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Accueil > Recherche & Enseignement

M. Etienne Liénard


Professeur des universités


Université Caen Normandie


Groupe Interactions FOndamentales et nature du Neutrino


TEL : +33 2 31 45 24 20


lienard lpccaen.in2p3.fr


 



 


PUBLICATIONS


 

[in2p3-01377559] First high-statistics and high-resolution recoil-ion data from the WITCH retardation spectrometer

7 octobre 2016

The first high-statistics and high-resolution data set for the integrated recoil-ion energy spectrum following the decay of 35Ar has been collected with the WITCH retardation spectrometer located at CERN-ISOLDE. Over 25 million recoil-ion events were recorded on a large-area multichannel plate (...)

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[in2p3-01323815] High accuracy position response calibration method for a micro-channel plate ion detector

6 octobre 2016

We have developed a position response calibration method for a micro-channel plate (MCP) detector with a delay-line anode position readout scheme. Using an \em in situ calibration mask, an accuracy of 8~$\mu$m and a resolution of 85~$\mu$m (FWHM) have been achieved for MeV-scale $\alpha$ (...)

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[in2p3-01176181] Primary processes: from atoms to diatomic molecules and clusters

25 janvier 2016

This article presents a short review of the main progresses achieved at the GANIL facilities during the last thirty years in the field of ion-atom and ion-diatomic molecule collisions. Thanks to the wide range of projectile energies and species available on the different beam lines of the (...)

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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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[in2p3-00089852] $\beta$-decay studies of neutron-rich K isotopes

3 juillet 2015

The beta decay of the neutron-rich nuclei $^51-53$K has been used to populate bound and unbound states in $^50-53$Ca. Measurements of gamma rays as well as beta-delayed neutrons enabled detailed decay schemes to be established and levels identified in $^50-53$Ca. A delayed one-neutron emission (...)

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[in2p3-00024152] Study of $^{19} $Na at SPIRAL

3 juillet 2015

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 (...)

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[in2p3-00024846] Performance of a micro-channel plates position sensitive detector

1er juillet 2015

The absolute detection efficiency of large area micro-channel plates (MCPs) detectors has been measured with $^6$Li$^+$ and $^23$Na$^+$ ions in the 0.5–7.5 keV energy range. Two detectors of 47mm and 83mm active diameter have been tested. They consist in a pair of MCPs mounted in a chevron (...)

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[in2p3-01133535] Space-charge effects in Penning ion traps

1er juillet 2015

The influence of space-charge on ion cyclotron resonances and magnetron eigenfrequency in a gas-filled Penning ion trap has been investigated. Off-line measurements with 39 K + using the cooling trap of the WITCH retardation spectrometer-based setup at ISOLDE / CERN were performed. Experimental (...)

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[hal-00012793] Transport and cooling of singly-charged noble gas ion beams

1er juillet 2015

The transport and cooling of noble gas singly-charged ion beams by means of a Radio Frequency Quadrupole Cooler Buncher (RFQCB) have been studied at the LIMBE low energy beam line of the GANIL facility. Ions as light as $^4He^+$ have been cooled and stored before their extraction in bunches (...)

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[in2p3-00868612] Electron shakeoff following the Β+ decay of trapped 35Ar+ ions

30 juin 2015

The electron shakeoff of $^35$Cl atoms resulting from the $\beta$$^+$ decay of $^35$Ar$^+$ ions has been investigated using a Paul trap coupled to a recoil-ion spectrometer. The charge-state distribution of the recoiling daughter nuclei is compared to theoretical calculations accounting for (...)

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[in2p3-00091845] The LPCTrap facility: A novel transparent Paul trap for high-precision experiments

30 juin 2015

A trap system has been built to perform high-precision β-decay experiments. The system is coupled to the low-energy beam line of the SPIRAL source at GANIL. The continuous ion beam from SPIRAL with energies between 10 and 20 keV is slowed down by means of a buffer-gas-filled RFQ trap and ejected (...)

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[in2p3-00019880] Weak interaction studies using a Paul trap

30 juin 2015

New developments in ion cooling and ion bunching allow the trapping of radioactive ions from a low energy beam, in a very short time scale and with very good efficiency. The performances of Radio Frequency Quadrupole (RFQ) coolers, recently developed in several laboratories in Europe and USA, (...)

