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Accueil > Recherche & Enseignement

M. Miguel Marques


Chercheur CNRS


Groupe : Structure nucléaire


marques lpccaen.in2p3.fr


Tél : +33 2 31 45 29 67



PUBLICATIONS

[in2p3-01394089] Experimental study of high-lying states in $^{28}$Mg using the resonant elastic scattering of α particles

8 novembre 2016

The excitation function of Mg28 above the α-decay threshold has been measured for the first time using the resonant scattering of α particles with the technique of a thick target in inverse kinematics. Thirteen new states are reported between Ex=15.5 and Ex=20.5 MeV, and suggestions for (...)

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[in2p3-01367797] Interaction cross section study of the two-neutron halo nucleus $^{22}$C

16 septembre 2016

The interaction cross sections (σI) of the very neutron-rich carbon isotopes 19C, 20C and 22C have been measured on a carbon target at 307, 280, and 235MeV/nucleon, respectively. A σIof 1.280 ±0.023bwas obtained for 22C, significantly larger than for 19,20C, supporting the halo character of 22C. A (...)

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[in2p3-01285922] Nucleus $^{26}$O: A Barely Unbound System beyond the Drip Line

10 mars 2016

The unbound nucleus 26O has been investigated using invariant-mass spectroscopy following one-proton removal reaction from a 27F beam at 201 MeV/nucleon. The decay products, 24O and two neutrons, were detected in coincidence using the newly commissioned SAMURAI spectrometer at the RIKEN (...)

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[in2p3-01090228] Neutron occupancy of the 0d5/2 orbital and the N = 16 shell closure in 24O

3 juillet 2015

One-neutron knockout from 24O leading to the first excited state in 23O has been measured for a proton target at a beam energy of 62 MeV/nucleon. The decay energy spectrum of the neutron unbound state of 23O was reconstructed from the measured four momenta of the 22O fragment and emitted (...)

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[hal-00112249] Radiative proton capture on $^6$He

3 juillet 2015

Radiative capture of protons is investigated as a probe of clustering in nuclei far from stability. The first such measurement on a halo nucleus is reported here for the reaction $^6$He(p,$\gamma$) at 40 MeV. Capture into $^7$Li is observed as the strongest channel. In addition, events have (...)

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[in2p3-00005951] Neutral meson production in p-Be and p-Au collisions at 450 GeV beam energy

3 juillet 2015

We propose a "targeted" XML markup to computerize old dictionaries whose structure is "vague". It stands for a markup halfway between the "minimal" markup and the "analytic" markup already available. As regards this paper, it is meant to supply a brief (...)

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[in2p3-01044774] N=16 Spherical Shell Closure in O-24

3 juillet 2015

The unbound excited states of the neutron drip-line isotope O-24 have been investigated via the O-24(p, p')O-23 + n reaction in inverse kinematics at a beam energy of 62 MeV/nucleon. The decay energy spectrum of O-24* was reconstructed from the momenta of O-23 and the neutron. The spin parity (...)

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[in2p3-00010793] Two-neutron interferometry as a probe of the nuclear halo

1er juillet 2015

The technique of intensity interferometry is proposed as a probe of the spatial configuration of two-neutron haloes. After exploring the sensitivity of interferometry to the n-n configuration, it is demonstrated that the application of the standard method for constructing the correlation (...)

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Neutron occupancy of 0d5/2 orbital in 24O

2 juillet 2014

The partial one-neutron removal cross section of 24O leading to the first excited state in 23O has been measured to be 65.7 ± 5.3 mb with a proton target in inverse kinematics at the beam energy of 62 MeV/nucleon. The decay energy spectrum of the neutron unbound state of 23O was reconstructed (...)

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Near barrier scattering of 8He on 208Pb

27 mars 2014

The exotic nucleus 8He is investigated by means of the measurement of the angular distributions of the elastic channel and the 6He and 4He fragment yields produced in the collision with a 208Pb target at two energies around the Coulomb barrier, 16 and 22 MeV. The experiment was performed at the (...)

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[in2p3-00920222] Structure of $^{13}$Be probed via secondary beam reactions

18 décembre 2013

The low-lying level structure of the unbound neutron-rich nucleus $^13$Be has been investigated via breakup on a carbon target of secondary beams of $^14,15$B at 35 MeV/nucleon. The coincident detection of the beam velocity $^12$Be fragments and neutrons permitted the invariant mass of the (...)

