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1.
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2.
  • Almehed, Sverker, et al. (författare)
  • A Silicon-Tungsten Electromagnetic Calorimeter for LEP
  • 1991
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 305:2, s. 320-330
  • Tidskriftsartikel (refereegranskat)abstract
    • This report describes a silicon-tungsten electromagnetic calorimeter used to determine some beam properties and luminosity in the DELPHI experiment at LEP. The polar angular range covered by this detector is 5–8 mrad, which allows the detection of a Bhabha rate about 10 times the rate of produced Z particles at the peak cross section.
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3.
  • Andersson, Åke, et al. (författare)
  • Beam profile measurements at MAX
  • 1995
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 364:1, s. 4-12
  • Tidskriftsartikel (refereegranskat)abstract
    • An electron beam profile monitor system is described. It utilizes the visible bending magnet synchrotron radiation (SR) to form an image of the beam. A model for calculating diffraction and depth of field effects is introduced. Assuming a Gaussian distributed electron beam, the relation between beam image size and actual beam size is then calculated with this model, for a number of practical measuring situations. In a series of measurements at the MAX I electron storage ring at a current of 1 mA, the beam image size has been measured for these calculated situations. The measured values are presented, and their behaviour is in good agreement with the model. With this model the horizontal and vertical rms beam sizes were determined to σx = (203 ± 3) μm and σy = (19 ± 3) μm respectively. The corresponding vertical emittance is approximately 0.05 nm rad.
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4.
  • Andersson, Åke, et al. (författare)
  • Emittance manipulation by first- and second-order lattice control
  • 1997
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0168-9002. ; 387:3, s. 463-470
  • Tidskriftsartikel (refereegranskat)abstract
    • The lattice of the MAX-I electron storage ring has been investigated and tuned towards small momentum compaction values. By measurements of the synchrotron frequency, bunch length, horizontal beam size and beam movement, the beam has been found to behave in reasonable agreement with the predictions of the lattice model up to second order in energy deviation. Both longitudinal and horizontal emittance could be varied within a relatively large range with lattice changes and/or controlled beam energy changes.
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5.
  • Andersson, Åke, et al. (författare)
  • Experiences with the narrow gap undulator at MAX-lab
  • 1995
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 362:2-3, s. 586-591
  • Tidskriftsartikel (refereegranskat)abstract
    • An undulator with short poles (period 24 mm) and extremely narrow gap (magnet gap 7.7 mm) using a squeezable vacuum chamber has been installed and is in operation at the MAX-lab 550 MeV storage ring. The device operates with a vacuum chamber aperture down to 6.2 mm. The behaviour of the storage ring concerning lifetime, emittance, tune shift and closed orbit is well described by conventional models. We present here the design of the device, the influence on the storage ring and the spectral characteristics, as well as comparison with expected theoretical results and an overview of the activities at the beam line.
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6.
  • Andersson, Åke, et al. (författare)
  • Positron production for ESRF
  • 1988
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 267:1, s. 15-21
  • Tidskriftsartikel (refereegranskat)abstract
    • In this report, we first discuss some different pre-injector possibilities for the ESRF booster synchrotron, using estimated machine performances. We then focus on the commercially available linac schemes carrying out more detailed calculations. We also look into the possibility of recyling the particles through the linacs.
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7.
  • Andersson, Åke, et al. (författare)
  • The MAX II synchrotron radiation storage ring
  • 1994
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 343:2-3, s. 644-649
  • Tidskriftsartikel (refereegranskat)abstract
    • A 1.5 GeV third generation storage ring optimised for the VUV and soft X-ray spectral region is currently being built at MAX-lab. The magnet lattice, ring architecture and production choices are optimised to fit within rather tight boundary conditions without sacrificing performance. In this paper, the magnet lattice, light characteristics, injection and technical solutions for the ring are presented.
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8.
  • Ausmees, A., et al. (författare)
  • Secondary photoelectron spectra of ionic solids as a function of the incident photon energy
  • 1991
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0168-9002. ; 308:1-2, s. 219-222
  • Tidskriftsartikel (refereegranskat)abstract
    • Energy distributions of slow electrons (0-10 eV) emitted by thin layers of NaCl, KBr, CsBr, and CsI irradiated by monochromatic XUV photons with various energies in the interval of 50-300 eV are measured. The contributions of slow secondaries, hot secondaries and primary photoelectrons are obtained. It is shown that the higher the absorption coefficient for incident photons, the stronger the contribution of hot secondaries. The relationship between their contribution and the electron-phonon scattering process is discussed.
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9.
