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Accueil > Recherche & Enseignement

M. Thomas Lefort


Maître de conférences UCBN


Groupe : Interactions fondamentales et nature du neutrino


lefort lpccaen.in2p3.fr


Tél : +33 2 31 45 24 12


 



PUBLICATIONS

[in2p3-01337513] Ultracold neutron detection with 6Li-doped glass scintillators, NANOSC: a fast ultracold neutron detector for the nEDM experiment at the Paul Scherrer Institute

2 novembre 2016

This paper summarizes the results from measurements aiming to characterize ultracold neutron detection with 6Li-doped glass scintillators. Single GS10 or GS20 scintillators, with a thickness of 100-200 micrometer, fulfill the ultracold neutron detection requirements with an acceptable (...)

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[in2p3-01213941] A highly stable atomic vector magnetometer based on free spin precession

15 décembre 2015

We present a magnetometer based on optically pumped Cs atoms that measures the magnitude and direction of a 1 $\mu$T magnetic field. Multiple circularly polarized laser beams were used to probe the free spin precession of the Cs atoms. The design was optimized for long-time stability and (...)

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[in2p3-01140188] Measurement of a false electric dipole moment signal from $^{199}$Hg atoms exposed to an inhomogeneous magnetic field

18 novembre 2015

We report on the measurement of a Larmor frequency shift proportional to the electric-field strength for $^199\rm Hg$ atoms contained in a volume permeated with aligned magnetic and electric fields. This shift arises from the interplay between the inevitable magnetic field gradients and the (...)

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[in2p3-01120938] A device for simultaneous spin analysis of ultracold neutrons

18 novembre 2015

We report on the design and first tests of a device allowing for measurement of ultracold neutrons polarisation by means of the simultaneous analysis of the two spin components. The device was developed in the framework of the neutron electric dipole moment experiment at the Paul Scherrer (...)

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[in2p3-01227909] Observation of Gravitationally Induced Vertical Striation of Polarized Ultracold Neutrons by Spin-Echo Spectroscopy

13 novembre 2015

We describe a spin-echo method for ultracold neutrons (UCNs) confined in a precession chamber and exposed to a vertical bar B-0 vertical bar = 1 mu T magnetic field. We have demonstrated that the analysis of UCN spin-echo resonance signals in combination with knowledge of the ambient magnetic (...)

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[in2p3-01199753] A revised experimental upper limit on the electric dipole moment of the neutron

6 novembre 2015

We present for the first time a detailed and comprehensive analysis of the experimental results that set the current world sensitivity limit on the magnitude of the electric dipole moment (EDM) of the neutron. We have extended and enhanced our earlier analysis to include recent developments in (...)

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[in2p3-01159876] Observation of gravitationally induced vertical striation of polarized ultracold neutrons by spin-echo spectroscopy

19 octobre 2015

We describe a spin-echo method for ultracold neutrons (UCNs) confined in a precession chamber and exposed to a $|B_0|=1~\text\mu T$ magnetic field. We have demonstrated that the analysis of UCN spin-echo resonance signals in combination with knowledge of the ambient magnetic field provides an (...)

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[in2p3-01169555] Gravitational depolarization of ultracold neutrons: Comparison with data

9 octobre 2015

We compare the expected effects of so-called gravitationally enhanced depolarization of ultracold neutrons to measurements carried out in a spin-precession chamber exposed to a variety of vertical magnetic-field gradients. In particular, we have investigated the dependence upon these field (...)

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[in2p3-00010822] Emission time scale of light particles in the system Xe+Sn at 50 A.MeV - A probe for dynamical emission ?

3 juillet 2015

Proton and deuteron correlation functions have been investigated with both impact parameter and emission source selections. The correlations of the system 129Xe+NatSn at 50 AMeV have been measured with the 4π INDRA which provides a complete kinematical description of each event. The emission (...)

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[in2p3-00003952] Study of intermediate velocity products in the Ar+Ni collisions between 52 and 95 A.MeV

3 juillet 2015

Intermediate velocity products in Ar+Ni collisions from 52 to 95 A.MeV are studied in an experiment performed at the GANIL facility with the 4$\pi$ multidetector INDRA. It is shown that these emissions cannot be explained by statistical decays of the quasi-projectile and the quasi-target in (...)

