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The article provides an overview of the Super-FRS instrument at the FAIR facility and its capabilities for studying exotic nuclei. The Super-FRS is equipped with various detector systems and has the unique feature of placing ancillary detectors between magnetic stages, allowing for new experimental opportunities. The article also mentions planned experiments in hadron physics and the search for superheavy nuclei beyond the proton drip-line. Overall, the article emphasizes the importance of these experiments in advancing our understanding of nuclear physics and the potential for groundbreaking discoveries at FAIR. [Extracted from the article]

Gottfried Münzenberg, a prominent scientist in the field of nuclear physics, passed away in January 2024. He played a significant role in shaping the scientific and instrumental portfolio of the Society for Heavy Ion Research (GSI) in Germany. Münzenberg made important contributions to various areas of nuclear physics, including the discovery of new chemical elements and the development of in-beam positron emission tomography. He was also involved in international collaborations and received numerous awards and honors for his work. Münzenberg is remembered not only for his scientific achievements but also for his wit and friendship. [Extracted from the article]

In Memoriam: We Mourn Prof. Dr. Dr h.c. mult. The first highlights were the synthesis of the new elements bohrium (Bh), hassium (Hs), and meitnerium (Mt) in the years 1981 to 1984, with which GSI for the first time - and at the same time very prominently - entered the international stage of this renowned research field. At the same time, Sigurd Hofmann had begun work on the synthesis, unambiguous identification, and study of the properties of the heaviest chemical elements, which were to shape his further scientific life. [Extracted from the article]

The article discusses the highlights of several meetings related to nuclear physics. The 16th Euroschool on Exotic Beams conference was held in Leuven, Belgium from September 4-11, 2009. The 5th Workshop on Shape-Phase Transition and Critical Point Phenomena in Nuclei conference was held in Istanbul, Turkey from September 16-18, 2009. The 5th International Summer School on Subatomic Physics was held in Peking University in Beijing, China on August 23, 2009.

Deals with experiments that investigate the exotic nuclei in a heavy-ion storage and cooler rings. Mapping of mass surface benefits of cocktail beams from Fragment Separator; Production of secondary beams through projectile fragmentation; Development of the Schottky spectroscopy detection method.

We report the charge-changing cross sections ( σ cc ) of 24 p -shell nuclides on both hydrogen and carbon at about 900 A MeV, of which 8,9Li, 10–12Be, 10,14,15B, 14,15,17–22N and 16O on hydrogen and 8,9Li on carbon are for the first time. Benefiting from the data set, we found a new and robust relationship between the scaling factor of the Glauber model calculations and the separation energies of the nuclei of interest on both targets. This allows us to deduce proton radii ( R p ) for the first time from the cross sections on hydrogen. Nearly identical R p values are deduced from both target data for the neutron-rich carbon isotopes; however, the R p from the hydrogen target is systematically smaller in the neutron-rich nitrogen isotopes. This calls for further experimental and theoretical investigations. [ABSTRACT FROM AUTHOR]

Reports on the 12th Euroschool on Exotic Beams summer meeting from August 25 through September 2, 2005 in Mainz, Germany. Objectives of the meeting; Participants of the event; Activity highlights.

A Laser Ablation Carbon Cluster Ion source (LACCI) has been developed and commissioned at the FRS Ion Catcher at GSI. It is the first laser ablation ion source for long-term measurements with a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). This is enabled by two key developments: (i) a two-dimensional movable target platform that ensures the long-term stable production of ions and (ii) a mass filter for the isolation of the ions of interest. LACCI is capable of providing closely-spaced reference ions in the mass range up to ∼ 300 u for accurate mass measurements of exotic nuclei (relative mass uncertainty ∼ 1 0 − 8 ) and systematic studies of the mass uncertainties with the multiple-reflection time-of-flight mass spectrometer. Investigations of the laser energy and repetition rate and long-term measurements have been carried out with carbon targets (Sigradur®, Fullerene) and metallic targets (silver, gold, copper, tungsten, and erbium). In a test experiment, LACCI has delivered a stable ion current for more than 20 h at a laser repetition rate of 100 Hz, corresponding to an operation for one week at 10 Hz. It thus fully satisfies the requirements for long-term accurate mass measurements of exotic nuclei with an MR-TOF-MS. This enables the access of exotic ions, detected with rates as low as 0.1 per hour at the FRS Ion Catcher. [ABSTRACT FROM AUTHOR]

