Neutron-rich nuclei produced at zero degrees in damped collisions induced by a beam of 18O on a 238U target

Cross sections and corresponding momentum distributions have been measured for the first time at zero degrees for the exotic nuclei obtained from a beam of 18O at 8.5 MeV/A impinging on a 1 mg/cm2 238U target. Sizable cross sections were found for the production of exotic species arising from the neutron transfer and proton removal from the projectile. Comparisons of experimental results with calculations based on deep-inelastic reaction models, taking into account the particle evaporation process, indicate that zero degree is a scattering angle at which the differential reaction cross section for production of exotic nuclei is at its maximum. This result is important in view of the new generation of zero degrees spectrometers under construction, such as the S3 separator at GANIL, for example

Fusion-Fission is a new reaction mechanism to produce exotic radioactive beams

International audiencePioneering in-flight fission experiments at GSI intensively explored neutron-rich isotopes with Z=28-60. Elements with Z > 60 were weakly produced in these experiments. The alternative technique to produce these nuclei, fusion-fission reactions with heavy targets in normal kinematics, suffers from difficulties with fragment extraction from the target and their identification. In-flight fusion-fission could be a useful production method to enable a large number of experiments aimed to identify new neutron-rich isotopes and study their properties. In particular, the study of the beta decay properties of fission products and their lifetimes is of central importance to numerous applications in nuclear physics and related disciplines, such as astrophysics, particle physics and nuclear engineering. A fast analytical Fusion-Fission model has been developed in the LISE++ framework to estimate the expected yields in in-flight fusion-fission experiments

The response of a large CsI (TI) detector to light particles and heavy ions in the intermediate energy range

Particle dependent response of a CsI(Tl) scintillation detector with an entrance surface of 314 cm2 has been investigated using a secondary beam facility at the energy range from 2 to 77 MeV/A. The mass and charge identification of particles with Z = 1-18 has been performed by means of time-of-flight and energy measurements. The dependence of light output on E, Z and A has been studied. Using a pulse shape analysis possibility to identify the masses of momentum separated particles with charges of Z = 1-7 is presented

Fission fragment yields from heavy-ion-induced reactions measured with a fragment separator

The systematic study of fission fragment yields under different initial conditions has provided valuable experimental data for benchmarking models of fission product yields. Nuclear reactions using inverse kinematics coupled to the use of a high-resolution spectrometer with good fragment identification are shown here to be a powerful tool to measure the inclusive isotopic yields of fission fragments. In-flight fusion-fission was used in this work to produce secondary beams of neutron-rich isotopes in the collisions of a$^{238}$U beam at 24 MeV/u with$^{9}$Be and$^{12}$C targets at GANIL using the LISE3 fragment separator. Unique identification of the A, Z, and atomic charge state, q, of fission products was attained with the $\Delta E$ -TKE-B $\rho$ -ToF measurement technique. Mass, and atomic number distributions are reported for the two reactions. The results show the importance of different reaction mechanisms in the two cases. The optimal target material for higher yields of neutron-rich high-Z isotopes produced in fusion-fission reactions as a function of projectile energy is discussed