The availability of the very neutron-rich beams of the SPES facility at relatively low intensities is very tempting to extend the study of near- and sub-barrier fusion to exotic systems. However, the use of RIBs is often very challenging because of the low available intensities and the forward focusing of the fusion evaporation residues (ER). Thus, applications of radioactive beams require detection systems with very high efficiency and detectors that avoid unnecessary energy straggling and angular dispersion and assure fast response.
A new set-up for fusion cross section measurements, especially designed for the low intensity beams which will be delivered by the SPES facility, especially designed for the low-intensity beams delivered by the SPES facility, has been developed at the National Laboratories of Legnaro (LNL). The set-up is inspired on a similar one built at Oak Ridge some years ago, with a significant improvement due to the use of a very fast ionization chamber (IC). This new fast IC is designed to ensure a high counting rate particle identification for fusion studies involving exotic beams up to 105 pps. Indeed, the IC will be placed at 0° with respect to the beam direction without filtering out the beam ions in any way. To reduce the response time of the ionization chamber, a design using a series of tilted electrodes has been adopted. The aim is to be able to detect and identify fusion events within a total counting rate up to 100-200 kHz.
The set-up already existing at LNL for fusion measurements (based on the electrostatic beam deflector) has been upgraded by using the new IC, and will remain in use for experiments with high-intensity stable (and upcoming exotic) beams. Several tests with stable beams have been performed to optimize the performance of the IC. The results of the in-beam tests performed so far will be showed in this seminar.