2,081 research outputs found
CEDA and JASMIN Services
No full textThe Centre for Environmental Data Analysis (CEDA) is based at the STFC Rutherford Appleton Laboratory. CEDA operates 4 environmental data centres, offers data analysis environments (JASMIN), and professional data management services for the UK academic community to ensure the availability of stored data for the future
Studies of the fast ignition route to inertial confinement fusion at the Rutherford Appleton Laboratory
No full textThe Rutherford Appleton Laboratory has been at the forefront of investigations into the physics associated with the fast ignition concept for inertial confinement fusion. This scheme involves complex laser-plasma processes, the theoretical understanding of which relies heavily on particle-in-cell calculations. In this paper, three experiments displaying quantitative agreement with detailed multi-dimensional PIC calculations are reviewed: hole-boring velocity measurements; relativistic self-focusing; and harmonic generation from plasma surfaces. Qualitative agreement of hot electron temperature measurements with PIC simulations are also discussed. The authors believe these results are very encouraging for the fast ignition concept. (C) 1999 Published by Elsevier Science S.A. All rights reserved
Tuneable graphite intercalates for hydrogen storage
No full textThe development of hydrogen as an energy transfer mechanism is of great
importance to alleviate environmental damage and economic destabilisation
caused by over-reliance on oil, as long as the hydrogen can be generated renewably. To be suitable for road transport applications, safe and compact
hydrogen storage systems need to be developed, the primary technological
motivation for this PhD project which investigates hydrogen absorbed into
graphite intercalation compounds (GICs), to gain a fundamental physical understanding of the sorption processes to improve such materials' capacity for
hydrogen storage. Literature searching has led to a principal investigation,
primarily using neutron scattering and thermogravimetry, of potassium and
calcium-GICs with hydrogen. Inelastic neutron scattering on hydrogenated
KC24 has shown hydrogen sorption in this system to be quantitatively different from its analogues RbC24 and CsC24. A consistent model of the H2 sites
and dynamics has been proposed. Time-resolved structural data on the hydriding phase transition in KC8Hx have been obtained. A calcium-ammonia
intercalate has shown most promise for hydrogen storage, with uptake of 3.2
wt.% H2 at 77 K and 2 bar, a signifcant amount of the 6 wt.% target set by
the US DoE. It is concluded that available internal volume and donor charge
in GICs are critical parameters for optimising hydrogen uptake
Search for the rare decay K 0 S →μ + μ −
No full textA search for the decay K 0 S →μ + μ − is performed, based on a data sample of 1.0 fb−1 of pp collisions at s √ =7TeV collected by the LHCb experiment at the Large Hadron Collider. The observed number of candidates is consistent with the background-only hypothesis, yielding an upper limit of B(K 0 S →μ + μ − ) < 11(9) × 10−9 at 95 (90)% confidence level. This limit is a factor of thirty below the previous measurement
The role of cation and anion on the solvation structure of phenol dissolved in ionic liquids
No full textDatasets from SANDALS, RB1510233 Abstract: Phenols are widely used in industry, however, many phenolic compounds are endocrine-disruptors hazardous to human reproductive health and present a serious source of pollution and contamination of water. This proposed work will reveal information about the molecular interactions between ionic liquid cations and anions with phenol, which will help us to design new, potentially better materials for phenol extraction from water. Public release date: 24 July 2018 Experimenter: Professor John Holbrey Local Contact: Dr Silvia Imberti Experimenter: Mr Adam Turner DOI: 10.5286/ISIS.E.61784761 Parent DOI: 10.5286/ISIS.E.RB1510233 ISIS Experiment Number: RB1510233 Part Number: 1 Date of Experiment: 19 July 2015 Publisher: STFC ISIS Neutron and Muon Source Data format: RAW/Nexus Data Citation The recommended format for citing this dataset in a research publication is as: [author], [date], [title], [publisher], [doi] For Example: Professor John Holbrey et al; (2015): The role of cation and anion on the solvation structure of phenol dissolved in ionic liquids, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.6178476
Optically responsive ionogels II