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[in2p3-00003421] Is reducibility in nuclear multifragmentation related to thermal scaling?

3 juillet 2015

Thermal scaling (Arrhenius law for an “elementary” probability p of binomial function) and reducibility in intermediate mass fragments (IMF's) production are examined for data of the reaction 129Xe+ natSn at 50 MeV/u. The study of the longitudinal velocities and of the average transverse energies (...)

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[in2p3-00005978] Evidence for dynamical proton emission in peripheral Xe + Sn collisions at 50 MeV/u

3 juillet 2015

Relative angle correlation functions for mid-rapidity protons built up from 50 MeV/u Xe+Sn data recorded by the INDRA multidetector exhibit the characteristics of a non-equilibrated emission: they show an energy dependent anisotropy which cannot be accounted for by standard evaporation (...)

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[in2p3-00005276] Digital filtering a common analysis for data and mean field theories in heavy-ions collisions at intermediate energy

3 juillet 2015

To select well-defined event configurations from heavy-ion collisions in the Fermi energy domain, a digital filtering technique of the charge density distribution along the deflection axis in the velocity space is presented. Charge density appears as a robust variable and can be used for a (...)

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[in2p3-00003451] Surveying the nuclear caloric curve

3 juillet 2015

The 4π array INDRA was used to detect nearly all charged products emitted in Ar + Ni collisions between 52 and 95 MeV/u. The charge, mass and excitation energy E∗ of the quasi-projectiles have been reconstructed event by event. Excitation energies up to 25 MeV per nucleon are (...)

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[in2p3-00000114] A hot expanding source in 50 A MeV Xe+Sn central reactions

3 juillet 2015

The INDRA multidetector has been used to study multifragmentation processes in central collisions for the Xe + Sn reaction at 50 A MeV. A single isotropic source formed at an excitation energy of 12 A MeV exhausting most of the emitted charged products has been isolated in such collisions. The (...)

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[in2p3-00000038] Independence of fragment charge distributions of the size of heavy multifragmenting sources

3 juillet 2015

Charged product multiplicities and Z distributions were measured for single multifragmenting sources produced in collisions between Full-size image ( 1 K) and Full-size image ( 1 K) at the same available energy per nucleon. Z distributions are found identical for both reactions while fragment (...)

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[in2p3-01079065] A measurement of the neutron to 199Hg magnetic moment ratio

1er juillet 2015

The neutron gyromagnetic ratio has been measured relative to that of the 199Hg atom with an uncertainty of 0.8 ppm. We employed an apparatus where ultracold neutrons and mercury atoms are stored in the same volume and report the result $\gamma_\rm n/\gamma_\rm Hg = (...)

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[in2p3-01158512] Constraining interactions mediated by axion-like particles with ultracold neutrons

30 juin 2015

We report a new limit on a possible short range spin-dependent interaction from the precise measurement of the ratio of Larmor precession frequencies of stored ultracold neutrons and Hg-199 atoms confined in the same volume. The measurement was performed in a similar to 1 mu T vertical magnetic (...)

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[in2p3-01062292] Dynamic stabilization of the magnetic field surrounding the neutron electric dipole moment spectrometer at the Paul Scherrer Institute

30 juin 2015

The Surrounding Field Compensation (SFC) system described in this work is installed around the four-layer Mu-metal magnetic shield of the neutron electric dipole moment spectrometer located at the Paul Scherrer Institute. The SFC system reduces the DC component of the external magnetic field by (...)

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Combination of liver intravoxel incoherent motion imaging with MR fat quantification at 3.0 T to distinguish between pure steatosis and NASH

24 juillet 2013

Purpose: To evaluate the combination of liver intra-voxel incoherent motion imaging (IVIM) and a MRI fat quantification method at 3.0 T to make the distinction between NASH and pure steatosis. Methods and Materials: A multi-angle multi-gradient echo acquisition combined with a dedicated (...)

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[in2p3-00823240] An endoscopic detector for ultracold neutrons

16 mai 2013

A new versatile detector for ultracold neutrons (UCN) has been built and operated which combines multi-pixel photon counters and GS10 lithium-doped scintillators. Such detectors can be very small and can be used to monitor UCN inside storage vessels or guides with negligible influence (of order (...)