  • Backlund, Y., et al. (författare)
  • Micromachining of Silicon for Thermal and Position-Sensitive Nuclear-Detector Applications
  • 1989
  • Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 279:3, s. 555-559
  • Tidskriftsartikel (refereegranskat)abstract
    • As part of a programme aiming at the development of small nuclear radiation detectors, for example thermal detectors and position sensitive mosaic structures of surface barrier type, a technique for micromachining the detector bodies in silicon has been developed. The technique is based on an anisotropic etching property of a solution, mainly consisting of KOH. The etch rate is strongly orientation dependent with a speed in the 〈100〉 direction about 400 times faster than in the 〈111〉 direction. The major steps in the etching procedure are described and some examples of deep etching in Si are shown.
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10.
  • Bässler, M., et al. (författare)
  • Beam line I411 at MAX II - Performance and first results
  • 2001
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0168-9002. ; 469:3, s. 382-393
  • Tidskriftsartikel (refereegranskat)abstract
    • We report on the characteristics and first results from the soft X-ray beam line I411, based on an undulator at the third generation synchrotron facility MAX II, Sweden. The beam line is designed for high-resolution, angle-resolved electron spectroscopy on gases, liquids and solids. Main components are the modified SX700 monochromator and the end station, both of which were previously used at beam line 51 at MAX I. The end station is equipped with a rotatable SES-200 hemispherical electron-analyser. Before the end station, a one-metre section is reserved for exchangeable experimental set-ups. The usable photon energy range is 50-1500 eV and the photon flux is two orders of magnitudes higher compared to beam line 51. At 400 eV a resolving power of about 5700 in the first order of the monochromator grating could be obtained. In gas phase, a total electron energy resolution of 16 meV has been achieved. Detailed results on the undulator performance, flux, photon and electron energy resolution as well as some technical details are presented here. As an example of the capabilities of the beam line I411, we present the fully vibrationally resolved Auger resonant Raman electron spectrum of gas-phase N 2.
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11.
  • Cronqvist, M., et al. (författare)
  • Experimental-Determination of Cross-Talk between Neutron Detectors
  • 1992
  • Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - 0168-9002. ; 317:1-2, s. 273-280
  • Tidskriftsartikel (refereegranskat)abstract
    • Neutron cross-talk measurements have been performed with 14.1 MeV neutrons for organic scintillator detectors with n-gamma discrimination capability. The probability for cross-talk between two 156 mm thick neutron detectors with a hexagonal cross section (effective diameter 167 mm) placed 0.33 m apart was found to be (2.5+/-1.1) 10(-4). A similar measurement between two 100 mm thick, cylindrically shaped detectors with 50 mm diameter and at 75 mm distance from each other yielded a cross-talk probability of (2.5+/-0.4) 10(-3). The measured cross-talk probabilities are in agreement with values from a Monte Carlo calculation.
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12.
  • Da Via, C, et al. (författare)
  • Lightwave Analogue Links For LHC Detector Front-ends
  • 1994
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 344:1, s. 199-211
  • Tidskriftsartikel (refereegranskat)abstract
    • The requirements on optical links for transferring analog and digital signals from the detector front-ends to the readout electronics at future high-luminosity colliders are reviewed. The advantages of external modulation techniques are discussed. An outline is given of the the R&D programme recently started at CERN by a collaboration involving high-energy physics institutes, optoelectronics research laboratories and industry, in order to develop electro-optic intensity modulator arrays, particularly for analogue applications, and to investigate the feasibility of volume production. The design of multichannel demonstrators in lithium niobate and III-V semiconductor technology is described. Preliminary results of the performance measurements are presented.
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13.
  • Eriksson, Mikael, et al. (författare)
  • A VUV undulator for MAX
  • 1988
  • Ingår i: Nuclear Inst. and Methods in Physics Research, A. - 0168-9002. ; 265:3, s. 587-595
  • Tidskriftsartikel (refereegranskat)abstract
    • An undulator operating at radiation wavelengths between 250 and 2000 Å has been constructed at the Technical Research Centre of Finland and recently installed at the MAX storage ring in Lund. The undulator utilizes ferrite permanent magnets in the hybrid configuration. The magnetic and mechanical design, calculated performance and influence on the electron beam of the undulator are discussed.
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14.
  • Glänneskog, Henrik, 1975, et al. (författare)
  • Apparatus for on-line measurements of iodine species concentration in aqueous and gaseous phases
  • 2003
  • Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - 0168-9002. - 9904363455 ; 498:1-3, s. 517-521
  • Tidskriftsartikel (refereegranskat)abstract
    • An apparatus was constructed for on-line measurements of the concentration of iodine species in aqueous and gas phases using radioactive tracers. The apparatus and procedures for determining detector efficiencies and flow rates of both phases are described in detail. A complete description of experimental procedures is given and reactions between gaseous iodine and reactor containment construction materials such as copper, zinc and aluminium are investigated using the apparatus.
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15.