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Scattering of 8He on 208Pb at 22 MeV

1er juillet 2013

The skin nucleus 8He is investigated by measuring the angular distribution of the elasticly scattered 8He and the 6,4He fragments produced in the collision with a 208Pb target at 22 MeV, just above the Coulomb barrier. The experiment was carried out at SPIRAL/GANIL in 2010. Here we present (...)

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The four-neutron system

16 mai 2013

The development of light, neutron-rich beams has opened new perspectives for the study of many-neutron systems in the last decade. Breakup experiments at GANIL are described, using beams of (6,8)He, (11)Li, (14)Be and (15)B at several tens of MeV/N. Our approach is based on the detection in (...)

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Invariant Mass Spectroscopy of O-23 via the (p, p') Reaction in Inverse Kinematics

16 mai 2013

The neutron-rich oxygen isotope O-23 has been investigated via proton inelastic scattering on a liquid hydrogen target at 63.5 MeV/nucleon. The invariant mass method in inverse kinematics was employed to reconstruct the energy spectrum. A sharp resonance state was observed at 42(5) keV above (...)

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The N=16 Spherical Shell Closure in O-24

16 mai 2013

The unbound excited states of the most neutron-rich dripline oxygen isotope, O-24, have been investigated by using the O-24(p,p')O-24(*) reaction at the beam energy of 62 MeV/nucleon in inverse kinematics. The first and second unbound excited states of O-24 have been observed at MeV and MeV (...)

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Elastic scatterring of the 8He + 208PB at 22 MeV

25 mars 2013

The dynamics of 8He around the Coulomb barrier is investigated by measuring the energy and angular distribution of the elastic 8He and the 6He and 4He fragment yields in the collision process with a 208Pb target. The experiment was carried out at SPIRAL/GANIL in October 2010. The experimental (...)

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The N = 16 spherical shell closure in 24O

6 février 2013

The unbound excited states of the neutron drip-line isotope 24O have been investigated via the 24O(p,p')23O+n reaction in inverse kinematics at a beam energy of 62 MeV/nucleon. The decay energy spectrum of 24O* was reconstructed from the momenta of 23O and the neutron. The spin-parity of the (...)

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[in2p3-00785471] Comment on "First Observation of Ground State Dineutron Decay: 16Be

6 février 2013

A recent measurement [Spyrou et al., PRL 108, 102501 (2012)] of the in-flight decay of 16Be into 14Be+n+n has been interpreted as the first case of dineutron emission. Here we point out that the inclusion of the n-n interaction neglected in the description of the direct three-body decay can (...)

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Neutron and charged particle identification by means of various detectors

11 septembre 2012

Identification methods for photons, neutrons and heavy ions by using scintillator and semiconductor detectors are discussed by stressing the advantages of signal digitization.

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The first 2 + excited state of 24O

27 avril 2012

The unbound excited states of the most neutron-rich dripline oxygen isotope, O (Z=8, N=16), have been investigated using the 24O(p, p′)O* reaction at the beam energy of 63 MeV/nucleon in inverse kinematics at RIKEN. The 24O beam was produced in the projectile-like fragmentation process of a 95 (...)

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Invariant Mass Spectroscopy of 23O via the (p, p′) Reaction in Inverse Kinematics

27 avril 2012

The neutron-rich oxygen isotope 23O has been investigated via proton inelastic scattering on a liquid hydrogen target at 63.5 MeV/nucleon. The invariant mass method in inverse kinematics was employed to reconstruct the energy spectrum. A sharp resonance state was observed at 42(5) keV above the (...)

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The N = 16 Spherical Shell Closure in 24O

27 avril 2012

The unbound excited states of the most neutron-rich dripline oxygen isotope, 24O, have been investigated by using the 24O(p, p′) 24O * reaction at the beam energy of 62 MeV/nucleon in inverse kinematics. The first and second unbound excited states of 24O have been observed at Mathematical (...)

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β-delayed neutron emission from 12,14Be

17 février 2012

The existence of β-delayed particle emission allows one to study the β-strength distribution, and thereby the ground-state structure, of exotic drip-line nuclei. A time-correlation method has been applied to recent data on the heaviest Be-isotopes to determine their neutron branches. Improved (...)

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Probing the halo with intensity interferometry

17 février 2012

The technique of intensity interferometry is presented as a probe of n-n haloes. After exploring the sensitivity of interferometry to the n-n configuration, it is demonstrated that, owing to the specific characteristics of the halo (principally the low momentum content), this technique can only (...)

