Studies of X-Rays and cosmic rays of galactic origin.

[摘要] This thesis discusses the results of research in two independent fields. Part A. presents an analysis of cosmic ray variations using techniques evolved from the calculation of cosmic ray trajectories in a spiral interplanetary magnetic field model, while Part B discusses the design, preparation and results of two rocket-borne X-ray astronomy experiments. The cosmic ray section divides into a consideration of galactic cosmic rays which (a) reach the Earth without being appreciably scattered, and (b) experience significant scattering eo-route to Earth. In category (a), for selected energies (> 50GeV) and for 24 times of day, asymptotic directions at the edge of the solar cavity are calculated in a 4-sector spiral interplanetary magnetic field model, for cosmic rays which arrive in the equatorial plane. These asymptotic directions are strongly dependent on the position of the Earth within the sector structure, and when used to derive the sidereal variations associated with a l-way and 2-way anisotropy in the galaxy, this dependence causes a 27 cycle/year (13.5 day period ) modulation in both the diurnal and semidiurnal variations. For a 1-way galactic anisotropy the diurnal and semi diurnal variations have approximately the same amplitude and the diurnal variation is further modulated at 1 and 2 cycles/year, and the semidiurnal at 1 cycle/year. In category (b) a new technique is developed which allows the daily variation associated with any arbitrary dependence of cosmic ray number density on heliocentric radius r. to be calculated. For 24 times of day T.

[发布机构] The University of ADELAIDE

[效力级别] cosmic rays