1. Target and detectors 9Li 11Li n n Coulomb breakup Target nucleus
The detection of -rays from Coulomb excitation and neutron transfer reactions in RIBs requires a very efficient Ge-detector array. The -ray multiplicity is low, typically less than three, which entails the Ge-detectors to be placed closer to the target than usual. Moreover, the anti-Comptons on the sides are not really needed allowing a denser coverage of the solid angle by Ge-detectors.
11Li n n
Coulomb breakup
Target nucleus
Although the bombarding energy of 2 MeV/u is rather small, the reaction products have typical velocities of 5-10% c which results in significant Doppler shifts of the deexcitation -rays. A high Ge-array granularity is therefore absolutely necessary to reduce the Doppler-broadening of the -rays. To further allow for Doppler shift correction a position-sensitive silicon detector (DSSSD) detects scattered ions (or the recoiling target nuclei) in relevant solid angle.
In order to detect also -rays spectra without coincidence with the scattered (recoiling) nuclei, despite of the large anticipated background radiation, a standard start detector will be used and allow a better timing than the LINAC reference.