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The Search for Neutral Nuclei

17 février 2012

The long debate on the possible existence of neutral nuclei has been recently revived by the application of a new experimental approach, which lead to the observation of few events consistent with the formation of a bound 4n in the breakup of 14Be. The description of these events by a resonant (...)

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Scattering of 8He on 208Pb at Energies Around the Coulomb Barrier

16 février 2012

We have measured the angular distributions of elastic scattering and 6,4He fragments produced in the collisions of an exotic beam of 8He on a 208Pb target at laboratory energies of 18 and 22 MeV, just around the Coulomb barrier (19 MeV). The measurements were performed at the SPIRAL/GANIL (...)

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A la recherche d'un femtomêtre

25 janvier 2012

Mes recherches au cours des 21 dernières années ont débuté à IFICValencia, puis quelques années au GANIL et de Valencia à nouveau, et enfin au labo depuis 1994. Bien que mon passage à LPC représenté une forte variation thématique, j'ai fait un effort pour trouver un scénario qui suit la plupart des (...)

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Measurement of Unbound Excited States of (24)O

17 novembre 2011

The unbound excited states of the most neutron-rich oxygen isotope, (24)O (Z = 8, N = 16), have been investigated using the (24)O(p,p')(24)O*-->(23)O+n reaction at RIKEN, where a 63 MeV/neuclon secondary beam of (24)O was produced in a Be production target by the projectile-like (...)

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[in2p3-00642050] Measurement of Unbound Excited States of (24)O

17 novembre 2011

The unbound excited states of the most neutron-rich oxygen isotope, (24)O (Z = 8, N = 16), have been investigated using the (24)O(p,p')(24)O*-->(23)O+n reaction at RIKEN, where a 63 MeV/neuclon secondary beam of (24)O was produced in a Be production target by the projectile-like (...)

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Invariant Mass Spectroscopy for the Neutron Rich Nuclei

17 novembre 2011

The neutron-rich carbon isotopes (19,17)C and a boron isotope (14)B are investigated respectively via proton inelastic and charge-exchange reactions on a liquid hydrogen target at around 70 MeV/nucleon at RIKEN. The invariant mass method in inverse kinematics involving coincidence detection of (...)

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[in2p3-00642043] Invariant Mass Spectroscopy for the Neutron Rich Nuclei

17 novembre 2011

The neutron-rich carbon isotopes (19,17)C and a boron isotope (14)B are investigated respectively via proton inelastic and charge-exchange reactions on a liquid hydrogen target at around 70 MeV/nucleon at RIKEN. The invariant mass method in inverse kinematics involving coincidence detection of (...)

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Nuclear weak response from the combined study of beta-decay and charge-exchange reaction

6 janvier 2010

Studying the weak nuclear response, especially the Gamow-Teller (GT) transitions, of stable as well as unstable pf-shell nuclei, is one of the key issues in nuclear and astro- nuclear physics. We study the decay half-lives and the GT transitions starting from Tz = 1 and 2 mirror nuclei, (...)

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Nuclear weak response from the combined study of beta-decay and charge-exchange reaction

6 janvier 2010

Studying the weak nuclear response, especially the Gamow-Teller (GT) transitions, of stable as well as unstable pf-shell nuclei, is one of the key issues in nuclear and astro- nuclear physics. We study the decay half-lives and the GT transitions starting from Tz = 1 and 2 mirror nuclei, (...)

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On the possible detection of 4n events in the breakup of 14Be

27 novembre 2009

In a recent paper --F.M. Marques et al, PRC 65 (2002) 044006-- a new approach to the production and detection of free neutron clusters was proposed and applied to data acquired for the breakup of 14Be. Six events that exhibited characteristics consistent with a bound tetraneutron were observed (...)

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On the possible detection of 4n events in the breakup of 14Be

27 novembre 2009

In a recent paper --F.M. Marques et al, PRC 65 (2002) 044006-- a new approach to the production and detection of free neutron clusters was proposed and applied to data acquired for the breakup of 14Be. Six events that exhibited characteristics consistent with a bound tetraneutron were observed (...)

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Light Nuclei in the Continuum

5 novembre 2009

The development of light, neutron-rich beams has opened in the last decade new perspectives for the study of many-neutron systems. Breakup experiments at GANIL are described, using beams of 6,8He, 11Li, 14Be and 15B at several tens of MeV/N. Our approach is based on the detection in coincidence (...)

