The Rare ISotopes INvestigation at GSI project combines the former EUROBALL Ge-Cluster detectors, the MINIBALL Ge detectors, BaF
2-HECTOR detectors, and the fragment separator at GSI for ...high-resolution in-beam
γ
-ray spectroscopy measurements with radioactive beams. These secondary beams produced at relativistic energies are used for Coulomb excitation or secondary fragmentation experiments in order to explore the nuclear structure of the projectiles or projectile like nuclei by measuring de-excitation photons. The newly designed detector array is described and the performance characteristics are given. Moreover, particularities of the experimental technique are discussed.
The lifetimes of eight lower spin levels of the yrast band in 168Yb, populated via the 154Sm(18O,4n) and 124Sn(48Ca,4n) reactions, were measured, six of them for the first time, by means of the ...recoil-distance Doppler-shift method. Two versions of the differential decay-curve method have been applied for the data analysis resulting in a very good agreement. The reduced transition probabilities indicate some reduction of the collectivity for states just above the 61+ level, i.e. well below the band-crossing. The reasons of this effect are discussed in terms of an interaction between the ground-state band and yet unknown part of the two-quasiparticle (ν13/2) spin-aligned S-band by invoking the shell-structure or alternatively/additionally, as changes in the internal structure/shape induced by the rotation.
The objective of the present study was to provide a complete and detailed report of technical and logistical feasibility problems with the implementation of routine computerized HRQoL measurement at ...a busy outpatient department of Hepatology that can serve as a tool for future researchers interested in the procedure.
Practical feasibility was assessed by observing problems encountered during the development of the computer program, observing patients' ability to complete the HRQoL questionnaires, monitoring the number of times that patients completed the HRQoL questionnaires and observing logistics at the outpatient department. Patients' reasons for not completing the HRQoL questionnaires were assessed retrospectively by means of a mailed questionnaire. Physicians' attitudes towards the availability of computerized HRQoL information about their patients were assessed by means semi-structured interviews and by means of checklists administered after each consultation with s study participant.
All physicians (n = 11) and 587 patients agreed to participate in the study. Practical feasibility problems concerned complicated technical aspects of developing a user-friendly computer program and safe data transmission over the Internet, patients' lack of basic computer skills and patients' lack of compliance (completion of questionnaires on only 43% of the occasions). The main reason given for non-compliance was simply forgetting, which seemed to be related to reception employees' passive attitude towards sending patients to the computer. Physicians were generally positive about the instant computerized availability of HRQoL information. They requested the information in 92% of the consultations and found the information useful in 45% of the consultations, especially when it provided them with new information.
This study was among the first to implement the complete procedure of routine computerized HRQoL measurements in clinical practice and to subsequently describe the feasibility issues encountered. It was shown that the attitudes of physicians were generally positive. Several barriers towards successful implementation of such a procedure were encountered, and subsequently solutions were provided. Most importantly, when implementing routine computerized HRQoL measurements in clinical practice, assistance of an IT professional for the development of a tailor-made computer program, availability of questionnaires in multiple languages and the use of touch-screen computers to optimise patient participation are essential. Also, all staff of the department concerned should approve of the intervention and consider it as part of standard clinical routine if successful implementation is to be obtained.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The first evidence for β-delayed proton emission from the 16+ spin gap isomer in 96Cd is presented. The data were obtained from the Rare Isotope Beam Factory, at the RIKEN Nishina Center, using the ...BigRIPS spectrometer and the EURICA decay station. βp branching ratios for the ground state and 16+ isomer have been extracted along with more precise lifetimes for these states and the lifetime for the ground state decay of 95Cd. Large scale shell model (LSSM) calculations have been performed and WKB estimates made for ℓ=0,2,4 proton emission from three resonance-like states in 96Ag, that are populated by the β decay of the isomer, and the results compared to the new data. The calculations suggest that ℓ=2 proton emission from the resonance states, which reside ∼5 MeV above the proton separation energy, dominates the proton decay. The results highlight the importance of core-excited wavefunction components for the 16+ state.
At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using low-energy Coulomb excitation. These experiments have resulted in B(E2,2{sub 1}{sup +}{yields}0{sub ...1}{sup +}) values in {sup 74-80}Zn, B(E2,4{sub 1}{sup +}{yields}2{sub 1}{sup +}) values in {sup 74,76}Zn and the determination of the energy of the first excited 2{sub 1}{sup +} states in {sup 78,80}Zn. The zinc isotopes were produced by high-energy proton- (A=74,76,80) and neutron- (A=78) induced fission of {sup 238}U, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondary target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and how a reliable normalization of the experiment can be achieved. The results for zinc isotopes and the N=50 isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, including a recent empirical residual interaction constructed to describe the present experimental data up to 2004 in this region of the nuclear chart.
