A dedicated decay-spectroscopy station for the collinear resonance ionization experiment at ISOLDE

Abstract A new decay-spectroscopy station (DSS) has been developed to be coupled to the collinear resonance ionization spectroscopy (CRIS) beam line at CERN-ISOLDE. The system uses a rotatable wheel with ten 20 μ g / cm 2 carbon foils as beam implantation sites for the efficient measurement of charged decay products. Silicon detectors are placed on either side of the carbon foil in an optimal geometry to cover a large solid angle for detecting these charged particles. In addition to the silicon detectors at the on-beam axis position, a second pair of off-beam axis detectors are placed at the wheel position 108° away, allowing longer-lived species to be studied. Up to three high purity germanium detectors can be placed around the chamber for particle-gamma correlated measurement. The radioactive beam is transported through the CRIS beam line before implantation into a carbon foil at the DSS. All materials used in the DSS are UHV-compatible to maintain high vacuum conditions required by the CRIS beam line. This paper describes the DSS and presents the first data collected at the setup during the commissioning run with 221 Fr.