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Neutron and Light Charged Particle Production in Neutron or Proton‐induced Reaction on Iron, Lead and Uranium at Intermediate Energy (20 to 200 MeV)

17 février 2012

The process of particle emission in the pre‐equilibrium stage has a very important contribution in this energy region and several approaches have been proposed to explain it. Their prediction power must be tested using comparison with the data for a variety of configurations. Calculations have (...)

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The search for the neutron electric dipole moment at the Paul Scherrer Institute

17 novembre 2011

The measurement of the neutron electric dipole moment (nEDM) constrains the contribution of CP-violating terms within both the Standard Model and its extensions. The experiment uses ultracold neutrons (UCN) stored in vacuum at room temperature. This technique provided the last (and best) limit (...)

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The search for the neutron electric dipole moment at the Paul Scherrer Institute

17 novembre 2011

The measurement of the neutron electric dipole moment (nEDM) constrains the contribution of CP-violating terms within both the Standard Model and its extensions. The experiment uses ultracold neutrons (UCN) stored in vacuum at room temperature. This technique provided the last (and best) limit (...)

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An improved measurement of the electric dipole moment of the neutron

30 mai 2011

We describe the status of the new measurement of the neutron electric dipole moment (nEDM) to be performed at the strong source of ultra-cold neutrons at the Paul Scherrer Institut. The experimental technique is based on Ramsey's method of separated oscillatory fields, applied to UCN stored in (...)

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An improved measurement of the electric dipole moment of the neutron

30 mai 2011

We describe the status of the new measurement of the neutron electric dipole moment (nEDM) to be performed at the strong source of ultra-cold neutrons at the Paul Scherrer Institut. The experimental technique is based on Ramsey's method of separated oscillatory fields, applied to UCN stored in (...)

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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 (...)

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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 (...)

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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 (...)

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[in2p3-00495497] 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 (...)

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UCN detection with 6Li-doped glass scintillators

23 mars 2010

We report the results of test measurements aimed at determining the performance of 6Li-doped glass scintillators for ultra-cold neutron detection. Investigations have mainly focused on the reduction of the gamma-ray sensitivity of the scintillators. The probability of gamma interaction has been (...)

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UCN detection with 6Li-doped glass scintillators

23 mars 2010

We report the results of test measurements aimed at determining the performance of 6Li-doped glass scintillators for ultra-cold neutron detection. Investigations have mainly focused on the reduction of the gamma-ray sensitivity of the scintillators. The probability of gamma interaction has been (...)

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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 (...)

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[in2p3-00164661] 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 (...)

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Similarity of fragment characteristics at mid-velocity for mid-peripheral and central collisions

27 novembre 2009

The characteristics, in particular the isotopic composition (N/Z), of intermediate mass fragments (IMF : 3<=Z<=20) produced near the center-of-mass in mid-peripheral and central collisions of 114Cd ions with 92Mo target nuclei at E/A=50 MeV are compared to that of IMFs emitted from (...)

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Similarity of fragment characteristics at mid-velocity for mid-peripheral and central collisions

27 novembre 2009

The characteristics, in particular the isotopic composition (N/Z), of intermediate mass fragments (IMF : 3<=Z<=20) produced near the center-of-mass in mid-peripheral and central collisions of 114Cd ions with 92Mo target nuclei at E/A=50 MeV are compared to that of IMFs emitted from (...)

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Coulomb proximity decay: A clock for measuring the particle emission time scale

27 novembre 2009

A new method to examine the time scale of particle emission from hot nuclei is explored. Excited projectile-like and target-like fragments decay as they separate following a peripheral heavy-ion collision. Their mutual Coulomb influence results in an anisotropic angular distribution of emitted (...)

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Coulomb proximity decay: A clock for measuring the particle emission time scale

27 novembre 2009

A new method to examine the time scale of particle emission from hot nuclei is explored. Excited projectile-like and target-like fragments decay as they separate following a peripheral heavy-ion collision. Their mutual Coulomb influence results in an anisotropic angular distribution of emitted (...)