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[in2p3-00092266] Linear radio frequency quadrupole for the cooling and bunching of radioactive ion beams

30 juin 2015

A linear radio frequency quadrupole has been built for the transport, cooling, and bunching of radioactive ions extracted from an ECR source. The device uses the buffer gas cooling technique and was designed such as to extend the technique for the cooling of very light ions using H2 as buffer (...)

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[in2p3-00960923] Simulation of ion behavior in an open three-dimensional Paul trap using a power series method

31 mars 2014

Simulations of the dynamics of ions trapped in a Paul trap with terms in the potential up to the order 10 have been carried out. The power series method is used to solve numerically the equations of motion of the ions. The stability diagram has been studied and the buffer gas cooling has been (...)

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Electron shakeoff following the Β+ decay of trapped 35Ar+ ions

1er octobre 2013

The electron shakeoff of $^35$Cl atoms resulting from the $\beta$$^+$ decay of $^35$Ar$^+$ ions has been investigated using a Paul trap coupled to a recoil-ion spectrometer. The charge-state distribution of the recoiling daughter nuclei is compared to theoretical calculations accounting for (...)

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In gas laser ionization and spectroscopy experiments at the Superconducting Separator Spectrometer (S3): Conceptual studies and preliminary design

3 septembre 2013

The results of preparatory experiments and the preliminary designs of a new in-gas laser ionization and spectroscopy setup, to be coupled to the Super Separator Spectrometer S3 of SPIRAL2-GANIL, are reported. Special attention is given to the development and tests to carry out a full (...)

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[in2p3-00846623] Publisher's Note: In-beam spectroscopic studies of the 44S nucleus [Phys. Rev. C 85, 024311 (2012)]

19 juillet 2013

This paper was published online on 15 February 2012 with errors in Figs. 2 and 4. The figures has been replaced as of 28 February 2012. The figures are correct in the printed version of the journal.

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[in2p3-00843506] Precision measurements in nuclear β-decay with LPCTrap

11 juillet 2013

The experimental achievements and the current program with the LPCTrap device installed at the LIRAT beam line of the SPIRAL1-GANIL facility are presented. The device is dedicated to the study of the weak interaction at low energy by means of precise measurements of the β−ν angular correlation (...)

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Weak Interaction Studies with 6He

6 février 2013

The 6He nucleus is an ideal candidate to study the weak interaction. To this end we have built a high-intensity source of 6He delivering ~10^10 atoms/s to experiments. Taking full advantage of that available intensity we have performed a high-precision measurement of the 6He half-life that (...)

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Measurement of the 6Li charge state distributions following the 6He+ beta decay

19 novembre 2012

We measure the probability of "shake-off" ionization of the daughter nucleus in the β decay of 6He+ ions confined in a transparent Paul trap. This measurement, in good agreement with theoretical calculations, allows to reduce systematic error contributions in previous β-v correlation experiments (...)

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[in2p3-00709325] First Measurement of Pure Electron Shakeoff in the β Decay of Trapped 6He+ Ions

18 juin 2012

The electron shakeoff probability of 6Li2+ ions resulting from the β- decay of 6He+ ions has been measured with high precision using a specially designed recoil ion spectrometer. This is the first measurement of a pure electron shakeoff following nuclear β decay, not affected by multielectron (...)

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First Measurement of Pure Electron Shakeoff in the $\beta$ Decay of Trapped 6He+ Ions

18 juin 2012

The electron shakeoff probability of 6Li2+ ions resulting from the decay $\beta^-$ of 6He+ ions has been measured with high precision using a specially designed recoil ion spectrometer. This is the first measurement of a pure electron shakeoff following nuclear $\beta$ decay, not affected by (...)

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In-beam spectroscopic studies of $^{44}$S nucleus

6 janvier 2012

The structure of the $^44$S nucleus has been studied at GANIL through the one proton knock-out reaction from a $^45$Cl secondary beam at 42~A$\cdot$MeV. The $\gamma$ rays following the de-excitation of $^44$S were detected in flight using the 70 BaF$_2$ detectors of the Ch\^ateau de Cristal (...)

