Professeur ENSICAEN
Groupes :
Applications industrielles et médicales
Aval du cycle électronucléaire
Interactions fondamentales et nature du neutrino
+33 2 31 45 24 21
PUBLICATIONS
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 (...)
Testing isotropy of the universe using the Ramsey resonance technique on ultracold neutron spins
5 octobre 2010
Physics at the Planck scale could be revealed by looking for tiny violations of fundamental symmetries in low energy experiments. In 2008, a sensitive test of the isotropy of the Universe using has been performed with stored ultracold neutrons (UCN), this is the first clock-comparison (...)
New constraints on Lorentz invariance violation from the neutron electric dipole moment
28 juin 2010
We propose an original test of Lorentz invariance in the interaction between a particle spin and an electromagnetic field and report on a first measurement using ultracold neutrons. We used a high sensitivity neutron electric dipole moment (nEDM) spectrometer and searched for a direction (...)
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 (...)
12C nuclear reaction measurements for hadrontherapy
21 janvier 2010
Hadrontherapy treatments require a very high precision on the dose deposition ( 2.5% and 1-2mm) in order to keep the benefits of the precise ions’ ballistic. The largest uncertainty on the physical dose deposition is due to ion fragmentation. Up to now, the simulation codes are not able to (...)
Direct experimental limit on neutron-mirror-neutron oscillations
13 janvier 2010
In case a mirror world with a copy of our ordinary particle spectrum would exist, the neutron n and its degenerate partner, the mirror neutron $\rm n’$, could potentially mix and undergo $\rm nn’$ oscillations. The interaction of an ordinary magnetic field with the ordinary neutron would lift (...)
Measurement of the Transverse Polarization of Electrons Emitted in Free Neutron Decay
27 novembre 2009
Both components of the transverse polarization of electrons emitted in the beta-decay of polarized, free neutrons have been measured. The T-odd, P-odd correlation coefficient quantifying the component perpendicular to the decay plane defined by neutron polarization and electron momentum, was (...)
The GUINEVERE Project for Accelerator Driven System Physics
9 septembre 2009
The GUINEVERE project is part of the EUROTRANS Integrated Project of the 6th EURATOM Framework Programme. It is mainly devoted to ADS on-line reactivity monitoring validation, sub-criticality determination and operational procedures (loading, start-up, shut-down, ...) as a follow-up of the MUSE (...)
Test of Lorentz invariance with spin precession of ultracold neutrons
28 juillet 2009
A clock comparison experiment, analyzing the ratio of spin precession frequencies of stored ultracold neutrons and $^199$Hg atoms is reported. %57 No daily variation of this ratio could be found, from which is set an upper limit on the Lorentz invariance violating cosmic anisotropy field (...)
Neutron to mirror-neutron oscillations in the presence of mirror magnetic fields
27 mai 2009
We performed ultracold neutron (UCN) storage measurements to search for additional losses due to neutron (n) to mirror-neutron (n’) oscillations as a function of an applied magnetic field B. In the presence of a mirror magnetic field B’, UCN losses would be maximal for B = B’. We did not (...)
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 (...)
An improved neutron electric dipole moment experiment
1er juillet 2008
A new measurement of the neutron EDM, using Ramsey’s method of separated oscillatory fields, is in preparation at the new high intensity source of ultra-cold neutrons (UCN) at the Paul Scherrer Institute, Villigen, Switzerland (PSI). The existence of a non-zero nEDM would violate both parity (...)
On-line monitoring of fluence distributions and imaging of scanning ion beams
25 février 2008
In this paper we describe the design of an ion beam monitor developed to control irradiations of biological samples with ions at GANIL (Grand Accélérateur National d’Ions Lourds). This device can be used as an on-line monitor to provide transverse fluence distributions for active scanning ion (...)
A novel fast neutron detector for nuclear data measurements
24 novembre 2006
Accelerator driven system will use a heavy element target such as lead. Many calculations are available to simulate high-energy spallation neutron induced reactions, but little data are available for comparison with the simulations. In order to constrain the simulation tools we have measured (...)
A novel micromegas detector for in-core nuclear neutron flux measurement
14 novembre 2006
Future fast nuclear reactors designed for energy production and transmutation of nuclear wastes need new neutrons detectors able to measure the neutron flux over a large energy range from thermal energies to several MeV. A novel compact and very small detector, named Piccolo-Micromegas has been (...)
A new scintillating fiber dosimeter using a single optical fiber and a CCD camera
23 août 2006
Radiotherapy treatments become more and more accurate, using very small irradiation fields and complex dose depositions. So small dosimeters for real time and in vivo dosimetry, suitable for photons as well as for electrons beams are highly desired. In this context, a scintillating fiber (...)
New neutron detector based on micromegas technology for ADS projects
27 juin 2006
A new neutron detector based on Micromegas technology has been developed for the measurement of the simulated neutron spectrum in the ADS project. After the presentation of simulated neutron spectra obtained in the interaction of 140MeV protons with the spallation target inside the TRIGA core, (...)
Monitoring of 14 MeV neutrons
6 juin 2006
Long-lived fission products and minor actinides produced in nuclear power plants are the most radiotoxic nuclear wastes. They can be transmuted into stable nuclei or into nuclei with shorter lifetime thanks to the so-called Accelerator Driven Systems (ADS), consisting of the coupling of an (...)
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 (...)
Nucleon-induced reactions at intermediate energies : New data at 96 MeV and theoretical status
20 juillet 2004
Double-differential cross sections for light charged particle production (up to A = 4) were measured in 96 MeV neutron-induced reactions, at the TSL Laboratory Cyclotron in Uppsala (Sweden). Measurements for three targets, Fe, Pb, and U, were performed using two independent devices, SCANDAL and (...)