A complex, long-range experimental program for the production of neutron-rich nuclei via multi-nucleon transfer (MNT) reactions and spontaneous fission (SF) inside the Cryogenic Stopping Cell (CSC) of the FRS Ion Catcher facility at GSI has been suggested and is under development. A key component is a new experimental set-up, consisting of a modified DC cage, a target-wheel, a beam-dump and a space charge suppression system. This setup replaces the standard electrode structure of the CSC, enabling generation of radioactive isotope beams by in-cell MNT reactions inside the CSC and the efficient and fast extraction of ions produced by MNT reactions or spontaneous fission. Furthermore, the system allows to do experiments with beams from the FRS with much higher rates and shorter half-lives. We present the specifications, design and production of this device. We also present the technical solution adopted against the space charge effect and the simulations that validate it. [ABSTRACT FROM AUTHOR]

Graphical abstract: Display Omitted Highlights: [•] An overview of MR-TOF-MS developments for the research with short-lived nuclei is given. [•] For the first time a comprehensive review of different instrumental approaches and solutions for MR-TOF-MS is made. [•] A novel performance criterion for the measurement of exotic nuclei is suggested and applied to compare the performance MR-TOF-MS to that of the established technique of TOF-ICR. [•] The MR-TOF-MS for the Low-Energy Branch of the Super-FRS at the Facility for Antiproton and Ion Research (FAIR) and its performance is presented. [•] Applications of MR-TOF-MS at accelerator facilities as well as their scientific potential outside the field of nuclear physics are discussed. [ABSTRACT FROM AUTHOR]

Neutron-deficient iodine isotopes, 116 I and 114 I, were produced at relativistic energies by in-flight fragmentation at the Fragment Separator (FRS) at GSI. The FRS Ion Catcher was used to thermalize the ions and to perform highly accurate mass measurements with a Multiple-Reflection Time-of-Flight Mass-Spectrometer (MR-TOF-MS). The masses of both isotopes were measured directly for the first time. The half-life of the 114 I was measured by storing the ions in an RF quadrupole for different storage times and counting the remaining nuclei with the MR-TOF-MS. The measured half-life was used to assign the ground state to the measured 114 I ions. Predictions on the possible α -decay branch for 114 I are presented based on the reduced uncertainties obtained for the Q α -value. Systematic studies of the mass surface were performed with the newly obtained masses, showing better agreement with the expected trend in this mass region. [ABSTRACT FROM AUTHOR]

Experiments with low-energy rare ion beams often suffer from a large amount of molecular contaminant ions. We present the simple isolation-dissociation-isolation method to suppress this kind of contamination. The method can be applied to almost all types of low-energy beamlines. In a first step, a coarse isolation of the mass-to-charge ratio of interest is performed, e.g. by a dipole magnet. In a second step, the ions are dissociated. The last step is again a coarse isolation of the mass-to-charge ratio around the ion of interest. The method was tested at the FRS Ion Catcher at GSI with a radioactive ion source installed inside the cryogenic stopping cell as well as with relativistic ions delivered by the synchrotron SIS-18 and stopped in the cryogenic stopping cell. The isolation and dissociation, here collision-induced dissociation, have been implemented in a gas-filled RFQ beamline. A reduction of molecular contamination by more than 4 orders of magnitude was achieved. [ABSTRACT FROM AUTHOR]

The combination of in-flight separation with a gas-filled stopping cell has opened a new field for experiments with exotic nuclei. For instance, at the SHIP/SHIPTRAP facility at GSI in Darmstadt high-precision mass measurements of rare nuclei have been successfully performed. In order to extend the reach of SHIPTRAP to exotic nuclei that are produced together with high rates of unwanted reaction products, a novel compact radio frequency quadrupole (RFQ) system has been developed. It implements ion cooling, identification and separation according to mass numbers and bunching capabilities. The system has a total length of one meter only and consists of an RFQ cooler, an RFQ mass filter and an RFQ buncher. A mass resolving power (FWHM) of 240 at a transmission efficiency of 90% has been achieved. The suppression of contaminants from neighboring masses by more than four orders of magnitude has been demonstrated at rates exceeding 1 0 6 ions/s. A longitudinal emittance of 0.45 eV μ s has been achieved with the RFQ buncher, which will enable improved time-of-flight mass spectrometry downstream of the device. With this triple RFQ system the measurement of e.g. N = Z nuclides in the region up to tin will become possible at SHIPTRAP. The technology is also well suited for other rare-isotope facilities with experimental setups behind a stopping cell, such as the fragment separator FRS with the FRS Ion Catcher at GSI. [ABSTRACT FROM AUTHOR]