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[in2p3-00657202] In-beam spectroscopic studies of $^{44}$S nucleus

6 janvier 2012

The structure of the $^44$S nucleus has been studied at GANIL through the one proton knock-out reaction from a $^45$Cl secondary beam at 42~A$\cdot$MeV. The $\gamma$ rays following the de-excitation of $^44$S were detected in flight using the 70 BaF$_2$ detectors of the Ch\^ateau de Cristal (...)

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Spectroscopy of 39,41Si and the border of the N = 28 island of inversion

6 septembre 2011

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 (...)

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[in2p3-00619310] Spectroscopy of 39,41Si and the border of the N = 28 island of inversion

6 septembre 2011

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 (...)

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The LPCTrap experiment: measurement of the β-ν angular correlation in 6He+ decay using a transparent Paul trap

6 juillet 2011

The LPCTrap experiment is devoted to the precise measurement of the β-ν angular correlation parameter, a βν , in the pure Gamow-Teller decay of 6He+. This experiment is motivated by the search of the presence of tensor type contributions in the weak interaction. The radioactive source is confined (...)

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The LPCTrap experiment: measurement of the β-ν angular correlation in 6He+ decay using a transparent Paul trap

6 juillet 2011

The LPCTrap experiment is devoted to the precise measurement of the β-ν angular correlation parameter, a βν , in the pure Gamow-Teller decay of 6He+. This experiment is motivated by the search of the presence of tensor type contributions in the weak interaction. The radioactive source is confined (...)

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Temperature measurement of 6He + ions confined in a transparent Paul trap

6 juillet 2011

The LPCTrap setup is a transparent Paul trap dedicated to the measurement of the β-ν correlation coefficient aβν in the β decay of trapped radioactive nuclides. In a first experiment, the system has been used to record ∼105 coincidences between the β particles and recoiling ions emitted from the decay (...)

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Temperature measurement of 6He + ions confined in a transparent Paul trap

6 juillet 2011

The LPCTrap setup is a transparent Paul trap dedicated to the measurement of the β-ν correlation coefficient aβν in the β decay of trapped radioactive nuclides. In a first experiment, the system has been used to record ∼105 coincidences between the β particles and recoiling ions emitted from the decay (...)

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Production and Separation of T = 1/2 Nuclides for $\beta$ $\nu$ angular correlation measurements

23 juin 2011

The SPIRAL facility at GANIL, which uses the so-called ISOL method to produce radioactive ion beams, is being upgraded to extend its production capabilities to the metallic beams of neutron deficient isotopes. We discuss here the potentialities offered by this upgrade for the measurement of the (...)

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Production and Separation of T = 1/2 Nuclides for $\beta$ $\nu$ angular correlation measurements

23 juin 2011

The SPIRAL facility at GANIL, which uses the so-called ISOL method to produce radioactive ion beams, is being upgraded to extend its production capabilities to the metallic beams of neutron deficient isotopes. We discuss here the potentialities offered by this upgrade for the measurement of the (...)

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Measurement of the beta-nu correlation coefficient a(beta nu) in the beta decay of trapped He-6(+) ions

30 mars 2011

We have measured the β-ν angular correlation in the β decay of 6He+ ions using a transparent Paul trap. The 6He+ ions, produced at GANIL, were first cooled and bunched before being injected in the LPCTrap setup. The angular correlation was inferred from the time of flight of recoil nuclei detected (...)

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[in2p3-00581086] Measurement of the beta-nu correlation coefficient a(beta nu) in the beta decay of trapped He-6(+) ions

30 mars 2011

We have measured the β-ν angular correlation in the β decay of 6He+ ions using a transparent Paul trap. The 6He+ ions, produced at GANIL, were first cooled and bunched before being injected in the LPCTrap setup. The angular correlation was inferred from the time of flight of recoil nuclei detected (...)

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Mesures du coefficient de corrélation angulaire B-v dans les transitions B nucléaires

17 mars 2011

Les mesures de corrélation dans les transitions B sont des mesures de précision effectuées à basse énergie dans le but de mettre en évidence une physique au-delà du Modèle Standard. Le groupe Interactions fondamentales du LPC Caen a développé dans ce cadre un dispositif de piégeage d'ions, LPCTrap, (...)

