FATIMA — FAst TIMing Array for DESPEC at FAIR Rudigier, M.; Podolyák, Zs; Regan, P.H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2020, Letnik:
969
Journal Article
Recenzirano
Odprti dostop
The components, working principle and characteristics of FATIMA (FAst TIMing Array), a fast-timing detector system for DESPEC at FAIR, are described. The core system includes 36 LaBr3(Ce) ...scintillator detectors, a mounting frame for the DESPEC station and a VME-based fast-timing data acquisition system. The current electronic timing circuit is based on V812 constant fraction discriminators and V1290 time-to-digital converters. Gamma-ray energies are measured using V1751 digitisers. Characteristics of the core FATIMA system including efficiency, energy, and coincidence resolving time, as well as limitations, are discussed on the basis of test measurements performed in the S4 cave at GSI, Germany. The coincidence γ-γ time resolution for the prompt 60Co cascade is determined to be ∼320 ps full width at half maximum. The total full energy peak efficiency at 1 MeV for the 36 detector array in the DESPEC setup is 2.9%. The energy-dependent prompt response centroid curve with the current CFD/TDC combination is shown to be smooth; the centroid shift method can be applied for the measurement of half-lives below 200 ps. An overview of applications of the FATIMA detectors as an ancilliary system in combination with other detector arrays during recent years is given. Data on the operation of the detectors in the presence of magnetic fields are presented.
The Advanced Implantation Detector Array (AIDA) Hall, O.; Davinson, T.; Griffin, C.J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
20/May , Letnik:
1050
Journal Article
Recenzirano
Odprti dostop
The Advanced Implantation Detector Array (AIDA) is a state-of-the-art detector system for the measurement of the decay properties of exotic nuclei at fragmentation/fission facilities. Built around ...stacks of up to eight 8cm×8cm, 128 × 128 strip (16384 pixels) or up to four 24cm×8cm, 384 × 128 strip (49152 pixels) double sided silicon strip detectors, the positions of both implanted ions and their subsequent decay products can be measured to sub-mm precision. The large number of pixels per detector provide implant-decay correlations at implantation rates ∼kHz. To process signals from the large number of strips application specific integrated circuits provide low and high gain signal processing per strip (20 GeV and 20 MeV full scale range) with a dynamic range of 1000:1, or better. A summary of the system and the analysis methodologies used are presented.
Conceptual design of the AGATA 1π array at GANIL Clément, E.; Michelagnoli, C.; de France, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2017, Letnik:
855
Journal Article
Recenzirano
Odprti dostop
The Advanced GAmma Tracking Array (AGATA) has been installed at the GANIL facility, Caen-France. This set-up exploits the stable and radioactive heavy-ions beams delivered by the cyclotron ...accelerator complex of GANIL. Additionally, it benefits from a large palette of ancillary detectors and spectrometers to address in-beam γ-ray spectroscopy of exotic nuclei. The set-up has been designed to couple AGATA with a magnetic spectrometer, charged-particle and neutron detectors, scintillators for the detection of high-energy γ rays and other devices such as a plunger to measure nuclear lifetimes. In this paper, the design and the mechanical characteristics of the set-up are described. Based on simulations, expected performances of the AGATA 1π array are presented.
A new detection system has been installed at the RIKEN Nishina Center (Japan) to investigate decay properties of very neutron-rich nuclei. The setup consists of three main parts: a moderated neutron ...counter, a detection system sensitive to the implantation and decay of radioactive ions, and γ-ray detectors. We describe here the setup, the commissioning experiment and some selected results demonstrating its performance for the measurement of half-lives and β-delayed neutron emission probabilities. The methodology followed in the analysis of the data is described in detail. Particular emphasis is placed on the correction of the accidental neutron background.
β-delayed γ-neutron spectroscopy has been performed on the decay of A = 84 to 87 gallium isotopes at the RI-beam Factory at the RIKEN Nishina Center using a high-efficiency array of 3He neutron ...counters (BRIKEN). β-2n-γ events were measured in the decays of all of the four isotopes for the first time, which is direct evidence for populating the excited states of two-neutron daughter nuclei. Detailed decay schemes with the γ branching ratios were obtained for these isotopes, and the neutron emission probabilities (Pxn) were updated from the previous study. Hauser-Feshbach statistical model calculations were performed to understand the experimental branching ratios. We found that the P1n and P2n values are sensitive to the nuclear level densities of 1n daughter nuclei and showed that the statistical model reproduced the P2n/P1n ratio better when experimental levels plus shell-model level densities fit by the Gilbert-Cameron formula were used as the level-density input. We also showed the neutron and γ branching ratios are sensitive to the ground-state spin of the parent nucleus. Our statistical model analysis suggested J ≤ 3 for the unknown ground-state spin of the odd-odd nucleus 86Ga, from the Iγ(4+ → 2+)/Iγ(2+ → 0+) ratio of 84Ga and the P2n/P1n ratio. In conclusion, these results show the necessity of detailed understanding of the decay scheme, including data from neutron spectroscopy, in addition to γ measurements of the multineutron emitters.
Study of exotic decay of Cs isotope close to the proton drip line Das, P.; Dattaf, Ushasi; Chakraborty, S. ...
27th International Nuclear Physics Conference, INPC 2019,Glasgow, United Kingdom,2019-07-29 - 2019-08-02,
12/2020, Letnik:
1643, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The neutron-deficient 115Cs was produced at ISOLDE, CERN by spallation reaction using 1.4 GeV proton on LaC2 target. The exotic decay modes were studied by using a charged particle array (DSSD and ...pad detectors) and a γ-detector array (four Clovers) at the ISOLDE decay station (IDS). In this report, results on observed β-delayed particle emission from 115Cs, a nucleus close to proton drip line, is presented. By measuring the time distribution in the delayed proton spectrum, the half-life of the ground state of 115Cs was extracted. The obtained half-life is in agreement with previous reported value. For the first time, the p-unbound states of 115Xe, obtained by measuring beta-delayed protons from 115Cs is reported.
A compact, quasi-
4
π
position sensitive silicon array, TIARA, designed to study direct reactions induced by radioactive beams in inverse kinematics is described here. The Transfer and Inelastic ...All-angle Reaction Array (TIARA) consists of 8 resistive charge division detectors forming an octagonal barrel around the target and a set of double-sided silicon-strip annular detectors positioned at each end of the barrel. The detector was coupled to the
γ
-ray
array EXOGAM and the spectrometer VAMOS at the GANIL Laboratory to demonstrate the potential of such an apparatus with radioactive beams. The
N
(
d
,
p
)
14
N
15
reaction, well known in direct kinematics, has been carried out in inverse kinematics for that purpose. The observation of the
N
15
ground state and excited states at 7.16 and 7.86
MeV is presented here as well as the comparison of the measured proton angular distributions with DWBA calculations. Transferred
l-values are in very good agreement with both theoretical calculations and previous experimental results obtained in direct kinematics.
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