589 research outputs found
Production cross-sections and momentum distributions of fragments from neutron-deficient 36Ar at 1.05 A.GeV
We have measured production cross sections and longitudinal momentum
distributions of fragments from neutron-deficient 36Ar at 1.05 A.GeV. The
production cross-sections show excellent agreement with the predictions of the
semiempirical formula EPAX. We have compared these results, involving extremly
neutron deficient nuclei, with model calculations to extract informa tion about
the response of these models close to the driplines. The longitudinal momentum
distributions have also been extracted and are compared with the Goldhaber and
Morrissey systematics.Comment: 16 pages, 6 figure
Performances of multi-gap timing RPCs for relativistic ions in the range Z=1-6
We present the performance of Multi-gap timing RPCs under irradiation by
fully stripped relativistic ions (gamma*beta=2.7, Z=1-6). A time resolution of
80 ps at high efficiency has been obtained by just using standard `off the
shelf' 4-gap timing RPCs from the new HADES ToF wall. The resolution worsened
to 100 ps for ~ 1 kHz/cm2 proton flux and for ~ 100 Hz/cm2 Carbon flux. The
chambers were operated at a standard field of E=100 kV/cm and showed a high
stability during the experiment, supporting the fact that RPCs are a convenient
choice when accommodating a very broad range of ionizing particles is needed.
The data provides insight in the region of very highly ionizing particles (up
to x 36 mips) and can be used to constrain the existing avalanche and
Space-Charge models far from the usual `mip valley'. The implications of these
results for the general case of detection based on secondary processes (n,
gamma) resulting in highly ionizing particles with characteristic energy
distributions will be discussed, together with the nature of the time-charge
correlation curve.Comment: 31 pages, 19 figures, submitted to JINS
Design, manufacturing and set-up tests of a wave energy converter prototype in the context of the European Project LIFE-Demowave
LifeDemoWave Project is a real case of development of a R&D project, from the initial idea to the final construction and installation of a prototype for testing in operational environment. This project was born from an idea of the main researcher of the CIMA Group that finally led to two patents of two wave generation systems. Based on these patents, CIMA sought different ways for funding with the aim of developing prototypes with a high TRL and being able to test the operating principle of the patented systems. Finally, funding was obtained through the Life Program of the European Union and in collaboration with five other partners. The main objective of the LifeDemoWave project (http://www. life-demowave.eu/en/) is the demonstration of the feasibility of the use of wave power for electric generation in order to reduce greenhouse gases' emissions. For demonstration purposes, prototypes of wave power generation, reproducible and scalable at high level, are installed in the Galician coast. LifeDemoWave project considers, as well as its design and implementation, the environmental impact in the installation areas and its effect on biodiversity.Peer Reviewe
Geant4-GATE Simulation of a Large Plastic Scintillator for Muon Radiography
Envisaging the possibility of using large-area plastic scintillator slabs as robust detectors for high spatial resolution muon radiography, and prior to prototype development, we study expected basic performance by Monte Carlo simulation. We present preliminary results for a scalable square footprint detector unit of similar to 1 m(2), defining a representative simulation model volume of 50 cm x 50 cm, with reflective surfaces and a light readout by direct coupling of 4 small PMTs (in a square arrangement) at one face of the scintillator slab. Light detection efficiency is calculated for several light collection configurations, considering different values of surface roughness, reflectivity, optical coupling index and scintillator thickness. Values maximizing photon detection have been identified. The light response function of 2.5-3.5 cm diameter PMTs for the proposed configuration has been determined. A detector intrinsic spatial resolution of the order of 1 cm is estimated for muon interactions at the center region of the detector module, using a simple centroid positioning algorithm (Anger logic)
Experimental Indications for the Response of the Spectators to the Participant Blast
Precise momentum distributions of identified projectile fragments, formed in
the reactions 238U + Pb and 238U + Ti at 1 A GeV, are measured with a
high-resolution magnetic spectrometer. With increasing mass loss, the
velocities first decrease as expected from previously established systematics,
then level off, and finally increase again. Light fragments are on the average
even faster than the projectiles. This finding is interpreted as the response
of the spectators to the participant blast. The re-acceleration of projectile
spectators is sensitive to the nuclear mean field and provides a new tool for
investigating the equation of state of nuclear matter.Comment: 7 pages, 3 figures, background information on
http://www-wnt.gsi.de/kschmidt
Experimental study of fragmentation products in the reactions 112Sn + 112Sn and 124Sn + 124Sn at 1 AGeV
Production cross-sections and longitudinal velocity distributions of the
projectile-like residues produced in the reactions 112Sn + 112Sn and 124Sn +
124Sn both at an incident beam energy of 1 AGeV were measured with the
high-resolution magnetic spectrometer, the Fragment Separator (FRS) of GSI. For
both reactions the characteristics of the velocity distributions and nuclide
production cross sections were determined for residues with atomic number Z
10. A comparison of the results of the two reactions is presented.Comment: 14 pages, 12 figure
Production of new neutron-rich isotopes of heavy elements in fragmentation reactions of U projectiles at 1 A GeV
The production of heavy neutron-rich nuclei has been investigated using cold
fragmentation reactions of U projectiles at relativistic energies. The
experiment performed at the high-resolving-power magnetic spectrometer FRS at
GSI allowed to identify 45 new heavy neutron-rich nuclei: Pt,
Au, Hg, Tl, Pb, Bi,
Po, At, Rn and Fr. The production
cross sections of these nuclei were also determined and used to benchmark
reaction codes that predict the production of nuclei far from stability.Comment: 5 pages, 2 figure
Deep excursion beyond the proton dripline. I. Argon and chlorine isotope chains
The proton-unbound argon and chlorine isotopes have been studied by measuring trajectories
of their decay-in-flight products by using a tracking technique with micro-strip detectors. The
proton (1p) and two-proton (2p) emission processes have been detected in the measured angular
correlations âheavy-fragmentâ+p and âheavy-fragmentâ+p+p, respectively. The ground states of
the previously unknown isotopes 30Cl and 28Cl have been observed for the first time, providing the
1p separation energies Sp of â0.48(2) and â1.60(8) MeV, respectively. The relevant systematics of
1p and 2p separation energies have been studied theoretically in the core+p and core+p+p cluster
models. The first-time observed excited states of 31Ar allow to infer the 2p-separation energy S2p
of 6(34) keV for its ground state. The first-time observed state in 29Ar with S2p = â5.50(18) MeV
can be identified either as a ground or an excited state according to different systematics.Helmholtz Association grant IK-RU-002Helmholtz International Center for FAIR HIC for FAIRRussian Science Foundation grant No. 17-12-01367Polish National Science Center Contract No. UMO- 2015/17/B/ST2/00581Polish Ministry of Science and Higher Education Grant No. 0079/DIA/2014/43, Grant DiamentowyHelmholtz- CAS Joint Research Group grant HCJRG-10
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