TARGET STRUCTURE AND IN-BEAM ELECTRON-SPECTRA

The main features of the interplay between the target structure and th e accelerated ion beam characteristics suitable for an in-beam e-gamma measurement are discussed in detail. In particular, the different typ es of ''spurious'' electron (and photon) spectra overlapped with in-be am internal conversion electrons (and discrete gamma-rays) are reviewe d as well as the most efficient experimental methods used for their at tenuation. Furthermore, the general characteristics of particle beams, targets and electron spectrometers required for prompt and delayed in -beam e, gamma and e-gamma measurements are also compared. Moreover, t he relative magnitude of the electron line Doppler broadening correspo nding to the perpendicular and the collinear geometry is briefly discu ssed and illustrated by a few in-beam e-gamma studies of Pm and Eu iso topes produced by accelerated ions (H-2(1) and Li-7(3)) bombarding ver y thin Nd(+C) backed targets. Finally the most recent developments mad e at Orsay towards multi e-gamma detector assemblies lead to a broad d iscussion concerning the most suitable targets to be inserted within s uch instrumental arrangements.