The EXOTIC project at INFN-LNL Pierroutsakou, Dimitra; Boiano, Alfonso; Boiano, Ciro ...
Nucleus,
06/2018
Journal Article
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Abstract The low-energy light radioactive ion beam in-flight facility EXOTIC and the associated experimental set-up,operational at Legnaro National Laboratories of the National Institute of Nuclear ...Physics (LNL-INFN, Italy) and designed for nuclear physics and nuclear astrophysics experiments, were described. The outline of the experimental program carried out employing the produced radioactive ion beams was presented and the perspectives of the EXOTIC project were discussed.
A Measurement-Domain Specific Language (MDSL) for test procedure definition, measurement tasks synchronization, and instrument configuration is proposed. MDSL is a formal language specially designed ...for a specific domain of measurement and test, aimed at specifying complete, easy-to-understand, -reuse, and -maintain applications efficiently and quickly. Owing to MDSL constructs capability of abstracting key concepts of the domain, the test engineer can write more concise and higher level programs in shorter time without being a skilled programmer. The MDSL has been applied to the specifications of superconducting magnet tests of the Large Hadron Collider at CERN.
The stability and spontaneous decay of naturally occurring atomic nuclei have been much studied ever since Becquerel discovered natural radioactivity in 1896. In 1960, proton-rich nuclei with an odd ...or an even atomic number Z were predicted to decay through one- and two-proton radioactivity, respectively. The experimental observation of one-proton radioactivity was first reported in 1982, and two-proton radioactivity has now also been detected by experimentally studying the decay properties of super(45)Fe and super(54)Zn. Here we report proton- proton correlations observed during the radioactive decay of a spinning long- lived state of the lightest known isotope of silver, super(94)Ag, which is known to undergo one-proton decay. We infer from these correlations that the long-lived state must also decay through simultaneous two-proton emission, making super(94)Ag the first nucleus to exhibit one- as well as two-proton radioactivity. We attribute the two-proton emission behaviour and the unexpectedly large probability for this decay mechanism to a very large deformation of the parent nucleus into a prolate (cigar-like) shape, which facilitates emission of protons either from the same or from opposite ends of the 'cigar'.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The stability and spontaneous decay of naturally occurring atomic nuclei have been much studied ever since Becquerel discovered natural radioactivity in 1896. In 1960, proton-rich nuclei with an odd ...or an even atomic number Z were predicted to decay through one- and two-proton radioactivity, respectively. The experimental observation of one-proton radioactivity was first reported in 1982, and two-proton radioactivity has now also been detected by experimentally studying the decay properties of 45Fe (refs 3, 4) and 54Zn (ref. 5). Here we report proton–proton correlations observed during the radioactive decay of a spinning long-lived state of the lightest known isotope of silver, 94Ag, which is known to undergo one-proton decay. We infer from these correlations that the long-lived state must also decay through simultaneous two-proton emission, making 94Ag the first nucleus to exhibit one- as well as two-proton radioactivity. We attribute the two-proton emission behaviour and the unexpectedly large probability for this decay mechanism to a very large deformation of the parent nucleus into a prolate (cigar-like) shape, which facilitates emission of protons either from the same or from opposite ends of the ‘cigar’.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The prompt gamma ray emission was investigated in the 16A MeV energy region by means of the 36,40Ar+96,92Zr fusion reactions leading to a compound nucleus in the vicinity of 132Ce. We show that the ...prompt radiation, which appears to be still effective at such a high beam energy, has an angular distribution pattern consistent with a dipole oscillation along the symmetry axis of the dinuclear system. The data are compared with calculations based on a collective bremsstrahlung analysis of the reaction dynamics.
We investigate the isospin transport with 40,48 Ca+ 40,48 Ca reactions at 35 MeV/nucleon, measured with the coupling of the VAMOS high acceptance spectrometer and the INDRA charged particle ...multidetector. Using the quasi-projectile remnant measured with VAMOS and carefully selected light-charged-particles measured in coincidence with INDRA, a reconstruction method is applied to estimate the excited quasi-projectile (QP) on an event-by-event basis. The isospin diffusion is investigated using the isospin transport ratio with the asymmetry δ = (N − Z)/A of the projectile as an isospin-sensitive observable and the total transverse energy of Z ≤ 2 nuclei for experimental centrality sorting. The experimental isospin transport ratios present, for both the reconstructed QP and its remnant, a clear evolution towards isospin equilibration with increasing dissipation of the collision while the full equilibration is not reached. A smoother evolution with less discrepancies between the two mixed systems in the case of the reconstructed QP is also observed. The isospin migration is investigated using the neutron-to-proton ratio of the light-charged-clusters and the velocity of the QP remnant as a sorting parameter. More particularly, we focused on an angular region centered around the mid-rapidity of the reaction so as to characterize the low-density neck emissions. A systematic neutron-enrichment is observed and interpreted as a consequence of isospin migration, more particularly for the symmetric systems which present no isospin gradient between the projectile and the target. We also noticed that the ^{2}H and ^{4}He particles exhibit very close multiplicities independently of the sorting variable for the symmetric systems.
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