Production cross sections of more than 270 isotopes ranging from Z = 59 to Z = 82 were measured in the reaction 208Pb(1 GeV A)+Cu. The method of identifying the projectile fragments and evaluating the production cross sections is described. The experimental data are compared with a modern version of the abrasion-ablation model and with the empirical parameterization EPAX. Apart from deviations in the details they both show an overall good agreement. The cross sections of those fragments which are produced by the removal of protons only test the lower part of the excitation energy distribution. For the first time, the four-proton removal channel could be observed.

For isotopically separated secondary beams of neutron-deficient nuclei delivered by the SIS-FRS facility at the GSI, electromagnetic fission-in-flight induced at 430 · A MeV in a secondary lead target was observed. Electromagnetic fission cross sections were measured for 232,233,234U, 232Pa, 220,221,222Th, 218,…,222Ac and 215,217,218,219Ra. By using a simple analysis, fission barrier were derived from the electromagnetic fission cross sections. For the U- and Pa-isotopes, these barriers agree with those measured previously by other methods. The new barriers for Th- and Ac-isotopes are smaller than predicted theoretically.

The proton-rich nuclei Cr-44, Mn-47, Fe-48,Fe-49 and Co-50 have been produced by fragmentation of a Ni-58 beam at 650 MeV/u. The isotopic separation of these nuclei has been achieved with the GSI Projectile-Fragment Separator FRS. The isotopes have been identified in flight by Delta E-ToF-B rho measurements. After implantation in a stack of seven silicon detectors, the signals measured for implantation and radioactive decay were unambiguously correlated in time due to low counting rates. On the basis of the two proton peaks observed for Co-50 at (2034+/-30) keV and (2740+/-41) keV with a half-life of (44+/-4) ms, a partial decay scheme is proposed for this nucleus. A single proton peak at (959+/-33) keV was observed for Fe-48 with a half-life of (44+/-7) ms. This emission is attributed to the decay of the T = 2 isobaric analog state in Mn-48. No deviation from the quadratic form of the isobaric multiplet mass equation is observed. Additional information on beta-delayed proton branches of Fe-49, Cr-44 and Mn-47 was also obtained.

The proton-rich nuclei 44Cr, 47Mn, 48,49Fe and 50Co have been produced by fragmentation of a 58Ni beam at 650 MeV/u. The isotopic separation of these nuclei has been achieved with the GSI Projectile-Fragment Separator FRS. The isotopes have been identified in flight by ΔE-ToF-Bϱ measurements. After implantation in a stack of seven silicon detectors, the signals measured for implantation and radioactive decay were unambiguously correlated in time due to low counting rates. On the basis of the two proton peaks observed for 50Co at (2034±30) keV and (2740±41) keV with a half-life of (44±4) ms, a partial decay scheme is proposed for this nucleus. A single proton peak at (959±33) keV was observed for 48Fe with a half-life of (44±7) ms. This emission is attributed to the decay of the T = 2 isobaric analog state in 48Mn. No deviation from the quadratic form of the isobaric multiplet mass equation is observed. Additional information on β-delayed proton branches of 49Fe, 44Cr and 47Mn was also obtained.

A complete identification in mass and nuclear charge for relativistic projectile fragments up to uranium is possible at the fragment separator (FRS) at GSI by using the scintillation detector equipment described in this paper. It was successfully used in experiments with primary beams ranging from oxygen to uranium with energies from 300 to 1000 A MeV. A mass-resolving power of A/Delta A = 407 (FWHM) was obtained for 0.95 A GeV U-238 fragments.

The projectile fragmentation in peripheral nuclear collisions was studied using ≈ 1 GeV·A of 208 Pb and 238 U from the SIS at GSI, impinging on a copper target. Lead and thallium isotopes from the fragmentation of 208 Pb as well as uranium and protactinium isotopes from 238 U, were selected by the fragment separator FRS. In contrast to the fragmentation of 208 Pb, the cross sections for the production of heavy fragments from 238 U are strongly reduced by fission. The measured isotopic yields may be explained quantitatively by calculations in the framework of the abrasion-ablation model, if fission is allowed to compete with particle evaporation in the deexcitation of the prefragments.

At the projectile-fragment separator FRS of GSI, relativistic secondary beams of about 520 MeV/nucleon were produced by fragmentation of a primary beam of58Ni at 650 MeV/nucleon in a beryllium target. By means of aΔE—Bρ—TOF measurement, the fragments were identified and their charge-changing probabilities in targets of (CH2)n, C, Al, and Pb placed at the exit of the FRS were determined. Whereas a first article dealt with the total charge-changing cross sections, we describe in this second article the element distributions of these secondary fragments, which are found to depend strongly on the isospin of the secondary projectile as well as on the target material. In the case of the lead target, the influence of the electromagnetic dissociation is clearly visible in the one-proton and two-proton removal channels. The preference for the formation of even-Z fragments is much more pronounced for exotic secondary projectiles than for projectiles close to stability. Calculations with a geometrical abrasion-ablation model allow to understand the global features of the experimental data. However, far from stability, the discrepancies between calculations and experimental data increase.

This paper reviews two experiments performed at GSI and GANIL. Using a primary beam of 58Ni at 650 MeV/nucleon impinging on a beryllium target, production cross sections of proton-rich fragments from projectile fragmentation have been measured at the projectile-fragment separator FRS at GSI. The production rates measured demonstrate that counting rates much higher than expected can be obtained at the proton drip line. The results from spectroscopy measurements show that no Thomas-Ehrmann effect is present in our data which means that the decay energies and masses can be well predicted by using e.g. the IMME. The secondary reactions evidence a slight increase of the interaction cross sections when approaching the proton drip line. Finally, in an experiment performed at the SISSI/LISE facility at GANIL using a 78Kr primary beam, we have observed the 5 new isotopes 60Ga, 64As, 69,70Kr, and 74Sr. However, we have not found any evidence for 69Br which was reported to be observed with a few counts at MSU. These new findings change our understanding of the path and of the ending point of the rp process.

