[en] Complete text of publication follows. In order to clarify the role of proton excitations across the Z = 14 subshell closure in neutron-rich Si isotopes, we investigated the structure of the ₁₄³⁹Si₂₅ isotope, having three neutron-hole configurations with respect to an N = 28 core. The excited states of ³⁹Si were studied by in-beam γ-ray spectroscopy trough fragmentation of radioactive beams. The experiment was performed at the GANIL facility in France. The radioactive beams were produced by the fragmentation of the stable ⁴⁸Ca beam of 60 MeV/u energy and 4μA intensity on a ¹²C target in the SISSI device. The cocktail beam produced was impinged onto a ⁹Be target. The nuclei produced in the secondary fragmentation reaction were selected and unambiguously identified by the SPEG spectrometer. In the performed experiment the ³⁹Si nuclei were obtained via 1p, 1p1n, 2p1n and 2p2n knockout reactions from the ^40,41P and ^42,43S secondary beams. To measure the γ rays emitted from the excited states, the secondary target was surrounded by the 4π 'Chateau de Crystal' array consisting of 74 BaF₂ scintillators. The γ-ray spectra were generated by gating event-by-event on the incoming secondary beam particles and the ejectiles after the secondary target. For the γ rays emitted by the fast moving fragments accurate Doppler correction was performed. From the obtained γ spectra of ³⁹Si displayed in Figure 1, two strong γ transitions at 163 and 397 keV as well as weaker ones at 303, 657, 906, 1143 and 1551 keV have been identified. γγ coincidences were obtained in ³⁹Si after having added all data from the various reaction channels giving rise to ³⁹Si. Analysing these data the 163 keV transition was found to be in coincidence with the 657, 1143 and 1551 keV ones, but not with the 397 keV transition. The two lines of the 303+397 keV doublet are in mutual coincidence, and one or both of them are found in coincidence with the 906 keV transition.

[en] Experimental nuclear structure data from various reactions and decays have been evaluated for all known nuclides of mass 39 (Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti). Detailed evaluated nuclear structure information is presented for each reaction and decay and the best values combining all available data are recommended for level energies, half-lives, γ-ray energies and intensities, decay properties (energies, intensities and placement of radiations), and other spectroscopic data. The ³⁹K, ³⁹Ca and ³⁹Ar are the most extensively studied nuclides; no excited states are known in ³⁹Mg and ³⁹Ti. This work supersedes the earlier full evaluation of A=39 by B. Singh and J. Cameron (2006Si02).

[en] The structure of the very neutron-rich nuclei ³⁹Si and ⁴¹Si has been investigated via in-beam γ-ray spectroscopy and few-nucleon knockout from radioactive beams. The observation of low-lying states in ³⁹Si is a clear evidence for a drastic lowering of the intruder neutron 3/2^- state when going from Z=20 to Z=14. The energy of the only γ-ray transition (672(14) keV) observed in ⁴¹Si is significantly lower than that of the first excited state in ⁴⁷Ca (2014 keV) suggesting a deformed ground state for ⁴¹Si. These results are consistent with large-scale shell-model calculations implying that strong proton-neutron correlations are the main reason for the lowering of the intruder configurations over the normal ones.

[en] The masses of 16 neutron-rich nuclei in the mass range from 35 to 45 have been measured using a direct time of flight technique following the fragmentation of a ⁴⁸Ca beam at 60 MeV/nucleon. The masses of ^35,36Mg, ³⁸Al, ^39,40Si, ^42,43P and ^43,44S are reported for the first time. Preliminary analysis shows that the N=28 shell closure persists, even if weakened by the large neutron excess

[en] Nuclear spectroscopic information for the known nuclides of mass 39 (Mg,Al,Si,P,S,Cl,Ar,K,Ca,Sc,Ti) has been evaluated. The principal sources of the 'adopted levels' presented are Endt's evaluations (1990En08, 1978En02). The data sets for reactions and decays, including all available gamma-ray data, are based mostly on the original literature. There are no data available for the excited states in ³⁹Mg, ³⁹Al, ³⁹Si and ³⁹Ti

[en] Results of investigations of effects of spin-dependent recombination (SDR) manifesting in experiments on spin resonance and optical polarization of nuclei in irradiated with γ quanta and electrons crystals of silicon are presented. It is shown that the use of SDR phenomena and its registration according to crystal SHF photoconductivity measurement with the help of common spin resonance spectrometer makes the method of spin resonance sensitive enough for investigation of defects is silicon

[en] The one-neutron removal cross section from ²⁹Ne, ^33,35,37Mg, and ^39,41Si on a Pb target have been measured at around 240 MeV/nucleon at the RIBF (RI-Beam Factory) at RIKEN. This main goal of the experiment was to extract the inclusive Coulomb breakup cross sections in order to probe possible halo structures through their enhanced low-energy E1 strengths - so-called soft E1 excitations. The results showed significant enhancement of the one-neutron removal Coulomb breakup cross section for ³⁷Mg. This in turn provides evidence for the existence of halo structure in ³⁷Mg. (author)

[en] The cross sections of one-neutron removal via Coulomb and nuclear breakup from the very neutron-rich nuclei ^29,31Ne, ^33,35,37Mg and ^39,41Si and the momentum distributions of the fragments have been measured at around 240 MeV/nucleon. These reactions are combined to identify halo nuclei and obtain the spectroscopic factors, separation energies and spin-parities of ground states. The Coulomb breakup cross sections showed significant enhancement for ³¹Ne and ³⁷Mg, which suggests halo formation. Further analysis is in progress.

[en] Yields of neutron-rich projectile fragments have been measured at 0⁰ for the reaction of 212-MeV/amu ⁴⁸Ca ions on an 890-mg-cm^-2 beryllium target. Fourteen nuclides have been observed for the first time. The systematics of production cross sections are discussed

[en] Energy integrated reaction cross-section measurements of around sixty neutron-rich nuclei covering the region of closed shells N=20 and N=28 were performed at intermediate energy (30-65 A. MeV) using direct method. In this experiment, silicon detectors were used as active targets. The reduced strong absorption radii, r₀², for 19 new nuclei (²⁷F, ^27,30Ne, ³³Na, ^28,34-35Mg, ^36-38Al, ^38-40Si, ^41-42P, ^42-44S and ⁴⁵Cl) are deduced for the first time. An additional 60 radii, also measured in this experiment, are compared to results from literature. A new quadratic parametrization is proposed for the nuclear radius as a function of the isospin in the region of closed shells N=8 and N=28. According to this parametrization, the skin effect is well reproduced and anomalous behaviour on the radii are observed in ²³N, ²⁹Ne, ³³Na, ³⁵Mg, ⁴⁴S, ⁴⁵Cl and ⁴⁵Ar nuclei. (orig.)