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Excitation and decay of projectile-like fragments formed in dissipative peripheral collisions at intermediate energies

27 novembre 2009

Projectile-like fragments (PLF:15<=Z<=46) formed in peripheral and mid-peripheral collisions of 114Cd projectiles with 92Mo nuclei at E/A=50 MeV have been detected at very forward angles, 2.1 deg.<=theta_lab<=4.2 deg. Calorimetric analysis of the charged particles observed (...)

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Excitation and decay of projectile-like fragments formed in dissipative peripheral collisions at intermediate energies

27 novembre 2009

Projectile-like fragments (PLF:15<=Z<=46) formed in peripheral and mid-peripheral collisions of 114Cd projectiles with 92Mo nuclei at E/A=50 MeV have been detected at very forward angles, 2.1 deg.<=theta_lab<=4.2 deg. Calorimetric analysis of the charged particles observed (...)

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Isospin Fractionation in Nuclear Multifragmentation

27 novembre 2009

Isotopic distributions for light particles and intermediate mass fragments have been measured for 112Sn+112Sn, 112Sn+124Sn, 124Sn+112Sn and 124Sn+124Sn collisions at E/A=50 MeV. Isotope, isotone and isobar yield ratios are utilized to obtain an estimate of the isotopic composition of the gas (...)

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[in2p3-00436634] Isospin Fractionation in Nuclear Multifragmentation

27 novembre 2009

Isotopic distributions for light particles and intermediate mass fragments have been measured for 112Sn+112Sn, 112Sn+124Sn, 124Sn+112Sn and 124Sn+124Sn collisions at E/A=50 MeV. Isotope, isotone and isobar yield ratios are utilized to obtain an estimate of the isotopic composition of the gas (...)

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Fragment Production in Non-central Collisions of Intermediate Energy Heavy Ions

27 novembre 2009

The defining characteristics of fragment emission resulting from the non-central collision of 114Cd ions with 92Mo target nuclei at E/A = 50 MeV are presented. Charge correlations and average relative velocities for mid-velocity fragment emission exhibit significant differences when compared to (...)

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[in2p3-00436626] Fragment Production in Non-central Collisions of Intermediate Energy Heavy Ions

27 novembre 2009

The defining characteristics of fragment emission resulting from the non-central collision of 114Cd ions with 92Mo target nuclei at E/A = 50 MeV are presented. Charge correlations and average relative velocities for mid-velocity fragment emission exhibit significant differences when compared to (...)

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Effects of in-medium cross-sections and optical potential on thermal-source formation in p+197Au reactions at 6.2-14.6 GeV/c

27 novembre 2009

Effects of in-medium cross-sections and of optical potential on pre-equilibrium emission and on formation of a thermal source are investigated by comparing the results of transport simulations with experimental results from the p+197Au reaction at 6.2-14.6 GeV/c. The employed transport model (...)

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[in2p3-00436621] Effects of in-medium cross-sections and optical potential on thermal-source formation in p+197Au reactions at 6.2-14.6 GeV/c

27 novembre 2009

Effects of in-medium cross-sections and of optical potential on pre-equilibrium emission and on formation of a thermal source are investigated by comparing the results of transport simulations with experimental results from the p+197Au reaction at 6.2-14.6 GeV/c. The employed transport model (...)

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Breakup time scale studied in the 8 GeV/c pi- + 197Au reaction

27 novembre 2009

Experimental data from the reaction of an 8.0 GeV/c pi- beam incident on a 197Au target have been analyzed in order to investigate the integrated breakup time scale for hot residues. Alpha-particle energy spectra and particle angular distributions supported by a momentum tensor analysis suggest (...)

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Breakup time scale studied in the 8 GeV/c pi- + 197Au reaction

27 novembre 2009

Experimental data from the reaction of an 8.0 GeV/c pi- beam incident on a 197Au target have been analyzed in order to investigate the integrated breakup time scale for hot residues. Alpha-particle energy spectra and particle angular distributions supported by a momentum tensor analysis suggest (...)