Total nuclear charge-changing cross sections σΔz in a CH2 target were measured for 54 isotopically identified secondary beams around A = 60 produced from a 1A·GeV86Kr beam via projectile fragmentation. With secondary beams between Tz = 12 and −3, the isospin dependence of σΔz was investigated systematically. Contrary to the predictions of so-called overlap formulae, the σΔz values are not a function of the projectile mass alone, but are found to depend on the projectile isospin. A comparison of the data with the predictions of the statistical abrasion model reveals that this behaviour can be understood by the combined influence of the abrasion and the ablation phase in relativistic heavy-ion collisions. On the basis of this improved understanding, previous findings of anomalously large cross sections of secondary-reaction products are discussed.

As part of a comprehensive study of uranium fragmentation at relativistic energies at the GSI projectile fragment separator, FRS, inclusive neutron-removal cross sections have been measured for severalxn channels at projectile energies of 600 and 950A MeV using targets of Al, Cu and Pb. The variation of the experimental cross sections with target nuclear charge is used to disentangle nuclear and electromagnetic contributions. The electromagnetic cross sections agree surprisingly well with a simple harmonic oscillator calculation of giant dipole resonances based on measured photonuclear cross sections and do not require an extra enhancement of the two-phonon giant dipole excitation as concluded from similar measurements with197Au.

A method for measuring the cross sections for the neutron removal from relativistic secondary projectiles by means of a two-stage magnetic spectrometer is presented. Its application to the 1n- and 2n-removal from 56Ni and 52Fe at 470 A·MeV in an aluminum target is described. The results are compared to the intranuclear-cascade plus evaporation model and to the statistical abrasion-ablation model. The influence of the nuclear surface on the few-nucleon removal reactions is discussed. The neutron-removal cross sections are combined with total charge-changing cross sections to obtain the total interaction cross sections of 56Ni and 52Fe.

Spatial isotopic separation of relativistic uranium projectile fragments has been achieved for the first time. The fragments were produced in peripheral nuclear collisions and spatially separated in-flight with the fragment separator FRS at GSI. A two-fold magnetic-rigidity analysis was applied exploiting the atomic energy loss in specially shaped matter placed in the dispersive central focal plane. Systematic investigations with relativistic projectiles ranging from oxygen up to uranium demonstrate that the FRS is a universal and powerful facility for the production and in-flight separation of monoisotopic, exotic secondary beams of all elements up to Z = 92. This achievement has opened a new area in heavy-ion research and applications.

Using a primary beam of $^{58}\mathrm{Ni}$ at 650 MeV/nucleon impinging on a beryllium target, production cross sections of proton-rich fragments from projectile fragmentation have been measured at the projectile-fragment separator FRS at Gesellschaft f\ur Schwerionenforschung Darmstadt m.b.H. The experimental data ranging from nickel to scandium for isotopes close to stability as well as for fragments at the proton drip line are compared to predictions of the microscopic ISApace code, to calculations with a revised abrasion-ablation model and with the statistical abrasion model, and to the results of the empirical parametrization EPAX. Besides these systematic measurements, evidence for the particle stability of $^{50}\mathrm{Ni}$ has been found for the first time, whereas the nuclei $^{49}\mathrm{Co}$ and $^{54}\mathrm{Cu}$ are shown to be unbound. These observations are compared to mass predictions.

The isotope 52Ni has been produced by fragmentation of a Ni-58 beam at 68 MeV/nucleon on a nickel target and separated using the LISE spectrometer at GANIL. We have measured the half-life of 52Ni and the energies of beta-delayed protons emitted during the decay. Two proton lines have been observed at E(p) = 1.06+/-0.05 MeV and 1.34+/-0.06 MeV with branching ratios of 0.06+/-0.01 and 0.11+/-0.01, respectively. The measured half-life of 52Ni is T1/2 = 38+/-5 ms. A partial decay scheme is proposed.

Experimental data on energy deposition for argon, krypton and xenon ions in the energy range from 100 to 950 MeV/u passing through an ionization chamber filled with an Ar (90%) + CH4 (10%) gas mixture of thickness equivalent to 60 mg/cm2 of argon are reported. Measured values are compared with the proposed model of energy deposition and with the model of Badhwar and Adams et al. The observed data support the picture of the escape of high energy δ rays from the active detector volume.

Low-energy fission of neutron-deficient actinium, thorium, protactinium and uranium isotopes has been investigated using a new experimental technique. The isotopes were produced as secondary beams by projectile fragmentation from a 950 A MeV 238U primary beam. Their fission was induced by electromagnetic excitation and nuclear reactions in a lead and in a plastic target at energies between 510 A MeV and 150 A MeV. The transition from symmetric fission is shown to take place around N = 138.

A description of peripheral nuclear collisions at high energies in terms of quasi-free nucleon-nucleon collisions is proposed. The statistical removal of nucleons from diffuse nuclear-density distributions is formulated in the framework of the abrasion model. Based on the nucleon-nucleon cross sections, energy-dependent partial and total abrasion cross sections are obtained. The total abrasion cross section is found to be equivalent to the total interaction cross section resulting from a microscopic Glauber-type calculation. In contrast to geometrical and optical abrasion models, the statistical abrasion formalism describes the fluctuations of the prefragment neutron-to-proton ratio without need for further assumptions. The predictions of the statistical abrasion model are compared to experimental data.