Angular resolution of particle experiments on board spacecrafts without magnetic stabilisation

Abstract

For a particle telescope looking into an anisotropic pitch-angle distribution the gathering power depends on the particle distribution function F( ϑ) and on the angular aspect of the experiment ψ( t) with regard to a preferential direction. The response function of three cylindrically symmetric detector configurations on different angular particle distributions and, as a consequence, the enlargement of the path lengths of particles passing through the detector combined with accordingly higher energy loss is discussed. Finally the mechanical shielding around the detectors is investigated according to its effectiveness. Highly energetic particles penetrating through the shielding into the sensitive detector volume cause a background counting rate which is modulated with the aspect angle ψ( t).