Chercheur CNRS
Groupe : Structure nucléaire
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PUBLICATIONS
Spectroscopy of $^18$Na : Bridging the two-proton radioactivity of $^19$Mg
7 octobre 2011
The unbound nucleus $^18$Na, the intermediate nucleus in the two-proton radioactivity of $^19$Mg, was studied by the measurement of the resonant elastic scattering reaction $^17$Ne(p,$^17$Ne)p performed at 4 A.MeV. Spectroscopic properties of the low-lying states were obtained in a R-matrix (...)
Structure of 23Al from one-proton breakup reaction and astrophysical implications
6 avril 2011
The ground state of the proton-rich nucleus 23Al has been studied by one-proton removal on a carbon target at about 50 MeV/nucleon using the EXOGAM + SPEG experimental setup at GANIL. Longitudinal momentum distributions of the 22Mg breakup fragments, inclusive and in coincidence with gamma rays (...)
Emergence of the N=16 shell gap in $^21$O
21 décembre 2010
The spectroscopy of 21O has been investigated using a radioactive 20O beam and the (d,p) reaction in inverse kinematics. The ground and first excited states have been determined to be Jpi=5/2+ and Jpi=1/2+ respectively. Two neutron unbound states were observed at excitation energies of 4.76 +- (...)
Spectroscopy of the unbound nucleus $^18$Na
15 septembre 2010
The unbound nucleus 18Na, the intermediate nucleus in the two-proton radioactivity of 19Mg, is studied through the resonant elastic scattering 17Ne(p,17Ne)p. The spectroscopic information obtained in this experiment is discussed and put in perspective with previous measurements and the (...)
Prolate-Spherical Shape Coexistence at N=28 in $^44$S
28 juillet 2010
The structure of $^44$S has been studied using delayed $\gamma$ and electron spectroscopy at \textscganil. The decay rates of the 0$^+_2$ isomeric state to the 2$^+_1$ and 0$^+_1$ states have been measured for the first time, leading to a reduced transition probability (...)
The β–γ decay of 21Na
12 avril 2010
A new and independent determination of the Gamow–Teller branching ratio in the β-decay of 21Na is reported. The value 5.13 ± 0.43% obtained is in agreement with the currently adopted value and the most recent measurement. In contrast to previous experiments, the present method was based on the (...)
Migration of nuclear shell gaps studied in the d(24Ne,p gamma)25Ne reaction
12 avril 2010
The transfer of neutrons onto 24Ne has been measured using a reaccelerated radioactive beam of 24Ne to study the (d,p) reaction in inverse kinematics. The unusual raising of the first 3/2+ level in 25Ne and its significance in terms of the migration of the neutron magic number from N=20 to N=16 (...)
Structure around the island of inversion with single-neutron knockout reactions at GANIL
20 janvier 2010
The nuclear structure of the 31Mg nucleus has been studied with the singleneutron knockout reaction. We report on the preliminary results of an experiment performed with the EXOGAM array coupled, for the first time, to the SPEG spectrometer at GANIL.We present a provisional result for the (...)
TIARA : a large solid angle silicon array for direct reaction studies with radioactive beams
31 août 2009
A compact, quasi-4pi 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-strip silicon detectors forming an octagonal (...)
Discovery of a new broad resonance in $^19$Ne : Implications for the destruction of the cosmic $gamma-ray emitter $^18$F
25 mars 2009
Six proton-emitting states in 19Ne were studied through the inelastic scattering reaction H(19Ne ; p)19Ne*(p)18F. Their energies and widths were derived from the protons detected at zero degree, while proton-proton angular correlations between the detector at zero degree and a segmented annular (...)
Beta-delayed proton decay of proton-rich nuclei 23Al and 31Cl and explosive H-burning in classical novae
3 février 2009
We have developed a technique to measure beta-delayed proton decay of proton-rich nuclei produced and separated with the MARS recoil spectrometer of Texas A&M University. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and (...)
Single-Proton Removal Reaction Study of $^16$B
29 février 2008
The low-lying level structure of the unbound system $^16$B has been investigated via single-proton removal from a 35 MeV/nucleon $^17$C beam. The coincident detection of the beam velocity $^15$B fragment and neutron allowed the relative energy of the in-flight decay of $^16$B to be (...)
Evidence for core excitation in single-particle states of $^19$Na
5 février 2008
We present an experimental study of $^19$Na states in the excitation energy range between 2 and 3 MeV. The presence of $^19$Na single-particle levels at these energies was first predicted by a microscopic cluster model and then experimentally confirmed by measuring the elastic and inelastic (...)
Breakup reaction study of the Brunnian nucleus $^10$C
5 février 2008
The structure and 2α + 2p breakup of $^10$C, the only known Brunnian nucleus, has been studied at 33.3 MeV/nucleon. The breakup kinematics were used to reconstruct the $^10$C→$^9$B +p, $^9$B→$^8$Be +p, $^8$Be→ α + α and $^10$C → $^6$Be +α, $^6$Be → $^5$Li +p, $^5$Li → α + p decay paths. Proton emission (...)
Etude de la radioactivité de $^22$Al et spectroscopie par diffusion élastique résonante
28 août 2007
Ce travail de thèse s’inscrit dans le cadre général de l’étude de la structure des noyaux radioactifs riches en protons. Il se compose de deux parties.<br /> La première partie est consacrée à l’étude de la décroissance Β- particules retardées de 22Al. L’expérience décrite dans cette partie a (...)
Collapse of the N=28 shell closure in $^42$Si
9 mai 2007
The energies of the excited states in very neutron-rich $^42$Si and $^41,43$P have been measured using in-beam$gamma$-ray spectroscopy from the fragmentation of secondary beams of $^42,44$S at 39 A.MeV. The low $2^+ $ energy of $^42$Si, 770(19) keV, together with the level schemes of $^41,43$P (...)
The beta-decay of 22Al
22 août 2006
In an experiment performed at the LISE3 facility of GANIL, we studied the decay of $^22$Al produced by the fragmentation of a $^36$Ar primary beam. The $\beta$-decay half-life and $\beta$-delayed one- and twoproton emission as well as by $\beta-\alpha$ and $\beta$-delayed $\gamma$ decay were (...)
The $^7Be(d,p)2alpha$ cross section at Big Bang energies and the primordial $^7$Li abundance
26 septembre 2005
The WMAP satellite, devoted to the observations of the anisotropies of the Cosmic Microwave Background (CMB) radiation, has recently provided a determination of the baryonic density of the Universe with unprecedented precision. Using this, Big Bang Nucleosynthesis (BBN) calculations predict a (...)
Study of 19Na at SPIRAL
5 septembre 2005
The excitation function for the elastic-scattering reaction p18Ne, p18Ne was measured with the first radioactive beam from the SPIRAL facility at the GANIL laboratory and with a solid cryogenic hydrogen target. Several broad resonances have been observed, corresponding to new excited states in (...)
Beta-decay properties of $^25$Si and $^26$P
15 novembre 2004
The $\beta$-decay properties of the neutron-deficient nuclei $^25$Si and $^26$P have been investigated at the GANIL/LISE3 facility by means of charged-particle and $\gamma$-ray spectroscopy. The decay schemes obtained and the Gamow-Teller strength distributions are compared to shell-model (...)
