Search results for " synchrotron"
showing 10 items of 29 documents
Beam study of irradiated ATLAS-SCT prototypes
2002
Abstract Prototypes of ATLAS-SCT modules with ABCD readout chips were tested in a 4 GeV/c pion beam at KEK's proton synchrotron. Of both SCT module geometries—barrel and forward—three identical modules were placed in the beam. One module of each type had been irradiated to 3×1014 protons/cm2 in the CERN PS previous to the beam test. A method has been developed to reconstruct the time-resolved shaper pulse from the binary hit information, allowing a more detailed study of the timing properties of the ABCD. The present results will be compared to a simulation of the charge collection and Front End electronics response.
New results from testing of coplanar-grid CdZnTe detectors
2005
New results from studies of coplanar-grid CdZnTe (CZT) detectors are presented. The coplanar-grid detectors were investigated by using a highly collimated X-ray beam available at Brookhaven's National Synchrotron Light Source and by applying a pulse-shape analysis. The coplanar-grid detector operates as a single-carrier device. Despite the fact that its operational principle is well known and has been investigated by many groups in the past, we found some new details that may explain the performance limits of these types of devices. The experimental results have been confirmed by extensive computer modeling.
EXTRACTION OF ΛΛ SCATTERING LENGTH
2009
We determine ΛΛ scattering parameters from a ΛΛ invariant mass spectrum that was obtained by 12 C (K-, K+ΛΛ) reaction at the KEK Proton Synchrotron. In the framework of Watson's procedure, the obtained scattering length [Formula: see text] and effective range [Formula: see text] are most consistent with the values predicted by using the Nijmegen soft core models (NSC97's). However, the predicted values by using the Nijmegen hard-core ND ( G -matrix) and the extended soft-core (ESC00) models are out of two standard deviations from the determined scattering parameters.
Pressure-Induced Polymerization of Polycyclic Arene-Perfluoroarene Cocrystals: Single Crystal X-ray Diffraction Studies, Reaction Kinetics, and Desig…
2020
Pressure-induced polymerization of aromatic compounds leads to novel materials containing sp3 carbon-bonded networks. The choice of the molecular species and the control of their arrangement in the crystal structures via intermolecular interactions, such as the arene–perfluoroarene interaction, can enable the design of target polymers. We have investigated the crystal structure compression and pressure-induced polymerization reaction kinetics of two polycyclic 1:1 arene–perfluoroarene cocrystals, naphthalene/octafluoronaphthalene (NOFN) and anthracene/octafluoronaphthalene (AOFN), up to 25 and 30 GPa, respectively, using single-crystal synchrotron X-ray diffraction, infrared spectroscopy, a…
Sprouting and intussusceptive angiogenesis in postpneumonectomy lung growth: mechanisms of alveolar neovascularization
2013
In most rodents and some other mammals, the removal of one lung results in compensatory growth associated with dramatic angiogenesis and complete restoration of lung capacity. One pivotal mechanism in neoalveolarization is neovascularization, because without angiogenesis new alveoli can not be formed. The aim of this study is to image and analyze three-dimensionally the different patterns of neovascularization seen following pneumonectomy in mice on a sub-micron-scale. C57/BL6 mice underwent a left-sided pneumonectomy. Lungs were harvested at various timepoints after pneumonectomy. Volume analysis by microCT revealed a striking increase of 143 percent in the cardiac lobe 14 days after pneum…
Precision luminosity measurements at LHCb
2014
Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy $\sqrt{s}$. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for $\sqrt{s}$ = 2.76, 7 and 8 TeV (proton-proton collisions) and for $\sqrt{s_{NN}}$ = 5 TeV (proton-lead collisions). Both the "van der Meer scan" and "beam-gas imaging" luminosity calibration methods were employed. It is observed that the beam density profile cannot always be described by a function that is factorizable in the two transverse coordinates. The introduction of a two-dimensional description of the beams improves sig…
Carbon nanotubes thin filters for x-ray detectors in space
2022
In this paper, we present the first results from an investigation performed on nanometric thin pellicles based on carbon nanotubes (CNT) of potential interest for manufacturing large area optical blocking filters to protect soft X-ray detectors in astrophysics space missions. In order to evaluate the effective capability of such materials to block UV/VIS/IR radiation, while being highly transparent in the soft X-rays and strong enough to withstand the severe launch stresses, we have performed a suite of characterization measurements. These include: UV/VIS/IR and X-ray absorption spectroscopy, X-ray Photoelectron Spectroscopy and Scanning Electron Microscopy on bare and Al coated small self-…
Investigating protein structure and dynamics through wide-angle X-ray solution scattering
2016
Wide-angle X-ray scattering (WAXS) is a powerful tool that can be used to gain information on the structure and dynamics of proteins and other biomolecules in solution. Improved methods for the calculation of WAXS patterns from available or putative protein models allow to better exploit the structural information contained in the experimental data. These methods, together with recent applications of static and time-resolved WAXS, are briefly reviewed.
Recent results from the ATLAS SCT irradiation programme
2000
Abstract The irradiation facility at the CERN proton synchrotron, set up to irradiate full-size prototypes of silicon microstrip detectors for the ATLAS semiconductor tracker, is described and measurements of the detector currents during irradiation are reported. The detector dark currents can be described by bulk radiation damage models demonstrating the radiation hardness of the detector design and allowing the current damage factor α and the acceptor introduction term β to be determined. Results from testbeam studies of a module with an irradiated detector and binary readout in a magnetic field and with the beam incident over a range of angles are reported. The hit efficiency and spatial…
Liquid structure and dynamics in the choline acetate:urea 1:2 deep eutectic solvent
2021
We report on the thermodynamic, structural, and dynamic properties of a recently proposed deep eutectic solvent, formed by choline acetate (ChAc) and urea (U) at the stoichiometric ratio 1:2, hereinafter indicated as ChAc:U. Although the crystalline phase melts at 36-38 degrees C depending on the heating rate, ChAc:U can be easily supercooled at sub-ambient conditions, thus maintaining at the liquid state, with a glass-liquid transition at about -50 degrees C. Synchrotron high energy x-ray scattering experiments provide the experimental data for supporting a reverse Monte Carlo analysis to extract structural information at the atomistic level. This exploration of the liquid structure of ChA…