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Accueil > Recherche & Enseignement

M. Xavier Fléchard


Chercheur CNRS


Groupe : Interactions fondamentales et nature du neutrino


flechard lpccaen.in2p3.fr


Tél : +33 2 31 45 25 42



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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[in2p3-01278441] Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

26 février 2016

To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (...)

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[in2p3-01278441] Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

24 février 2016

To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (...)

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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-01218203] Electron Capture in Collisions of Slow Highly Charged Ions with an Atom and a Molecule: Processes and Fragmentation Dynamics

2 décembre 2015

Processes involved in slow collisions between highly charged ions (HCI) and neutral targets are presented. First, the mechanisms responsible for double electron capture are discussed. We show that, while the electron-nucleus interaction is expected to be dominant at projectile velocities of (...)

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[in2p3-01079961] Interatomic Coulombic Decay as a New Source of Low Energy Electrons in slow Ion-Dimer Collisions

1er juillet 2015

We provide the experimental evidence that the single electron capture process in slow collisions between O$^3+$ ions and neon dimer targets leads to an unexpected production of low-energy electrons. This production results from the interatomic Coulombic decay process, subsequent to inner shell (...)

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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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[in2p3-00078088] Kinematically complete study of dissociative ionization of D$_{2}$ by ion impact

1er juillet 2015

We present a kinematically complete study of dissociative ionization of D$_2$ by 13.6 MeV/u S$^15+$ ions. The experiment allows us to unravel the competing mechanisms, namely, direct single ionization, autoionization of doubly excited states, ionization excitation, and double ionization, and to (...)

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[hal-00556832] Asymmetry in Multiple-Electron Capture Revealed by Radiative Charge Transfer in Ar Dimers

1er juillet 2015

We measured kinetic energies of the fragment ions of argon dimers multiply ionized by low-energy Ar9+ collisions. For (Ar2)4+ dissociation, the asymmetric channel (Ar3+ + Ar+) yield is found unexpectedly higher than the symmetric channel (Ar2+ + Ar2+) yield in contrast with previous observation (...)

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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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[in2p3-00077172] Differential charge-transfer cross sections for Na $^{+}$ with Rb collisions at low energies

30 juin 2015

We report on a theoretical and experimental study of state-selective differential single-electron transfer cross sections between Na$^+$ ions and Rb(5s,5p) atoms at collision energies of 2, 5, and 7 keV. A two-center multichannel semiclassical impact parameter close-coupling method with (...)

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[cea-00344081] A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus for ion-atom collisions and trapped atom studies

30 juin 2015

A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus has been built and tested at the LPC-CAEN. Dedicated to ion-atom collisions studies and excited fraction measurements, the setup combines a projectile ion beam line, a target of cold rubidium atoms provided by a (...)

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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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[in2p3-00097775] Relative charge transfer cross section from Rb(4d)

30 juin 2015

Relative charge transfer cross section measurements for the excited state Rb(4d) with 7 keV Na$^+$ is reported. The specific channels reported are Na$^+$+Rb(4d5/2) \to Na(nl)+Rb$^+$, where the dominant transfer cross sections channels were nl=3d and 4s. Using a combination of a magneto-optical (...)

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[in2p3-00097764] Recoil ion momentum spectroscopy using magneto-optically trapped atoms

30 juin 2015

A novel apparatus has been developed in which atoms in a magneto-optical trap are used as targets in ion-atom collision experiments. The apparatus is an extension of earlier methodology in which the momentum of the recoiling target is measured and used to deduce the collision Q value and (...)

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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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[in2p3-00092266] 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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[in2p3-00989772] Atomic site sensitive processes in low energy ion-dimer collisions

30 juin 2015

Electron capture processes for low energy Ar9+ ions colliding on Ar2 dimer targets are investigated, focusing attention on charge sharing as a function of molecule orientation and impact parameter. A preference in charge-asymmetric dissociation channels is observed, with a strong correlation (...)

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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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[in2p3-00843506] 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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[in2p3-00835364] High resolution probe of coherence in low-energy charge exchange collisions with oriented targets

18 juin 2013

The trapping lasers of a magneto-optical trap (MOT) are used to bring Rb atoms into well defined oriented states. Coupled to recoil-ion momentum spectroscopy (RIMS), this yields a unique MOTRIMS setup which is able to probe scattering dynamics, including their coherence features, with (...)

