On the angular distribution of secondary particles of high energy jet showers

Abstract

The data from nucleonic component detectors (neutron intensity monitors) are analyzed for the amplitude and phase of maximum intensity of the 24 hr variation at the geomagnetic equator and at 48 deg N. The same analysis is performed on selected charged particle detectors. The analysis covers 1953-55, which includes the time of solar cycle (sunspot) minimun in 1954. Puring 1954 it is known that the 24 hr variation possesses an anomalous behavior. It is shown that during 1953 there is an interval of 9 months or more when the solar daily variation appears to undergo a progressive phase shifi whose time of maximun lies in the range of 0800-1000 hr on a sidereal time scale. This anisotropy certainly exists in the radiation falling upon the atmosphere, and it is likely, although not proven, that the anisotropy prevails even outside the terrestrial field. The question of whether this sidereal effect is spurious or real is discussed in relationship to the recent results on the modulation of cosmic ray intensity within the solar system. (auth)