of extensive air showers. Primary particle energies of 10 15 ev were selected by an array recording vertical showers whilst energies of 2 x 10 16 ev were studied by detecting extensive showers incident in the East-West plane from directions through which the centre of the galaxy passed. Fourier analysis of the results has shown no significant variation in either solar or sidereal time for primary cosmic rays of these energies. No variation was apparent in the results of observations of the meson intensity recorded with two narrow angle telescopes (± 15°) inclined at angles of 48° to the vertical in the East-West plane. Such results as these appear to be consistent with those reported by most other observers.