  • Guo, J. H., et al. (författare)
  • Characterization of undulator radiation at MAXII using a soft X-ray fluorescence spectrometer
  • 1999
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0168-9002. ; 431:1, s. 285-293
  • Tidskriftsartikel (refereegranskat)abstract
    • A grazing-incidence grating spectrometer has been used for the investigation of the undulator radiation from beamline 411 at MAX-lab. The direct detection of undulator light is expected to obtain the information of the quality of the undulator. Regular undulator radiation and some higher harmonics were observed. The effects of electronic beam coupling and Landau cavities have been studied. The experiment presents an easy and quick method to characterize the undulator radiation before the permanent monochromator is installed.
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16.
  • Hedin, Lars (författare)
  • Properties of electron self-energies and their role in electron spectroscopies
  • 1991
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; A308:1-2, s. 169-177
  • Tidskriftsartikel (refereegranskat)abstract
    • The GW approximation for the self-energy connected with the one-electron Green's function has been very successful in predicting band structures for a large class of semiconductors and insulators. The physical basis for this approximation and general features of its nonlocality are discussed, as well as possible improvements. Besides quasiparticle energies the self-energy also gives the intrinsic part of the photoelectron spectrum. In general, however, a full description of experimental spectra measured with synchrotron radiation, such as photoemission, Auger spectra and EXAFS, cannot be given by the one-electron Green's function. A new theoretical approach to synchrotron radiation spectroscopies is given in terms of the coupling functions involved in the GW approximation and on-the-energy-shell one-electron Green's functions.(14 refs)
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17.
  • Jensen, B. N., et al. (författare)
  • Design and performance of a spherical grating monochromator used at MAX I
  • 1997
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0168-9002. ; 394:1-2, s. 243-250
  • Tidskriftsartikel (refereegranskat)abstract
    • We report on the performance of a grazing incidence spherical grating monochromator installed at MAX I and designed to cover the photon energy range from about 15-200 eV with high resolving power. It is intended mainly for angle-resolved photoemission work. Therefore, both refocusing optics, to obtain a small spot size at the sample, and a higher order light suppressor, to reduce the content of higher orders, have been incorporated in the design. The theoretically calculated energy resolution is presented and compared to the resolution obtained in photoabsorption measurements of gas-phase He, Ne, Kr, Xe, and N2. The possibility to reduce the influence of higher orders is illustrated by photoemission data collected on Si (100). The experimental results show that the monochromator fulfills the expected design goals.
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18.
  • Levin, J.C., et al. (författare)
  • Production of very cold, highly charged ions by synchrotron radiation: Comparisons of the “scalpel” and “hammer” methods
  • 1987
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 262:1, s. 106-109
  • Tidskriftsartikel (refereegranskat)abstract
    • Measurements of kinetic energies of highy charged argon ions produced by inner-shell photoionization and by ion-beam impact have been made using time-of-flight techniques. High-charge-state recoil ions produced by beams of ∼ 0.5-1 MeV/u Cl5+ are found to have energies one to two orders of magnitude higher than ions of the same charge produced by vacancy cascades following inner-shell photoionization by synchrotron radiation. The results may have application to the development of a very cold ion source useful for angle-resolved atomic collision studies.
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19.
  • Nyholm, R., et al. (författare)
  • Beamline I311 at MAX-LAB : A VUV/soft X-ray undulator beamline for high resolution electron spectroscopy
  • 2001
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0168-9002. ; 467-468, s. 520-524
  • Tidskriftsartikel (refereegranskat)abstract
    • We describe a beamline based on a plane-grating monochromator and an end-station designed for high resolution photoemission and photoabsorption spectroscopy on surfaces and interfaces using undulator radiation in the energy range 30 1500 eV. The general design of the beamline is based on a horizontally focusing pre-mirror, an SX-700 type of plane-grating monochromator and re-focusing optics of Kirkpatrick-Baez design.
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20.
  • Nyholm, R., et al. (författare)
  • SURFACE SCIENCE AT MAX-LAB
  • 1989
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 282:2-3, s. 553-558
  • Tidskriftsartikel (refereegranskat)
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21.
  • Peterson, Carsten (författare)
  • Track finding with neural networks
  • 1989
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 279:3, s. 537-545
  • Tidskriftsartikel (refereegranskat)abstract
    • A neural network algorithm for finding tracks in high energy physics experiments is presented. The performance of the algorithm is explored on modest size samples with encouraging results. It is inherently parallel and thus suitable for execution on a conventional SIMD architecture. More important, it naturally lends itself to direct implementations in custom made hardware, which would permit real time operations and hence facilitate fast triggers. Both VLSI and optical technology implementations are briefly discussed.
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22.
  • Schulz, Joachim, et al. (författare)
  • Energy absorption of free rare gas clusters irradiated by intense VUV pulses of a free electron laser
  • 2003
  • Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - 0168-9002. ; 507:1-2, s. 572-576
  • Konferensbidrag (refereegranskat)abstract
    • As one of the first experiments at the free electron laser of the TESLA Test Facility (TTF) the Coulomb explosion of Xenon clusters irradiated with high intensity pulses at a wavelength of 98 nm has been observed. Classical trajectory calculations have been performed in order to illuminate the energy absorption process. Comparison with typical parameters in the infrared regime shows that above barrier ionization is suppressed due to the fast oscillating field and thermionic ionization prevails.