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Light Nuclei in the Continuum

5 novembre 2009

The development of light, neutron-rich beams has opened in the last decade new perspectives for the study of many-neutron systems. Breakup experiments at GANIL are described, using beams of 6,8He, 11Li, 14Be and 15B at several tens of MeV/N. Our approach is based on the detection in coincidence (...)

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Study of β-delayed charged particle emission of 11Li: evidence of new decay channels

27 mai 2009

The break-up of the 18.2 MeV state in 11Be was studied in a 11Li beta-decay experiment. We report here on the study of the dominating breakup channels involving n alpha 6He or 3n2 alpha in the final state, with special emphasis dedicated in this contribution to the three-particle channel. The (...)

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Study of β-delayed charged particle emission of 11Li: evidence of new decay channels

27 mai 2009

The break-up of the 18.2 MeV state in 11Be was studied in a 11Li beta-decay experiment. We report here on the study of the dominating breakup channels involving n alpha 6He or 3n2 alpha in the final state, with special emphasis dedicated in this contribution to the three-particle channel. The (...)

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Study of beta-delayed 3-body and 5-body breakup channels from the decay of 11Li

25 septembre 2008

The beta-delayed charged particle emission from 11Li has been studied with emphasis on the three-body n+alpha+6He and five-body 2alpha+3n channels from the 10.59 and 18.15 MeV states in 11Be. Monte Carlo simulations using an R-matrix formalism lead to the conclusion that the AHe resonance (...)

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[in2p3-00324001] Study of beta-delayed 3-body and 5-body breakup channels from the decay of 11Li

25 septembre 2008

The beta-delayed charged particle emission from 11Li has been studied with emphasis on the three-body n+alpha+6He and five-body 2alpha+3n channels from the 10.59 and 18.15 MeV states in 11Be. Monte Carlo simulations using an R-matrix formalism lead to the conclusion that the AHe resonance (...)

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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 (...)

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[in2p3-00259696] 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 (...)

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Correlations of neutral and charged particles in $^{40}$Ar- $^{58}$Ni reaction at 77 MeV/u

24 mai 2007

The measurement of the two-particle correlation function for different particle species allows to obtain information about the development of the particle emission process: the space-time properties of emitting sources and the emission time sequence of different particles. The single-particle (...)

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[in2p3-00149009] Correlations of neutral and charged particles in $^{40}$Ar- $^{58}$Ni reaction at 77 MeV/u

24 mai 2007

The measurement of the two-particle correlation function for different particle species allows to obtain information about the development of the particle emission process: the space-time properties of emitting sources and the emission time sequence of different particles. The single-particle (...)

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Radiative proton capture on $^6$He

8 novembre 2006

Radiative capture of protons is investigated as a probe of clustering in nuclei far from stability. The first such measurement on a halo nucleus is reported here for the reaction $^6$He(p,$\gamma$) at 40 MeV. Capture into $^7$Li is observed as the strongest channel. In addition, events have (...)

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Radiative proton capture on $^6$He

8 novembre 2006

Radiative capture of protons is investigated as a probe of clustering in nuclei far from stability. The first such measurement on a halo nucleus is reported here for the reaction $^6$He(p,$\gamma$) at 40 MeV. Capture into $^7$Li is observed as the strongest channel. In addition, events have (...)

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Clustering and Correlations at the Neutron Dripline

10 juillet 2006

Some recent experimental studies of clustering and correlations within very neutron-rich light nuclei are reviewed. In particular, the development of the novel probes of neutron-neutron interferometry and Dalitz-plot analyses is presented through the example of the dissociation of the (...)

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[in2p3-00084797] Clustering and Correlations at the Neutron Dripline

10 juillet 2006

Some recent experimental studies of clustering and correlations within very neutron-rich light nuclei are reviewed. In particular, the development of the novel probes of neutron-neutron interferometry and Dalitz-plot analyses is presented through the example of the dissociation of the (...)

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Three-body correlations in Borromean halo nuclei

10 juillet 2006

Three-body correlations in the dissociation of Borromean halo nuclei are explored for the first time using a technique based on intensity interferometry and Dalitz plots. As an example, the breakup of $^14$Be into $^12$Be+n+n by Pb and C targets is analysed. The combined treatment of n-n and (...)