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Caloric curve of 8 GeV/c negative pion and antiproton + Au reactions

27 novembre 2009

The relationship between nuclear temperature and excitation energy of hot nuclei formed by 8 GeV/c negative pion and antiproton beams incident on 197Au has been investigated with the ISiS 4-pidetector array at the BNL AGS accelerator. The double-isotope-ratio technique was used to calculate the (...)

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[in2p3-00436630] Caloric curve of 8 GeV/c negative pion and antiproton + Au reactions

27 novembre 2009

The relationship between nuclear temperature and excitation energy of hot nuclei formed by 8 GeV/c negative pion and antiproton beams incident on 197Au has been investigated with the ISiS 4-pidetector array at the BNL AGS accelerator. The double-isotope-ratio technique was used to calculate the (...)

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Tracking the phase-transition energy in disassembly of hot nuclei

27 novembre 2009

In efforts to determine phase transitions in the disintegration of highly excited heavy nuclei, a popular practice is to parametrise the yields of isotopes as a function of temperature in the form $Y(z)=z^-\tauf(z^\sigma(T-T_0))$, where $Y(z)$'s are the measured yields and $\tau, \sigma$ and (...)

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[in2p3-00436629] Tracking the phase-transition energy in disassembly of hot nuclei

27 novembre 2009

In efforts to determine phase transitions in the disintegration of highly excited heavy nuclei, a popular practice is to parametrise the yields of isotopes as a function of temperature in the form $Y(z)=z^-\tauf(z^\sigma(T-T_0))$, where $Y(z)$'s are the measured yields and $\tau, \sigma$ and (...)

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Isospin Diffusion in Heavy Ion Reactions

27 novembre 2009

Using symmetric 112Sn+112Sn, 124Sn+124Sn collisions as references, we probe isospin diffusion in peripheral asymmetric 112Sn+124Sn, 124Sn+112Sn systems at incident energy of E/A=50 MeV. Isoscaling analyses imply that the quasi-projectile and quasi-target in these collisions do not achieve (...)

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Isospin Diffusion in Heavy Ion Reactions

27 novembre 2009

Using symmetric 112Sn+112Sn, 124Sn+124Sn collisions as references, we probe isospin diffusion in peripheral asymmetric 112Sn+124Sn, 124Sn+112Sn systems at incident energy of E/A=50 MeV. Isoscaling analyses imply that the quasi-projectile and quasi-target in these collisions do not achieve (...)

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Centrality dependence of the thermal excitation-energy deposition in 8-15 GeV/c hadron-Au reactions

27 novembre 2009

The excitation energy per residue nucleon (E*/A) and fast and thermal light particle multiplicities are studied as a function of centrality defined as the number of grey tracks emitted N_grey and by the mean number of primary hadron-nucleon scatterings and mean impact parameter <b> (...)

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Centrality dependence of the thermal excitation-energy deposition in 8-15 GeV/c hadron-Au reactions

27 novembre 2009

The excitation energy per residue nucleon (E*/A) and fast and thermal light particle multiplicities are studied as a function of centrality defined as the number of grey tracks emitted N_grey and by the mean number of primary hadron-nucleon scatterings and mean impact parameter <b> (...)

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Additional results from the first dedicated search for neutron–mirror neutron oscillations

24 novembre 2009

The existence of a mirror world holding a copy of our ordinary particle spectrum could lead to oscillations between the neutron (n) and its mirror partner (n′). Such oscillations could manifest themselves in storage experiments with ultracold neutrons whose storage lifetime would depend on the (...)

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Additional results from the first dedicated search for neutron–mirror neutron oscillations

24 novembre 2009

The existence of a mirror world holding a copy of our ordinary particle spectrum could lead to oscillations between the neutron (n) and its mirror partner (n′). Such oscillations could manifest themselves in storage experiments with ultracold neutrons whose storage lifetime would depend on the (...)

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Towards a new measurement of the neutron electric dipole moment

24 novembre 2009

The effort towards a new measurement of the neutron electric dipole moment (nEDM) at the Paul Scherrer Institut's (PSI) new high intensity source of ultracold neutrons (UCN) is described. The experimental technique relies on Ramsey's method of separated oscillatory fields, using UCN in vacuum (...)