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[in2p3-00834132] Energy-dependent relative charge transfer cross sections of Cs+ + Rb(5s, 5p)

14 juin 2013

Magneto optical trap recoil ion momentum spectroscopy is used to measure energy-dependent charge exchange cross sections in the Cs+ + Rb(5s, 5p) system over a range of projectile energies from 3.2 to 6.4 keV. The measurements are kinematically complete and yield cross sections that are (...)

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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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La spectroscopie d'ions de recul en Physique Atomique et en Physique Nucléaire: Applications à l'étude des collisions à basse énergie et à la mesure de la corrélation b-v en décroissance b

14 janvier 2013

A partir des années 1990, la spectroscopie d'impulsion d'ions de recul s'est imposée comme l'outil idéal pour l'étude des collisions ion-atome et ion -molécule. Le développement de cette technique expérimentale au cours des vingt dernières années est ici détaillé et illustré par des résultats marquants (...)

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Study of low energy ion-atom collisions using a magneto-optical trap

22 novembre 2012

A magneto-optical trap (MOT) has been coupled to a recoil-ion momentum spectrometer to study the charge exchange process in Na+ +87Rb collisions in the keV impact energy range. The relative cross sections of the active charge exchange channels and the associated distributions in scattering (...)

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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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[in2p3-00682613] Atomic-matter-wave diffraction evidenced in low-energy Na++Rb charge-exchange collisions

26 mars 2012

Single charge transfer in low-energy Na++87Rb(5s,5p) collisions is investigated using magneto-optically trapped Rb atoms and high-resolution recoil-ion momentum spectroscopy. The three-dimensional reconstruction of the recoil-ion momentum provides accurate relative cross sections for the active (...)

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Multiple-ionization and dissociation dynamics of a rare gas dimer induced by highly charged ion impact

21 novembre 2011

Low-energy collision experiments of an argon dimer with Ar(9+) were performed to measure branching ratios and kinetic energy release (KER) distributions for multiply ionized dimers. Two well-separated KER peaks are observed at 3.8 and 5.3 eV for the doubly ionized dimers, and are assigned to (...)

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Multiple-ionization and dissociation dynamics of a rare gas dimer induced by highly charged ion impact

21 novembre 2011

Low-energy collision experiments of an argon dimer with Ar(9+) were performed to measure branching ratios and kinetic energy release (KER) distributions for multiply ionized dimers. Two well-separated KER peaks are observed at 3.8 and 5.3 eV for the doubly ionized dimers, and are assigned to (...)

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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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Asymmetry in Multiple-Electron Capture Revealed by Radiative Charge Transfer in Ar Dimers

17 janvier 2011

We measured kinetic energies of the fragment ions of argon dimers multiply ionized by low-energy Ar9+ collisions. For (Ar2)4+ dissociation, the asymmetric channel (Ar3+ + Ar+) yield is found unexpectedly higher than the symmetric channel (Ar2+ + Ar2+) yield in contrast with previous observation (...)

Lire la suite

Asymmetry in Multiple-Electron Capture Revealed by Radiative Charge Transfer in Ar Dimers

17 janvier 2011

We measured kinetic energies of the fragment ions of argon dimers multiply ionized by low-energy Ar9+ collisions. For (Ar2)4+ dissociation, the asymmetric channel (Ar3+ + Ar+) yield is found unexpectedly higher than the symmetric channel (Ar2+ + Ar2+) yield in contrast with previous observation (...)

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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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A new MOTRIMS apparatus for high resolution measurements in ion-atom collisions and trapped atoms studies

7 septembre 2009

A new MOTRIMS (magneto-optical trap-target recoil ion momentum spectroscopy) apparatus has been built at the LPC-CAEN, and recently tested with a beam of 2 keV Na+ projectiles colliding on a trapped Rb target. In this work, we demonstrate the capability of the setup to provide, with a very high (...)