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23.
  • Sorensen, S.L., et al. (författare)
  • A normal-incidence beam line at the MAX storage ring
  • 1990
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0168-9002. ; 297:1-2, s. 296-300
  • Tidskriftsartikel (refereegranskat)abstract
    • A 1-m normal-incidence monochromator has been designed and installed on a bending-magnet beam line at the MAX storage ring in Lund. The optical properties of the beam line have been investigated via ray-tracing studies and with flux measurements of the beam line-monochromator combination. A resolution of 0.9 Å at 919.8 Å was measured in first-order diffraction with an argon hollow-cathode lamp for slit openings of 100 μm. A photon flux of 2.0 × 1010 at 550 Å with 250 μm slits was measured with a calibrated GaAs photodiode through a 1.5-mm diameter aperture in an aluminum mask on the photodiode. The new instrument has a microcomputer controlled mechanism which optimizes focussing requirements for a scanning monochromator with the requirement of fixed slits and fixed exit beam.
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24.
  • Vavra, I, et al. (författare)
  • The influence of thermal processing on structural and electrical properties of WxSi1−x/Si multilayers
  • 1994
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0168-9002. ; 350:1-2, s. 379-390
  • Tidskriftsartikel (refereegranskat)abstract
    • Thermal stability of WxSi1−x/Si multilayers (MLs) with x varying from 1 to 0.11 is studied by TEM and LAXS. The structure of the prepared samples is amorphous. Doping of W sublayers with silicon affects the interdiffusion process as well as the crystallization in these sublayers. We investigated these two processes (which have a detrimental influence on e.g. X-ray mirror stability) by annealing our samples at 400°C for 40 min. The structural changes were monitored by resistance measurement in the temperature range of 1.5–300 K. A correlation between structural and electrical characteristics was found, which is based on the comparison between three different R(T) curves. It is shown in our paper that the R(T) curve of a ML lies between the R(T) curves of two extreme types of single layers. The first single layer is the analogue of a fully intermixed ML and the second one represents a parallel connection of all conductive sublayers. Thus, a simple resistance measurement can give additional information about the quality of interfaces. We claim that in MLs with ultrathin sublayers the reported highest thermal stability of the amorphous mixture W0.72Si0.28 cannot be utilized because interdiffusion dominates over crystallization so that the superlattice structure is not retained.
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25.
  • Walker, R.P., et al. (författare)
  • The European UV/VUV storage ring FEL at ELETTRA : First operation and future prospects
  • 2001
  • Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - 0168-9002. ; 467-468, s. 34-37
  • Tidskriftsartikel (refereegranskat)abstract
    • A European project to develop the first storage ring free-electron laser on a third-generation synchrotron radiation facility is presented, including a description of the main features, initial performance at 350 and 220 nm and future prospects.
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26.
  • Werin, Sverker (författare)
  • Second order bunching in an optical klystron
  • 1997
  • Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - 0168-9002. ; 391:2, s. 381-384
  • Tidskriftsartikel (refereegranskat)abstract
    • A method to achieve spatial bunching on the double frequency of the induced energy spread in an optical klystron is described. Criteria necessary to construct such a second order buncher and the phase space evolution are presented.
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27.
  • Abdalla, Munir A, et al. (författare)
  • A CMOS APS for dental X-ray imaging using scintillating sensors
  • 2001
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 460:1, s. 197-203
  • Tidskriftsartikel (refereegranskat)abstract
    • In this paper we present an integrating CMOS Active Pixel Sensor (APS) circuit to be used with scintillator type X-ray sensors for intra oral dental X-ray imaging systems. Different pixel architectures were constructed to explore their performance characteristics and to study the feasibility of the development of such systems using the CMOS technology. A prototype 64 x 80 pixel array has been implemented in a CMOS 0.8 mum double poly n-well process with a pixel pitch of 50 mum. A spectral sensitivity measurement for the different pixels topologies, as well as measured X-ray direct absorption in the different APSs are presented. A measurement of the output signal showed a good linearity over a wide dynamic range. This chip showed that the very low sensitivity of the CMOS APSs to direct X-ray exposure adds a great advantage to the various CMOS advantages over CCD-based imaging systems,
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28.