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Towards a new measurement of the neutron electric dipole moment

24 novembre 2009

The effort towards a new measurement of the neutron electric dipole moment (nEDM) at the Paul Scherrer Institut's (PSI) new high intensity source of ultracold neutrons (UCN) is described. The experimental technique relies on Ramsey's method of separated oscillatory fields, using UCN in vacuum (...)

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A compact, large-diameter adiabatic spinflipper for ultracold neutrons

25 août 2009

We report the design and test of a compact, large-diameter spinflipper for ultracold neutrons based on the principle of adiabatic spinflip. A solenoid rf coil with a high diameter-to-length ratio (d/l~1.7) is surrounded by up to three short magnet coils (d/l~0.4...1.7) to provide the static (...)

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[in2p3-00410915] A compact, large-diameter adiabatic spinflipper for ultracold neutrons

25 août 2009

We report the design and test of a compact, large-diameter spinflipper for ultracold neutrons based on the principle of adiabatic spinflip. A solenoid rf coil with a high diameter-to-length ratio (d/l~1.7) is surrounded by up to three short magnet coils (d/l~0.4...1.7) to provide the static (...)

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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 (...)

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[in2p3-00407985] 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 (...)

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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 (...)

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[in2p3-00388703] 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 (...)

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Multifragmentation and spinodal decomposition of finite nuclear systems

28 avril 2009

A bulk effect in multifragmentation of very heavy fused systems has been experimentally evidenced. Such an effect is very well reproduced by a complete dynamical simulation of collisions in which multifragmentation occurs through the growth of density fluctuations in the unstable spinodal (...)

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Multifragmentation and spinodal decomposition of finite nuclear systems

28 avril 2009

A bulk effect in multifragmentation of very heavy fused systems has been experimentally evidenced. Such an effect is very well reproduced by a complete dynamical simulation of collisions in which multifragmentation occurs through the growth of density fluctuations in the unstable spinodal (...)

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Studies of neutron-induced light-ion production with the MEDLEY facility

22 juillet 2008

The growing interest in applications involving high-energy neutrons (E > 20 MeV) demands high-quality experimental data on neutron-induced reactions. Such data have been measured with the MEDLEY setup at the The Svedberg Laboratory (TSL), Uppsala, Sweden. It has been used to measure (...)

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Studies of neutron-induced light-ion production with the MEDLEY facility

22 juillet 2008

The growing interest in applications involving high-energy neutrons (E > 20 MeV) demands high-quality experimental data on neutron-induced reactions. Such data have been measured with the MEDLEY setup at the The Svedberg Laboratory (TSL), Uppsala, Sweden. It has been used to measure (...)

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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 (...)

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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 (...)

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Neutron-induced light-ion production from Fe, Pb and U at 96 MeV

2 mai 2008

Double-differential cross-sections for light-ion production (up to A = 4) induced by 96 MeV neutrons have been measured for Fe, Pb and U. The experiments have been performed at The Svedberg Laboratory in Uppsala, using two independent devices, MEDLEY and SCANDAL. The recorded data cover a wide (...)

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Neutron-induced light-ion production from Fe, Pb and U at 96 MeV

2 mai 2008

Double-differential cross-sections for light-ion production (up to A = 4) induced by 96 MeV neutrons have been measured for Fe, Pb and U. The experiments have been performed at The Svedberg Laboratory in Uppsala, using two independent devices, MEDLEY and SCANDAL. The recorded data cover a wide (...)

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Towards a new measurement of the neutron electric dipole moment

29 octobre 2007

Precision measurements of particle electric dipole moments (EDMs) provide extremely sensitive means to search for non-standard mechanisms of T (or CP) violation. For the neutron EDM, the upper limit has been reduced by eight orders of magnitude in 50 years thereby excluding several CP violation (...)

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Towards a new measurement of the neutron electric dipole moment

29 octobre 2007

Precision measurements of particle electric dipole moments (EDMs) provide extremely sensitive means to search for non-standard mechanisms of T (or CP) violation. For the neutron EDM, the upper limit has been reduced by eight orders of magnitude in 50 years thereby excluding several CP violation (...)

