| 1. |
- Saito, T. R., et al.
(author)
-
The WASA-FRS project at GSI and its perspective
- 2023
-
In: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier. - 0168-583X .- 1872-9584. ; 542, s. 22-25
-
Journal article (peer-reviewed)abstract
- A novel technique to study bound states of exotic hadrons in subatomic nuclei, such as hypernuclei and mesic nuclei, has been developed by employing the Fragment Separator FRS and the WASA central detector at GSI. Two experiments, S447 for studying light hypernuclei, especially hypertriton and a Ann bound state, and S490 for searching for ri' mesic-nuclei, were recently performed. Data analyses are currently in progress, and light charged particles such as protons and x & PLUSMN; are clearly observed and identified in the both experiments. For S447, light nuclear fragments that can also be residual nuclei from decays of hypernuclei of interests have been analysed by the FRS, and a momentum resolution, Ap/p, of 5 x 10-4 has been achieved. Further data analyses are to be completed. The WASA-FRS project will be continued and extended with the FRS at FAIR Phase 0, and upgrading of the WASA magnet and detectors is currently in progress. Furthermore, construction of a larger detector system with the Super-FRS at FAIR Phase 1 is also under consideration.
|
|
| 2. |
- Tanaka, Y. K., et al.
(author)
-
WASA-FRS EXPERIMENTS IN FAIR PHASE-0 AT GSI
- 2023
-
In: ACTA PHYSICA POLONICA B PROCEEDINGS SUPPLEMENT. - : Jagiellonian University.
-
Conference paper (peer-reviewed)abstract
- We have developed a new and unique experimental setup integrating the central part of the Wide Angle Shower Apparatus (WASA) into the Fragment Separator (FRS) at GSI. This combination opens up possibilities of new experiments with high-resolution spectroscopy at forward 0 and measurements of light decay particles with nearly full solid-angle acceptance in coincidence. The first series of the WASA-FRS experiments have been successfully carried out in 2022. The developed experimental setup and two physics experiments performed in 2022 including the status of the preliminary data analysis are introduced.
|
|
| 3. |
- Saito, T. R., et al.
(author)
-
Studies of three-and four-body hypernuclei with heavy-ion beams, nuclear emulsions and machine learning
- 2023
-
In: Journal of Physics, Conference Series. - : Institute of Physics (IOP). - 1742-6588 .- 1742-6596. ; 2586
-
Journal article (peer-reviewed)abstract
- Interests on few-body hypernuclei have been increased by recent results of experiments employing relativistic heavy ion beams. Some of the experiments have revealed that the lifetime of the lightest hypernucleus, hypertriton, is significantly shorter than 263 ps which is expected by considering the hypertriton to be a weakly-bound system. The STAR collaboration has also measured the hypertriton binding energy, and the deduced value is contradicting to its formerly known small binding energy. These measurements have indicated that the fundamental physics quantities of the hypertriton such as its lifetime and binding energy have not been understood, therefore, they have to be measured very precisely. Furthermore, an unprecedented Lambda nn bound state observed by the HypHI collaboration has to be studied in order to draw a conclusion whether or not such a bound state exists. These three-body hypernuclear states are studied by the heavy-ion beam data in the WASA-FRS experiment and by analysing J-PARC E07 nuclear emulsion data with machine learning.
|
|
| 4. |
- Heil, M., et al.
(author)
-
A new Time-of-flight detector for the R 3 B setup
- 2022
-
In: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 58:12
-
Journal article (peer-reviewed)abstract
- We present the design, prototype developments and test results of the new time-of-flight detector (ToFD) which is part of the R3B experimental setup at GSI and FAIR, Darmstadt, Germany. The ToFD detector is able to detect heavy-ion residues of all charges at relativistic energies with a relative energy precision σΔE/ ΔE of up to 1% and a time precision of up to 14 ps (sigma). Together with an elaborate particle-tracking system, the full identification of relativistic ions from hydrogen up to uranium in mass and nuclear charge is possible.
|
|
| 5. |
- Polettini, M., et al.
