TRANSMISSION AND ABSORPTION MEASUREMENTS OF HIGH ENERGY ELECTRONS WITH METALLIC AND INSULATING FOILS

📄 Project Abstract

The possible dependence of the extrapolated ranges of electrons on the detector characteristics has been investigated by two methods. These experiments were performed under well standardised geometrical conditions, employing electron beams (0.25 - 0.75 MeV) derived from a Van de Graaff electrostatic generator. The possible effects of poor geometry and small bias voltages on range values have also been investigated, but the results show that these effects could be kept very small in normal transmission measurements. The range values obtained in five metals (Be, Al, cu Ag and Au) and in four dielectrics (glass, mica, sulphur and polystyrene)by direct curre.it collection method and in Al, Ag and mica by an ionisation method, show that the latter method yields larger range values. A comparison with other results showed that the range value6 obtained with the Geiger counter are also greater than those obtained by the current collection method. The ionisation-in- depth results in Al showed g...