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Mesures du coefficient de corrélation angulaire B-v dans les transitions B nucléaires

17 mars 2011

Les mesures de corrélation dans les transitions B sont des mesures de précision effectuées à basse énergie dans le but de mettre en évidence une physique au-delà du Modèle Standard. Le groupe Interactions fondamentales du LPC Caen a développé dans ce cadre un dispositif de piégeage d'ions, LPCTrap, (...)

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Shell and shapes in the $^{44}S nucleus

25 octobre 2010

The results obtained from electron and in-beam spectroscopy experiments reveal that the 44S nucleus is located in a transitional region between the spherical 48Ca and the oblate 42Si. The comparison of the results with Large Scale Shell Model calculations points towards prolate-spherical shape (...)

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Shell and shapes in the $^{44}S nucleus

25 octobre 2010

The results obtained from electron and in-beam spectroscopy experiments reveal that the 44S nucleus is located in a transitional region between the spherical 48Ca and the oblate 42Si. The comparison of the results with Large Scale Shell Model calculations points towards prolate-spherical shape (...)

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Measurement of the 8Li half-life

30 août 2010

We report a newmeasurement of the 8Li half-life using a plastic scintillator and an ultrafastwaveform digitizing module. The result, T1/2 = (838.40 ± 0.36) ms, improves by a factor of 2.5 the most precise result obtained so far and is furthermore deduced with negligible corrections due to dead (...)

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[in2p3-00512350] Measurement of the 8Li half-life

30 août 2010

We report a newmeasurement of the 8Li half-life using a plastic scintillator and an ultrafastwaveform digitizing module. The result, T1/2 = (838.40 ± 0.36) ms, improves by a factor of 2.5 the most precise result obtained so far and is furthermore deduced with negligible corrections due to dead (...)

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Beta Neutrino Correlation Measurement with Trapped Radioactive Ions

18 mai 2010

The beta-neutrino angular correlation coefficient provides a sensitive observable to search for physics beyond the standard electroweak model in nuclear beta decay. We address here the measurement of this parameter in the pure Gamow-Teller transition of 6He. A deviation from the standard model (...)

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Beta Neutrino Correlation Measurement with Trapped Radioactive Ions

18 mai 2010

The beta-neutrino angular correlation coefficient provides a sensitive observable to search for physics beyond the standard electroweak model in nuclear beta decay. We address here the measurement of this parameter in the pure Gamow-Teller transition of 6He. A deviation from the standard model (...)

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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 (...)

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[in2p3-00467536] 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 (...)

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The LPCTrap for the measurement of the β-ν correlation in 6He

25 août 2009

The application of traps to precision measurements of the β-ν angular correlation coefficient a in nuclear β-decay is pursued by several laboratories world wide. Various nuclear transitions are addressed and different trap devices are used. At GANIL, a novel transparent Paul trap (LPCTrap) has (...)

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The LPCTrap for the measurement of the β-ν correlation in 6He

25 août 2009

The application of traps to precision measurements of the β-ν angular correlation coefficient a in nuclear β-decay is pursued by several laboratories world wide. Various nuclear transitions are addressed and different trap devices are used. At GANIL, a novel transparent Paul trap (LPCTrap) has (...)

Lire la suite

Correlation measurement in the $\beta$ decay of trapped $^{6}$He ions

18 juin 2009

The LPCTrap facility coupled to the low-energy beam line LIRAT of the SPIRAL installation at GANIL is a transparent Paul trap designed to perform in-trap decay experiments [1]. The first detection setup installed at this facility has been designed in order to precisely determine the b-n angular (...)

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Correlation measurement in the $\beta$ decay of trapped $^{6}$He ions

18 juin 2009

The LPCTrap facility coupled to the low-energy beam line LIRAT of the SPIRAL installation at GANIL is a transparent Paul trap designed to perform in-trap decay experiments [1]. The first detection setup installed at this facility has been designed in order to precisely determine the b-n angular (...)

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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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Geant4 Monte Carlo simulations for the LPCTrap setup

9 avril 2009

The LPCTrap setup at GANIL is fully operational since 2006. The first breakthrough was the detection of 100000 coincidences between the β particles and the recoil ions from the decay of 6He+ produced by the SPIRAL source. After preparation, the decaying nuclei are confined in a transparent Paul (...)

