A5027791290- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- High-pressure geophysics and materials
- Radiation Detection and Scintillator Technologies
- Advanced Condensed Matter Physics
- Advanced NMR Techniques and Applications
- Physics of Superconductivity and Magnetism
- Nuclear reactor physics and engineering
- Astrophysical Phenomena and Observations
- Particle Detector Development and Performance
- X-ray Diffraction in Crystallography
- Magnetic properties of thin films
- Magnetic and transport properties of perovskites and related materials
- Advanced X-ray Imaging Techniques
- Theoretical and Computational Physics
- NMR spectroscopy and applications
- Particle Accelerators and Free-Electron Lasers
- X-ray Spectroscopy and Fluorescence Analysis
- Rare-earth and actinide compounds
- Cold Atom Physics and Bose-Einstein Condensates
- Magnetic Properties and Applications
- Inorganic Fluorides and Related Compounds
- Quasicrystal Structures and Properties
- Superconducting Materials and Applications
Oak Ridge National Laboratory
2021-2024
European Organization for Nuclear Research
2024
European Spallation Source
2011-2020
Institut Laue-Langevin
2006-2018
University of Copenhagen
2015
Institut Langevin
1994-2008
Rutherford Appleton Laboratory
1994-2007
University of St Andrews
2001
Instituto de Ciencia de Materiales de Madrid
1999
Centre National de la Recherche Scientifique
1998
The technique of longitudinal neutron polarization analysis on a multi-detector spectrometer (so-called ` xyz '-polarization analysis) is presented. This allows the simultaneous and unambiguous determination nuclear, magnetic nuclear spin-incoherent scattering cross sections as function both momentum transfer energy transfer. implementation -polarization recently upgraded D7 at Institut Laue–Langevin in Grenoble described. Several examples studies disordered systems are given, illustrating...
Due to the very limited availability of 3He, new kinds neutron detectors, not based on are urgently needed. Here, we present a method produce thin films 10B4C, with maximized detection efficiency, intended be part generation large area detectors. B4C have been deposited onto Al-blade and Si wafer substrates by dc magnetron sputtering from natB4C 10B4C targets in an Ar discharge, using industrial deposition system. The were characterized scanning electron microscopy, elastic recoil analysis,...
An overview is provided of the 15 neutron beam instruments making up initial instrument suite European Spallation Source (ESS), and being made available to user community. The ESS source consists a high-power accelerator target station, providing unique long-pulse time structure slow neutrons. design considerations behind structure, moderator geometry layout are presented. 15-instrument two small-angle instruments, reflectometers, an imaging beamline, single-crystal diffractometers; one for...
Mesoscopic (500-2000 Angstrom) and microscopic (5-20 phase segregation with temperature magnetic field was studied in the model manganite Pr0.7Ca0.3MnO3 by high-resolution neutron diffraction inelastic scattering. Intra-granular strain-driven mesoscopic between two insulating phases, one of which is charge ordered (CO), sets below CO zero field. The orders antiferromagnetically, while other shows spin-glass behavior. After field-induced metallization, coexists a ferromagnetic metallic phase.
The OSIRIS neutron instrument on the ISIS pulsed source now affords option of high-resolution quasi-elastic and inelastic spectroscopy. In this paper, performance is presented, with spectroscopic characteristics being discussed in terms energy resolution, signal to background ratio count rate. Recent improvements spectrometer are described, particular effect cooling crystal analysers close liquid helium temperature enhance sensitivity instrument. also likened back-scattering, analyser...
The vertical sample-plane reflectometer D17 at the Institut Laue–Langevin in Grenoble, France, has undergone several major upgrades since its commissioning, which are summarized this article. three improvements (i) a new focusing guide, increasing usable flux on sample by factor of 2.5; (ii) beam polarizer and spin flippers, allowing for use polarized neutrons time-of-flight mode; (iii) detector with particularly uniform response under homogeneous exposure, improved stability...
The crystal structures of the polymer electrolyte complexes PEO6:LiPF6 and PEO6:LiSbF6 have been obtained from powder diffraction data collected deuterated molecules on OSIRIS neutron diffractometer at ISIS, Rutherford Appleton Laboratory. are similar to that recently reported for PEO6:LiAsF6 complex consist rows Li+ ions encapsulated within columns formed by pairs nonhelical PEO chains. ion is coordinated five ether oxygens. anions reside between not ions. Despite broad similarities, do...
We have studied the relaxation of a spin-polarized gas in magnetic field, presence short-range spin-dependent interactions. As main result we established link between specific properties interaction and dependence spin-relaxation rate on magnitude holding field. This allows us to formulate new, extremely sensitive method study (pseudo) at submillimeter scale, which are difficult access by other means. The has been used as probe for nucleon-nucleon axionlike $P$, $T$ violating interactions...
A global approach coupling the moderator to beam extraction system has been applied for design optimization of thermal and cold moderators European Spallation Source (ESS), which will be brightest neutron source in world condensed-matter studies. The is based on recently developed high-brightness low-dimensional concepts. Para -hydrogen used source, while neutrons are provided by moderation water. overall configuration was chosen order satisfy a range requirements bispectral extraction,...
Magnetic diffuse scattering in the Zn-Mg-Ho icosahedral quasicrystal has been studied by neutron over a wide $\mathit{Q}$ range using single-quasicrystalline sample. It was found that obeys symmetry, and appears as satellite peaks of intense nuclear Bragg reflections. The diffuse-scattering patterns were successfully accounted for assuming short-range spin correlations six-dimensional hypercubic crystal with magnetic modulation vector...
We report neutron scattering measurements of the dynamic structure factor S(Q, omega ) liquid 4He in collective excitation regime. The use IN6 time-of-flight spectrometer at Institut Laue-Langevin has enabled us to cover wavevector region from 0.3 2.1 AA-1 a continuous manner with an accurately calibrated energy scale and resolution approximately 0.1 meV; temperatures between 1.24 4.95 K were examined saturated vapour pressure. In investigated, sharp excitations are seen that unique...
The European Spallation Source being constructed in Lund, Sweden will provide the user community with a neutron source of unprecedented brightness. By 2025, suite 15 instruments be served by high-brightness moderator system placed above spallation target. ESS infrastructure, consisting proton linac, target station, and instrument halls, allows for implementation second below We propose to develop high-intensity able (1) deliver larger total cold flux, (2) high intensities at longer...
Systematic high-resolution measurements of the collective excitations in normal and superfluid have been made as a function both pressure (density) temperature using neutron inelastic scattering. The IN6 time-of-flight spectrometer at Institut Laue-Langevin has used to obtain accurate consistent data over wavevector range . We present discuss experimental data. An analysis, based on simple-subtraction model, is made; single-excitation energies, widths, magnitudes are extracted. Many changes...
We studied the vibrational modes of H-doped nanocrystalline Pd $\mathrm{H}/\mathrm{Pd}\ensuremath{\le}0.04)$ by neutron spectroscopy, using small H content as a probe for separate determination vibrations atoms at surfaces and/or grain boundaries. find that these are responsible additional low-frequency which characteristic materials, and their local density states is essentially linear in frequency. The within grains do not noticeably contribute to modes.
The technique of longitudinal (“xyz”) polarization analysis has been used successfully for many years to study disordered magnetic materials in thermal and cold neutron diffraction experiments. allows the simultaneous unambiguous separation nuclear, magnetic, nuclear spin-incoherent contributions scattering. technical advances seen recent years, such as availability polarized 3He analyzer cells cover a large detector solid angle, ability detect out-of-plane scattering multi-detector,...