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A new MOTRIMS apparatus for high resolution measurements in ion-atom collisions and trapped atoms studies

7 septembre 2009

A new MOTRIMS (magneto-optical trap-target recoil ion momentum spectroscopy) apparatus has been built at the LPC-CAEN, and recently tested with a beam of 2 keV Na+ projectiles colliding on a trapped Rb target. In this work, we demonstrate the capability of the setup to provide, with a very high (...)

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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 (...)

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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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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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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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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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A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus for ion-atom collisions and trapped atom studies

3 décembre 2008

A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus has been built and tested at the LPC-CAEN. Dedicated to ion-atom collisions studies and excited fraction measurements, the setup combines a projectile ion beam line, a target of cold rubidium atoms provided by a (...)

Lire la suite

A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus for ion-atom collisions and trapped atom studies

3 décembre 2008

A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus has been built and tested at the LPC-CAEN. Dedicated to ion-atom collisions studies and excited fraction measurements, the setup combines a projectile ion beam line, a target of cold rubidium atoms provided by a (...)

Lire la suite

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 LPC Trap

5 juillet 2007

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The LPC Trap

5 juillet 2007

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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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MOTRIMS as a generalized probe of AMO processes

29 janvier 2007

Magneto-optical trap recoil ion momentum spectroscopy (MOTRIMS) is one of the newest offshoots of the generalized TRIMS approach to ion–atom collisions. By using lasers instead of the more usual supersonic expansion to cool the target, MOTRIMS has demonstrated two distinct advantages over (...)

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MOTRIMS as a generalized probe of AMO processes

29 janvier 2007

Magneto-optical trap recoil ion momentum spectroscopy (MOTRIMS) is one of the newest offshoots of the generalized TRIMS approach to ion–atom collisions. By using lasers instead of the more usual supersonic expansion to cool the target, MOTRIMS has demonstrated two distinct advantages over (...)

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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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Relative charge transfer cross section from Rb(4d)

25 septembre 2006

Relative charge transfer cross section measurements for the excited state Rb(4d) with 7 keV Na$^+$ is reported. The specific channels reported are Na$^+$+Rb(4d5/2) \to Na(nl)+Rb$^+$, where the dominant transfer cross sections channels were nl=3d and 4s. Using a combination of a magneto-optical (...)

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Swift heavy ion-induced small molecule fragmentation dynamics

25 septembre 2006

We present here a review of the experimental results obtained these last years at CIRIL laboratory in the field of swift heavy ion-induced small molecule fragmentation dynamics. Using the high ionizing power of highly charged ions, we study the formation and decay dynamics of charged molecules. (...)

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Recoil ion momentum spectroscopy using magneto-optically trapped atoms

25 septembre 2006

A novel apparatus has been developed in which atoms in a magneto-optical trap are used as targets in ion-atom collision experiments. The apparatus is an extension of earlier methodology in which the momentum of the recoiling target is measured and used to deduce the collision Q value and (...)

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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 (...)

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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 (...)

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Kinematically complete study of dissociative ionization of D$_{2}$ by ion impact

6 juin 2006

We present a kinematically complete study of dissociative ionization of D$_2$ by 13.6 MeV/u S$^15+$ ions. The experiment allows us to unravel the competing mechanisms, namely, direct single ionization, autoionization of doubly excited states, ionization excitation, and double ionization, and to (...)

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Differential charge-transfer cross sections for Na $^{+}$ with Rb collisions at low energies

29 mai 2006

We report on a theoretical and experimental study of state-selective differential single-electron transfer cross sections between Na$^+$ ions and Rb(5s,5p) atoms at collision energies of 2, 5, and 7 keV. A two-center multichannel semiclassical impact parameter close-coupling method with (...)

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First tests of Li-6 doped glass scintillators for ultracold neutron detection.

17 février 2006

We report the results of test measurements aimed at determining the performances of [.sup.6]Li doped glass scintillators for the detection of ultra-cold neutrons. Four types of scintillators, GS1, GS3, GS10 and GS20, which differ by their [.sup.6]Li concentrations, have been tested. The signal (...)

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The LPCTrap for the measurement of the $\beta$-v correlation in $^{6}$He

8 novembre 2005

The application of traps to precision measurements of the $\beta$-ν angular correlation coefficient a in nuclear $\beta$-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 (...)

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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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