Electron capture for fast highly charged ions in gas targets: An empirical scaling rule

Shell-differential electron capture in heavy ion-atom collisions at moderate collision velocities

“…Charge exchange cross sections have been deduced from the target thickness dependence of the charge state distribution. Both the values, those extracted from the x-ray emission and the above ones, are in consonance with calculations performed using the Eikonal approximation of Eichler [2] and the semi empirical, non-relativistic scaling prescription for non-radiative capture by Schlachter et al [3].…”

Storage ring at HIE-ISOLDE

“…In the octupole Z ∼ 56, N ∼ 88 and Z ∼ 88, N ∼ 134 regions it is now possible to provide more precise information on the nature of the octupole collectivity through the Coulomb excitation of radioactive beams. Recent measurements have demonstrated that B(E3) values of nuclear transitions, a direct measure of octupole correlations, can be measured in nuclei such as 224 Ra. In both of these examples the combination of the high quality of the cooled beams that are extracted from the storage ring together with advances in particle spectrometer design (particularly the HELIOS concept, see chapter 2.7.4) allow the nuclear state population from (mostly) single-step excitation be directly measured.…”

“…For 3 MeV/u and above the capture cross-section in the residual gas according to Schlachter [194] is < 10 −15 cm 2 for one of the worst cases (q = 85+). Thus a relaxed vacuum pressure of < 10 −6 mbar in the high energy end of the linac and the transfer line to TSR is sufficient in order not to lose more than 10% of the beam.…”

“…Schlachter et al [224] have determined an universal scaling rule for electron capture rates for all ions. They introduced a reduced cross sectionσ = σZ 1.8 gas /q 0.5 and a reduced energy per nucleonẼ = E/(Z 1.25 gas q 0.7 ), where the projectile energy is given in kev/A and σ is the cross section in cm 2 .…”

Multiple-electron processes in fast ion-atom collisions

“…Early charge-transfer results have been summarized [ 4] and a scaling rule for electron capture has been determined [5]. This scaling rule is useful for predicting the magnitude of as-yet unmeasured cross sections.…”