Direct mass measurements of neutron-deficient nuclides around the N = 50 shell closure below 100Sn were performed at the FRS Ion Catcher (FRS-IC) at GSI, Germany. The nuclei were produced by projectile fragmentation of 124Xe, separated in the fragment separator FRS and delivered to the FRS-IC. The masses of 14 ground states and two isomers were measured with relative mass uncertainties down to 1 × 10 − 7 using the multiple-reflection time-of-flight mass spectrometer of the FRS-IC, including the first direct mass measurements of 98Cd and 97Rh. A new Q EC = 5437 ± 67 keV was obtained for 98Cd, resulting in a summed Gamow-Teller (GT) strength for the five observed transitions (0 + ⟶ 1 +) as B (GT) = 2.94 − 0.28 + 0.32. Investigation of this result in state-of-the-art shell model approaches accounting for the first time experimentally observed spectrum of GT transitions points to a perfect agreement for N = 50 isotones. The excitation energy of the long-lived isomeric state in 94Rh was determined for the first time to be 293 ± 21 keV. This, together with the shell model calculations, allows the level ordering in 94Rh to be understood. [ABSTRACT FROM AUTHOR]

A novel method for (ultra-)high-resolution spatial mass separation in time-of-flight mass spectrometers is presented. Ions are injected into a time-of-flight analyzer from a radio frequency (rf) trap, dispersed in time-of-flight according to their mass-to-charge ratios and then re-trapped dynamically in the same rf trap. This re-trapping technique is highly mass-selective and after sufficiently long flight times can provide even isobaric separation. A theoretical treatment of the method is presented and the conditions for optimum performance of the method are derived. The method has been implemented in a multiple-reflection time-of-flight mass spectrometer and mass separation powers (FWHM) in excess of 70,000, and re-trapping efficiencies of up to 35% have been obtained for the protonated molecular ion of caffeine. The isobars glutamine and lysine (relative mass difference of 1/4000) have been separated after a flight time of 0.2 ms only. Higher mass separation powers can be achieved using longer flight times. The method will have important applications, including isobar separation in nuclear physics and (ultra-)high-resolution precursor ion selection in multiple-stage tandem mass spectrometry. [ABSTRACT FROM AUTHOR]

A new method is presented for making the overall flight path of ions in a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) isochronous. Here, the ions undergo an arbitrary number of turns in a TOF analyzer, which itself is tuned to be isochronous from turn to turn. The overall isochronicity from the ion source or injection trap to the detector is established by changing the voltage settings of the analyzer dynamically to a different mode for one turn. This approach combines the advantages of an MR-TOF-MS with a time focus shift reflector with the simplicity of an MR-TOF-MS with only the TOF analyzer as an isochronous tool. Measurements have been performed, in which an MR-TOF-MS was operated with this dynamical time focus shift. These are compared to measurements, in which the time focus was shifted onto the detector using a variation of the extraction field strength in the injection trap. A mass resolving power was achieved that is up to three times larger for the same time-of-flight. For Cs ions, mass resolving powers of 100,000 and 200,000 were obtained after flight times of 1.7 ms and 4.9 ms, respectively. These flight times are a factor of 3 shorter than those with the time focus shift with the injection trap. The smaller number of turns required for a given mass resolving power results in a larger unambiguous mass range, a higher transmission efficiency, a higher ion capacity and a shorter measurement time. This yields advantages in precision experiments in nuclear physics and for applications in analytical mass spectrometry. [ABSTRACT FROM AUTHOR]

