EXPLORATION OF X-RAY AND CHARGED-PARTICLE SPECTROSCOPY WITH CCDS AND PSDS

Two alternative detector types have been studied for use in the Eindho ven Scanning Ion Microprobe set-up. First, the applicability of a Char ge Coupled Device (CCD) system for X-ray spectroscopy has been explore d. Second, some properties of the SiTek type 1L30 Position Sensitive D etector (PSD) for charged-particle spectroscopy have been studied. A l iterature survey shows that excellent X-ray spectroscopy with a CCD sy stem is feasible, particularly with a deep-depletion backside-illumina ted CCD and low speed read-out. If, however; high-speed CCD read-out i s required, such as for scanning microprobe experiments, a CCD system cannot be used for spectroscopy due to excess read-out noise. For the PSD, noise theory calculations are presented, which result in a noise shaping time for optimal energy and position resolution. In practice, however, a much longer time is needed to obtain sufficient energy and position linearity. Characterization measurements of the PSD using our 4 MeV He+ microprobe are also described. A position resolution of 0.4 7 mm and a position linearity of better than 0.15% detector length are found. In addition, an energy linearity better than 0.3% and an energ y resolution of 36 keV are measured. The latter will have to be improv ed, to make the PSD suitable for charged-particle spectroscopy applica tions. (C) 1998 Elsevier Science B.V.