Search

Magnetic spectrometers of charged nuclear reaction products, properly matched with an accelerator beam line, have become a very effective setup for the performance of precise nuclear experiments involving ultrasensitive accelerator-based mass spectrometry and investigation of rare events, as well as experiments with radioactive nuclear beams. The procedure for increasing the efficiency and resolution of the available magnetic spectrometer at the Flerov Laboratory of Nuclear Reactions by a few orders of magnitude by means of its matching with the beam line is described.

International audience; Some regularities in the production of isotopes with 6 ≤ Z ≤ 14 are investigated in reactions induced by 32,34,36S beams at 6 < E < 75 MeV/A on targets of natC, 181Ta and 197Au. The isotope yields and the most probable fragment mass A (for a given Z) are studied as a function of target, projectile mass and energy. A comparison is made of the experimental data at low energies with calculations in the framework of the dynamical model of deep inelastic collisions. The obtained data are considered from the point of view of the feasibility of heavy ion beams for producing nuclei far from the line of stability.

A combined heavy reaction product spectrometer capable of operation at zero degree is described. It performs the simultaneous analysis of charged particles according to several parameters: magnetic and electrical rigidity, time of flight and kinetic energy. The spectrometer selectivity was tested by measurement of the 197 Au recoil nuclei elastically scattered at 0 ± 0.5° from a gold target by a 175 Mev 40 Ar ion beam and was found to be ∼ 10 −13 .

The time dependence of the ionization for isotopically different heavy ion fusion recoil ions has been observed. Delayed nuclear-induced autoionization of recoil ions caused by the decay of high-spin nuclear isomeric states by internal conversion was established. Internal conversion in isolated recoil atoms results in a drastic rearrangement in the atomic cloud with a loss of a great number of orbital electrons. Possibilities for the use of the observed phenomena in atomic and nuclear physics are discussed.

A new beam line is now fully operational at Laboratori Nazionali di Legnaro (LNL) TANDEM/ALPI accelerator for the in-flight production of light low-energy Radioactive Nuclear Beams (RNBs). The RNBs are produced by inverse kinematics reactions induced by heavy ions, such as 17O and 6Li, on 1H and 3He gas targets. The beam line has a large solid angle acceptance ( Δ Ω = 10 msr ) and a high rejection capability of spurious beams due to the combined action of magnetic rigidity and velocity filtering. A very pure (100%) and high intensity ( 3.6 × 10 6 pps ) 17 F 9 + secondary beam at E lab = 86 ± 1 MeV has been produced and used for experiments. A 8 B 5 + beam at E lab = 33 MeV , with a production rate of ∼ 2 × 10 3 pps , is presently under commissioning.

The EXOTIC collaboration is installing a facility for the in flight production of exotic ion beams at INFN Legnaro National Laboratories (LNL). The RIBs are produced in inverse kinematics mode via intense TANDEM/ALPI primary beams hitting a light gas target (H, d, 3 He, 4 He). The results of the optics calculation for 17 F produced by the 17 O(p,n) 17 F reaction are presented. Special care has been adopted to stop, at several points perpendicular to the beam direction, the contaminants due to the primary beam.