A time-of-flight (TOF) detector is used for Isochronous Mass Spectrometry (IMS) with the projectile fragment separator FRS and the heavy-ion storage ring ESR. Exotic nuclei are spatially separated in flight with the FRS at about 70% of the speed of light and are injected into the ESR. The revolution times of the stored ions circulating in the ESR are measured with a thin transmission foil detector. When the ions penetrate the thin detector foil, secondary electrons (SEs) are emitted from the surface and provide the timing information in combination with microchannel plate (MCP) detectors. The isochronous transport of the SEs is performed by perpendicular superimposed electric and magnetic fields. The detection efficiency and the rate capability of the TOF detector have been studied in simulations and experiments. As a result the performance of the TOF detector has been improved substantially: (i) The SE collection efficiency was doubled by use of an optimized set of electric and magnetic field values; now SEs from almost the full area of the foil are transmitted to the MCP detectors. (ii) The rate capability of the TOF detector was improved by a factor of four by the use of MCPs with 5 μm pore size. (iii) With these MCPs and a carbon foil with a reduced thickness of 10 μg/cm 2 the number of recorded revolutions in the ESR has been increased by nearly a factor of 10. The number of recorded revolutions determine the precision of the IMS experiments. Heavy-ion measurements were performed with neon ions at 322 MeV/u and uranium fission fragments at about 370 MeV/u. In addition, measurements with an alpha source were performed in the laboratory with a duplicate of the TOF detector. [ABSTRACT FROM AUTHOR]

At TRIUMF's Ion Trap for Atomic and Nuclear Science (TITAN) a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) will extend TITAN's capabilities and facilitate mass measurements and in-trap decay spectroscopy of exotic nuclei that so far have not been possible due to strong isobaric contamination. This MR-TOF-MS will also enable mass measurements of very short-lived nuclides (half-life > 1 ms) that are produced in very low quantities (a few detected ions overall). In order to allow the installation of an MR-TOF-MS in the restricted space on the platform, on which the TITAN facility is located, novel mass spectrometric methods have been developed. Transport, cooling and distribution of the ions inside the device is done using a buffer gas-filled RFQ-based ion beam switchyard. Mass selection is achieved using a dynamic retrapping technique after time-of-flight analysis in an electrostatic isochronous reflector system. Only due to the combination of these novel methods the realization of an MR-TOF-MS based isobar separator at TITAN has become possible. The device has been built, commissioned off-line and is currently under installation at TITAN. [ABSTRACT FROM AUTHOR]

The ion-optical design of a multiple reflection time-of-flight mass spectrometer and isobar separator (MR-TOF-MS) is presented. The MR-TOF-MS has been developed for the research with exotic nuclides at accelerator facilities and has been designed to provide a mass resolving power (FWHM) exceeding 300,000 and a mass accuracy of down to 10 −7 . High-performance axially symmetric four-electrode gridless ion mirrors have been developed and optimized for the device. In addition, the MR-TOF-MS comprises several further novel ion-optical elements such as an isochronous post-analyzer reflector and an energy bunching and deceleration system for ion injection into an accumulation trap. The device has been built and commissioned and shows superb performance characteristics in accordance with the design criteria. [ABSTRACT FROM AUTHOR]

Abstract: A multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) system for low-energy radioactive ion beam facilities has been developed, which can be used for (i) isobar separation and (ii) direct mass measurements of very short-lived nuclei with half-lives of about 1ms or longer, and (iii) for identification and diagnosis of the ion beam by mass spectrometry. The system has been designed and simulated, and individual subsystems have been built and characterized experimentally. An injection trap for cooling and bunching of the ion beam has been developed, and cooling times of less than one millisecond have been achieved. The performance of the MR-TOF-MS was characterized using the isobaric doublet of carbon monoxide and nitrogen molecular ions. A mass resolving power of 105 (FWHM) has been obtained even with an uncooled ion population. The separator capabilities of the MR-TOF-MS have been demonstrated by removing either carbon monoxide or nitrogen ions from the beam in a Bradbury-Nielsen Gate after a flight time of 320μs. The separation power achieved is thus at least 7000 (FWHM) and increases for longer time-of-flight. An energy buncher stage has been designed that compresses the energy spread of the beam after the separation and facilitates efficient injection of the selected ions into an accumulation trap prior to transfer of the ions to experiments downstream of the MR-TOF-MS. [Copyright &y& Elsevier]