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[in2p3-00018884] Three-body correlations in Borromean halo nuclei

10 juillet 2006

Three-body correlations in the dissociation of Borromean halo nuclei are explored for the first time using a technique based on intensity interferometry and Dalitz plots. As an example, the breakup of $^14$Be into $^12$Be+n+n by Pb and C targets is analysed. The combined treatment of n-n and (...)

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High-energy two-neutron removal from $^{10}$Be

6 février 2006

A kinetically complete measurement of the $^12$C($^10$Be, alpha+alpha+n) and ($^10$Be, alpha+alpha) reactions has been performed at a beam energy of 30 MeV/nucleon. The charged beam velocity particles were detected in an array of Si-CsI detectors placed at zero degrees, and the neutrons in an (...)

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[in2p3-00025564] High-energy two-neutron removal from $^{10}$Be

6 février 2006

A kinetically complete measurement of the $^12$C($^10$Be, alpha+alpha+n) and ($^10$Be, alpha+alpha) reactions has been performed at a beam energy of 30 MeV/nucleon. The charged beam velocity particles were detected in an array of Si-CsI detectors placed at zero degrees, and the neutrons in an (...)

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Multineutron clusters Perspectives to create nuclei 100% neutron-rich

8 novembre 2005

A new approach to the production and detection of multineutrons, based on breakup reactions of beams of very neutron-rich nuclei, is presented. The first application of this technique to the breakup of $^14$Be into $^10$Be and 4n revealed 6 events consistent with the formation of a bound (...)

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Spectroscopy around N = 20 shell closure: $\beta$–n decay study of $^{35}$Al

10 octobre 2005

An experimental spectroscopic investigation of $^35$Al has been performed. The delayed neutron and $gamma$ spectra, following the $\beta$ decay of $^35$Al, have been measured using the delayed neutron detector array TONNERRE coupled with high efficiency $\gamma$ detectors. A detailed analysis (...)

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Spectroscopy around N = 20 shell closure: $\beta$–n decay study of $^{35}$Al

10 octobre 2005

An experimental spectroscopic investigation of $^35$Al has been performed. The delayed neutron and $gamma$ spectra, following the $\beta$ decay of $^35$Al, have been measured using the delayed neutron detector array TONNERRE coupled with high efficiency $\gamma$ detectors. A detailed analysis (...)

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The halo of $^{14}$Be

19 avril 2005

The two-neutron halo nucleus 14Be has been investigated in a kinematically complete measurement of the fragments (12Be and neutrons) produced in dissociation at 35 MeV/nucleon on C and Pb targets. Two-neutron removal cross-sections, neutron angular distributions and invariant mass spectra (...)

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[in2p3-00024052] The halo of $^{14}$Be

19 avril 2005

The two-neutron halo nucleus 14Be has been investigated in a kinematically complete measurement of the fragments (12Be and neutrons) produced in dissociation at 35 MeV/nucleon on C and Pb targets. Two-neutron removal cross-sections, neutron angular distributions and invariant mass spectra (...)

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Influence of the Coulomb field on charged particle emission in Ar + Ni reaction at 77 MeV/u

17 mars 2004

Ar+Ni collisions at 77 MeV/u were studied in the experiment E286 performed at GANIL. An important advantage of this experiment was an application of the neutron detector DEMON for registration of both neutral and charged particles. This feature allows to compare characteristics of neutrons and (...)

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Helium breakup states in $^{10}$Be and $^{12}$Be

2 avril 2001

The breakup of 10,12Be into He clusters has been studied using the p,12C(12Be,6He,6He) and 12C(12Be,4He,6He) inelastic scattering and two neutron transfer reactions with a 378 MeV 12Be beam incident on 12C and (CH2)n targets. Evidence has been found for three new states in 10Be at excitation (...)

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[in2p3-00019245] Helium breakup states in $^{10}$Be and $^{12}$Be

2 avril 2001

The breakup of 10,12Be into He clusters has been studied using the p,12C(12Be,6He,6He) and 12C(12Be,4He,6He) inelastic scattering and two neutron transfer reactions with a 378 MeV 12Be beam incident on 12C and (CH2)n targets. Evidence has been found for three new states in 10Be at excitation (...)

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[in2p3-00005799] Comment on analysis of hard two-photon correlations measured in heavy-ion reactions at intermediate energies

10 août 2000

F. Fialkoff's has led us to wonder about the most widely borrowed novels in public libraries and how they are promoted. We analysed the best lending statistics in three libraries in Lorraine (North-East France) and tried to identify the most frequently borrowed novels. This project led us to (...)

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