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The neutron EDM project at PSI

2 octobre 2007

We propose to perform a new high precision measurement of the neutron Electric Dipole Moment (nEDM). Our goal is to reach an accuracy of $5\times10^-28$ e.cm or better, i.e an improvement of nearly two orders of magnitude over the present best measurement. Our experiment will use the new (...)

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The neutron EDM project at PSI

2 octobre 2007

We propose to perform a new high precision measurement of the neutron Electric Dipole Moment (nEDM). Our goal is to reach an accuracy of $5\times10^-28$ e.cm or better, i.e an improvement of nearly two orders of magnitude over the present best measurement. Our experiment will use the new (...)

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Neutron-induced light-ion production from Fe, Pb and U at 96 MeV

11 juillet 2007

Double-differential cross sections for light-ion production (up to A=4) induced by 96 MeV neutrons have been measured for $^nat$Fe, $^nat$Pb and $^nat$U. The experiments have been performed at the The Svedberg Laboratory in Uppsala, using two independent devices, MEDLEY and SCANDAL. The (...)

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Neutron-induced light-ion production from Fe, Pb and U at 96 MeV

11 juillet 2007

Double-differential cross sections for light-ion production (up to A=4) induced by 96 MeV neutrons have been measured for $^nat$Fe, $^nat$Pb and $^nat$U. The experiments have been performed at the The Svedberg Laboratory in Uppsala, using two independent devices, MEDLEY and SCANDAL. The (...)

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(n,Xn) measurements at 96 MeV

5 juillet 2007

Double differential cross section for neutron production were measured in 96MeV neutrons induced reactions at the TSL laboratory in Uppsala (Sweden). Measurements for Fe and Pb targets were performed using simultaneously two independent setups: DECOI-DEMON and CLODIA-SCANDAL. The double (...)

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(n,Xn) measurements at 96 MeV

5 juillet 2007

Double differential cross section for neutron production were measured in 96MeV neutrons induced reactions at the TSL laboratory in Uppsala (Sweden). Measurements for Fe and Pb targets were performed using simultaneously two independent setups: DECOI-DEMON and CLODIA-SCANDAL. The double (...)

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Effect of the intermediate velocity emissions on the quasi-projectile properties for the Ar + Ni system at 95 A.MeV

4 janvier 2007

The quasi-projectile (QP) properties are investigated in the Ar+Ni collisions at 95 A.MeV taking into account the intermediate velocity emission. Indeed, in this reaction, between 52 and 95 A.MeV bombarding energies, the number of particles emitted in the intermediate velocity region is related (...)

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[in2p3-00006315] Effect of the intermediate velocity emissions on the quasi-projectile properties for the Ar + Ni system at 95 A.MeV

4 janvier 2007

The quasi-projectile (QP) properties are investigated in the Ar+Ni collisions at 95 A.MeV taking into account the intermediate velocity emission. Indeed, in this reaction, between 52 and 95 A.MeV bombarding energies, the number of particles emitted in the intermediate velocity region is related (...)

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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 (...)

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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 (...)

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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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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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Neutron and light-charged-particle productions in proton-induced reactions on $^{208}$Pb at 62.9 MeV

8 février 2005

Neutrons and light charged particles produced in 62.9MeV proton-induced reactions on 208Pb were measured during a single experiment performed at the CYCLONE facility in Louvain-la-Neuve (Belgium). Two independent experimental set-ups were used to extract double differential cross-sections for (...)

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[in2p3-00023692] Neutron and light-charged-particle productions in proton-induced reactions on $^{208}$Pb at 62.9 MeV

8 février 2005

Neutrons and light charged particles produced in 62.9MeV proton-induced reactions on 208Pb were measured during a single experiment performed at the CYCLONE facility in Louvain-la-Neuve (Belgium). Two independent experimental set-ups were used to extract double differential cross-sections for (...)

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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 (...)

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[in2p3-00022117] 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 (...)

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Study of intermediate velocity products in the Ar+Ni collisions between 52 and 95 A.MeV

7 février 2000

Intermediate velocity products in Ar+Ni collisions from 52 to 95 A.MeV are studied in an experiment performed at the GANIL facility with the 4$\pi$ multidetector INDRA. It is shown that these emissions cannot be explained by statistical decays of the quasi-projectile and the quasi-target in (...)

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