(author)
-
Decay studies in the A∼225 Po-Fr region from the DESPEC campaign at GSI in 2021
- 2022
-
In: Il Nuovo Cimento. - : Società Italiana di Fisica. - 2037-4909. ; 45:5
-
Journal article (peer-reviewed)abstract
- The HISPEC-DESPEC collaboration aims at investigating the structure of exotic nuclei formed in fragmentation reactions with decay spectroscopy measurements, as part of the FAIR Phase-0 campaign at GSI. This paper reports on first results of an experiment performed in spring 2021, with a focus on beta-decaystudies in the Po-Fr nuclei in the 220 < A <230 island of octupole deformation exploiting the DESPEC setup. Ion-beta correlations and fast-timing techniques are being employed, giving an insight into this difficult-to-reach region.
|
|
| 6. |
- Yaneva, A., et al.
(author)
-
FAST-TIMING MEASUREMENT IN 96Pd: IMPROVED ACCURACY FOR THE LIFETIME OF THE 4+1 STATE
- 2023
-
In: Acta Physica Polonica B, Proceedings Supplement. - : Jagiellonian University. - 1899-2358 .- 2082-7865. ; , s. 1-1
-
Conference paper (peer-reviewed)abstract
- Direct lifetime measurements via γ–γ coincidences using the FATIMA fast-timing LaBr3(Ce) array were performed for the excited states below previously reported isomers. In the N = 50 semi-magic 96Pd nucleus, lifetimes below the Iπ = 8+ seniority isomer were addressed as a benchmark for further analysis. The results for the Iπ = 2+ and 4+ states confirm the published values. Increased accuracy for the lifetime value was achieved for the 4+ state.
|
|
| 7. |
- Gobel, K., et al.
(author)
-
Coulomb dissociation of 16O into 4He and 12C
- 2020
-
In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1668:1
-
Conference paper (peer-reviewed)abstract
- We measured the Coulomb dissociation of 16O into 4He and 12C at the R3B setup in a first campaign within FAIR Phase 0 at GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt. The goal was to improve the accuracy of the experimental data for the 12C(a,?)16O fusion reaction and to reach lower center-ofmass energies than measured so far. The experiment required beam intensities of 109 16O ions per second at an energy of 500 MeV/nucleon. The rare case of Coulomb breakup into 12C and 4He posed another challenge: The magnetic rigidities of the particles are so close because of the same mass-To-charge-number ratio A/Z = 2 for 16O, 12C and 4He. Hence, radical changes of the R3B setup were necessary. All detectors had slits to allow the passage of the unreacted 16O ions, while 4He and 12C would hit the detectors' active areas depending on the scattering angle and their relative energies. We developed and built detectors based on organic scintillators to track and identify the reaction products with sufficient precision.
|
|
| 8. |
- Boretzky, K., et al.
(author)
-
NeuLAND: The high-resolution neutron time-of-flight spectrometer for R 3 B at FAIR
- 2021
-
In: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 1014
-
Journal article (peer-reviewed)abstract
- NeuLAND (New Large-Area Neutron Detector) is the next-generation neutron detector for the R3B (Reactions with Relativistic Radioactive Beams) experiment at FAIR (Facility for Antiproton and Ion Research). NeuLAND detects neutrons with energies from 100 to 1000 MeV, featuring a high detection efficiency, a high spatial and time resolution, and a large multi-neutron reconstruction efficiency. This is achieved by a highly granular design of organic scintillators: 3000 individual submodules with a size of 5 × 5 × 250 cm3 are arranged in 30 double planes with 100 submodules each, providing an active area of 250 × 250 cm2 and a total depth of 3 m. The spatial resolution due to the granularity together with a time resolution of σt≤ 150 ps ensures high-resolution capabilities. In conjunction with calorimetric properties, a multi-neutron reconstruction efficiency of 50% to 70% for four-neutron events will be achieved, depending on both the emission scenario and the boundary conditions allowed for the reconstruction method. We present in this paper the final design of the detector as well as results from test measurements and simulations on which this design is based.
|
|
| 9. |
|
|
| 10. |
|
|