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Geant4 Monte Carlo simulations for the LPCTrap setup

9 avril 2009

The LPCTrap setup at GANIL is fully operational since 2006. The first breakthrough was the detection of 100000 coincidences between the β particles and the recoil ions from the decay of 6He+ produced by the SPIRAL source. After preparation, the decaying nuclei are confined in a transparent Paul (...)

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Gas scintillation chamber for superheavy elements detection at GANIL

30 mars 2009

In the paper we present scintillation-ionization detector (SID) — a new device for support of the superheavy elements (SHE) identification in the standard, complete fusion methods. We highlight problems with background effects in SHE production and their minimization by introducing SID to the (...)

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Gas scintillation chamber for superheavy elements detection at GANIL

30 mars 2009

In the paper we present scintillation-ionization detector (SID) — a new device for support of the superheavy elements (SHE) identification in the standard, complete fusion methods. We highlight problems with background effects in SHE production and their minimization by introducing SID to the (...)

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Recent results from GANIL

30 mars 2009

The shell structure of the nucleus implies the existence of magic numbers. Since several years many indications have been accumulated, theoretically as well as through experiments at various laboratories around the world, that if one moves away from stability, the location of the magic numbers (...)

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Recent results from GANIL

30 mars 2009

The shell structure of the nucleus implies the existence of magic numbers. Since several years many indications have been accumulated, theoretically as well as through experiments at various laboratories around the world, that if one moves away from stability, the location of the magic numbers (...)

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Measurement of the Gamow-Teller Branching Ratio in the $\beta$-Decay of ${21}$Na

17 mars 2009

The beta-decay branching ratio of the GT transition in 21Na to the first excited state in 21Ne has been measured. The value obtained of 4.93(20)% is in agreement with the most recent measurement and with the value adopted so far. This confirms that the branching ratio is not the source of (...)

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Search for tensor couplings in the weak interaction

27 janvier 2009

The existence of exotic couplings in the weak interaction can be tested by a precise measurement of the β-ν angular correlation parameter a in nuclear beta decay. In the case of 6He, the ratio of tensor and axial-vector couplings can be determined. The goal of the LPC Trap experiment is to (...)

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Search for tensor couplings in the weak interaction

27 janvier 2009

The existence of exotic couplings in the weak interaction can be tested by a precise measurement of the β-ν angular correlation parameter a in nuclear beta decay. In the case of 6He, the ratio of tensor and axial-vector couplings can be determined. The goal of the LPC Trap experiment is to (...)

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Status of the LPCTrap facility at GANIL

10 novembre 2008

The LPCTrap is a device whose central element is a transparent Paul trap for the efficient trapping of low energy radioactive ions produced by the SPIRAL facility at GANIL. The installation comprises a linear RFQ cooler and buncher for the beam preparation, and a decay chamber where the Paul (...)

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Status of the LPCTrap facility at GANIL

10 novembre 2008

The LPCTrap is a device whose central element is a transparent Paul trap for the efficient trapping of low energy radioactive ions produced by the SPIRAL facility at GANIL. The installation comprises a linear RFQ cooler and buncher for the beam preparation, and a decay chamber where the Paul (...)

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Paul trapping of radioactive $^{6}$He+ ions and direct observation of their beta-decay

17 octobre 2008

We demonstrate that abundant quantities of short-lived beta unstable ions can be trapped in a novel transparent Paul trap and that their decay products can directly be detected in coincidence. Low energy 6He+ (807 ms half-life) ions were extracted from the SPIRAL source at GANIL, then (...)

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[in2p3-00331783] Paul trapping of radioactive $^{6}$He+ ions and direct observation of their beta-decay

17 octobre 2008

We demonstrate that abundant quantities of short-lived beta unstable ions can be trapped in a novel transparent Paul trap and that their decay products can directly be detected in coincidence. Low energy 6He+ (807 ms half-life) ions were extracted from the SPIRAL source at GANIL, then (...)

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The LPCTrap experiment: measurement of the $\beta$–ν angular correlation in $^{6}$He using a transparent Paul trap

30 novembre 2007

We report on the status of the LPCTrap experiment, devoted to measure the β–ν angular correlation in the pure Gamow–Teller decay of $^6$He. This measurement is motivated by the search for the presence of tensor type contributions to the weak interaction. The $^6$He ions are confined in a novel (...)

