How precisely can the energy of a marker peak in an RBS spectrum be determined?

We studied, how precisely the position of a marker peak in an Rutherford ba ckscattering (RBS) spectrum can be determined. For that purpose, we chose t he following approach. Repeatedly, the primary energy of a proton beam was set to one of three selected energies ( 100, 350 and 700 keV). RES spectra of a thin Pt marker (on carbon) were measured by a conventional PIPS detect or, and the energy position of the marker peak was determined by a least sq uares fit. During the measurement, the electronic system was kept at a cons tant temperature within +/-0.1 degreesC in order to avoid any signal drift. From a statistical evaluation of the peak position and of the actual prima ry energy information on the precision of both, energy setting and RES eval uation was obtained. A relative uncertainty of 4 x 10(-4) for the energy se tting, and an uncertainty of approximate to1% of the detector FWHM for the evaluation of the marker position are found. (C) 2001 Elsevier Science B.V. All rights reserved.