No full textNeutron datasets from ISIS, RB1410172 Abstract: This proposal follows on from earlier studies on ionic liquid-aromatic charge transfer complexes (see Ref. [ ]), and from the investigation of the effects of immobilisation within an ionogel matrix on the ability of the ionic liquids to form charge-transfer complexes (RB1320201, beam-time scheduled for 26 Oct 2013). In this continuation of the studies, we propose to examine the effects of covalently tethering the ionic liquid receptor cation within an ionogel matrix by incorporating a triethoxysilyl-pendant group. This will immobilise the CT-complex within the ionogel through covalent chemical bonds, contrasting with the physisorbed ion liquids present in our most recent studies. This research on immobilised CT-active aromatic sensors forms the basis of the PhD work of Mr Adam Turner (supported through a Northern Ireland, Department of Education and Learning studentship). Public release date: 25 July 2017 Principal Investigator: Professor John Holbrey Experimenter: Ms Caithlin White Experimenter: Dr Tristan Youngs Experimenter: Mr Adam Turner DOI: 10.5286/ISIS.E.54809326 ISIS Experiment Number: RB1410169 Part Number: 1 Date of Experiment: 22 July 2014 Publisher: STFC ISIS Neutron and Muon Source Data format: RAW/Nexus Select the data format above to find out more about it. Data Citation The recommended format for citing this dataset in a research publication is as: [author], [date], [title], [publisher], [doi] For Example: Professor John Holbrey et al; (2014): Optically responsive ionogels II, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.5480932
Analysis and demonstration of a fast tunable fiber-ring-based optical frequency comb generator
No full textFiber-ring-based optical frequency comb generators are analyzed to understand their behavior and limitations. A numerical frequency-domain model is described for studying dispersion and other phase mismatch causing effects in the fiber ring cavity, as well as for predicting the spectral and temporal evolutions of the comb in time. The results from this analysis are verified with experimental measurements. A flat optical comb, with a terahertz span within a 6-dB power envelope and containing 100 comb lines, with a suppressed central comb line, is demonstrated. The comb shows an excellent coherence dependent on the phase noise from the radio frequency synthesizer that drives the comb generator. Improvement in the error correction loop also enables the comb spacing to be set at precise 12.5-MHz intervals without having to adjust the system. Fast frequency switching of the comb line spacing is demonstrated for the first time. The comb line spacing,can be switched to any operation frequency with a resolution of 12.5 MHz between 6 and 12.5 GHz, as limited only by the microwave circuit used. The switching time is less than 1 s, and the spectral profile of the comb is maintained
Measurements of the branching fractions of the decays B0s→D∓sK± and B0s→D−sπ+
No full textThe decay mode B0s→D∓sK± allows for one of the theoretically cleanest measurements of the CKM angle γ through the study of time-dependent CP violation. This paper reports a measurement of its branching fraction relative to the Cabibbo-favoured mode B0s→D−sπ+ based on a data sample corresponding to 0.37 fb−1 of proton-proton collisions at s√=7TeV collected in 2011 with the LHCb detector. In addition, the ratio of B meson production fractions f s /f d , determined from semileptonic decays, together with the known branching fraction of the control channel B 0 → D −π+, is used to perform an absolute measurement of the branching fractions: B(B0s→D−sπ+)=(2.95±0.05±0.17+0.18−0.22)×10−3,\hfillB(B0s→D∓sK±)=(1.90±0.12±0.13+0.12−0.14)×10−4,\hfill where the first uncertainty is statistical, the second the experimental systematic uncertainty, and the third the uncertainty due to f s /f d
The MICE Muon Beam on ISIS and the beam-line instrumentation of the Muon Ionization Cooling Experiment
No full textThe international Muon Ionization Cooling Experiment (MICE), which is under construction at the Rutherford Appleton Laboratory (RAL), will demonstrate the principle of ionization cooling as a technique for the reduction of the phase-space volume occupied by a muon beam. Ionization cooling channels are required for the Neutrino Factory and the Muon Collider. MICE will evaluate in detail the performance of a single lattice cell of the Feasibility Study 2 cooling channel. The MICE Muon Beam has been constructed at the ISIS synchrotron at RAL, and in MICE Step I, it has been characterized using the MICE beam-instrumentation system. In this paper, the MICE Muon Beam and beam-line instrumentation are described. The muon rate is presented as a function of the beam loss generated by the MICE target dipping into the ISIS proton beam. For a 1 V signal from the ISIS beam-loss monitors downstream of our target we obtain a 30 KHz instantaneous muon rate, with a neglible pion contamination in the beam
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