  • Abdalla, Munir A, et al. (författare)
  • An integrating CMOS APS for X-ray imaging with an in-pixel preamplifier
  • 2001
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 466:1, s. 232-236
  • Tidskriftsartikel (refereegranskat)abstract
    • We present in this paper an integrating CMOS Active Pixel Sensor (APS) circuit coated with scintillator type sensors for intra-oral dental X-ray imaging systems. The photosensing element in the pixel is formed by the p-diffusion on the n-well diode. The advantage of this photosensor is its very low direct absorption of X-rays compared to the other available photosensing elements in the CMOS pixel. The pixel features an integrating capacitor in the feedback loop of a preamplifier of a finite gain in order to increase the optical sensitivity. To verify the effectiveness of this in-pixel preamplification, a prototype 32 x 80 element CMOS active pixel array was implemented in a 0.8 mum CMOS double poly, n-well process with a pixel pitch of 50 mum. Measured results confirmed the improved optical sensitivity performance of the APS. Various measurements on device performance are presented.
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29.
  • Adiels, Lars, et al. (författare)
  • A π0 and η spectrometer of lead glass and BGO for momenta up to 1 GeV/c
  • 1986
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 244:3, s. 380-390
  • Tidskriftsartikel (refereegranskat)abstract
    • A spectrometer consisting of two sets of bismuth germanium oxide (BGO) crystals and a lead-glass array has been used to measure the [pi]0 and [eta] momentum spectra produced from proton-antiproton annihilations at rest. We describe the test of the BGO sets in electron beams of energies from 50 to 450 MeV. We discuss the method of construction and calibration of the lead-glass array, as well as procedures to extract the energy and position resolutions for detected photons. A momentum resolution ([sigma]) for [pi]0’s and [eta]’s of 4% and 3%, respectively has been achieved at momenta below 1 GeV/c.
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30.
  • Adriani, O., et al. (författare)
  • The PAMELA experiment on satellite and its capability in cosmic rays measurements
  • 2002
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 478:02-jan, s. 114-118
  • Tidskriftsartikel (refereegranskat)abstract
    • The PAMELA equipment will be assembled in 2001 and installed on board the Russian satellite Resurs. PAMELA is conceived mainly to study the antiproton and positron fluxes in cosmic rays up to high energy (190 GeV for (p) over bar and 270 GeV for e(+)) and to search antinuclei, up to 30 GeV/n, with a sensitivity of 10(-7) in the He/He ratio. The PAMELA telescope consists of. a magnetic spectrometer made up of a permanent magnet system equipped with double sided microstrip silicon detectors a transition radiation detector made up of active layers of proportional straw tubes interleaved with carbon fibre radiators; and a silicon-tungsten imaging calorimeter made up of layers of tungsten absorbers and silicon detector planes. A time-of-flight system and anti-coincidence counters complete the PAMELA equipment. In the past years, tests have been done on each subdetector of PAMELA; the main results are presented and their implications on the anti-particles identification capability in cosmic rays are discussed here.
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31.
  • Akhmadaliev, S., et al. (författare)
  • Hadron energy reconstruction for the ATLAS calorimetry in the framework of the non-parametrical method
  • 2002
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 480:03-feb, s. 508-523
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) in the framework of the non-parametrical method. The non-parametrical method utilizes only the known e/h ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to an easy use in a first level trigger. The reconstructed mean values of the hadron energies are within +/-1% of the true values and the fractional energy resolution is [(58+/-3)%/rootE+(2.5+/-0.3)%]circle plus(1.7+/-0.2)/E. The value of the e/h ratio obtained for the electromagnetic compartment of the combined calorimeter is 1.74+/-0.04 and agrees with the prediction that e/h > 1.66 for this electromagnetic calorimeter. Results of a study of the longitudinal hadronic shower development are also presented. The data have been taken in the H8 beam line of the CERN SPS using pions of energies from 10 to 300 GeV.
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32.
  • Akhmadaliev, S., et al. (författare)
  • Results from a new combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter
  • 2000
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 449:3, s. 461-477
  • Tidskriftsartikel (refereegranskat)abstract
    • A new combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 10 to 300 GeV at an incident angle a of about 12 degrees is well described by the expression sigma/E = ((41.9 +/- 1.6)%/root E + (1.8 +/- 0.1)%)circle plus(1.8 +/- 0.1)/E, where E is in GeV. The response to electrons and muons was evaluated. Shower profiles, shower leakage and the angular resolution of hadronic showers were also studied. Results are compared with those from the previous beam test.
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33.
  • Ambrosio, M, et al. (författare)
  • Muon energy estimate through multiple scattering with the MACRO detector
  • 2002
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 492:3, s. 376-386
  • Tidskriftsartikel (refereegranskat)abstract
    • Muon energy measurement represents an important issue for any experiment addressing neutrino-induced up-going muon studies. Since the neutrino oscillation probability depends on the neutrino energy, a measurement of the muon energy adds an important piece of information concerning the neutrino system. We show in this paper how the MACRO limited streamer tube system can be operated in drift mode by using the TDCs included in the QTPs, an electronics designed for magnetic monopole search. An improvement of the space resolution is obtained, through an analysis of the multiple scattering of muon tracks as they pass through our detector. This information can be used further to obtain an estimate of the energy of muons crossing the detector. Here we present the results of two dedicated tests, performed at CERN PS-T9 and SPS-X7 beam lines, to provide a full check of the electronics and to exploit the feasibility of such a multiple scattering analysis. We show that by using a neural network approach, we are able to reconstruct the muon energy for E-mu < 40 GeV. The test beam data provide an absolute energy calibration, which allows us to apply this method to MACRO data. (C) 2002 Elsevier Science B.V. All rights reserved.
