6 research outputs found
\b{eta}-delayed three-proton decay of 31Ar
The beta decay of 31Ar, produced by fragmentation of a 36Ar beam at 880
MeV/nucleon, was investigated. Identified ions of 31Ar were stopped in a
gaseous time projection chamber with optical readout allowing to record decay
events with emission of protons. In addition to \b{eta}-delayed emission of one
and two protons we have clearly observed the beta-delayed three-proton branch.
The branching ratio for this channel in 31Ar is found to be 0.07(2)%.Comment: 5 pages, 3 figures, submitted to Physical Rev.
Structure of 24Mg excited states and their influence on nucleosynthesis
The main idea of the two presented experiments is to study the decay of resonances in 24Mg at excitation energies above the 12C+12C decay thresh- old, in the astrophysical energy region of interest. The measurement of the 12C(16O,α)24Mg* reaction was performed at INFN-LNS in Catania. Only the α+20Ne decay channel of 24Mg is presented here, because it was a motivation for conducting a new experiment, a study of the 4He(20Ne,4He)20Ne reaction, performed at INFN-LNL in Legnaro. Some preliminary results of this measurement are also presented
Spectroscopy of excited states of unbound nuclei Ar and Cl
Several states of proton-unbound isotopes Ar and Cl were investigated by measuring their in-flight decay products, S+proton+proton and S+proton, respectively. A refined analysis of S-proton angular correlations indicates that the ground state of Ar is located at MeV above the two-proton emission threshold. The theoretical investigation of the Ar ground state decay demonstrates that its mechanism has the transition dynamics with a surprisingly strong sensitivity of the correlation patterns of the decay products to the two-proton decay energy of the Ar ground state and the one-proton decay energy as well as the one-proton decay width of the Cl ground state. The comparison of the experimental S-proton angular correlations with those resulting from Monte Carlo simulations of the detector response illustrates that other observed Ar excited states decay by sequential emission of protons via intermediate resonances in Cl. Based on the findings, the decay schemes of the observed states in Ar and Cl were constructed. For calibration purposes and for checking the performance of the experimental setup, decays of the previously-known states of a two-proton emitter Mg were remeasured. Evidences for one new excited state in Mg and two unknown states in Na were found
Deep excursion beyond the proton dripline. II. Toward the limits of existence of nuclear structure
Prospects of experimental studies of argon and chlorine isotopes located far
beyond the proton dripline are studied by using systematics and cluster models.
The deviations from the widespread systematics observed in Cl and
Ar have been theoretically substantiated, and analogous deviations
predicted for the lighter chlorine and argon isotopes. The limits of nuclear
structure existence are predicted for Ar and Cl isotopic chains, with Ar
and Cl found to be the lightest sufficiently long-living nuclear
systems. By simultaneous measurements of protons and -rays following
decays of such systems as well as their -delayed emission, an
interesting synergy effect may be achieved, which is demonstrated by the
example of Cl and Ar ground state studies. Such synergy effect
may be provided by the new EXPERT setup (EXotic Particle Emission and
Radioactivity by Tracking), being operated inside the fragment separator and
spectrometer facility at GSI, Darmstadt.Comment: 10 pages, 9 figures. Chapter added, language and some figures
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