Electron spectrometer for “in-beam” spectroscopy

A spectrometer that uses a set of silicon detectors and a combination of two magnetic fields for separation and for transportation of electrons from the target position to the silicon detectors has been constructed at the University of Lodz for “in-beam” studies of internal conversion electrons. The separation of electrons from positrons is achieved in a simplified mini-orange set-up. The transportation field is produced by a set of permanent magnets arranged in a form of coaxial rings. The background from delta electrons and gamma rays is highly reduced. The spectrometer was designed to be coupled to OSIRIS-II, the array of gamma-ray detectors at the Warsaw Heavy Ion Laboratory. The performance of the spectrometer is illustrated by examples of spectra obtained from the conversion electron spectrometer and also the OSIRIS-II array, which were recorded in- and off- beam.