  •  
34.
  • Ambrosio, M, et al. (författare)
  • The MACRO detector at Gran Sasso
  • 2002
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 486:3, s. 663-707
  • Tidskriftsartikel (refereegranskat)abstract
    • MACRO was an experiment that ran in the Laboratori Nazionali del Gran Sasso from 1988 to 2000. Its principal goal was to observe magnetic monopoles or set significantly lower experimental flux limits than had been previously available in the velocity range from about beta = 10(-4) to unity. In addition it made a variety of other observations. Examples are: setting flux limits on other so far unobserved particles such as nuclearites and lightly ionizing particles, searching for WIMP annihilations in the Earth and the Sun and for neutrino bursts from stellar collapses in or near our Galaxy, and making measurements relevant to high energy muon and neutrino astronomy and of the flux of up-going muons as a function of nadir angle showing evidence for neutrino oscillations. The apparatus consisted of three principal types of detectors: liquid scintillator counters, limited streamer tubes, and nuclear track etch detectors. In addition, over part of its area it contained a transition radiation detector. The general design philosophy emphasized redundancy and complementarity. This paper describes the technical aspects of the complete MACRO detector, its operational performance, and the techniques used to calibrate it and verify its proper operation. It supplements a previously published paper which described the first portion of the detector that was built and operated. (C) 2002 Elsevier Science B.V. All rights reserved.
  •  
35.
  • Andrieux, M. L., et al. (författare)
  • Construction and test of the first two sectors of the ATLAS barrel liquid argon presampler
  • 2002
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 479:03-feb, s. 316-333
  • Tidskriftsartikel (refereegranskat)abstract
    • The electromagnetic (e.m.) calorimeter of the ATLAS experiment for the Large Hadron Collider will be a sampling liquid argon accordion calorimeter. To achieve sufficient energy resolution, it is necessary to correct for the energy loss in the material upstream of the calorimeter. For this purpose, a separate presampler detector fixed on the inner face of the e.m. calorimeter, in the same cryostat, is being built by the ATLAS collaboration. Two presampler sectors have already been built and tested in their final version. The geometry of the detector and the various steps of its construction are reviewed. The hardware performance of the detector measured both at CERN and at the ISN-Grenoble (specific test bench) is discussed. It is concluded that the presampler will adequately fulfill its role for future operation at the CERN Large Hadron Collider.
  •  
36.
  • Andrieux, M. L., et al. (författare)
  • Single-event upset studies of a high-speed digital optical data link
  • 2001
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 456:3, s. 342-351
  • Tidskriftsartikel (refereegranskat)abstract
    • The results from a series of neutron and photon irradiation tests of a high-speed digital optical data link based on a commercial serialiser and a vertical cavity surface emitting laser are described. The link was developed as a candidate for the front-end readout of the ATLAS electromagnetic calorimeter. The components at the emitting end of the link were unaffected by neutron and photon irradiation levels exceeding those expected during 10 years of LHC running. However, the link suffered from Single-Event Upsets (SEUs) when irradiated with energetic neutrons. A very general method based on the Burst Generation Rate (BGR) model has been developed and is used to extrapolate the error rate observed during tests to that expected at the LHC. A model-independent extrapolation was used to check the BGR approach and the results were consistent once systematic errors were taken into account.
  •  
37.
  • Armijo, V., et al. (författare)
  • A fast MWPC with cathode strips and utilizing CF4-isobutane
  • 1991
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 303:2, s. 298-308
  • Tidskriftsartikel (refereegranskat)abstract
    • A planar wire chamber has been developed at LAMPF as a prototype for wire chambers of cylindrical configuration for electron detection in the MEGA experiment. Results form tests with the planar chamber have been used to set the geometrical parameters and predict the performance characteristics of the cylindrical chambers. The behavior of the planar chamber with CF4-isobutane gas demonstrates that 15 μm wire of 1 mm pitch is practical, that lifetimes greater than 0.045 C/cm are achievable and that gate widths of 25 ns are possible. © 1991.
  •  
38.
  • Ashrafi, S., et al. (författare)
  • Monte-Carlo simulation of the charged particle detector used in the NORDBALL gamma-ray spectrometer
  • 2001
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 458:3, s. 690-697
  • Tidskriftsartikel (refereegranskat)abstract
    • The NORDBALL silicon detector array for detecting light charged particles emitted in fusion evaporation reactions was simulated with the Monte-Carlo method. The data from the reaction of 261 MeV Ni-58 ions with Cr-50 nuclei in a 4.8 mg/cm(2) thick target was used to adjust the simulation parameters. Relative population of residual nuclei in the reaction was determined, by comparing the intensities of gamma -rays.