Gas-filled stopping cells are used at accelerator laboratories for the thermalization of high-energy radioactive ion beams. Common challenges of many stopping cells are a high molecular background of extracted ions and limitations of extraction efficiency due to space-charge effects. At the FRS Ion Catcher at GSI, a new technique for removal of ionized molecules prior to their extraction out of the stopping cell has been developed. This technique utilizes the RF carpet for the separation of atomic ions from molecular contaminant ions through their difference in ion mobility. Results from the successful implementation and test during an experiment with a 600 MeV/u 124Xe primary beam are presented. Suppression of molecular contaminants by three orders of magnitude has been demonstrated. Essentially background-free measurement conditions with less than 1 % of background events within a mass-to-charge range of 25 u/e have been achieved. The technique can also be used to reduce the space-charge effects at the extraction nozzle and in the downstream beamline, thus ensuring high efficiency of ion transport and highly-accurate measurements under space-charge-free conditions. Image 1 • Extraction of thermalized ions out of a gas-filled stopping cell with an RF carpet. • Atomic and molecular ions can be separated with the RF carpet by their ion mobility. • Suppression of molecular background by three orders of magnitude with the RF carpet. • Removal of space charge prior to extraction of ions out of the stopping cell. [ABSTRACT FROM AUTHOR]

Due to technical constraints this article was published in volume 240:1 with erroneous article citation ID number 3 whereas this should have been 73 which is corrected as such. Springer Nature sincerely apologizes towards the author(s) for the inconvenience caused. [ABSTRACT FROM AUTHOR]

A novel method for simultaneous measurement of masses, Q-values, isomer excitation energies, half-lives and decay branching ratios of exotic nuclei has been demonstrated. The method includes first use of a stopping cell as an ion trap, combining storage of mother and daughter nuclides for variable durations in a cryogenic stopping cell (CSC), and afterwards the identification and counting of them by a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). We utilized our method to record the decay and growth of the 216Po and 212Pb isotopes (alpha decay) and of the 119m2Sb isomer ( t 1 / 2 = 850 ± 90 ms) and 119gSb isotope (isomer transition), obtaining half-lives consistent with literature values. The amount of non-nuclear-decay losses in the CSC up to ∼ 10 s is negligible, which exhibits its extraordinary cleanliness. For 119Sb isotopes, we present the first direct measurements of the mass of its ground state, and the excitation energy and decay branching ratios of its second isomeric state (119m2Sb). This resolves discrepancies in previous excitation energy data, and is the first direct evidence that the 119m2Sb isomer decays dominantly via γ emission. These results pave the way for the measurement of branching ratios of exotic nuclei. [ABSTRACT FROM AUTHOR]

The FRS Ion Catcher at GSI enables precision experiments with thermalized projectile and fission fragments. At the same time it serves as a test facility for the Low-Energy Branch of the Super-FRS at FAIR. The FRS Ion Catcher has been commissioned and its performance has been characterized in five experiments with 238U and 124Xe projectile and fission fragments produced at energies in the range from 300 to 1000 MeV/u. High and almost element-independent efficiencies for the thermalization of short-lived nuclides produced at relativistic energies have been obtained. High-accuracy mass measurements of more than 30 projectile and fission fragments have been performed with a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) at mass resolving powers of up to 410,000, with production cross sections down to the microbarn-level, and at rates down to a few ions per hour. The versatility of the MR-TOF-MS for isomer research has been demonstrated by the measurement of various isomers, determination of excitation energies and the production of a pure isomeric beam. Recently, several instrumental upgrades have been implemented at the FRS Ion Catcher. New experiments will be carried out during FAIR Phase-0 at GSI, including direct mass measurements of neutron-deficient nuclides below 100Sn and neutron-rich nuclides below 208Pb, measurement of β-delayed neutron emission probabilities and reaction studies with multi-nucleon transfer. [ABSTRACT FROM AUTHOR]

A multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been installed and integrated into the TITAN experiment at TRIUMF. The MR-TOF-MS extends the capabilities and improves the performance of the TITAN experiment, for instance it provides fast isobar separation, short measurement cycles, yield measurements and broad-band beam diagnosis, and enhanced rate capabilities and dynamic range. Thereby, even more exotic nuclides become accessible at TITAN for experiments. Such improved capabilities of TITAN have been used in first experiments to investigate the sub-shell closure of neutron-rich nuclides at N = 32 and the r-process nucleo-synthesis for masses at A ∼ 85. The vacuum system, electronics and data-acquisition hardware and software have been recently upgraded. For the first time an isomeric state has been measured with TITAN′s MR-TOF-MS, 84mRb (excitation energy: 464 keV). The accurate measurement of excitation energies of low-lying isomeric states is possible due to the high mass resolving power of TITAN′s MR-TOF-MS and a specialized data-analysis procedure. [ABSTRACT FROM AUTHOR]