A study of the diurnal variations of the cosmic ray intensity

The Cosmic Ray Intensity was measured in London over the years 1955 to 1958 using G.M. telescopes, measuring the hard component of the intensity at sea-level.The thesis concerns mainly the solar diurnal variation of the intensity.An analysis of the results for individual days, over the period of the IGY, shows the amplitude and direction of the anisotrophy changes in an amazing pattern.Careful study shows a correlation with magnetic activity, Comparison with neutron monitor results shows close agreement in phase and an amplitude ratio varying from 1:1 to about 4:1.It is suggested the higher neutron amplitude is due to greater modulation of the particles of energy E where 3 Gev E 4. 10 Gev, these limiting energies being the threshold energies of the two types of detector, and that the solar diurnal variation reflects the interplanetary state in the neighbourhood of the earth.A study has also been made of the sidereal variation.The experimental results show this is small, of the order of 0.01%.Calculation of the theoretically expected sidereal variation confirms this figure, Corrections to be applied for the changing solar dailyvariatic:of the-same order of magnitude, making the effect extremely difficult to confirm or disprove.Contents.Chapter 1. Introduction.