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Abstract: The Super-FRS in-flight fragment separator at FAIR will be used to produce exotic nuclei at relativistic energies. High resolution experiments in ion traps with the separated fragments will be performed after they are slowed-down in matter and quickly extracted from a gas-filled stopping cell. Such experiments require an effective range bunching with a high-resolution magnetic spectrometer in combination with a wedge-shaped degrader at the dispersive focal plane. The ion-optical system of the spectrometer proposed here is rather versatile because it consists of several dipole and quadrupole magnets arranged such to serve as an energy-buncher and also as a large-acceptance spectrometer for the analysis of secondary reaction products. The performance and the experimental potential of such a multi-purpose spectrometer are described. [Copyright &y& Elsevier]

A novel system has been developed to detect simultaneous double-alpha emission from purified and weightless sources. The system includes the collection of 224Ra low-energy recoils in purified helium buffer gas from the decay of 228Th. The recoil products are thermalized and collected in a cryogenic buffer gas cell and extracted into an RF-ion guide for mass selection. The mass-separated ions are implanted at low kinetic energy into a thin carbon foil placed between two large-area double-sided silicon strip detectors to observe correlated alpha-particle emission. The apparatus is described in detail, including insights into its experimental performance. [ABSTRACT FROM AUTHOR]

In this paper, the major upgrades and technical improvements of the buffer gas handling system for the cryogenic stopping cell of the FRS Ion Catcher at GSI/FAIR (in Darmstadt, Germany) are described. The upgrades include implementation of new gas lines and gas purifiers to achieve a higher buffer gas cleanliness for a more efficient extraction of reactive ions as well as suppression of the molecular background ionized in the stopping cell. Furthermore, additional techniques have been implemented for improved monitoring and quantification of the purity of the helium buffer gas. [ABSTRACT FROM AUTHOR]

The HISPEC/DESPEC collaboration envisages long experimental campaigns exploiting the expected beam performances of Super-FRS. The experiments will be performed at the Low-Energy Branch of the upcoming FAIR and will focus on the physics of exotic isotopes, primarily in the heavy neutron-rich region. The goal of the HISPEC/DESPEC experimental campaigns is to explore the excitation and decay properties of rare isotopes produced via fragmentation and fission. First rare-isotope beam simulations of representative future HISPEC/DESPEC experimental cases are presented. The simulations provide an insight into the forthcoming state-of-art experiments in the future FAIR facility. [ABSTRACT FROM AUTHOR]

A novel multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) and isobar separator for the research with exotic nuclides at low-energy rare isotope beam facilities has been developed, commissioned and characterized. It can be used (i) as broadband mass spectrometer with medium resolution, (ii) as highly accurate mass spectrometer for direct mass measurements and (iii) as high-resolution mass separator. The device features a worldwide unique combination of performance characteristics: a mass resolving power of 600,000 (FWHM), a mass measurement accuracy of ~ 10 − 7 , large ion capacities in excess of 10 6 ions per second, a transmission efficiency of up to 70%, single-ion sensitivity, and cycle frequencies of up to 400 Hz have been achieved. The spatial separation of close-lying isobars with an intensity ratio of 200:1 and a binding energy difference as small as 4 MeV has been demonstrated. The MR-TOF-MS is ideally suited for experiments with rare and very short-lived nuclei at present and future in-flight, ISOL or IGISOL facilities, such as the FRS Ion-Catcher and SHIP/SHIPTRAP at GSI, TITAN at TRIUMF, IGISOL at the University of Jyväskylä and the Low-Energy Branch of the Super-FRS at FAIR. [ABSTRACT FROM AUTHOR]

Abstract: We report on a new experimental setup for the investigation of proton induced reactions on exotic nuclei in inverse kinematics. It was installed and successfully used in the scattering study of intermediate-energy protons () on neutron-rich nuclei 6,8He produced with the FRagment Separator (FRS) at the GSI facility, Darmstadt. A new pure liquid-hydrogen target was successfully adapted allowing to obtain low-background data as compared to commonly used (CH2) n targets. Absolute differential cross-sections for elastic (p,6,8He) scattering were obtained at angles corresponding to (GeV/c)2 of the four-momentum transfer squared (−t) leading to the first diffraction minimum and spanning more than two orders of magnitude. They complement an earlier measurement at smaller angles (GeV/c)2 performed at the same energy with an active target. Both data sets agree well in the overlap region (GeV/c)2 and enable a refined and comparative study of the radial distribution of the nuclear matter density. [Copyright &y& Elsevier]

Abstract: Time Projection Chambers with C-pads and integrated delay line readout were developed as position sensitive detectors for the Fragment separator at GSI Darmstadt. The main advantages of TPCs are a small amount of matter in the sensitive volume, high spatial resolution, and high tracking efficiency. Working parameters in experimental conditions are presented. Internal spatial resolutions of and were achieved. The tracking efficiency dependence on ion beam intensity was studied with 238U beam at 1 GeV/u energy. Efficiency of more than 99% was achieved up to 40kHz and over 90% for 250kHz 238U beam intensity. Different kinds of ions from proton to uranium were measured in many experiments and confirmed the result obtained. [Copyright &y& Elsevier]

Abstract: The lineshapes and peak position of Doppler corrected spectra from in-beam experiments at relativistic energies are investigated with respect to the intrinsic energy resolution of the employed detectors, the particles’ velocities, and the photons’ emission angle uncertainties at the moment of emission. The uncertainties in velocity and photon emission angle are dependent on the lifetime of the excited state. The impact of these two observables on the lineshape and energy resolution are studied for the RISING by means of simulations and experimental results from a two-step fragmentation experiment at . Potential use of the distinct lineshape for lifetime determination is demonstrated for measured transitions. [Copyright &y& Elsevier]

Abstract: The integrity of the liquid lithium jet after pulsed ion beam irradiation is investigated by means of three-dimensional hydrodynamic simulations combined with an analytical analysis of the target response. It is predicted that for the desired beam intensity the heated target will be destroyed due to spallation and following fragmentation of the heated matter. The stability of the liquid lithium jet after ion beam heating is a crucial question for design of the fragment separator Super-FRS, which will be a part of the new FAIR facility at GSI. [Copyright &y& Elsevier]

Abstract: Charged-particle decay spectroscopy of heavy suburanium isotopes produced by projectile fragmentation of 1GeV/u 238U was tested using a simple implantation–decay set-up equipped with fast-reset preamplifiers. The products were separated and identified with the GSI fragment separator (FRS) and implanted into a stack of Si detectors. Measurements were performed of implantation decay correlations of nuclei with half-lives in the range of 0.1–100ms. Yields of very neutron-deficient protactinium, thorium and actinium isotopes were measured and yield extrapolations imply that with the availability of a beam intensity of 109 ions/s, projectile fragmentation of relativistic 238U can be an effective method to access new nuclear species including possible proton emitters in the suburanium region. [Copyright &y& Elsevier]

We present a new approach to charged-particle spectroscopy of short-lived nuclei produced by relativistic projectile fragmentation. The system based on digital DGF-4C CAMAC modules and newly developed fast-reset preamplifiers was tested at the Fragment Separator of GSI. We were able to detect low-energy (≈1 MeV) decay signals occurring a few microseconds after a heavy-ion implantation accompanied by a release of ≈1 GeV energy. Applications for the study of one- and two-proton radioactivity are discussed. [Copyright &y& Elsevier]