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The LPCTrap experiment: measurement of the $\beta$–ν angular correlation in $^{6}$He using a transparent Paul trap

30 novembre 2007

We report on the status of the LPCTrap experiment, devoted to measure the β–ν angular correlation in the pure Gamow–Teller decay of $^6$He. This measurement is motivated by the search for the presence of tensor type contributions to the weak interaction. The $^6$He ions are confined in a novel (...)

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The LPCTrap facility for in-trap decay experiments

26 juin 2007

The LPCTrap is a device devoted to the determination of the angular correlation coefficient in the nuclear beta decay of $^6$He^+$ ions by detection of the electron and the recoil ion in coincidence in a Paul trap.The LPCTrap facility comprises an RFQ trap for beam preparation and a transparent (...)

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The LPCTrap facility for in-trap decay experiments

26 juin 2007

The LPCTrap is a device devoted to the determination of the angular correlation coefficient in the nuclear beta decay of $^6$He^+$ ions by detection of the electron and the recoil ion in coincidence in a Paul trap.The LPCTrap facility comprises an RFQ trap for beam preparation and a transparent (...)

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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 (...)

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[in2p3-00145207] 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 (...)

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$\beta$-decay studies at the N=28 shell closure: indications for a weakening of the spin-orbit force far from stability ?

10 novembre 2006

A β-decay experiment on nuclei in the region of N=28 has been performed at the GANIL facility. New measured half-lives for the Si isotopes from N=25 to N=28 are reported and discussed in the light of the deformation occuring in this region. Comparison with QRPA calculations suggests that a (...)

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$\beta$-decay studies at the N=28 shell closure: indications for a weakening of the spin-orbit force far from stability ?

10 novembre 2006

A β-decay experiment on nuclei in the region of N=28 has been performed at the GANIL facility. New measured half-lives for the Si isotopes from N=25 to N=28 are reported and discussed in the light of the deformation occuring in this region. Comparison with QRPA calculations suggests that a (...)

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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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The LPCTrap facility for in-trap decay experiments

26 septembre 2006

The LPCTrap facility is coupled to the low-energy beam line LIRAT of the SPIRAL source at GANIL (France). The facility comprises an RFQ trap for beam preparation and a transparent Paul trap for in-trap decay studies. The system has been tested for several ion species. The Paul trap has been (...)

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The LPCTrap facility for in-trap decay experiments

26 septembre 2006

The LPCTrap facility is coupled to the low-energy beam line LIRAT of the SPIRAL source at GANIL (France). The facility comprises an RFQ trap for beam preparation and a transparent Paul trap for in-trap decay studies. The system has been tested for several ion species. The Paul trap has been (...)

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Measurement of the β−ν correlation in 6He using a transparent Paul trap

15 septembre 2006

The angular correlationbetween the electron and the neutrino in nuclear β−decay constitutes a sensitive observable to search for the existence of exotic couplings in the weak interaction. In this contribution, we describe the progress of the LPCTrap experiment, devoted to measure the β−ν angular (...)

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Linear radio frequency quadrupole for the cooling and bunching of radioactive ion beams

8 septembre 2006

A linear radio frequency quadrupole has been built for the transport, cooling, and bunching of radioactive ions extracted from an ECR source. The device uses the buffer gas cooling technique and was designed such as to extend the technique for the cooling of very light ions using H2 as buffer (...)

Lire la suite

The LPCTrap facility: A novel transparent Paul trap for high-precision experiments

7 septembre 2006

A trap system has been built to perform high-precision β-decay experiments. The system is coupled to the low-energy beam line of the SPIRAL source at GANIL. The continuous ion beam from SPIRAL with energies between 10 and 20 keV is slowed down by means of a buffer-gas-filled RFQ trap and ejected (...)

Lire la suite

Transport and cooling of singly-charged noble gas ion beams

27 octobre 2005

The transport and cooling of noble gas singly-charged ion beams by means of a Radio Frequency Quadrupole Cooler Buncher (RFQCB) have been studied at the LIMBE low energy beam line of the GANIL facility. Ions as light as $^4He^+$ have been cooled and stored before their extraction in bunches (...)

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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 (...)

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