  •  
39.
  • Aubert, B., et al. (författare)
  • Performance of the ATLAS electromagnetic calorimeter barrel module 0
  • 2003
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 500:03-jan, s. 202-231
  • Tidskriftsartikel (refereegranskat)abstract
    • The construction and performance of the barrel pre-series module 0 of the future ATLAS electromagnetic calorimeter at the LHC is described. The signal reconstruction and performance of ATLAS-like electronics has been studied. The signal to noise ratio for muons has been found to be 7.11 +/- 0.07. An energy resolution of better than 9.5% GeV1/2 / rootE (sampling term) has been obtained with electron beams of up to 245 GeV. The uniformity of the response to electrons in an area of Deltaeta x Deltaphi = 1.2 x 0.075 has been measured to be better than 0.8%.
  •  
40.
  • Aubert, B., et al. (författare)
  • Performance of the ATLAS electromagnetic calorimeter end-cap module 0
  • 2003
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 500:03-jan, s. 178-201
  • Tidskriftsartikel (refereegranskat)abstract
    • The construction and beam test results of the ATLAS electromagnetic end-cap calorimeter pre-production module 0 are presented. The stochastic term of the energy resolution is between 10% and 12.5% GeV1/2 over the full pseudorapidity range. Position and angular resolutions are found to be in agreement with simulation. A global constant term of 0.6% is obtained in the pseudorapidity range 2.5 < η < 3.2 (inner wheel).
  •  
41.
  • Badel, Xavier, et al. (författare)
  • Formation of pn junctions in deep silicon pores for X-ray imaging detector applications
  • 2003
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 509:1-3, s. 96-101
  • Tidskriftsartikel (refereegranskat)abstract
    • The formation of pn junctions in deep silicon pores has been studied for a new concept of X-ray imaging detectors. The sensitive part of the device is an array of CsI(Tl) columns formed by filling a silicon matrix of pores having pn junctions in their walls. Under X-ray illumination, the CsI(TI) scintillator emits photons that are collected by the pn junctions. Relatively high signal collection efficiency is expected. However, the formation of pn junctions inside pore walls represents a challenging step in the detector fabrication. In this work pore matrices were fabricated in n-type silicon by deep reactive ion etching and by photo-electrochemical etching. The pn junctions were formed either by boron diffusion or deposition of boron doped poly-silicon. Various techniques were used to analyze the transverse depth profiles of boron atoms at different pore depths. The study shows successful results for pn-junctions formed both by diffusion and by poly-silicon deposition.
  •  
42.
  • Badel, Xavier, et al. (författare)
  • Improvement of an X-ray imaging detector based on a scintillating guides screen
  • 2002
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 487:1-2, s. 129-135
  • Tidskriftsartikel (refereegranskat)abstract
    • An X-ray imaging detector has been developed for dental applications. The principle of this detector is based on application of a silicon charge coupled device covered by a scintillating wave-guide screen. Previous studies of such a detector showed promising results concerning the spatial resolution but low performance in terms of signal to noise ratio (SNR) and sensitivity. Recent results confirm the wave-guiding properties of the matrix and show improvement of the detector in terms of response uniformity, sensitivity and SNR. The present study is focussed on the fabrication of the scintillating screen where the principal idea is to fill a matrix of Si pores with a CsI scintillator. The photoluminescence technique was used to prove the wave-guiding property of the matrix and to inspect the filling uniformity of the pores. The final detector was characterized by X-ray evaluation in terms of spatial resolution, light output and SNR. A sensor with a spatial resolution of 9 LP/mm and a SNR over 50 has been achieved using a standard dental X-ray source and doses in the order of those used at the moment by dentists (around 25 mR).
  •  
43.
  • Balcerzyk, M., et al. (författare)
  • Energy resolution and light yield non-proportionality of ZnSe : Te scintillator studied by large area avalanche photodiodes and photomultipliers
  • 2002
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 482:3, s. 720-727
  • Tidskriftsartikel (refereegranskat)abstract
    • The ZnSe: Te scintillator has been studied by means of a photomultiplier with an extended bialkali photocathode, a large area avalanche photodiode (LAAPD) and a PIN photodiode. The light output was determined to be 28 300+/-1700 photons/MeV. Results indicate good proportionality for light output versus gamma-ray energy. Measurements of the 662 keV gamma-ray energy spectrum recorded using a LAAPD resulted in an energy resolution of 5.4+/-0.3%. Based on these results, an intrinsic energy resolution of 3.3+/-0.7% has been calculated.
  •  
44.
  •  
45.
