Search results for "Deute"

showing 10 items of 549 documents

Deuteron NMR investigations of glass and phase transitions in(KI)1−x(ND4I)xmixed crystals

1998

Powdered potassium ammonium iodide mixed crystals with ammonium concentrations of 20% and 70% have been studied using deuteron NMR techniques. For the less doped sample the deuteron line starts to broaden and the spin-lattice relaxation time ${T}_{1}$ becomes nonexponential below about 20 K. These observations indicate the breakdown of ergodicity and the onset of orientational glass freezing. At the lowest temperatures ${T}_{1}$ reaches a plateau value. For the 70% sample a relatively abrupt onset of two-phase behavior at $Tl35\mathrm{K}$ is inferred from measurements of the spin-spin and spin-lattice relaxation times. These observations are taken to indicate an order-disorder transition to…

Phase transitionMaterials scienceCondensed matter physicsRelaxation (NMR)DopingAnalytical chemistryAmmonium iodidechemistry.chemical_compoundDeuteriumchemistryLattice (order)Condensed Matter::Strongly Correlated ElectronsAmmoniumOrientational glassPhysical Review B
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Diffusive motions in HD films physisorbed on graphite

2003

Abstract High-resolution quasielastic neutron scattering was used to study diffusive motions in two-dimensional liquid and solid phases of deuterium hydride submonolayers adsorbed on graphite (Papyex). For the first time it could be unambiguously clarified that the novel reentrant fluid phase at the commensurate–incommensurate transition has the character of a viscous fluid.

Phase transitionMaterials scienceHydrogenCondensed matter physicsHydridechemistry.chemical_elementViscous liquidCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsPhysics::Fluid DynamicsCondensed Matter::Materials SciencechemistryPhysisorptionDeuteriumChemical physicsQuasielastic neutron scatteringCondensed Matter::Strongly Correlated ElectronsGraphitePhysics::Chemical PhysicsElectrical and Electronic EngineeringNuclear ExperimentPhysica B: Condensed Matter
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Symmetry-species conversion in CD3systems

1993

The rates for symmetry-species conversion of CD3 groups are calculated using a model in which the interaction between the quadrupolar moment of the deuterons with electric-field gradient at the site of the nucleus causes symmetry-changing transitions. Just the same phonons are considered for energy conservation as are used to describe the temperature dependence of inelastic neutron scattering experiments. For the conversion rate, a similar temperature dependence is found as has already been obtained for CH3. For temperatures around the tunnelling energy, a behaviour is predicted for CD3 that is different from the behaviour in protonated systems according to all theories known to the authors…

PhononChemistryCondensed Matter PhysicsResonance (particle physics)Inelastic neutron scatteringTunnel effectsymbols.namesakeDeuteriumOrders of magnitude (time)symbolsddc:530General Materials ScienceAtomic physicsRaman spectroscopyQuantum tunnellingJournal of Physics: Condensed Matter
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The fast photon detection system of COMPASS RICH-1

2007

Abstract A fast photon detection system has been built for the upgrade of COMPASS RICH-1, the large size gaseous RICH detector in use at the COMPASS Experiment at the CERN SPS since 2001. The photon detectors of the central region have been replaced by a new system based on multi-anode photomultipliers coupled to individual fused silica lens telescopes and a fast readout electronics system, while in the outer region the existing MWPCs with CsI photocathodes have been equipped with a new readout system, based on the APV chip. RICH-1 has been successfully operated in its upgraded version during the 2006 run. We report on the upgrade design and construction, and on the preliminary characteriza…

PhotomultiplierNuclear and High Energy PhysicsPhotonMulti-anode photomultiplier tubesPhysics::Instrumentation and DetectorsUV lensesCOMPASS; Multi-anode photomultiplier tubes; Photon detection; RICH; UV lenses; Nuclear and High Energy Physics; InstrumentationCOMPASSlaw.inventionFAST-RICH; DEUTERON; READOUT; DESIGNOpticsDESIGNlawMulti-anode photomultiplier tubeCompassCOMPASS experimentRICHInstrumentationNuclear and High Energy PhysicPhysicsLarge Hadron Colliderbusiness.industryDetectorREADOUTDEUTERONLens (optics)UpgradePhoton detectionFAST-RICHUV lenseHigh Energy Physics::Experimentbusiness
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"gn-dcs35" of "Quasifree photoproduction of $\eta$ mesons off protons and neutrons"

2022

Differential cross section at W= 1.7850 GeV

PhotoproductionAstrophysics::High Energy Astrophysical PhenomenaExclusiveHigh Energy Physics::ExperimentNuclear ExperimentGAMMA "N" --> ETA NDeuterium
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"gn-dcs24" of "Quasifree photoproduction of $\eta$ mesons off protons and neutrons"

2022

Differential cross section at W= 1.6750 GeV

PhotoproductionAstrophysics::High Energy Astrophysical PhenomenaExclusiveHigh Energy Physics::ExperimentNuclear ExperimentGAMMA "N" --> ETA NDeuterium
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"gn-dcs26" of "Quasifree photoproduction of $\eta$ mesons off protons and neutrons"

2022

Differential cross section at W= 1.6950 GeV

PhotoproductionAstrophysics::High Energy Astrophysical PhenomenaExclusiveHigh Energy Physics::ExperimentNuclear ExperimentGAMMA "N" --> ETA NDeuterium
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"gn-dcs02" of "Quasifree photoproduction of $\eta$ mesons off protons and neutrons"

2022

Differential cross section at W= 1.4975 GeV

PhotoproductionAstrophysics::High Energy Astrophysical PhenomenaExclusiveHigh Energy Physics::ExperimentNuclear ExperimentGAMMA "N" --> ETA NDeuterium
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"gn-dcs29" of "Quasifree photoproduction of $\eta$ mesons off protons and neutrons"

2022

Differential cross section at W= 1.7250 GeV

PhotoproductionAstrophysics::High Energy Astrophysical PhenomenaExclusiveHigh Energy Physics::ExperimentNuclear ExperimentGAMMA "N" --> ETA NDeuterium
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"gn-dcs10" of "Quasifree photoproduction of $\eta$ mesons off protons and neutrons"

2022

Differential cross section at W= 1.5375 GeV

PhotoproductionAstrophysics::High Energy Astrophysical PhenomenaExclusiveHigh Energy Physics::ExperimentNuclear ExperimentGAMMA "N" --> ETA NDeuterium
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