In an attempt to describe the excitation spectra and transitions strengths of light even-even Cd-isotopes (A = 98 − 108), large-scale shell-model calculations in the proton (2p1/2, 1g9/2) and the ...neutron (2d5/2, 1g7/2, 2d3/2, 3s1/2, 1h11/2) model space were performed. Preliminary results are presented and discussed.
DESPEC Phase-0 campaign at GSI Polettini, M.; Das, Biswarup; Cederwall, Bo ...
HAL (Le Centre pour la Communication Scientifique Directe),
03/2021, Letnik:
44, Številka:
2-3
Journal Article
Recenzirano
Odprti dostop
This paper reports preliminary results of the DESPEC campaign at GSI, focused on the study of neutron-deficient nuclei approaching Sn-100. The results presented show the isomeric decays of excited ...states with I-pi = 14(+) and 8(+) in Pd-96 and Pd-94, respectively. The detailed characterisation of the DESPEC set-up and analysis methodologies, proven in this experimental run, are crucial for the future campaigns.
An array of eight Ge detectors for coincidence measurements of gamma rays from neutron-capture reactions has been constructed at the PF1B cold-neutron facility of the Institut Laue-Langevin. The ...detectors arranged in one plane every 45 degree can be used for angular correlation measurements. The neutron collimation line of the setup provides a neutron beam of 12 mm in diameter and the capture flux of about 10 super(8)/(sxcm super(2)) at the target position, with a negligible neutron halo. With the setup up to 10 super(9) gamma gamma and up to 10 super(8) triple- gamma coincidence events have been collected in a day measurement. Precise energy and efficiency calibrations up to 10 MeV are easily performed with 27Al(n, gamma ) super(28)Al and super(35)Cl(n, gamma ) super(36)Cl reactions. Test measurements have shown that neutron binding energies can be determined with an accuracy down to a few eV and angular correlation coefficients measured with a precision down to a percent level. The triggerless data collected with a digital electronics and acquisition allows to determine half-lives of excited levels in the nano- to microsecond range. The high resolving power of double- and triple- gamma time coincidences allows significant improvements of excitation schemes reported in previous (n, gamma ) works and complements high-resolution gamma -energy measurements at the double-crystal Bragg spectrometer GAMS of ILL.
The γ-ray decay of excited states of the one-valence-proton nucleus 133Sb has been studied using cold-neutron induced fission of 235U and 241Pu targets, during the EXILL campaign at the ILL reactor ...in Grenoble. By using a highly efficient HPGe array, coincidences between γ-rays prompt with the fission event and those delayed up to several tens of microseconds were investigated, allowing to observe, for the first time, high-spin excited states above the 16.6 μs isomer. Lifetimes analysis, performed by fast-timing techniques with LaBr3(Ce) scintillators, revealed a difference of almost two orders of magnitude in B(M1) strength for transitions between positive-parity medium-spin yrast states. The data are interpreted by a newly developed microscopic model which takes into account couplings between core excitations (both collective and non-collective) of the doubly magic nucleus 132Sn and the valence proton, using the Skyrme effective interaction in a consistent way. The results point to a fast change in the nature of particle-core excitations with increasing spin.
The even-even N=90 isotones with Z=60-66 are known to undergo a first order phase transition. Such a phase transition in atomic nuclei is characterized by a sudden change of the shape of the nucleus ...due to changes in the location of the potential minimum. In these proceedings we report a measurement of the B4/2 ratio of 148Ce, which will probe the location of the low-Z boundary of the N=90 phase transitional region. The measured B4/2 value is compared to the prediction from the X(5) symmetry within the interacting boson model at the critical point between the geometrical limits of vibrators and rigid/axial rotors. The EXILL&FATIMA campaign took place at the high-flux reactor of the Institut Laue Langevin, Grenoble, were 235U and 241Pu fission fragments were measured by a hybrid spectrometer consisting of high-resolution HPGe and fast LaBr3(Ce)-scintillator detectors. The fast LaBr3(Ce) detectors in combination with the generalized centroid difference method allowed lifetime measurements in the picosecond region. Furthermore, this kind of analysis can serve as preparation for the FATIMA experiments at FAIR.
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