  • Bertilsson, Kent, et al. (författare)
  • Simulation of a low atmospheric-noise modified four-quadrant position sensitive detector
  • 2001
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 466:1, s. 183-187
  • Tidskriftsartikel (refereegranskat)abstract
    • A modified four-quadrant position sensitive detector (PSD) is developed. This structure is less sensitive to atmospheric turbulence that is a major drawback with the traditional four-quadrant detector. The inter-electrode resistance is as high as for the four-quadrant detector, which is an advantage compared to the lateral effect PSD. The linearity for the modified four-quadrant detector is good in the whole active range of sensing. The structures are limited to small sensing areas with well focused beams and are suitable for use in detectors up to 1 mm in size.
  •  
46.
  •  
47.
  • Bonvicini, V., et al. (författare)
  • The PAMELA experiment in space
  • 2001
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 461:03-jan, s. 262-268
  • Tidskriftsartikel (refereegranskat)abstract
    • We provide in this paper a status report of the space experiment PAMELA. PAMELA aims primarily to measure the flux of antiparticles, namely antiprotons and positrons, in cosmic rays with unprecedented statistics over a large energy range. Tn addition, it will measure the light nuclear components of cosmic rays, investigate phenomena connected to Solar and Earth physics and it will search for cosmic ray antinuclei with sensitivity better than 10(-7) in the He/He ratio. PAMELA consists of a magnet spectrometer, a transition radiation detector, an imaging calorimeter, a time of flight system and an anticoincidence detector. The apparatus will be installed on board of the Russian satellite of the Resurs type in a polar orbit at about 680 km of altitude. The launch is foreseen for late 2002/early 2003.
  •  
48.
  • Brahme, A., et al. (författare)
  • Evaluation of a GEM and CAT-based detector for radiation therapy beam monitoring
  • 2000
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 454, s. 136-141
  • Tidskriftsartikel (refereegranskat)abstract
    • We are developing a radiation therapy beam monitor for the Karolinska Institute. This monitor will consist of two consecutive detectors confined in one gas chamber: a keV-photon detector, which will allow diagnostic quality visualization of the patient, and a MeV-photon detector, that will measure the absolute intensity of the therapy beam and its position with respect to the patient. Both detectors are based on highly radiation resistant gas and solid photon to electron converters, combined with GEMs and a CAT as amplification structures. We have performed systematic studies of the high-rate characteristics of the GEM and the CAT, as well as tested the electron transfer through these electron multipliers and various types of converters. The tests show that the GEM and the CAT satisfy all requirements for the beam monitoring system. As a result of these studies we successfully developed and tested a full section of the beam monitor equipped with a MeV-photon converter placed between the GEM and the CAT.
  •  
49.
  • Bäck, Torbjörn, et al. (författare)
  • A TOF-PET system for educational purposes
  • 2002
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 477, s. 82-82
  • Tidskriftsartikel (refereegranskat)abstract
    • A TOF-PET system has been designed and constructed for educational purposes. The aim of this system is to demonstrate the possibilities of positron emission tomography in general and the time-of-flight method in particular to the students of various courses at the Royal Institute of Technology, Stockholm, Sweden. The set-up consists of 48 small BaF2 crystals coupled to fast photomultipliers placed in a ring geometry. The signals of the photomultipliers are fed into fast constant fraction discriminators (CFD). The outputs of these are directed to a specially designed logic VME unit. which combines the CFD signals of 6 neighbouring channels to one signal by adding a different delay to each channel. The logic circuitry produces a prompt pulse for each event that serves as the start pulse for the 8-channel fast TDC. The delayed pulses act as the stop pulses for the TDC. In a computer. the measured times are converted into information about which the photomultipliers fired with the difference in the time of flight. The set-up is described and the results are presented.
  •  
50.
  • Bäck, Torbjörn, et al. (författare)
  • An educational tool for demonstrating the TOF-PET technique
  • 2001
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : AMERICAN PHYSICAL SOC. - 0168-9002 .- 1872-9576. ; 471:1-2, s. 200-204
  • Tidskriftsartikel (refereegranskat)abstract
    • A detector system for positron emission tomography with time-of-flight capability has been built to serve as an educational tool for undergraduate students. The set-up consists of 48 BaF2 scintillator crystals, each coupled to a fast photo-multiplier tube, mounted in a circular geometry. The analogue detector pulses are handled by fast constant fraction discriminators. A dedicated unit reduces the 48 channels to eight channels via delay-fine encoding, and the signals are then fed to an eight channel fast time-to-digital converter. A VME processor sorts the events and sends them to a workstation where the coincident events are extracted. The time resolution of the detectors together with fast VME based electronics allows for time-of-flight measurements to improve on the signal-to-noise ratio in the, reconstructed images. The system can be used for different types of exercises for the students, varying from the fundamentals of scintillator detectors to advanced image reconstruction. The set-up is described and some results are presented. (C) 2001 Elsevier Science B.V. All rights reserved.
  •  
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