Showing papers by "National Research Nuclear University MEPhI published in 1998"
Heidelberg University1, GSI Helmholtz Centre for Heavy Ion Research2, CERN3, University of Washington4, University of Birmingham5, Polish Academy of Sciences6, Goethe University Frankfurt7, University of California, Davis8, University of California, Berkeley9, Hungarian Academy of Sciences10, Max Planck Society11, University of Marburg12, Eötvös Loránd University13, University of Warsaw14, Yale University15, University of California, Los Angeles16, Joint Institute for Nuclear Research17, Kent State University18, National and Kapodistrian University of Athens19, National Research Nuclear University MEPhI20, Lawrence Berkeley National Laboratory21
TL;DR: In this paper, the authors observed the directed and elliptic flow of protons and charged pions from the semicentral collisions of a 158GeV/nucleon Pb beam with a Pb target.
Abstract: The directed and elliptic flow of protons and charged pions has been observed from the semicentral collisions of a 158GeV/nucleon Pb beam with a Pb target. The rapidity and transverse momentum dependence of the flow has been measured. The directed flow of the pions is opposite to that of the protons but both exhibit negative flow at low p{sub t} . The elliptic flow of both is fairly independent of rapidity but rises with p{sub t} . {copyright} {ital 1998} {ital The American Physical Society}
125 citations
01 Feb 1998
TL;DR: The Limited Geiger-mode Photodiode (LGP) as mentioned in this paper was the first type of silicon photodiode, which consists of many ≈104 mm−2 independent cells ≈10 mkm size around n+ -pins located between p-substrate and thin SiC layer and achieved very high gain more than 104 for 0.67 mkm wave length light source and up to 6·105 for single electron.
Abstract: The novel type of the Silicon Photodiode — Limited Geiger-mode Photodiode (LGP) has been produced and studied. The device consists of many ≈104 mm−2 independent cells ≈10 mkm size around n+ -“pins” located between p-substrate and thin SiC layer. Very high gain more than 104 for 0.67 mkm wave length light source and up to 6·105 for single electron have been achieved. The LGP photon detection efficiency at the level of one percent has been measured.
89 citations
TL;DR: In this article, the authors presented the first analysis of diffractive photon dissociation events in deep inelastic positron-proton scattering at HERA in which the proton in the final state is detected and its momentum measured.
Abstract: This paper presents the first analysis of diffractive photon dissociation events in deep inelastic positron-proton scattering at HERA in which the proton in the final state is detected and its momentum measured. The events are selected by requiring a scattered proton in the ZEUS leading proton spectrometer (LPS) with χL > 0.97, where xL is the fraction of the incoming proton beam momentum carried by the scattered proton. The use of the LPS significantly reduces the contamination from events with diffractive dissociation of the proton into low mass states and allows a direct measurement of t, the square of the four-momentum exchanged at the proton vertex. The dependence of the cross section ont is measured in the interval 0.073 < |t| < 0.4 GeV2 and is found to be described by an exponential shape with the slope parameterb = 7.2 ± 1.1(stat.)−0.9+0.7(syst.) GeV−2. The diffractive structure function FD (4) is presented as 0.9 a function of χH ≃ 1 − χL and β, the momentum fraction of the struck quark with respect to χH, and averaged over thet interval 0.073 < |t′ < 0.4 GeV2 and the photon virtuality range 5
82 citations
TL;DR: In this paper, the applicability of direct sampling time-of-flight (TOF) mass spectrometers for routine technological analysis is considered. The discussed set incorporates two TOF instruments together covering analysis of solid, liquid, and gas samples without the need for time consuming sample preparation.
Abstract: The practicability of direct sampling time-of-flight mass spectrometers for routine technological analysis is considered. The discussed set incorporates two TOF instruments together covering analysis of solid, liquid, and gas samples without the need for time consuming sample preparation. Both an electron ionization reflectron TOF mass analyzer designed for the analysis of gas and liquid samples and a laser ionization axial electrostatic TOF mass analyzer designed for analysis of solid and powder samples use a single system for data acquisition, collection and processing. These instruments achieve ng/g range sensitivity and mass resolution exceeding 1000. Because of its compact design the system also can be realized as a mobile laboratory for on-site analysis. Prospects for applying the instruments to different technological applications are discussed.
21 citations
TL;DR: In this paper, peak position pole figures of X-ray line peak position were used in the study of lattice elastic deformation as applied to textured metal materials and several modes of microstress equilibrium were revealed.
Abstract: Pole figures of X-ray line peak position were used in the study of lattice elastic deformation as applied to textured metal materials. Diffractometric texture measurements were carried out by a position sensitive detector. Peak position pole figures were constructed either in units of the Bragg angle 2θ Φψ or in units of lattice relative elastic deformation Δd/d sv . Several modes of microstress equilibrium are revealed. In most studied cases the distribution of lattice elastic deformation shows the cross-wise pattern, consisting in alternation of quadrants with predominance of extension and compression. In addition, the mutual arrangement of regions with opposite signs of elastic deformation varies depending on the texture character: breaking of texture maxima into halves with opposite signs of elastic deformation, predominance of one-sign elastic deformation within different texture maxima, stretched zones of elastic extension and compression at opposite slopes of texture maxima. Besides, the identical microstress distribution in all quadrants of pole figure develops in some cases.
4 citations
TL;DR: The results of the measurements for the samples with a shield thickness of 500mm which were obtained in the execution of the first year of the ISTC project No. 180 are represented in this article.
1 citations
TL;DR: In this paper, the authors considered the external interaction of the resonance states via common decay channels on the same footing as the internal residual interaction, and derived the strength function of the 4ℏω isoscalar monopole giant resonance in the framework of the random phase approximation in the continuum.
Abstract: A schematic model of multipole giant resonances is considered which treats the external interaction of the resonance states via common decay channels on the same footing as the internal residual interaction. At high excitation energy, the cross-section pattern is governed by the phenomenon of resonance trapping, i.e. by the formation of different time scales. The interplay of internal and external collectivity influences significantly the distribution of the dipole strengths over the single states as well as their widths and positions in energy. A realistic calculation is performed for208Pb. The strength function of the 4ℏω isoscalar monopole giant resonance is obtained in the framework of the random phase approximation in the continuum. The oneparticle continuum is shown to play an important role in the formation of the structure of the strength function. Some narrow resonances appear due to resonance trapping.