Charge state and energy loss of relativistic heavy ions in matter

Relativistic heavy-ion collisions of few-electron projectiles ranging from argon up to uranium have been investigated in solid and gaseous media. Electron-loss and electron-capture cross sections, charge-state distributions, as well as energy loss and energy deposition have been measured and are compared with theoretical predictions. Especially fully-ionized heavy projectiles represent a unique possibility to test atomic-collision theories. (orig.)Part of the Ph.D. thesis of C. ScheidenbergerAvailable from TIB Hannover: RO 801(93-77) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Direct observation of systematic deviations from the Bethe stopping theory for relativistic heavy ions

The SIS accelerator facilities at GSI in combination with the magnetic spectrometer FRS allow the direct measurement of stopping powers for relativistic heavy ions up to uranium with high precision for the first time. Here, we report on representative results obtained for projectiles up to xenon in the energy range from (700-1000) MeV/u. Systematic deviations from the Bethe stopping-power theory are observed, whereas the data are in good agreement with theory one Mott and Bloch corrections and the Fermi density effect are included. (orig.)Part of the Ph.D. thesis of C. ScheidenbergerAvailable from TIB Hannover: RO 801(94-11) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Proton removal in peripheral nuclear collisions at relativistic energies

SIGLEAvailable from TIB Hannover: RO 801(91-69) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

First spatial isotopic separation of relativistic uranium projectile fragments

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. (orig.)Available from TIB Hannover: RO 801(94-41) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Few-neutron removal from "2"3"8U at relativistic energies

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 several xn channels at projectile energies of 600 and 950 A 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 with "1"9"7Au. (orig.)Available from TIB Hannover: RO 801(95-19) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

First storage and cooling of secondary heavy-ion beams at relativistic energies

Also published in Phys. Rev. Lett. (8 Jun 1992) v. 68(23) p. 3412-3415SIGLEAvailable from TIB Hannover: RO 801(92-20) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Half-life measurements of bare, mass-resolved isomers in a storage-cooler ring

Secondary beams from fragmentation of "5"8Ni have been produced with energies of 200-220 A.MeV, separated with the fragment separator FRS and injected into the storage-cooler ring ESR for half-life measurements. The relative momentum spread #DELTA#p/p#approx#1.10"-"6 (FWHM) which we achieved allowed us to resolve the ground and isomeric states of cooled "5"2Mn and "5"3Fe nuclei in the measured mass spectra. The circulating beams were fully ionized which rendered possible, for the first time, to measure pure #beta#"+ branches for "5"2"gFe and "5"3"gFe and the sum of pure #beta#"+ and #gamma# branches in the decay of the isomers "5"2"mMn and "5"3"mFe. (orig.)15 refs.Available from TIB Hannover: RO 801(95-53) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Experiments with relativistic secondary beams of heavy ions at the GSI projectile fragment separator

At the GSI projectile fragment separator for the first time relativistic exotic nuclei throughout the whole periodic table of elements up to uranium were produced and isotopically separated. Systematic studies of the projectile fragmentation, complete mass- and charge distributions of fragments from fission of relativistic uranium nuclei, and first secondary-beam experiments such as the breakup of halo nuclei, the fragmentation of proton-rich secondary beams, and the fission of uranium fragments were made. In combination with the experimental heavy-ion storage ring experiments on the decay of exotic nuclei in exotic ionic charge states and direct mass measurements with stored and cooled ion beams were started. (orig.)Available from TIB Hannover: RO 801(93-53) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

The GSI projectile fragment separator (FRS) - a versatile magnetic system for relativistic heavy ions

Available from TIB Hannover: RO 801(91-46) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Invariant-mass spectroscopy of "1"0Li and "1"1Li

Break-up of secondary "1"1Li ion beams (280 MeV/nucleon) on C and Pb targets into "9Li and neutrons is studied experimentally. Cross sections and neutron multiplicity distributions are obtained, characterizing different reaction mechanisms. Invariant-mass spectroscopy for "1"1Li and "1"0Li is performed. The E1 strength distribution, deduced from electromagnetic excitation of "1"1Li up to an excitation energy of 4 MeV comprises #approx#8% of the Thomas-Reiche-Kuhn energy-weighted sum-rule strength. Two low-lying resonance-like structures are observed for "1"0Li at decay energies of 0.21(5) and 0.62(10) MeV, the former one carrying 26(10)% of the strength and likely to be associated with an s-wave neutron decay. A strong di-neutron correlation in "1"1Li can be discarded. Calculations in a quasi-particle RPA approach are compared with the experimental results for "1"0Li and "1"1Li. (orig.)SIGLEAvailable from TIB Hannover: RO 801(97-14) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman