International Nuclear Information System (INIS)
Araujo, Wilson Roberto Barbosa de
1995-01-01
In this dissertation, we present a model for the nucleon, which is composed by three relativistic quarks interacting through a contract force. The nucleon wave-function was obtained from the Faddeev equation in the null-plane. The covariance of the model under kinematical null-plane boots is discussed. The electric proton form-factor, calculated from the Faddeev wave-function, was in agreement with the data for low-momentum transfers and described qualitatively the asymptotic region for momentum transfers around 2 GeV. (author)
Proton relativistic model; Modelo relativistico do proton
Energy Technology Data Exchange (ETDEWEB)
Araujo, Wilson Roberto Barbosa de
1996-12-31
In this dissertation, we present a model for the nucleon, which is composed by three relativistic quarks interacting through a contract force. The nucleon wave-function was obtained from the Faddeev equation in the null-plane. The covariance of the model under kinematical null-plane boots is discussed. The electric proton form-factor, calculated from the Faddeev wave-function, was in agreement with the data for low-momentum transfers and described qualitatively the asymptotic region for momentum transfers around 2 GeV. (author) 42 refs., 22 figs., 1 tab.
Hot relativistic winds and the Crab nebula
International Nuclear Information System (INIS)
Fujimura, F.S.; Kennel, C.F.
1981-01-01
Efforts are reviewed to construct a self-consistent model of pulsar magnetospheres that links the particle source near the pulsar to the outflowing relativistic wind and couples the wind to the surrounding nebula. (Auth.)
Radiatively driven relativistic spherical winds under relativistic radiative transfer
Fukue, J.
2018-05-01
We numerically investigate radiatively driven relativistic spherical winds from the central luminous object with mass M and luminosity L* under Newtonian gravity, special relativity, and relativistic radiative transfer. We solve both the relativistic radiative transfer equation and the relativistic hydrodynamical equations for spherically symmetric flows under the double-iteration processes, to obtain the intensity and velocity fields simultaneously. We found that the momentum-driven winds with scattering are quickly accelerated near the central object to reach the terminal speed. The results of numerical solutions are roughly fitted by a relation of \\dot{m}=0.7(Γ _*-1)\\tau _* β _* β _out^{-2.6}, where \\dot{m} is the mass-loss rate normalized by the critical one, Γ* the central luminosity normalized by the critical one, τ* the typical optical depth, β* the initial flow speed at the central core of radius R*, and βout the terminal speed normalized by the speed of light. This relation is close to the non-relativistic analytical solution, \\dot{m} = 2(Γ _*-1)\\tau _* β _* β _out^{-2}, which can be re-expressed as β _out^2/2 = (Γ _*-1)GM/c^2 R_*. That is, the present solution with small optical depth is similar to that of the radiatively driven free outflow. Furthermore, we found that the normalized luminosity (Eddington parameter) must be larger than unity for the relativistic spherical wind to blow off with intermediate or small optical depth, i.e. Γ _* ≳ \\sqrt{(1+β _out)^3/(1-β _out)}. We briefly investigate and discuss an isothermal wind.
The Crab Pulsar and Relativistic Wind
Coroniti, F. V.
2017-12-01
The possibility that the Crab pulsar produces a separated ion-dominated and pair-plasma-dominated, magnetically striped relativistic wind is assessed by rough estimates of the polar cap acceleration of the ion and electron primary beams, the pair production of secondary electrons and positrons, and a simple model of the near-magnetosphere-wind zone. For simplicity, only the orthogonal rotator is considered. Below (above) the rotational equator, ions (electrons) are accelerated in a thin sheath, of order (much less than) the width of the polar cap, to Lorentz factor {γ }i≈ (5{--}10)× {10}7({γ }e≈ {10}7). The accelerating parallel electric field is shorted out by ion-photon (curvature synchrotron) pair production. With strong, but fairly reasonable, assumptions, a set of general magnetic geometry relativistic wind equations is derived and shown to reduce to conservation relations that are similar to those of the wind from a magnetic monopole. The strength of the field-aligned currents carried by the primary beams is determined by the wind’s Alfvén critical point condition to be about eight times the Goldreich-Julian value. A simple model for the transition from the dipole region wind to the asymptotic monopole wind zone is developed. The asymptotic ratio of Poynting flux to ion (pair plasma) kinetic energy flux—the wind {σ }w∞ -parameter—is found to be of order {σ }w∞ ≈ 1/2({10}4). The far wind zone is likely to be complex, with the ion-dominated and pair-plasma-dominated magnetic stripes merging, and the oppositely directed azimuthal magnetic fields annihilating.
The K-shell ionisation of atoms by relativistic protons
International Nuclear Information System (INIS)
Davidovic, D.M.; Moiseiwitsch, B.L.; Norrington, P.H.
1978-01-01
The K-shell ionisation of atoms by protons travelling with relativistic velocities is investigated using an extension of the first-order time-dependent perturbation-theory treatment of Moeller (Ann. Phys. Lpz.; 14:531 (1932)), taking Dirac plane waves for the description of the incident and scattered protons and the Darwin approximation for the relativistic wavefunctions of the K-shell atomic electrons and the ejected electron. The differential cross sections and total cross sections are calculated. Results are compared with those of earlier workers. (author)
Proton-proton bremsstrahlung in a relativistic covariant model
Martinus, Gerard Henk
1998-01-01
Proton-proton bremsstrahlung is one of the simplest processes involving the half off-shell NN interaction. Since protons are equally-charged particles with the same mass, electric-dipole radiation is suppressed and higher-order effects play an important role. Thus it is possible to get information
PROGNOSIS OF GLEs OF RELATIVISTIC SOLAR PROTONS
Energy Technology Data Exchange (ETDEWEB)
Pérez-Peraza, Jorge; Juárez-Zuñiga, Alan, E-mail: perperaz@geofisica.unam.mx, E-mail: z.alan.z@hotmail.com [Instituto de Geofísica, Universidad Nacional Autónoma de México, C.U., Coyoacán, 04510, México, D.F. (Mexico)
2015-04-10
Ground level enhancements (GLEs) are relativistic solar particles measured at ground level by the worldwide network of cosmic ray detectors. These sporadic events are associated with solar flares and are assumed to be of a quasi-random nature. Studying them gives information about their source and propagation processes, the maximum capacity of the Sun as a particle accelerator engine, the magnetic structure of the medium traversed, etc. Space vehicles, as well as electric transformers and gas pipes at high latitudes may be damaged by this kind of radiation. As a result, their prediction has turned out to be very important, but because of their random occurrence, up to now few efforts toward this goal have been made. The results of these efforts have been limited to possible warnings in real time, just before a GLE occurrence, but no specific dates have been predicted well enough in advance to prevent possible hazards. In this study we show that, in spite of the quasi-stochastic nature of GLEs, it is possible to predict them with relative precision, even for future solar cycles. Additionally, a previous study establishing synchronization among some periodicities of several layers of solar atmosphere argues against the full randomness of the phenomenon of relativistic particle production. Therefore, by means of wavelet spectral analysis combined with fuzzy logic tools, we reproduce previous known GLE events and present results for future events. The next GLE is expected to occur in the first semester of 2016.
International Nuclear Information System (INIS)
Hojsik, M.; Gmuca, S.
1998-01-01
Relativistic microscopic calculations are presented for proton elastic scattering from 40 Ca at 500 MeV. The underlying target densities are calculated within the framework of the relativistic mean-field theory with several parameter sets commonly in use. The self consistency of the scalar and vector densities (and thus to relativistic mean-field parameters) is investigated. Recently, the relativistic impulse approximation (RIA) has been widely and repeatedly used for the calculations of proton-nucleus scattering at intermediate energies. These calculations have exhibited significant improvements over the nonrelativistic approaches. The relativistic impulse approximation calculations. in particular, provide a dramatically better description of the spin observables, namely the analyzing power, A y , and the spin-rotation function, Q, at least for energies higher than 400 MeV. In the relativistic impulse approximation, the Dirac optical potential is obtained by folding of the local Lorentz-invariant amplitudes with the corresponding nuclear densities. For the spin zero targets the scalar and vector terms give the dominant contributions. Thus the scalar and vector nuclear densities (both, proton and neutron ones) play the dominant role in the relativistic impulse approximation. While the proton vector densities can be obtained by unfolding from the empirically known charge densities, all other densities used rely to a great extent on theoretical models. The various recipes are used to construct the neutron vector densities and the scalar densities for both, neutrons and protons. In this paper we will study the sensitivity of the relativistic impulse approximation results on the various sets of relativistic mean-field parameters currently in use
International Nuclear Information System (INIS)
Rubinstein, J.E.
1976-01-01
Circle Feynman diagrams for a specific permutation of variables along with their corresponding algebraic expressions are presented to evaluate [H] 2 for proton-proton electron-positron pair production. A Monte Carlo integration technique is introduced and is used to set up the multiple integral expression for the total pair production cross section. The technique is first applied to the Compton scattering problem and then to an arbitrary multiple integral. The relativistic total cross section for proton-proton electron-positron pair production was calculated for eight different values of incident proton energy. A variety of differential cross sections were calculated for the above energies. Angular differential cross section distributions are presented for the electron, positron, and proton. Invariant mass differential cross section distributions are done both with and without the presence of [H] 2 . Both WGHT and log 10 (TOTAL) distributions were also obtained. The general behavioral trends of the total and differential cross sections for proton-proton electron-positron pair production are presented. The range of validity for this calculation is from 0 to about 200 MeV
Modeling the Proton Radiation Belt With Van Allen Probes Relativistic Electron-Proton Telescope Data
Selesnick, R. S.; Baker, D. N.; Kanekal, S. G.; Hoxie, V. C.; Li, X.
2018-01-01
An empirical model of the proton radiation belt is constructed from data taken during 2013-2017 by the Relativistic Electron-Proton Telescopes on the Van Allen Probes satellites. The model intensity is a function of time, kinetic energy in the range 18-600 MeV, equatorial pitch angle, and L shell of proton guiding centers. Data are selected, on the basis of energy deposits in each of the nine silicon detectors, to reduce background caused by hard proton energy spectra at low L. Instrument response functions are computed by Monte Carlo integration, using simulated proton paths through a simplified structural model, to account for energy loss in shielding material for protons outside the nominal field of view. Overlap of energy channels, their wide angular response, and changing satellite orientation require the model dependencies on all three independent variables be determined simultaneously. This is done by least squares minimization with a customized steepest descent algorithm. Model uncertainty accounts for statistical data error and systematic error in the simulated instrument response. A proton energy spectrum is also computed from data taken during the 8 January 2014 solar event, to illustrate methods for the simpler case of an isotropic and homogeneous model distribution. Radiation belt and solar proton results are compared to intensities computed with a simplified, on-axis response that can provide a good approximation under limited circumstances.
Atmospheric nitrous oxide produced by solar protons and relativistic electrons
International Nuclear Information System (INIS)
Prasad, S.S.; Zipf, E.C.
1981-01-01
An alternative means of nitric oxide production in the stratosphere to that of direct formation in the upper atmosphere by solar proton (SP) events and by relativistic electron precipitation (REP) events from the Earth's radiation belt, is described. It is suggested that nitrous oxide is produced in the mesosphere and then migrates downward and is converted in the stratosphere to NO by the reaction N 2 O + O( 1 D) → 2 NO. Such a process could amplify the direct NO production by >10%. Mesospheric nitrous oxide mixing ratios increase to values as high as 6 x 10 -7 due to REP- and SP- related production. Lateral transport will reduce these high values but mesospheric mixing ratios of N 2 O in the high latitudes would approach 10 -7 , considerably greater than those expected on the basis of theories which neglect REP- and SP-related production of this species. (U.K.)
Suprathermal protons in the interplanetary solar wind
Goodrich, C. C.; Lazarus, A. J.
1976-01-01
Using the Mariner 5 solar wind plasma and magnetic field data, we present observations of field-aligned suprathermal proton velocity distributions having pronounced high-energy shoulders. These observations, similar to the interpenetrating stream observations of Feldman et al. (1974), are clear evidence that such proton distributions are interplanetary rather than bow shock associated phenomena. Large Alfven speed is found to be a requirement for the occurrence of suprathermal proton distribution; further, we find the proportion of particles in the shoulder to be limited by the magnitude of the Alfven speed. It is suggested that this last result could indicate that the proton thermal anisotropy is limited at times by wave-particle interactions
International Nuclear Information System (INIS)
Galazka-Friedman, J.; Sobczak, T.; Stepaniak, J.; Zielinski, I.P.; Bano, M.; Hlavacova, J.; Martinska, G.; Patocka, J.; Seman, M.; Sandor, L.; Urban, J.
1993-01-01
The reactions 4 Hep→pp+X, 3 Hep→pp+X and 4 Hep→ddp have been investigated and the correlation function has been measured for protons and deuterons with small relative momenta. Strong positive correlation has been observed for protons related mainly to the final state interactions in 1 S 0 state. The root mean square radius of the proton source calculated from the correlation function has been found to be equal to (1.7±0.3) fm and (2.1±0.3) fm for 4 He and 3 He respectively. It agrees with the known radii of these nuclei. (orig.)
Gill, Ramandeep; Granot, Jonathan; Lyubarsky, Yuri
2018-03-01
We study the linear and non-linear development of the Kruskal-Schwarzchild instability in a relativisitically expanding striped wind. This instability is the generalization of Rayleigh-Taylor instability in the presence of a magnetic field. It has been suggested to produce a self-sustained acceleration mechanism in strongly magnetized outflows found in active galactic nuclei, gamma-ray bursts, and micro-quasars. The instability leads to magnetic reconnection, but in contrast with steady-state Sweet-Parker reconnection, the dissipation rate is not limited by the current layer's small aspect ratio. We performed two-dimensional (2D) relativistic magnetohydrodynamic (RMHD) simulations featuring two cold and highly magnetized (1 ≤ σ ≤ 103) plasma layers with an anti-parallel magnetic field separated by a thin layer of relativistically hot plasma with a local effective gravity induced by the outflow's acceleration. Our simulations show how the heavier relativistically hot plasma in the reconnecting layer drips out and allows oppositely oriented magnetic field lines to reconnect. The instability's growth rate in the linear regime matches the predictions of linear stability analysis. We find turbulence rather than an ordered bulk flow near the reconnection region, with turbulent velocities up to ˜0.1c, largely independent of model parameters. However, the magnetic energy dissipation rate is found to be much slower, corresponding to an effective ordered bulk velocity inflow into the reconnection region vin = βinc of 10-3 ≲ βin ≲ 5 × 10-3. This occurs due to the slow evacuation of hot plasma from the current layer, largely because of the Kelvin-Helmholtz instability experienced by the dripping plasma. 3D RMHD simulations are needed to further investigate the non-linear regime.
Precipitation of relativistic electrons of the Van Allen belts into the proton aurora
International Nuclear Information System (INIS)
Jordanova, Vania K.; Miyoshi, Y.; Sakaguchi, K.; Shiokawa, K.; Evans, D.S.; Albert, Jay; Connors, M
2008-01-01
The Van Allen electron belts consist of two regions encircling the earth in which relativistic electrons are trapped in the earth's magnetic field. Populations of relativistic electrons in the Van Allen belts vary greatly with geomagnetic disturbance and they are a major source of damage to space vehicles. In order to know when and by how much these populations of relativistic electrons increase, it is important to elucidate not only the cause of acceleration of relativistic electrons but also the cause of their loss from the Van Allen belts. Here we show the first evidence that left-hand polarized electromagnetic ion cyclotron (EMIC) plasma waves can cause the loss of relativistic electrons into the atmosphere, on the basis of results of an excellent set of ground and satellite observations showing coincident precipitation of ions with energies of tens of keV and of relativistic electrons into an isolated proton aurora. The proton aurora was produced by precipitation of ions with energies of tens of keV due to EMIC waves near the plasma pause, which is a manifestation of wave-particle interactions. These observations clarify that ions with energies of tens of keV affect the evolution of relativistic electrons in the Van Allen belts via parasitic resonance with EMIC waves, an effect that was first theoretically predicted in the early 1970's
International Nuclear Information System (INIS)
Parvazian, A.; Javani, A.
2010-01-01
Fast ignition is a new method for inertial confinement fusion in which the compression and ignition steps are separated. In the first stage, fuel is compressed by laser or ion beams. In the second phase, relativistic electrons are generated by pettawat laser in the fuel. Also, in the second phase 5-35 MeV protons can be generated in the fuel. Electrons or protons can penetrate in to the ultra-dense fuel and deposit their energy in the fuel. More recently, cylindrical rather than spherical fuel chambers with magnetic control in the plasma domain have been also considered. This is called magnetized target fusion. Magnetic field has effects on relativistic electrons energy deposition rate in fuel. In this work, fast ignition method in cylindrical fuel chambers is investigated and transportation of the relativistic electrons and protons is calculated using MCNPX and FLUKA codes with 0.25 and 0.5 tesla magnetic field in single and dual hot spot. Furthermore, the transfer rate of relativistic electrons and high energy protons to the fuel and fusion gain are calculated. The results show that the presence of external magnetic field guarantees higher fusion gain, and relativistic electrons are much more appropriate objects for ignition. Magnetized target fusion in dual hot spot can be considered as an appropriate substitution for the current inertial confinement fusion techniques.
Directory of Open Access Journals (Sweden)
A Parvazian
2010-12-01
Full Text Available Fast ignition is a new method for inertial confinement fusion (ICF in which the compression and ignition steps are separated. In the first stage, fuel is compressed by laser or ion beams. In the second phase, relativistic electrons are generated by pettawat laser in the fuel. Also, in the second phase 5-35 MeV protons can be generated in the fuel. Electrons or protons can penetrate in to the ultra-dense fuel and deposit their energy in the fuel . More recently, cylindrical rather than spherical fuel chambers with magnetic control in the plasma domain have been also considered. This is called magnetized target fusion (MTF. Magnetic field has effects on relativistic electrons energy deposition rate in fuel. In this work, fast ignition method in cylindrical fuel chambers is investigated and transportation of the relativistic electrons and protons is calculated using MCNPX and FLUKA codes with 0. 25 and 0. 5 tesla magnetic field in single and dual hot spot. Furthermore, the transfer rate of relativistic electrons and high energy protons to the fuel and fusion gain are calculated. The results show that the presence of external magnetic field guarantees higher fusion gain, and relativistic electrons are much more appropriate objects for ignition. MTF in dual hot spot can be considered as an appropriate substitution for the current ICF techniques.
Radiative proton-deuteron capture in a gauge invariant relativistic model
Korchin, AY; Van Neck, D; Scholten, O; Waroquier, M
A relativistic model is developed for the description of the process p+dHe-3+gamma*. It is based on the impulse approximation, but is explicitly gauge invariant and Lorentz covariant. The model is applied to radiative proton-deuteron capture and electrodisintegration of He-3 nt intermediate
Elastic proton-deuteron backward scattering: relativistic effects and polarization observables
International Nuclear Information System (INIS)
Kaptari, L.P.; Semikh, S.S.
1997-10-01
The elastic proton-deuteron backward reaction is analyzed within a covariant approach based on the Bethe-Salpeter equation with 000. Lorentz boost and other relativistic effects in the cross section and spin correlation observables, like tensor analyzing power and polarization transfer etc., are investigated in explicit form. Results of numerical calculations for a complete set of polarization observables are presented. (orig.)
Dynamic of non relativistic electrons and protons in the plasmasphere
International Nuclear Information System (INIS)
Mendes Junior, O.; Pinto Junior, O.; Gonzalez, W.D.
1985-01-01
A study of the dynamics of electrons and protons inside the plasmasphere is presented. These particles are subjected to the geomagnetic field and to plasmaspheric electric fields, given by simple static models, during magnetically quiet and disturbed periods. (author) [pt
Proton-nucleus dynamics at ultra-relativistic energies
International Nuclear Information System (INIS)
McCubbin, N.A.
1988-01-01
Some of the basic properties of proton-nucleus (pA) collisions at ultrarelativistic energies are reviewed. These include total and 'partonic' cross-sections, and the differential cross-sections as functions of rapidity, transverse energy, and particle p T , with particular emphasis in all cases on the A dependence. The aim is to introduce a nuclear physics audience to the main trends and ideas; experts in the field will find nothing very new here. (orig.)
Local Equation of State for Protons, and Implications for Proton Heating in the Solar Wind.
Zaslavsky, A.; Maksimovic, M.; Kasper, J. C.
2017-12-01
The solar wind protons temperature is observed to decrease with distance to the Sun at a slower rate than expected from an adiabatic expansion law: the protons are therefore said to be heated. This observation raises the question of the evaluation of the heating rate, and the question of the heat source.These questions have been investigated by previous authors by gathering proton data on various distances to the Sun, using spacecraft as Helios or Ulysses, and then computing the radial derivative of the proton temperature in order to obtain a heating rate from the internal energy equation. The problem of such an approach is the computation of the radial derivative of the temperature profile, for which uncertainties are very large, given the dispersion of the temperatures measured at a given distance.An alternative approach, that we develop in this paper, consists in looking for an equation of state that links locally the pressure (or temperature) to the mass density. If such a relation exists then one can evaluate the proton heating rate on a local basis, without having any space derivative to compute.Here we use several years of STEREO and WIND proton data to search for polytropic equation of state. We show that such relationships are indeed a good approximation in given solar wind's velocity intervals and deduce the associated protons heating rates as a function of solar wind's speed. The obtained heating rates are shown to scale from around 1 kW/kg in the slow wind to around 10 kW/kg in the fast wind, in remarkable agreement with the rate of energy observed by previous authors to cascade in solar wind's MHD turbulence at 1 AU. These results therefore support the idea of proton turbulent heating in the solar wind.
Efficiencies for production of atomic nitrogen and oxygen by relativistic proton impact in air
Porter, H. S.; Jackman, C. H.; Green, A. E. S.
1976-01-01
Relativistic electron and proton impact cross sections are obtained and represented by analytic forms which span the energy range from threshold to 1 GeV. For ionization processes, the Massey-Mohr continuum generalized oscillator strength surface is parameterized. Parameters are determined by simultaneous fitting to (1) empirical data, (2) the Bethe sum rule, and (3) doubly differential cross sections for ionization. Branching ratios for dissociation and predissociation from important states of N2 and O2 are determined. The efficiency for the production of atomic nitrogen and oxygen by protons with kinetic energy less than 1 GeV is determined using these branching ratio and cross section assignments.
Study of two-proton radioactivity within the relativistic mean-field plus BCS approach
International Nuclear Information System (INIS)
Singh, D.; Saxena, G.
2012-01-01
Inspired by recent experimental studies of two-proton radioactivity in the light-medium mass region, we have employed relativistic mean-field plus state-dependent BCS approach (RMF+BCS) to study the ground state properties of selected even-Z nuclei in the region 20 ≤ Z ≤ 40. It is found that the effective potential barrier provided by the Coulomb interaction and that due to centrifugal force may cause a long delay in the decay of some of the nuclei even with small negative proton separation energy. This may cause the existence of proton-rich nuclei beyond the proton drip-line. Nuclei 38 Ti, 42 Cr, 45 Fe, 48 Ni, 55 Zn, 60 Ge, 63, 64 Se, 68 Kr, 72 Sr and 76 Zr are found to be the potential candidates for exhibiting two-proton radioactivity in the region 20 ≤ Z ≤ 40. The reliability of these predictions is further strengthened by the agreement of the calculated results for the ground state properties such as binding energy, one- and two-proton separation energy, proton and neutron radii, and deformation with the available experimental data for the entire chain of the isotopes of the nuclei in the region 20 ≤ Z ≤ 40. (author)
Biophysical characterization of a relativistic proton beam for image-guided radiosurgery.
Yu, Zhan; Vanstalle, Marie; La Tessa, Chiara; Jiang, Guo-Liang; Durante, Marco
2012-07-01
We measured the physical and radiobiological characteristics of 1 GeV protons for possible applications in stereotactic radiosurgery (image-guided plateau-proton radiosurgery). A proton beam was accelerated at 1 GeV at the Brookhaven National Laboratory (Upton, NY) and a target in polymethyl methacrylate (PMMA) was used. Clonogenic survival was measured after exposures to 1-10 Gy in three mammalian cell lines. Measurements and simulations demonstrate that the lateral scattering of the beam is very small. The lateral dose profile was measured with or without the 20-cm plastic target, showing no significant differences up to 2 cm from the axis A large number of secondary swift protons are produced in the target and this leads to an increase of approximately 40% in the measured dose on the beam axis at 20 cm depth. The relative biological effectiveness at 10% survival level ranged between 1.0 and 1.2 on the beam axis, and was slightly higher off-axis. The very low lateral scattering of relativistic protons and the possibility of using online proton radiography during the treatment make them attractive for image-guided plateau (non-Bragg peak) stereotactic radiosurgery.
Biophysical characterization of a relativistic proton beam for image-guided radiosurgery
International Nuclear Information System (INIS)
Yu, Z.; Vanstalle, M.; La Tessa, C.; Durante, M.; Jiang Guoliang
2012-01-01
We measured the physical and radiobiological characteristics of 1 GeV protons for possible applications in stereotactic radiosurgery (image-guided plateau-proton radiosurgery). A proton beam was accelerated at 1 GeV at the Brookhaven National Laboratory (Upton, NY) and a target in polymethyl methacrylate (PMMA) was used. Clonogenic survival was measured after exposures to 1-10 Gy in three mammalian cell lines. Measurements and simulations demonstrate that the lateral scattering of the beam is very small. The lateral dose profile was measured with or without the 20-cm plastic target, showing no significant differences up to 2 cm from the axis A large number of secondary swift protons are produced in the target and this leads to an increase of approximately 40% in the measured dose on the beam axis at 20 cm depth. The relative biological effectiveness at 10% survival level ranged between 1.0 and 1.2 on the beam axis, and was slightly higher off-axis. The very low lateral scattering of relativistic protons and the possibility of using online proton radiography during the treatment make them attractive for image-guided plateau (non-Bragg peak) stereotactic radiosurgery. (author)
Proton thermal energetics in the solar wind: Helios reloaded
Czech Academy of Sciences Publication Activity Database
Hellinger, Petr; Trávníček, P.; Štverák, Štěpán; Matteini, L.; Velli, M.
2013-01-01
Roč. 118, č. 4 (2013), s. 1351-1365 ISSN 2169-9380 Institutional support: RVO:68378289 Keywords : solar wind * proton energetics * turbulent heating Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/jgra.50107/abstract
Solar Wind Proton Temperature Anisotropy: Linear Theory and WIND/SWE Observations
Hellinger, P.; Travnicek, P.; Kasper, J. C.; Lazarus, A. J.
2006-01-01
We present a comparison between WIND/SWE observations (Kasper et al., 2006) of beta parallel to p and T perpendicular to p/T parallel to p (where beta parallel to p is the proton parallel beta and T perpendicular to p and T parallel to p are the perpendicular and parallel proton are the perpendicular and parallel proton temperatures, respectively; here parallel and perpendicular indicate directions with respect to the ambient magnetic field) and predictions of the Vlasov linear theory. In the slow solar wind, the observed proton temperature anisotropy seems to be constrained by oblique instabilities, by the mirror one and the oblique fire hose, contrary to the results of the linear theory which predicts a dominance of the proton cyclotron instability and the parallel fire hose. The fast solar wind core protons exhibit an anticorrelation between beta parallel to c and T perpendicular to c/T parallel to c (where beta parallel to c is the core proton parallel beta and T perpendicular to c and T parallel to c are the perpendicular and parallel core proton temperatures, respectively) similar to that observed in the HELIOS data (Marsch et al., 2004).
Effects of electrons on the solar wind proton temperature anisotropy
International Nuclear Information System (INIS)
Michno, M. J.; Lazar, M.; Schlickeiser, R.; Yoon, P. H.
2014-01-01
Among the kinetic microinstabilities, the firehose instability is one of the most efficient mechanisms to restrict the unlimited increase of temperature anisotropy in the direction of an ambient magnetic field as predicted by adiabatic expansion of collision-poor solar wind. Indeed, the solar wind proton temperature anisotropy detected near 1 AU shows that it is constrained by the marginal firehose condition. Of the two types of firehose instabilities, namely, parallel and oblique, the literature suggests that the solar wind data conform more closely to the marginal oblique firehose condition. In the present work, however, it is shown that the parallel firehose instability threshold is markedly influenced by the presence of anisotropic electrons, such that under some circumstances, the cumulative effects of both electron and proton anisotropies could describe the observation without considering the oblique firehose mode.
LONG-TERM TRENDS IN THE SOLAR WIND PROTON MEASUREMENTS
Energy Technology Data Exchange (ETDEWEB)
Elliott, Heather A.; McComas, David J. [Southwest Research Institute, San Antonio, TX (United States); DeForest, Craig E. [Southwest Research Institute, Boulder, CO (United States)
2016-11-20
We examine the long-term time evolution (1965–2015) of the relationships between solar wind proton temperature ( T {sub p}) and speed ( V {sub p}) and between the proton density ( n {sub p}) and speed using OMNI solar wind observations taken near Earth. We find a long-term decrease in the proton temperature–speed ( T {sub p}– V {sub p}) slope that lasted from 1972 to 2010, but has been trending upward since 2010. Since the solar wind proton density–speed ( n {sub p}– V {sub p}) relationship is not linear like the T {sub p}– V {sub p} relationship, we perform power-law fits for n {sub p}– V {sub p}. The exponent (steepness in the n {sub p}– V {sub p} relationship) is correlated with the solar cycle. This exponent has a stronger correlation with current sheet tilt angle than with sunspot number because the sunspot number maxima vary considerably from cycle to cycle and the tilt angle maxima do not. To understand this finding, we examined the average n {sub p} for different speed ranges, and found that for the slow wind n {sub p} is highly correlated with the sunspot number, with a lag of approximately four years. The fast wind n {sub p} variation was less, but in phase with the cycle. This phase difference may contribute to the n {sub p}– V {sub p} exponent correlation with the solar cycle. These long-term trends are important since empirical formulas based on fits to T {sub p} and V {sub p} data are commonly used to identify interplanetary coronal mass ejections, but these formulas do not include any time dependence. Changes in the solar wind density over a solar cycle will create corresponding changes in the near-Earth space environment and the overall extent of the heliosphere.
Relativistic corrections to η{sub c}-pair production in high energy proton–proton collisions
Energy Technology Data Exchange (ETDEWEB)
Martynenko, A.P., E-mail: a.p.martynenko@samsu.ru [Samara State University, Pavlov Street 1, 443011, Samara (Russian Federation); Samara State Aerospace University named after S.P. Korolyov, Moskovskoye Shosse 34, 443086, Samara (Russian Federation); Trunin, A.M., E-mail: amtrnn@gmail.com [Samara State Aerospace University named after S.P. Korolyov, Moskovskoye Shosse 34, 443086, Samara (Russian Federation)
2013-06-10
On the basis of perturbative QCD and the relativistic quark model we calculate relativistic corrections to the double η{sub c} meson production in proton–proton interactions at LHC energies. Relativistic terms in the production amplitude connected with the relative motion of heavy quarks and the transformation law of the bound state wave functions to the reference frame of moving charmonia are taken into account. For the gluon and quark propagators entering the amplitude we use a truncated expansion in relative quark momenta up to the second order. Relativistic corrections to the quark bound state wave functions are considered by means of the Breit-like potential. It turns out that the examined effects decrease total non-relativistic cross section more than two times and on 20 percents in the rapidity region of LHCb detector.
A Proton-Cyclotron Wave Storm Generated by Unstable Proton Distribution Functions in the Solar Wind
Wicks, R. T.; Alexander, R. L.; Stevens, M.; Wilson, L. B., III; Moya, P. S.; Vinas, A.; Jian, L. K.; Roberts, D. A.; O’Modhrain, S.; Gilbert, J. A.;
2016-01-01
We use audification of 0.092 seconds cadence magnetometer data from the Wind spacecraft to identify waves with amplitudes greater than 0.1 nanoteslas near the ion gyrofrequency (approximately 0.1 hertz) with duration longer than 1 hour during 2008. We present one of the most common types of event for a case study and find it to be a proton-cyclotron wave storm, coinciding with highly radial magnetic field and a suprathermal proton beam close in density to the core distribution itself. Using linear Vlasov analysis, we conclude that the long-duration, large-amplitude waves are generated by the instability of the proton distribution function. The origin of the beam is unknown, but the radial field period is found in the trailing edge of a fast solar wind stream and resembles other events thought to be caused by magnetic field footpoint motion or interchange reconnection between coronal holes and closed field lines in the corona.
Relativistic protons in the Coma galaxy cluster: first gamma-ray constraints ever on turbulent reacceleration
Brunetti, G.; Zimmer, S.; Zandanel, F.
2017-12-01
The Fermi-LAT (Large Area Telescope) collaboration recently published deep upper limits to the gamma-ray emission of the Coma cluster, a cluster hosting the prototype of giant radio haloes. In this paper, we extend previous studies and use a formalism that combines particle reacceleration by turbulence and the generation of secondary particles in the intracluster medium to constrain relativistic protons and their role for the origin of the radio halo. We conclude that a pure hadronic origin of the halo is clearly disfavoured as it would require excessively large magnetic fields. However, secondary particles can still generate the observed radio emission if they are reaccelerated. For the first time the deep gamma-ray limits allow us to derive meaningful constraints if the halo is generated during phases of reacceleration of relativistic protons and their secondaries by cluster-scale turbulence. In this paper, we explore a relevant range of parameter space of reacceleration models of secondaries. Within this parameter space, a fraction of model configurations is already ruled out by current gamma-ray limits, including the cases that assume weak magnetic fields in the cluster core, B ≤ 2-3 μG. Interestingly, we also find that the flux predicted by a large fraction of model configurations assuming magnetic fields consistent with Faraday rotation measures (RMs) is not far from the limits. This suggests that a detection of gamma-rays from the cluster might be possible in the near future, provided that the electrons generating the radio halo are secondaries reaccelerated and the magnetic field in the cluster is consistent with that inferred from RM.
Relativistic MHD modeling of magnetized neutron stars, pulsar winds, and their nebulae
Del Zanna, L.; Pili, A. G.; Olmi, B.; Bucciantini, N.; Amato, E.
2018-01-01
Neutron stars are among the most fascinating astrophysical sources, being characterized by strong gravity, densities about the nuclear one or even above, and huge magnetic fields. Their observational signatures can be extremely diverse across the electromagnetic spectrum, ranging from the periodic and low-frequency signals of radio pulsars, up to the abrupt high-energy gamma-ray flares of magnetars, where energies of ∼ {10}46 {erg} are released in a few seconds. Fast-rotating and highly magnetized neutron stars are expected to launch powerful relativistic winds, whose interaction with the supernova remnants gives rise to the non-thermal emission of pulsar wind nebulae, which are known cosmic accelerators of electrons and positrons up to PeV energies. In the extreme cases of proto-magnetars (magnetic fields of ∼ {10}15 G and millisecond periods), a similar mechanism is likely to provide a viable engine for the still mysterious gamma-ray bursts. The key ingredient in all these spectacular manifestations of neutron stars is the presence of strong magnetic fields in their constituent plasma. Here we will present recent updates of a couple of state-of-the-art numerical investigations by the high-energy astrophysics group in Arcetri: a comprehensive modeling of the steady-state axisymmetric structure of rotating magnetized neutron stars in general relativity, and dynamical 3D MHD simulations of relativistic pulsar winds and their associated nebulae.
Proton fire hose instabilities in the expanding solar wind
Czech Academy of Sciences Publication Activity Database
Hellinger, Petr
2017-01-01
Roč. 83, č. 1 (2017), č. článku 705830105. ISSN 0022-3778 Institutional support: RVO:68378289 Keywords : astrophysicals plasmas * plasma expansion * plasma simulation Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.160, year: 2016 https://www.cambridge.org/ core /journals/journal-of-plasma-physics/article/proton-fire-hose-instabilities-in-the-expanding-solar-wind/6BA70378B25728533588A1A68073AC2F
Proton thermal energetics in the solar wind: Helios reloaded
Czech Academy of Sciences Publication Activity Database
Hellinger, Petr; Trávníček, Pavel M.; Štverák, Štěpán; Matteini, L.; Velli, M.
2013-01-01
Roč. 118, č. 4 (2013), s. 3151-3165 ISSN 2169-9380 R&D Projects: GA ČR GAP209/12/2041; GA ČR GAP209/12/2023 EU Projects: European Commission(XE) 263340 - SWIFF Grant - others:EU(XE) SHOCK Project No. 284515 Institutional support: RVO:67985815 ; RVO:68378289 Keywords : solar wind * proton energetics * turbulent heating Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics; BL - Plasma and Gas Discharge Physics (UFA-U) Impact factor: 3.440, year: 2013
Geosynchronous Relativistic Electron Events Associated with High-Speed Solar Wind Streams in 2006
Directory of Open Access Journals (Sweden)
Sungeun Lee
2009-12-01
Full Text Available Recurrent enhancements of relativistic electron events at geosynchronous orbit (GREEs were observed in 2006. These GREE enhancements were associated with high-speed solar wind streams coming from the same coronal hole. For the first six months of 2006, the occurrence of GREEs has 27 day periodicity and the GREEs were enhanced with various flux levels. Several factors have been studied to be related to GREEs: (1 High speed stream, (2 Pc5 ULF wave activity, (3 Southward IMF Bz, (4 substorm occurrence, (5 Whistler mode chorus wave, and (6 Dynamic pressure. In this paper, we have examined the effectiveness about those parameters in selected periods.
Jolitz, Rebecca; Dong, Chuanfei; Lee, Christina; Lillis, Rob; Brain, David; Curry, Shannon; Halekas, Jasper; Bougher, Stephen W.; Jakosky, Bruce
2017-10-01
Precipitating energetic particles ionize and excite planetary atmospheres, increasing electron content and producing aurora. At Mars, the solar wind and solar energetic particles (SEPs) can precipitate directly into the atmosphere because solar wind protons can charge exchange to become neutral and pass the magnetosheath, and SEPs are sufficiently energetic to cross the magnetosheath unchanged. We will compare ionization and Lyman alpha emission rates for solar wind and SEP protons during nominal solar activity and a CME shock front impact event on May 16 2016. We will use the Atmospheric Scattering of Protons and Energetic Neutrals (ASPEN) model to compare excitation and ionization rates by SEPs and solar wind protons currently measured by the SWIA (Solar Wind Ion Analyzer) and SEP instruments aboard the MAVEN spacecraft. Results will help quantify how SEP and solar wind protons influence atmospheric energy deposition during solar minimum.
Solar wind proton temperature anisotropy: Linear theory and WIND/SWE observations
Czech Academy of Sciences Publication Activity Database
Hellinger, Petr; Trávníček, Pavel; Kasper, J. C.; Lazarus, A. J.
2006-01-01
Roč. 33, č. 9 (2006), L09101/1-L09101/4 ISSN 0094-8276 R&D Projects: GA AV ČR(CZ) IAA3042403 Grant - others:ESA(XE) PECS 98024; NASA (US) NAG-10915 Institutional research plan: CEZ:AV0Z30420517 Keywords : proton temperature anisotropy * solar wind * in situ observations Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.602, year: 2006
Source of proton anisotrophy in the high-speed solar wind
International Nuclear Information System (INIS)
Schwartz, S.J.; Feldman, W.C.; Gary, S.P.
1981-01-01
Two factors which can contribute to proton anisotropy in the high-speed solar wind are investigated. We present evidence that observed proton Tperpendicular< Tparallel anisotropies are maintained locally by plasma instabilities driven by proton and helium beams. The transfer of beam energy to T/sub perpendicular/ by means of these instabilities is shown to be sufficient to account for the aforementioned proton temperature anisotropy
Predicting Ionization Rates from SEP and Solar Wind Proton Precipitation into the Martian Atmosphere
Jolitz, R.; Dong, C.; Lee, C. O.; Curry, S.; Lillis, R. J.; Brain, D.; Halekas, J. S.; Larson, D. E.; Bougher, S. W.; Jakosky, B. M.
2017-12-01
Precipitating energetic particles ionize planetary atmospheres and increase total electron content. At Mars, the solar wind and solar energetic particles (SEPs) can precipitate directly into the atmosphere because solar wind protons can charge exchange to become neutrals and pass through the magnetosheath, while SEPs are sufficiently energetic to cross the magnetosheath unchanged. In this study we will present predicted ionization rates and resulting electron densities produced by solar wind and SEP proton ionization during nominal solar activity and a CME shock front impact event on May 16 2016. We will use the Atmospheric Scattering of Protons and Energetic Neutrals (ASPEN) model to compare ionization by SEP and solar wind protons currently measured by the SWIA (Solar Wind Ion Analyzer) and SEP instruments aboard the MAVEN spacecraft. Results will help to quantify how the ionosphere responds to extreme solar events during solar minimum.
PROBING RELATIVISTIC WINDS: THE CASE OF PSR J07370-3039 A and B
International Nuclear Information System (INIS)
Arons, J
2004-01-01
We propose synchrotron absorption in a magnetosheath forming a cocoon around the magnetosphere of pulsar B to be the origin of the eclipse phenomena seen in the recently discovered double pulsar system PSRJ07370-3039 A and B. The magnetosheath enfolds the magnetosphere of pulsar B, where the relativistic wind from A collides with B's magnetic field. If this model is correct, it predicts the eclipses will clear at frequencies higher than those of the observations reported to date (nominally, above ν ∼ 5 GHz.) The model also predicts synchrotron emission at the level of a few to 10 (micro)Jy, peaking at ν ∼ 2.5 GHz with possible orbital modulation. We use simplified semi-analytic models to elucidate the structure of the B magnetosphere, showing that the A wind's dynamic pressure confines B's magnetic field to within a radius less than 50,000 km from B, smaller than B's light cylinder radius, on the ''daytime'' side (the side facing A). Downstream of B (''nightime''), B forms a magnetotail. We use particle-in-cell simulations to include the effects of magnetospheric rotation, showing that the magnetosheath has an asymmetric density distribution which may be responsible for the observed eclipse asymmetries. We use simple estimates based upon the magnetic reconnection observed in the simulations to derive a ''propellor'' spindown torque on B, which is the dominant mode of angular mementum extraction from this star. Application of this torque to B's observed spindown yields a polar dipole field ∼ 7 x 10 11 Gauss (magnetic moment (micro) B ∼ 3.5 x 10 29 cgs). This torque has a braking index of unity. We show that the model can explain the known eclipses only if the A wind's density is at least 4 orders of magnitude greater than is expected from existing popular models of pair creation in pulsars. We discuss the implications of this result for our general understanding of pulsar physics
SOLAR WIND PROTONS AT 1 AU: TRENDS AND BOUNDS, CONSTRAINTS AND CORRELATIONS
Energy Technology Data Exchange (ETDEWEB)
Hellinger, Petr; Trávníček, Pavel M., E-mail: petr.hellinger@asu.cas.cz [Astronomical Institute, AS CR, Bocni II/1401,CZ-14100 Prague (Czech Republic)
2014-03-20
The proton temperature anisotropy in the solar wind exhibits apparent bounds which are compatible with the theoretical constraints imposed by temperature-anisotropy-driven kinetic instabilities. Recent statistical analyses based on conditional averaging indicate that near these theoretical constraints the solar wind protons typically have enhanced temperatures and a weaker collisionality. Here we carefully analyze the solar wind data and show that these results are a consequence of superposition of multiple correlations in the solar wind, namely, they mostly result from the correlation between the proton temperature and the solar wind velocity and from the superimposed anti-correlation between the proton temperature anisotropy and the proton parallel beta in the fast solar wind. Colder and more collisional data are distributed around temperature isotropy whereas hotter and less collisional data have a wider range of the temperature anisotropy anti-correlated with the proton parallel beta with signatures of constraints owing to the temperature-anisotropy-driven instabilities. However, most of the hot and weakly collisional data, including the hottest and least collisional ones, lies far from the marginal stability regions. Consequently, we conclude that there is no clear relation between the enhanced temperatures and instability constraints and that the conditional averaging used for these analyses must be used carefully and need to be well tested.
Energy Technology Data Exchange (ETDEWEB)
Maneva, Y.; Lazar, M.; Poedts, S. [Centre for Mathematical Plasma Astrophysics, Celestijnenlaan 200B, 3001 Heverlee (Belgium); Viñas, A., E-mail: yana.maneva@wis.kuleuven.be [NASA Goddard Space Flight Center, Heliophysics Science Division, Greenbelt, MD 20771 (United States)
2016-11-20
The double adiabatic expansion of the nearly collisionless solar wind plasma creates conditions for the firehose instability to develop and efficiently prevent the further increase of the plasma temperature in the direction parallel to the interplanetary magnetic field. The conditions imposed by the firehose instability have been extensively studied using idealized approaches that ignore the mutual effects of electrons and protons. Recently, more realistic approaches have been proposed that take into account the interplay between electrons and protons, unveiling new regimes of the parallel oscillatory modes. However, for oblique wave propagation the instability develops distinct branches that grow much faster and may therefore be more efficient than the parallel firehose instability in constraining the temperature anisotropy of the plasma particles. This paper reports for the first time on the effects of electron plasma properties on the oblique proton firehose (PFH) instability and provides a comprehensive vision of the entire unstable wave-vector spectrum, unifying the proton and the smaller electron scales. The plasma β and temperature anisotropy regimes considered here are specific for the solar wind and magnetospheric conditions, and enable the electrons and protons to interact via the excited electromagnetic fluctuations. For the selected parameters, simultaneous electron and PFH instabilities can be observed with a dispersion spectrum of the electron firehose (EFH) extending toward the proton scales. Growth rates of the PFH instability are markedly boosted by the anisotropic electrons, especially in the oblique direction where the EFH growth rates are orders of magnitude higher.
Maneva, Y.; Lazar, M.; Vinas, A.; Poedts, S.
2016-01-01
The double adiabatic expansion of the nearly collisionless solar wind plasma creates conditions for the firehose instability to develop and efficiently prevent the further increase of the plasma temperature in the direction parallel to the interplanetary magnetic field. The conditions imposed by the firehose instability have been extensively studied using idealized approaches that ignore the mutual effects of electrons and protons. Recently, more realistic approaches have been proposed that take into account the interplay between electrons and protons,? unveiling new regimes of the parallel oscillatory modes. However, for oblique wave propagation the instability develops distinct branches that grow much faster and may therefore be more efficient than the parallel firehose instability in constraining the temperature anisotropy of the plasma particles. This paper reports for the first time on the effects of electron plasma properties on the oblique proton firehose (PFH) instability and provides a comprehensive vision of the entire unstable wave-vector spectrum, unifying the proton and the smaller electron scales. The plasma ß and temperature anisotropy regimes considered here are specific for the solar wind and magnetospheric conditions, and enable the electrons and protons to interact via the excited electromagnetic fluctuations. For the selected parameters, simultaneous electron and PFH instabilities can be observed with a dispersion spectrum of the electron firehose (EFH) extending toward the proton scales. Growth rates of the PFH instability are markedly boosted by the anisotropic electrons, especially in the oblique direction where the EFH growth rates are orders of magnitude higher.
Future X-ray Polarimetry of Relativistic Accelerators: Pulsar Wind Nebulae and Supernova Remnants
Directory of Open Access Journals (Sweden)
Niccolò Bucciantini
2018-03-01
Full Text Available Supernova remnants (SNRs and pulsar wind nebulae (PWNs are among the most significant sources of non-thermal X-rays in the sky, and the best means by which relativistic plasma dynamics and particle acceleration can be investigated. Being strong synchrotron emitters, they are ideal candidates for X-ray polarimetry, and indeed the Crab nebula is up to present the only object where X-ray polarization has been detected with a high level of significance. Future polarimetric measures will likely provide us with crucial information on the level of turbulence that is expected at particle acceleration sites, together with the spatial and temporal coherence of magnetic field geometry, enabling us to set stronger constraints on our acceleration models. PWNs will also allow us to estimate the level of internal dissipation. I will briefly review the current knowledge on the polarization signatures in SNRs and PWNs, and I will illustrate what we can hope to achieve with future missions such as IXPE/XIPE.
Voyager observations of solar wind proton temperature - 1-10 AU
Gazis, P. R.; Lazarus, A. J.
1982-01-01
Simultaneous measurements are made of the solar wind proton temperatures by the Voyager 1 and 2 spacecraft, far from earth, and the IMP 8 spacecraft in earth orbit. This technique permits a separation of radial and temporal variations of solar wind parameters. The average value of the proton temperature between 1 and 9 AU is observed to decrease as r (the heliocentric radius) to the -(0.7 + or - 0.2). This is slower than would be expected for adiabatic expansion. A detailed examination of the solar wind stream structure shows that considerable heating occurs at the interface between high and low speed streams.
Non-thermal particle acceleration in collisionless relativistic electron-proton reconnection
Werner, G. R.; Uzdensky, D. A.; Begelman, M. C.; Cerutti, B.; Nalewajko, K.
2018-02-01
Magnetic reconnection in relativistic collisionless plasmas can accelerate particles and power high-energy emission in various astrophysical systems. Whereas most previous studies focused on relativistic reconnection in pair plasmas, less attention has been paid to electron-ion plasma reconnection, expected in black hole accretion flows and relativistic jets. We report a comprehensive particle-in-cell numerical investigation of reconnection in an electron-ion plasma, spanning a wide range of ambient ion magnetizations σi, from the semirelativistic regime (ultrarelativistic electrons but non-relativistic ions, 10-3 ≪ σi ≪ 1) to the fully relativistic regime (both species are ultrarelativistic, σi ≫ 1). We investigate how the reconnection rate, electron and ion plasma flows, electric and magnetic field structures, electron/ion energy partitioning, and non-thermal particle acceleration depend on σi. Our key findings are: (1) the reconnection rate is about 0.1 of the Alfvénic rate across all regimes; (2) electrons can form concentrated moderately relativistic outflows even in the semirelativistic, small-σi regime; (3) while the released magnetic energy is partitioned equally between electrons and ions in the ultrarelativistic limit, the electron energy fraction declines gradually with decreased σi and asymptotes to about 0.25 in the semirelativistic regime; and (4) reconnection leads to efficient non-thermal electron acceleration with a σi-dependent power-law index, p(σ _i)˜eq const+0.7σ _i^{-1/2}. These findings are important for understanding black hole systems and lend support to semirelativistic reconnection models for powering non-thermal emission in blazar jets, offering a natural explanation for the spectral indices observed in these systems.
Directory of Open Access Journals (Sweden)
Maruyama Tomoyuki
2016-01-01
Full Text Available We study pion production from proton synchrotron radiation in the presence of strong magnetic fields by using the exact proton propagator in a strong magnetic field and explicitly including the anomalous magnetic moment. Results in this exact quantum-field approach do not agree with those obtained in the semi-classical approach. Furthermore, we also find that the anomalous magnetic moment of the proton greatly enhances the production rate about by two orders of magnitude, and that the polar angle of an emitted pion is the same as that of an initial proton.
Czech Academy of Sciences Publication Activity Database
Adam, Jindřich; Adloff, J. C.; Balabekyan, A.; Bamblevski, V. P.; Barabanov, M. Y.; Brandt, R.; Bradnova, V.; Chaloun, P.; Debeauvais, M.; Dwivedi, K. K.; Guo, S. L.; Hashemi-Nezhad, R. S.; Hella, K. M.; Kalinnikov, V. G.; Kievets, M. K.; Krivopustov, M. I.; Kulakov, B. A.; Langrock, E. J.; Li, Li.; Lomonosova, E. M.; Modolo, G.; Odoj, R.; Perelygin, V. P.; Pronskikh, V. S.; Solnyshkin, A. A.; Sosnin, A. N.; Stegailov, V. I.; Tsoupko-Sitnikov, V. M.; Vater, P.; Wan, J. S.; Westmeier, W.; Zamani-Valasiadou, M.; Zhuk, I. V.
2002-01-01
Roč. 90, - (2002), s. 441-442 ISSN 0033-8230 R&D Projects: GA AV ČR KSK1048102 Keywords : relativistic protons * transmutation * subcritical nuclear systems * long-lived radiactive waste Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.809, year: 2002
Directory of Open Access Journals (Sweden)
Maruyama Tomoyuki
2016-01-01
Full Text Available We study pion production from proton synchrotron radiation in the presence of strong magnetic fields by using the exact proton propagator in a strong magnetic field and explicitly including the anomalous magnetic moment. Results in this exact quantum approach do not agree with those obtained in the semi-classical approach. Then, we find that the anomalous magnetic moment of the proton greatly enhances the production rate by about two orders magnitude, and that the decay width satisfies a robust scaling law.
Suzuki, Akihiro; Maeda, Keiichi
2017-04-01
The hydrodynamical interaction between freely expanding supernova ejecta and a relativistic wind injected from the central region is studied in analytic and numerical ways. As a result of the collision between the ejecta and the wind, a geometrically thin shell surrounding a hot bubble forms and expands in the ejecta. We use a self-similar solution to describe the early dynamical evolution of the shell and carry out a two-dimensional special relativistic hydrodynamic simulation to follow further evolution. The Rayleigh-Taylor instability inevitably develops at the contact surface separating the shocked wind and ejecta, leading to the complete destruction of the shell and the leakage of hot gas from the hot bubble. The leaking hot materials immediately catch up with the outermost layer of the supernova ejecta and thus different layers of the ejecta are mixed. We present the spatial profiles of hydrodynamical variables and the kinetic energy distributions of the ejecta. We stop the energy injection when a total energy of 1052 erg, which is 10 times larger than the initial kinetic energy of the supernova ejecta, is deposited into the ejecta and follow the subsequent evolution. From the results of our simulations, we consider expected emission from supernova ejecta powered by the energy injection at the centre and discuss the possibility that superluminous supernovae and broad-lined Ic supernovae could be produced by similar mechanisms.
Sputtering of Lunar Regolith Simulant by Protons and Multicharged Heavy Ions at Solar Wind Energies
International Nuclear Information System (INIS)
Meyer, Fred W.; Harris, Peter R.; Taylor, C.N.; Meyer, Harry M. III; Barghouty, N.; Adams, J. Jr.
2011-01-01
We report preliminary results on sputtering of a lunar regolith simulant at room temperature by singly and multiply charged solar wind ions using quadrupole and time-of-flight (TOF) mass spectrometry approaches. Sputtering of the lunar regolith by solar-wind heavy ions may be an important particle source that contributes to the composition of the lunar exosphere, and is a possible mechanism for lunar surface ageing and compositional modification. The measurements were performed in order to assess the relative sputtering efficiency of protons, which are the dominant constituent of the solar wind, and less abundant heavier multicharged solar wind constituents, which have higher physical sputtering yields than same-velocity protons, and whose sputtering yields may be further enhanced due to potential sputtering. Two different target preparation approaches using JSC-1A AGGL lunar regolith simulant are described and compared using SEM and XPS surface analysis.
International Nuclear Information System (INIS)
Rahmani, A.
1988-12-01
The study of the proton's production differential cross sections, in the collision of relativistic heavy ions, allows to obtain the nuclear-matter temperature and gives information about the nucleons large burst pulses in the nucleus. The chosen thermodynamic model is a generalized approach of the R. Hagedorn model, applied to heavy ions collisions: the nuclear matter is divided in volume elements δV assumed to be in thermal and chemical equilibrium and emitting particles and fragments isotropically, inside their own system. The applied nuclear-matter velocity distribution depended only on the impact parameter and on the relationship between the chemical potential and the temperature. The predictions of this thermodynamic model were compared to the Saturne experimental results, using Diogene detector. The obtained temperature values are similar to those given by D. Hahn and H. Stoker. The proton production cross sections were measured for backward emitting angles. A relationship between the cross sections and the burst pulse distribution in the nuclei was settled [fr
A quasilinear kinetic model for solar wind electrons and protons instabilities
Sarfraz, M.; Yoon, P. H.
2017-12-01
In situ measurements confirm the anisotropic behavior in temperatures of solar wind species. These anisotropies associated with charge particles are observed to be relaxed. In collionless limit, kinetic instabilities play a significant role to reshape particles distribution. The linear analysis results are encapsulated in inverse relationship between anisotropy and plasma beta based observations fittings techniques, simulations methods, or solution of linearized Vlasov equation. Here amacroscopic quasilinear technique is adopted to confirm inverse relationship through solutions of set of self-consistent kinetic equations. Firstly, for a homogeneous and non-collisional medium, quasilinear kinetic model is employed to display asymptotic variations of core and halo electrons temperatures and saturations of wave energy densities for electromagnetic electron cyclotron (EMEC) instability sourced by, T⊥}>T{∥ . It is shown that, in (β ∥ , T⊥}/T{∥ ) phase space, the saturations stages of anisotropies associated with core and halo electrons lined up on their respective marginal stability curves. Secondly, for case of electrons firehose instability ignited by excessive parallel temperature i.e T⊥}>T{∥ , both electrons and protons are allowed to dynamically evolve in time. It is also observed that, the trajectories of protons and electrons at saturation stages in phase space of anisotropy and plasma beta correspond to proton cyclotron and firehose marginal stability curves, respectively. Next, the outstanding issue that most of observed proton data resides in nearly isotropic state in phase space is interpreted. Here, in quasilinear frame-work of inhomogeneous solar wind system, a set of self-consistent quasilinear equations is formulated to show a dynamical variations of temperatures with spatial distributions. On choice of different initial parameters, it is shown that, interplay of electron and proton instabilities provides an counter-balancing force to slow
Neutron production in interactions of relativistic protons and deuterons with lead targets
International Nuclear Information System (INIS)
Yurevich, V.I.; Amelin, N.S.; Yakovlev, R.M.; Nikolaev, V.A.; Lyapin, V.G.; Tsvetkov, I.O.
2005-01-01
Results on the neutron double-differential cross sections and yields obtained in the time-of-flight measurements with different lead targets and beams of protons and deuterons at an energy of about 2 GeV are discussed. The neutron spatial-energy distribution for an extended lead target was studied by the threshold detector method in the energy range of protons and deuterons 1-3.7 GeV. A dependence of the mean neutron multiplicity, energy of neutrons, and process of neutron multiplication in lead on the target dimension, and the type and energy of the beam particle is analyzed. (author)
Half-lives of proton emitters using relativistic mean field theory
International Nuclear Information System (INIS)
Sahu, Bidhubhusan; Patra, S. K.; Agarwalla, S. K.
2011-01-01
The proton radioactivity lifetimes of proton emitters from the ground and the isomeric states are calculated using the microscopic M3Y + Ex and R3Y + Ex (proposed) nucleon-nucleus interaction potentials. These interaction potentials are obtained by single folding the densities of the daughter nuclei supplemented by a zero-range pseudopotential. The quantum-mechanical-tunneling probability is calculated within the WKB approximation. The calculated results are found to be in good agreement with the experimental data for both the M3Y and R3Y interactions.
International Nuclear Information System (INIS)
Krivopustov, M.I.; Adam, J.; Bradnova, V.
1997-01-01
First experiments on the transmutation of long-lived 129 I and 237 Np using relativistic protons of 3.7 GeV are described. Relativistic protons generate in extended Pb-targets substantial neutron fluences. These neutrons get moderated in paraffin and are used for transmutation as follows: 129 (n, γ) 130 I(β - ) → 130 Xe(stable) and 237 Np(n, γ) 238 Np(β - ) →. The isotopes 130 I (T 1/2 =12.36 h) and 238 Np (T 1/2 =2.117 days) were identified radiochemically. One can estimate the transmutation cross section (n, γ) in the given neutron field as σ( 129 I(n, γ))=(10±2)b and σ( 237 Np(n, γ))=(140±30)b. The experiments were carried out in November 1996 at the Synchrophasotron, Laboratory of High Energies (LHE), Dubna, Russia
Sarlanis, Christos; Heber, Bernd; Labrenz, Johannes; Kühl, Patrick; Marquardt, Johannes; Dimitroulakos, John; Papaioannou, Athanasios; Posner, Arik
2017-04-01
Solar Energetic Particle (SEP) events are one of the most important elements of space weather. Given that the complexity of the underlying physical processes of the acceleration and propagation of SEP events is still a very active research area, the prognosis of SEP event occurrence and their corresponding characteristics remains challenging. In order to provide up to an hour warning time before these particles arrive at Earth, relativistic electron and below 50 MeV proton data from the Electron Proton Helium Instrument (EPHIN) on SOHO were used to implement the 'Relativistic Electron Alert System for Exploration (REleASE)'. The REleASE forecasting scheme was recently rewritten in the open access programming language PYTHON and will be made publicly available. As a next step, along with relativistic electrons (v > 0.9 c) provided by SOHO, near-relativistic (v work, we demonstrate the real-time outputs derived by the end user from the REleASE using both SOHO/EPHIN and ACE/EPAM. We further, show a user friendly illustration of the outputs that make use of a "traffic light" to monitor the different warning stages: quiet, warning, alert offering a simple guidance to the end users. Finally, the capabilities offered by this new system, accessing both the pictorial and textural outputs REleASE are being presented. This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324.
A KINETIC ALFVEN WAVE AND THE PROTON DISTRIBUTION FUNCTION IN THE FAST SOLAR WIND
International Nuclear Information System (INIS)
Li Xing; Lu Quanming; Chen Yao; Li Bo; Xia Lidong
2010-01-01
Using one-dimensional test particle simulations, the effect of a kinetic Alfven wave on the velocity distribution function (VDF) of protons in the collisionless solar wind is investigated. We first use linear Vlasov theory to numerically obtain the property of a kinetic Alfven wave (the wave propagates in the direction almost perpendicular to the background magnetic field). We then numerically simulate how the wave will shape the proton VDF. It is found that Landau resonance may be able to generate two components in the initially Maxwellian proton VDF: a tenuous beam component along the direction of the background magnetic field and a core component. The streaming speed of the beam relative to the core proton component is about 1.2-1.3 Alfven speed.
Beam transfer functions for relativistic proton bunches with beam–beam interaction
Energy Technology Data Exchange (ETDEWEB)
Görgen, P., E-mail: goergen@temf.tu-darmstadt.de [Institut für Theorie Elektromagnetischer Felder (TEMF), Technische Universität Darmstadt, Schloßgartenstr. 8 64289 Darmstadt (Germany); Boine-Frankenheim, O. [Institut für Theorie Elektromagnetischer Felder (TEMF), Technische Universität Darmstadt, Schloßgartenstr. 8 64289 Darmstadt (Germany); Fischer, W. [Brookhaven National Laboratory, Upton, NY 11973 (United States)
2015-03-21
We present a method for the recovery of the transverse tune spread directly from the beam transfer function (BTF). The model is applicable for coasting beams and bunched beams at high energy with a tune spread from transverse nonlinearities induced by the beam–beam effect or by an electron lens. Other sources of tune spread can be added. A method for the recovery of the incoherent tune spread without prior knowledge of the nonlinearity is presented. The approach is based on the analytic model for BTFs of coasting beams, which agrees very well with simulations results for bunched beams at relativistic energies with typically low synchrotron tune. A priori the presented tune spread recovery method is usable only in the absence of coherent modes, but additional simulation data shows its applicability even in the presence of coherent beam–beam modes. Finally agreement of both the analytic and simulation models with measurement data obtained at RHIC is presented. The proposed method successfully recovers the tune spread from analytic, simulated and measured BTF.
Energy Technology Data Exchange (ETDEWEB)
He, Jiansen; Tu, Chuanyi; Wang, Linghua; Pei, Zhongtian [School of Earth and Space Sciences, Peking University, Beijing, 100871 (China); Marsch, Eckart [Institute for Experimental and Applied Physics, Christian-Albrechts-Universität zu Kiel, D-24118 Kiel (Germany); Chen, Christopher H. K. [Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom); Zhang, Lei [Sate Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100190 (China); Salem, Chadi S.; Bale, Stuart D., E-mail: jshept@gmail.com [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)
2015-11-10
Magnetohydronamic turbulence is believed to play a crucial role in heating laboratory, space, and astrophysical plasmas. However, the precise connection between the turbulent fluctuations and the particle kinetics has not yet been established. Here we present clear evidence of plasma turbulence heating based on diagnosed wave features and proton velocity distributions from solar wind measurements by the Wind spacecraft. For the first time, we can report the simultaneous observation of counter-propagating magnetohydrodynamic waves in the solar wind turbulence. As opposed to the traditional paradigm with counter-propagating Alfvén waves (AWs), anti-sunward AWs are encountered by sunward slow magnetosonic waves (SMWs) in this new type of solar wind compressible turbulence. The counter-propagating AWs and SWs correspond, respectively, to the dominant and sub-dominant populations of the imbalanced Elsässer variables. Nonlinear interactions between the AWs and SMWs are inferred from the non-orthogonality between the possible oscillation direction of one wave and the possible propagation direction of the other. The associated protons are revealed to exhibit bi-directional asymmetric beams in their velocity distributions: sunward beams appear in short, narrow patterns and anti-sunward in broad extended tails. It is suggested that multiple types of wave–particle interactions, i.e., cyclotron and Landau resonances with AWs and SMWs at kinetic scales, are taking place to jointly heat the protons perpendicular and in parallel.
The turbulent cascade and proton heating in the solar wind during solar minimum
International Nuclear Information System (INIS)
Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A.
2013-01-01
Solar wind measurements at 1 AU during the recent solar minimum and previous studies of solar maximum provide an opportunity to study the effects of the changing solar cycle on in situ heating. Our interest is to compare the levels of activity associated with turbulence and proton heating. Large-scale shears in the flow caused by transient activity are a source that drives turbulence that heats the solar wind, but as the solar cycle progresses the dynamics that drive the turbulence and heat the medium are likely to change. The application of third-moment theory to Advanced Composition Explorer (ACE) data gives the turbulent energy cascade rate which is not seen to vary with the solar cycle. Likewise, an empirical heating rate shows no significan changes in proton heating over the cycle.
Protons and alpha particles in the expanding solar wind: Hybrid simulations
Czech Academy of Sciences Publication Activity Database
Hellinger, Petr; Trávníček, Pavel M.
2013-01-01
Roč. 118, č. 9 (2013), s. 5421-5429 ISSN 2169-9380 R&D Projects: GA ČR GAP209/12/2023 Grant - others:EU(XE) SHOCK Project No. 284515 Institutional support: RVO:67985815 ; RVO:68378289 Keywords : solar wind * proton energetics * turbulent heating Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics; BL - Plasma and Gas Discharge Physics (UFA-U) Impact factor: 3.440, year: 2013
Mann, I. R.; Ozeke, L.; Murphy, K. R.; Claudepierre, S. G.; Rae, J.; Milling, D. K.; Kale, A.; Baker, D. N.
2017-12-01
The NASA Van Allen Probes have opened a new window on the dynamics of ultra-relativistic electrons in the Van Allen radiation belts. Under different solar wind forcing the outer belt is seen to respond in a variety of apparently diverse and sometimes remarkable ways. For example, sometimes a third radiation belt is carved out (e.g., September 2012), or the belts can remain depleted for 10 days or more (September 2014). More usually there is a sequential response of a strong and sometimes rapid depletion followed by a re-energization, the latter increasing outer belt electron flux by orders of magnitude on hour timescales during some of the strongest storms of this solar cycle (e.g., March 2013, March 2015). Such dynamics also appear to be often bounded at low-L by an apparently impenetrable barrier at L 2.8 through which ultra-relativistic electrons do not penetrate. Many studies in the Van Allen Probes era have sought explanations for these apparently diverse features, often incorporating the effects from multiple plasma waves. In contrast, we show how this apparently diverse behaviour can instead be explained by one dominant process: ULF wave radial transport. Once ULF wave transport rates are accurately specified by observations, and coupled to the dynamical variation of the outer boundary condition at the edge of the outer belt, the observed diverse responses can all be explained. However, in order to get good agreement with observations, the modeling reveals the importance of still currently unexplained very fast loss in the main phase which results in an almost total extinction of the belts and decouples pre- and post-storm ultra-relativistic electron flux on hour timescales. Similarly, varying plasmasheet source populations are seen to be of critical importance such that near-tail dynamics play a crucial role in Van Allen belt dynamics. Nonetheless, simple models incorporating accurate transport rates derived directly from ULF wave measurements are shown to
Multiplicities of pions and slow protons in nuclear interactions at relativistic energies
International Nuclear Information System (INIS)
Idh, J.
1993-02-01
The distributions of the transverse energy and the multiplicity of charged particles in oxygen induced reactions are examined in the Fritiof Monte Carlo model. The shape of the distributions are found to be determined by the distribution of the number of particle-emitting sources, i.e. strings. The fluctuations in particle emission from each string is hidden by these much larger fluctuations. The fluctuations of these distributions when partial phase space coverage is used is well described by purely stochastic emission. Distributions of slow singly-charged fragments in the target region is measured for both hadron and oxygen induced reactions. The distributions extends to much larger values than simulated data from the Monte Carlo models Fritiof 1.7 and Venus 3.14. The hadron induced reactions give distributions that can be reproduced assuming that each participating target nucleon produced fragments according to a geometric distribution, where the average number of fragments per participating target nucleon is target dependent. The extracted average number of produced fragments are similar for proton and pion induced reactions. When the tails of the distributions are studied their extension can be parametrized, and for such an approach a target dependence of A 2/3 is found for all projectiles. The data for 60 and 200 A GeV are almost identical for distributions as well as angular and energy examined distributions. The angular distributions follow an exponential in cos(θ). If the slopes of the angular distributions are examined and target dependences as well as centrality dependences are extracted. For light targets there is a strong target dependence, but for targets heavier than copper there is not any great differences. The centrality dependence is almost negligible for a gold-target but for a copper-target the most central collisions have more forward peaked distributions. (62 refs.)
CERN Proton Synchrotronworking point Matrix for extended pole face winding powering scheme
Freyermuth, P; Delrieux, M; Genoud, H; Gilardoni, S; Hanke, K; Hans, O; Mataguez, S; Metral, G; Peters, F; Steerenberg, R; Vandorpe, B
2010-01-01
The CERN Proton Synchrotron has been continuously improving its beam performances since 1959. The working point parameters of the accelerator are mainly controlled by dedicated windings installed on the poles of the main combined function magnets. In 2007, the power supplies of these windings were renovated and extended from three to five independent groups, allowing exploration of new working point settings. This configuration offers the flexibility of several adjustment strategies such as leaving one current free or to control an additional physical parameter, like Q′′ h. A non-linear chromaticity measurement campaign, at different beam momenta, resulted in matrices defining the relationship between the five pole face winding currents and the four beam parameters Qh, Qv, h, and v. Each cell of these matrices was fitted against momentum. The final result is a single matrix as a function of beam momentum, which is now used by the operational software to trim the working point. This paper summarises this m...
Directory of Open Access Journals (Sweden)
R. Kataoka
2008-06-01
Full Text Available We report average profiles of the solar wind and outer radiation belt during the extreme flux enhancement of relativistic electrons at geosynchronous orbit (GEO. It is found that seven of top ten extreme events at GEO during solar cycle 23 are associated with the magnetosphere inflation during the storm recovery phase as caused by the large-scale solar wind structure of very low dynamic pressure (<1.0 nPa during rapid speed decrease from very high (>650 km/s to typical (400–500 km/s in a few days. For the seven events, the solar wind parameters, geomagnetic activity indices, and relativistic electron flux and geomagnetic field at GEO are superposed at the local noon period of GOES satellites to investigate the physical cause. The average profiles support the "double inflation" mechanism that the rarefaction of the solar wind and subsequent magnetosphere inflation are one of the best conditions to produce the extreme flux enhancement at GEO because of the excellent magnetic confinement of relativistic electrons by reducing the drift loss of trapped electrons at dayside magnetopause.
Gelfand, Joseph
Core-collapse supernovae, the powerful explosions triggered by the gravitational collapse of massive stars, play an important role in evolution of star-forming galaxies like our Milky Way. Not only do these explosions eject the outer envelope of the progenitor star with extremely high velocities, creating a supernova remnant (SNR), the rotational energy of the resultant neutron star powers an ultra-relativistic outflow called a pulsar wind which creates a pulsar wind nebula (PWN) as it expands into its surroundings. Despite almost a century of study, many fundamental questions remain, including: How is a neutron star formed during a core-collapse supernova? How are particles created in the neutron star magnetosphere? How are particles accelerated to the PeV energies inside PWNe? Answering these questions requires measuring the properties of the progenitor star and pulsar wind for a diverse collection of neutron stars. Currently, this is best done by studying those PWNe inside a SNR, since their evolution is very sensitive to the initial spin period of the neutron star, the mass and initial kinetic energy of the supernova ejecta, and the magnetization and particle spectrum of the pulsar wind - quantities critical for answering the above questions. To this end, we propose to measure these properties for 17 neutron stars whose spin-down inferred dipole surface magnetic field strengths and characteristic ages differ by 1.5 orders of magnitude by fitting the broadband spectral energy distribution (SED) and dynamical properties of their associated PWNe with a model for the dynamical and spectral evolution of a PWN inside SNR. To do so, we will first re-analyze all archival X-ray (e.g., XMM, Chandra, INTEGRAL, NuSTAR) and gamma-ray (e.g., Fermi-LAT Pass 8) data on each PWN to ensure consistent measurements of the volume-integrated properties (e.g., X-ray photon index and unabsorbed flux, GeV spectrum) needed for this analysis. Additionally, we will use a Markoff Chain
International Nuclear Information System (INIS)
Leubner, M.P.
1978-01-01
Satellite measurements of the thermal anisotropy of solar wind protons have shown that the particle velocity distributions at 1 AU are not adequately described by a bi-Maxwellian distribution function. On the other hand, the stability criteria derived from a bi-Maxwellian distribution require T/sub perpendicular/>T/sub parallel/, which is, however, hardly ever observed. A modified axisymmetric distribution function for solar wind protons is used here to calculate the stability and growth rate of the iom cyclotron instability in a warm slow speed solar plasma at 1 AU. Cyclotron wave growth is found also in the case t/sub parallel/>T/sub perpendicular/
International Nuclear Information System (INIS)
Sobolev, A.V.; Kozlov, V.I.
1997-01-01
Correlation of the intensity of slowly changing regular background noise within 9.7 kHz frequency in Yakutsk (L = 3) and of the solar wind density protons was determined. This result explains the reverse dependence of the intensity of the regular background noise on the solar activity, 27-day frequency, increase before and following geomagnetic storms, absence of relation with K p index of geomagnetic activity. Conclusion is made that growth of density of the solar wind protons results in increase of the regular background noise and thunderstorm activity
International Nuclear Information System (INIS)
Adam, J.; Balabekyan, A.; Bamblevskij, V.P.
2001-01-01
Experimental studies on the transmutation of some long-lived radioactive waste nuclei, such as 129 I, 237 Np, and 239 Pu, as well as on natural uranium and lanthanum (all of them used as sensors) were carried out at the Synchrophasotron of the Laboratory of High Energies (JINR, Dubna). Spallation neutrons were produced by relativistic protons with energies in the range of 0.5 GeV ≤ E(p) ≤ 1.5 GeV interacting with 20 cm long uranium or lead target stacks. The targets were surrounded by 6 cm paraffin moderators. The radioactive sensors mentioned above were positioned on the outside surface of the moderator and contained typically approximately 0.5 up to 1 gram of long-lived isotopes. The highly radioactive targets were produced perfectly well-sealed in aluminium containers by the Institute of Physics and Power Engineering, Obninsk, Russia. From the experimentally observed transmutation rates one can easily extrapolate, that in a subcritical nuclear power assembly (or 'energy amplifier') using a 10 mA proton beam of 1 GeV onto a Pb-target as used here, one can transmute in one gram samples of the isotope within one month about 3 mg 129 I, 21 mg 237 Np, 3.3 mg 238 U, and 200 mg 239 Pu under the same geometrical conditions. Our observations show, that the transmutation ability of our system increases linearly with the proton energy within the energy interval studied
International Nuclear Information System (INIS)
Nahrgang, Marlene; Schuster, Tim; Stock, Reinhard; Mitrovski, Michael; Bleicher, Marcus
2012-01-01
We explore the potential of net-baryon, net-proton and net-charge kurtosis measurements to investigate the properties of hot and dense matter created in relativistic heavy-ion collisions. Contrary to calculations in a grand-canonical ensemble we explicitly take into account exact electric and baryon charge conservation on an event-by-event basis. This drastically limits the width of baryon fluctuations. A simple model to account for this is to assume a grand-canonical distribution with a sharp cut-off at the tails. We present baseline predictions of the energy dependence of the net-baryon, net-proton and net-charge kurtosis for central (b≤2.75 fm) Pb+Pb/Au+Au collisions from E lab =2A GeV to √(s NN )=200 GeV from the UrQMD model. While the net-charge kurtosis is compatible with values around zero, the net-baryon number decreases to large negative values with decreasing beam energy. The net-proton kurtosis becomes only slightly negative for low √(s NN ). (orig.)
Evolution of the solar wind proton temperature anisotropy from 0.3 to 2.5 AU
Czech Academy of Sciences Publication Activity Database
Matteini, L.; Landi, S.; Hellinger, Petr; Pantellini, F.; Maksimovic, M.; Velli, M.; Goldstein, B. E.; Marsch, E.
2007-01-01
Roč. 34, č. 20 (2007), L20105/1-L20105/5 ISSN 0094-8276 Grant - others:ASI(IT) I/015/07/0 Institutional research plan: CEZ:AV0Z30420517 Keywords : Proton temperature anisotropy * solar wind * radial evolution * observations Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.744, year: 2007
Energy Technology Data Exchange (ETDEWEB)
Hallerberg, Sarah [Chemnitz University of Technology (Germany); Ruzmaikin, Alexander; Feynman, Joan [Jet Propulsion Laboratory, California Institute of Technology (United States)
2011-07-01
Shock waves in the solar wind associated with solar coronal mass ejections produce fluxes of high-energy protons and ions with energies larger than 10 MeV. These fluxes present a danger to humans and electronic equipment in space, and also endanger passengers of over-pole air flights. The approaches that have been exploited for the prediction of high-energy particle events so far consist in training artificial neural networks on catalogues of events. Our approach towards this task is based on the identification of precursory structures in the fluxes of particles. In contrast to artificial neural networks that function as a ''black box'' transforming data into predictions, this classification approach can additionally provide information on relevant precursory events and thus might help to improve the understanding of underlying mechanisms of particle acceleration.
International Nuclear Information System (INIS)
Zhuk, I.V.; Lomonosova, E.M.; Boulyga, S.F.; Kievitskaia, A.I.; Rakhno, I.L.; Chigrinov, S.E.; Bradnova, V.; Krivopustov, M.I.; Kulakov, B.A.; Brandt, R.; Ochs, M.; Wan, J.-S.
1999-01-01
The experiments on transmutation of 129 I and 237 Np using uranium-lead targets surrounded by a paraffin moderator were performed at the Joint Institute for Nuclear Research (JINR, Russia). The targets were irradiated by 1.5 GeV and 7.4 GeV protons at the Synchrophasotron of JINR. In the frame of present work spatial and energy distributions of neutrons on the surface of the paraffin moderator were measured using SSNTD technique. It is shown that measured values of spectral indices do not depend on the energy of incident protons but depend on the target composition. The presence of the uranium insertion softens neutron spectra
Directory of Open Access Journals (Sweden)
Zabrodin E.
2017-01-01
Full Text Available Proton-proton collisions at energies from √s = 200 GeV up to √s = 14 TeV are studied within the microscopic quark-gluon string model. The model is based on Gribov’s Reggeon Field Theory accomplished by string phenomenology. Comparison with experimental data shows that QGSM describes well particle yields, rapidity - and transverse momentum spectra, rise of mean 〈 pT 〉 and forward-backward multiplicity correlations. The latter arise in QGSM because of the addition of various processes with different mean multiplicities. The model also indicates fulfillment of extended longitudinal scaling and violation of Koba-Nielsen-Olesen scaling at LHC. The origin of both features is traced to short-range particle correlations in the strings. Predictions are made for √s = 14 TeV.
Zhuk, I V; Boulyga, S F; Kievitskaia, A I; Rakhno, I L; Chigrinov, S E; Bradnova, V; Krivopustov, M I; Kulakov, B A; Brandt, R; Ochs, M; Wan, J S
1999-01-01
The experiments on transmutation of sup 1 sup 2 sup 9 I and sup 2 sup 3 sup 7 Np using uranium-lead targets surrounded by a paraffin moderator were performed at the Joint Institute for Nuclear Research (JINR, Russia). The targets were irradiated by 1.5 GeV and 7.4 GeV protons at the Synchrophasotron of JINR. In the frame of present work spatial and energy distributions of neutrons on the surface of the paraffin moderator were measured using SSNTD technique. It is shown that measured values of spectral indices do not depend on the energy of incident protons but depend on the target composition. The presence of the uranium insertion softens neutron spectra.
Energy Technology Data Exchange (ETDEWEB)
Zhuk, I.V.; Lomonosova, E.M.; Boulyga, S.F.; Kievitskaia, A.I.; Rakhno, I.L.; Chigrinov, S.E.; Bradnova, V.; Krivopustov, M.I.; Kulakov, B.A.; Brandt, R.; Ochs, M.; Wan, J.-S
1999-06-01
The experiments on transmutation of {sup 129}I and {sup 237}Np using uranium-lead targets surrounded by a paraffin moderator were performed at the Joint Institute for Nuclear Research (JINR, Russia). The targets were irradiated by 1.5 GeV and 7.4 GeV protons at the Synchrophasotron of JINR. In the frame of present work spatial and energy distributions of neutrons on the surface of the paraffin moderator were measured using SSNTD technique. It is shown that measured values of spectral indices do not depend on the energy of incident protons but depend on the target composition. The presence of the uranium insertion softens neutron spectra.
International Nuclear Information System (INIS)
Kobushkin, A.P.; Vizireva, L.
1981-01-01
A study of the nature of the short-range few-nucleon correlations in nuclei is proposed in the polarized high-energy deuteron fragmentation experiments. The presence of 6q-state in deuteron with probability of several percents is shown to change essentially the cross-section behaviour of this process in the momentum region where the fraction of the deuteron momentum carried out by proton in the infinite momentum frame is about 0.78. It is shown how the character of the cross-section of the transverse polarized deuteron fragmentation is changed depending on the parameters of 6q-admixure in deuteron [ru
International Nuclear Information System (INIS)
Papp, J.
1975-05-01
The yields of positive and negative particles resulting from the collision of 1.05 GeV/nucleon and 2.1 GeV/nucleon protons, deuterons, alpha particles, and 1.05 GeV/nucleon carbon nuclei with various targets have been measured. Single particle inclusive cross sections for production of π + , π - , p, d, 3 H, 3 He, and 4 He at 2.5 0 (lab) were obtained. How the results bear on the concepts of limiting fragmentation and scaling, the structure of the alpha particle and deuteron, and the possibility of ''coherent'' production of pions by heavy ions are discussed. (U.S.)
Electromagnetic Waves with Frequencies Near the Local Proton Gryofrequency: ISEF-3 1 AU Observations
Tsurutani, B.
1993-01-01
Low Frequency electromagnetic waves with periods near the local proton gyrofrequency have been detected near 1 AU by the magnetometer onboard ISEE-3. For these 1 AU waves two physical processes are possible: solar wind pickup of nuetral (interstellar?) particles and generation by relativistic electron beams propagating from the Sun.
Adam, J; Bamblevski, V P; Barabanov, M Yu; Bradnova, V; Chaloun, P; Hella, K M; Kalinnikov, V G; Krivopustov, M I; Kulakov, B A; Perelygin, V P; Pronskikh, V S; Pavliouk, A V; Solnyshkin, A A; Sosnin, A N; Stegailov, V I; Tsoupko-Sitnikov, V M; Zaverioukha, O S; Adloff, J C; Debeauvais, M; Brandt, R; Langrock, E J; Vater, P; Van, J S; Westmeier, W; Dwivedi, K K; Guo Shi Lun; Li Li Qiang; Hashemi-Nezhad, S R; Kievets, M K; Lomonosova, E M; Zhuk, I V; Modolo, G; Odoj, R; Zamani-Valassiadou, M
2001-01-01
Experimental studies on the transmutation of some long-lived radioactive waste nuclei, such as ^{129}I, ^{237}Np, and ^{239}Pu, as well as on natural uranium and lanthanum (all of them used as sensors) were carried out at the Synchrophasotron of the Laboratory for High Energies (JINR, Dubna). Spallation neutrons were produced by relativistic protons with energies in the range of 0.5 GeV\\le E(p)\\le 1.5 GeV interacting with 20 cm long uranium or lead target stacks. The targets were surrounded by 6 cm paraffin moderators. The radioactive sensors mentioned above were positioned on the outside surface of the moderator and contained typically approximately 0.5 up to 1 gram of long-lived isotopes. The highly radioactive targets were produced perfectly well-sealed in aluminum containers by the Institute of Physics and Power Engineering, Obninsk, Russia. From the experimentally observed transmutation rates one can easily extrapolate, that in a subcritical nuclear power assembly (or "energy amplifier") using a 10 mA pr...
SUNWARD PROPAGATING ALFVÉN WAVES IN ASSOCIATION WITH SUNWARD DRIFTING PROTON BEAMS IN THE SOLAR WIND
Energy Technology Data Exchange (ETDEWEB)
He, Jiansen; Pei, Zhongtian; Wang, Linghua; Tu, Chuanyi; Zhang, Lei [School of Earth and Space Sciences, Peking University, Beijing, 100871 (China); Marsch, Eckart [Institute for Experimental and Applied Physics, Christian-Albrechts-Universität zu Kiel, D-24118 Kiel (Germany); Salem, Chadi, E-mail: jshept@gmail.com [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)
2015-06-01
Using measurements from the WIND spacecraft, here we report the observation of sunward propagating Alfvén waves (AWs) in solar wind that is magnetically disconnected from the Earth's bow shock. In the sunward magnetic field sector, we find a period lasting for more than three days in which there existed (during most time intervals) a negative correlation between the flow velocity and magnetic field fluctuations, thus indicating that the related AWs are mainly propagating sunward. Simultaneous observations of counter-streaming suprathermal electrons suggest that these sunward AWs may not simply be due to the deflection of an open magnetic field line. Moreover, no interplanetary coronal mass ejection appears to be associated with the counter-streaming suprathermal electrons. As the scale goes from the magnetohydrodynamic down to the ion kinetic regime, the wave vector of magnetic fluctuations usually becomes more orthogonal to the mean magnetic field direction, and the fluctuations become increasingly compressible, which are both features consistent with quasi-perpendicular kinetic AWs. However, in the case studied here, we find clear signatures of quasi-parallel sunward propagating ion-cyclotron waves. Concurrently, the solar wind proton velocity distribution reveals a sunward field-aligned beam that drifts at about the local Alfvén speed. This beam is found to run in the opposite direction of the normally observed (anti-sunward) proton beam, and is apparently associated with sunward propagating Alfvén/ion-cyclotron waves. The results and conclusions of this study enrich our knowledge of solar wind turbulence and foster our understanding of proton heating and acceleration within a complex magnetic field geometry.
Pinto, Victor A.; Kim, Hee-Jeong; Lyons, Larry R.; Bortnik, Jacob
2018-02-01
We have identified 61 relativistic electron enhancement events and 21 relativistic electron persistent depletion events during 1996 to 2006 from the Geostationary Operational Environmental Satellite (GOES) 8 and 10 using data from the Energetic Particle Sensor (EPS) >2 MeV fluxes. We then performed a superposed epoch time analysis of the events to find the characteristic solar wind parameters that determine the occurrence of such events, using the OMNI database. We found that there are clear differences between the enhancement events and the persistent depletion events, and we used these to establish a set of threshold values in solar wind speed, proton density and interplanetary magnetic field (IMF) Bz that can potentially be useful to predict sudden increases in flux. Persistent depletion events are characterized by a low solar wind speed, a sudden increase in proton density that remains elevated for a few days, and a northward turning of IMF Bz shortly after the depletion starts. We have also found that all relativistic electron enhancement or persistent depletion events occur when some geomagnetic disturbance is present, either a coronal mass ejection or a corotational interaction region; however, the storm index, SYM-H, does not show a strong connection with relativistic electron enhancement events or persistent depletion events. We have tested a simple threshold method for predictability of relativistic electron enhancement events using data from GOES 11 for the years 2007-2010 and found that around 90% of large increases in electron fluxes can be identified with this method.
International Nuclear Information System (INIS)
Gross, F.
1986-01-01
Relativistic equations for two and three body scattering are discussed. Particular attention is paid to relativistic three body kinetics because of recent form factor measurements of the Helium 3 - Hydrogen 3 system recently completed at Saclay and Bates and the accompanying speculation that relativistic effects are important for understanding the three nucleon system. 16 refs., 4 figs
Simms, Laura; Engebretson, Mark; Clilverd, Mark; Rodger, Craig; Lessard, Marc; Gjerloev, Jesper; Reeves, Geoffrey
2018-05-01
Relativistic electron flux at geosynchronous orbit depends on enhancement and loss processes driven by ultralow frequency (ULF) Pc5, chorus, and electromagnetic ion cyclotron (EMIC) waves, seed electron flux, magnetosphere compression, the "Dst effect," and substorms, while solar wind inputs such as velocity, number density, and interplanetary magnetic field Bz drive these factors and thus correlate with flux. Distributed lag regression models show the time delay of highest influence of these factors on log10 high-energy electron flux (0.7-7.8 MeV, Los Alamos National Laboratory satellites). Multiple regression with an autoregressive term (flux persistence) allows direct comparison of the magnitude of each effect while controlling other correlated parameters. Flux enhancements due to ULF Pc5 and chorus waves are of equal importance. The direct effect of substorms on high-energy electron flux is strong, possibly due to injection of high-energy electrons by the substorms themselves. Loss due to electromagnetic ion cyclotron waves is less influential. Southward Bz shows only moderate influence when correlated processes are accounted for. Adding covariate compression effects (pressure and interplanetary magnetic field magnitude) allows wave-driven enhancements to be more clearly seen. Seed electrons (270 keV) are most influential at lower relativistic energies, showing that such a population must be available for acceleration. However, they are not accelerated directly to the highest energies. Source electrons (31.7 keV) show no direct influence when other factors are controlled. Their action appears to be indirect via the chorus waves they generate. Determination of specific effects of each parameter when studied in combination will be more helpful in furthering modeling work than studying them individually.
Oblique proton fire hose instability in the expanding solar wind: Hybrid simulations
Czech Academy of Sciences Publication Activity Database
Hellinger, Petr; Trávníček, Pavel M.
2008-01-01
Roč. 113, A10 (2008), A10109/1-A10109/9 ISSN 0148-0227 R&D Projects: GA AV ČR IAA300420702; GA AV ČR IAA300420602 Institutional research plan: CEZ:AV0Z30420517; CEZ:AV0Z10030501 Keywords : kinetic instability * fire hose * solar wind * fire hose instabilities * linear analysis * nonlinear evolution * solar wind Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.147, year: 2008
Proton core-beam system in the expanding solar wind: Hybrid simulations
Czech Academy of Sciences Publication Activity Database
Hellinger, Petr; Trávníček, Pavel M.
2011-01-01
Roč. 116, A11 (2011), A11101/1-A11101/13 ISSN 0148-0227 R&D Projects: GA AV ČR IAA300420702 Grant - others:European Space Agency(XE) PECS contract No. 98068; European Commissions(XE) SWIFF (project 263340) Institutional research plan: CEZ:AV0Z30420517; CEZ:AV0Z10030501 Keywords : ELECTROMAGNETIC PROTON/PROTON INSTABILITIES * VELOCITY SPACE DIFFUSION * WAVE-WAVE SCATTERING * TEMPERATURE ANISOTROPY * PLASMA * DRIFT * DISTRIBUTIONS Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.021, year: 2011 http://www.agu.org/pubs/crossref/2011/2011JA016940.shtml
Demianski, Marek
2013-01-01
Relativistic Astrophysics brings together important astronomical discoveries and the significant achievements, as well as the difficulties in the field of relativistic astrophysics. This book is divided into 10 chapters that tackle some aspects of the field, including the gravitational field, stellar equilibrium, black holes, and cosmology. The opening chapters introduce the theories to delineate gravitational field and the elements of relativistic thermodynamics and hydrodynamics. The succeeding chapters deal with the gravitational fields in matter; stellar equilibrium and general relativity
The upstream escape of energized solar wind protons from the bow shock
International Nuclear Information System (INIS)
Greenstadt, E.W.
1975-01-01
Recently, there have been some systematic observations of backstreaming protons at the Earth's bow shock with parallel velocity components and total energies much too high to be associated with the usual long-period upstream waves or to be produced by Sonnerup's simple reflection process (Lin et al., 1974), and these protons (30-100keV) were attributed to some unknown acceleration mechanism in the upstream region. The observations of Lof et al. involved protons in high pitch angle, and, although their reasons for favoring an upstream acceleration were quite different, it may seem intuitive that high pitch angle particles would have difficulty escaping the shock, especially at large field-normal angles. Such an inference would superficially support the notion of energization outside the bow shock. It seems worthwhile therefore to examine the extent to which the geometry of individual particle motion alone might select among reflected particles those that can escape upstream and those that cannot. In this paper the geometry of escape is described and some simple numerical examples are worked out for a few special cases. It is found that protons with rather high energies and pitch angles can escape the shock at only marginally quasi-parallel field orientations (i.e., thetasub(nB) approximately 50 0 ), even if they have quite moderate speeds parallel to B. (Auth.)
Schultz, David
As recognized prominently by the APRA program, interpretation of NASA astrophysical mission observations requires significant products of laboratory astrophysics, for example, spectral lines and transition probabilities, electron-, proton-, or heavy-particle collision data. Availability of these data underpin robust and validated models of astrophysical emissions and absorptions, energy, momentum, and particle transport, dynamics, and reactions. Therefore, measured or computationally derived, analyzed, and readily available laboratory astrophysics data significantly enhances the scientific return on NASA missions such as HST, Spitzer, and JWST. In the present work a comprehensive set of data will be developed for the ubiquitous proton-hydrogen and hydrogen-hydrogen collisions in astrophysical environments including ISM shocks, supernova remnants and bubbles, HI clouds, young stellar objects, and winds within stellar spheres, covering the necessary wide range of energy- and charge-changing channels, collision energies, and most relevant scattering parameters. In addition, building on preliminary work, a transport and reaction simulation will be developed incorporating the elastic and inelastic collision data collected and produced. The work will build upon significant previous efforts of the principal investigators and collaborators, will result in a comprehensive data set required for modeling these environments and interpreting NASA astrophysical mission observations, and will benefit from feedback from collaborators who are active users of the work proposed.
Solar Wind Protons at 1 AU: Trends and Bounds, Constraints and Correlations
Czech Academy of Sciences Publication Activity Database
Hellinger, Petr; Trávníček, Pavel M.
2014-01-01
Roč. 784, č. 1 (2014), L15/1-L15/5 ISSN 2041-8205 R&D Projects: GA ČR GAP209/12/2023 Grant - others:EU(XE) SHOCK Project No. 284515 Institutional support: RVO:67985815 Keywords : instabilities * plasmas * solar wind Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.339, year: 2014
Protons and alpha particles in the expanding solar wind: Hybrid simulations
Czech Academy of Sciences Publication Activity Database
Hellinger, Petr; Trávníček, Pavel M.
2013-01-01
Roč. 118, č. 9 (2013), s. 5421-5430 ISSN 2169-9380 Institutional support: RVO:68378289 Keywords : solar wind * ion energetics Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/jgra.50540/abstract
Relativistic ion acceleration by ultraintense laser interactions
International Nuclear Information System (INIS)
Nakajima, K.; Koga, J.K.; Nakagawa, K.
2001-01-01
There has been a great interest in relativistic particle generation by ultraintense laser interactions with matter. We propose the use of relativistically self-focused laser pulses for the acceleration of ions. Two dimensional PIC simulations are performed, which show the formation of a large positive electrostatic field near the front of a relativistically self-focused laser pulse. Several factors contribute to the acceleration including self-focusing distance, pulse depletion, and plasma density. Ultraintense laser-plasma interactions are capable of generating enormous electrostatic fields of ∼3 TV/m for acceleration of protons with relativistic energies exceeding 1 GeV
Fu, Hui; Madjarska, M. S.; Li, Bo; Xia, LiDong; Huang, ZhengHua
2018-05-01
Two main models have been developed to explain the mechanisms of release, heating and acceleration of the nascent solar wind, the wave-turbulence-driven (WTD) models and reconnection-loop-opening (RLO) models, in which the plasma release processes are fundamentally different. Given that the statistical observational properties of helium ions produced in magnetically diverse solar regions could provide valuable information for the solar wind modelling, we examine the statistical properties of the helium abundance (AHe) and the speed difference between helium ions and protons (vαp) for coronal holes (CHs), active regions (ARs) and the quiet Sun (QS). We find bimodal distributions in the space of AHeand vαp/vA(where vA is the local Alfvén speed) for the solar wind as a whole. The CH wind measurements are concentrated at higher AHeand vαp/vAvalues with a smaller AHedistribution range, while the AR and QS wind is associated with lower AHeand vαp/vA, and a larger AHedistribution range. The magnetic diversity of the source regions and the physical processes related to it are possibly responsible for the different properties of AHeand vαp/vA. The statistical results suggest that the two solar wind generation mechanisms, WTD and RLO, work in parallel in all solar wind source regions. In CH regions WTD plays a major role, whereas the RLO mechanism is more important in AR and QS.
Relativistic nuclear collisions: theory
International Nuclear Information System (INIS)
Gyulassy, M.
1980-07-01
Some of the recent theoretical developments in relativistic (0.5 to 2.0-GeV/nucleon) nuclear collisions are reviewed. The statistical model, hydrodynamic model, classical equation of motion calculations, billiard ball dynamics, and intranuclear cascade models are discussed in detail. Inclusive proton and pion spectra are analyzed for a variety of reactions. Particular attention is focused on how the complex interplay of the basic reaction mechanism hinders attempts to deduce the nuclear matter equation of state from data. 102 references, 19 figures
Luciano, Rezzolla
2013-01-01
Relativistic hydrodynamics is a very successful theoretical framework to describe the dynamics of matter from scales as small as those of colliding elementary particles, up to the largest scales in the universe. This book provides an up-to-date, lively, and approachable introduction to the mathematical formalism, numerical techniques, and applications of relativistic hydrodynamics. The topic is typically covered either by very formal or by very phenomenological books, but is instead presented here in a form that will be appreciated both by students and researchers in the field. The topics covered in the book are the results of work carried out over the last 40 years, which can be found in rather technical research articles with dissimilar notations and styles. The book is not just a collection of scattered information, but a well-organized description of relativistic hydrodynamics, from the basic principles of statistical kinetic theory, down to the technical aspects of numerical methods devised for the solut...
Schmidt, R.; Blanco Sancho, J.; Burkart, F.; Grenier, D.; Wollmann, D.; Tahir, N. A.; Shutov, A.; Piriz, A. R.
2014-08-01
A novel experiment has been performed at the CERN HiRadMat test facility to study the impact of the 440 GeV proton beam generated by the Super Proton Synchrotron on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed that leads to significant lengthening of the projectile range, which confirms our previous theoretical predictions [N. A. Tahir et al., Phys. Rev. Spec. Top.-Accel. Beams 15, 051003 (2012)]. Simulation results show very good agreement with the experimental measurements. These results have very important implications on the machine protection design for powerful machines like the Large Hadron Collider (LHC), the future High Luminosity LHC, and the proposed huge 80 km circumference Future Circular Collider, which is currently being discussed at CERN. Another very interesting outcome of this work is that one may also study the field of High Energy Density Physics at this test facility.
Schmidt, R; Sancho, J Blanco; Burkart, F; Grenier, D; Wollmann, D; Tahir, N A; Shutov, A; Piriz, A R
2014-01-01
A novel experiment has been performed at the CERN HiRadMat test facility to study the impact of the 440 GeV proton beam generated by the Super Proton Synchrotron on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed that leads to significant lengthening of the projectile range, which confirms our previous theoretical predictions [N. A. Tahir et al., Phys. Rev. Spec. Top.-Accel. Beams 15, 051003 (2012)]. Simulation results show very good agreement with the experimental measurements. These results have very important implications on the machine protection design for powerful machines like the Large Hadron Collider (LHC), the future High Luminosity LHC, and the proposed huge 80 km circumference Future Circular Collider, which is currently being discussed at CERN. Another very interesting outcome of this work is that one may also study the field of High Energy Density Physics at this test facility.
Shematovich, Valery I.
2017-04-01
One of the first surprises of the NASA MAVEN mission was the observation by the SWIA instrument of a tenuous population of protons with solar wind energies travelling anti-sunward near periapsis, at altitudes of 150-250 km (Halekas et al., 2015). While the penetration of solar wind protons to low altitude is not completely unexpected given previous Mars Express results, this population maintains exactly the same velocity as the solar wind observed. From previous studies it was known that some fraction of the solar wind can interact with the extended corona of Mars. By charge exchange with the neutral particles in this corona, some fraction of the incoming solar wind protons can gain an electron and become an energetic neutral hydrogen atom. Once neutral, these particles penetrate through the Martian induced magnetosphere with ease, with free access to the collisional atmosphere/ionosphere. The origin, kinetics and transport of the suprathermal O atoms in the transition region (from thermosphere to exosphere) of the Martian upper atmosphere due to the precipitation of the high-energy protons and hydrogen atoms are discussed. Kinetic energy distribution functions of suprathermal and superthermal (ENA) oxygen atoms formed in the Martian upper atmosphere were calculated using the kinetic Monte Carlo model (Shematovich et al., 2011, Shematovich, 2013) of the high-energy proton and hydrogen atom precipitation into the atmosphere. These functions allowed us: (a) to estimate the non-thermal escape rates of neutral oxygen from the Martian upper atmosphere, and (b) to compare with available MAVEN measurements of oxygen corona. Induced by precipitation the escape of hot oxygen atoms may become dominant under conditions of extreme solar events - solar flares and coronal mass ejections, - as it was shown by recent observations of the NASA MAVEN spacecraft (Jakosky et al., 2015). This work is supported by the RFBR project and by the Basic Research Program of the Praesidium of
Price, R H
1993-01-01
Work reported in the workshop on relativistic astrophysics spanned a wide varicy of topics. Two speciﬁc areas seemed of particular interest. Much attention was focussed on gravitational wave sources, especially on the waveforms they produce, and progress was reported in theoretical and observational aspects of accretion disks.
Sahoo, Raghunath
2016-01-01
This lecture note covers Relativistic Kinematics, which is very useful for the beginners in the field of high-energy physics. A very practical approach has been taken, which answers "why and how" of the kinematics useful for students working in the related areas.
International Nuclear Information System (INIS)
Font, J. A.
2015-01-01
The relativistic astrophysics is the field of astrophysics employing the theory of relativity Einstein as physical-mathematical model is to study the universe. This discipline analyzes astronomical contexts in which the laws of classical mechanics of Newton's law of gravitation are not valid. (Author)
Radiation dominated relativistic current sheets
International Nuclear Information System (INIS)
Jaroschek, C.H.
2008-01-01
Relativistic Current Sheets (RCS) feature plasma instabilities considered as potential key to magnetic energy dissipation and non-thermal particle generation in Poynting flux dominated plasma flows. We show in a series of kinetic plasma simulations that the physical nature of non-linear RCS evolution changes in the presence of incoherent radiation losses: In the ultra-relativistic regime (i.e. magnetization parameter sigma = 104 defined as the ratio of magnetic to plasma rest frame energy density) the combination of non-linear RCS dynamics and synchrotron emission introduces a temperature anisotropy triggering the growth of the Relativistic Tearing Mode (RTM). As direct consequence the RTM prevails over the Relativistic Drift Kink (RDK) Mode as competitive RCS instability. This is in contrast to the previously studied situation of weakly relativistic RCS (sigma ∼ 1) where the RDK is dominant and most of the plasma is thermalized. The simulations witness the typical life cycle of ultra-relativistic RCS evolving from a violent radiation induced collapse towards a radiation quiescent state in rather classical Sweet-Parker topology. Such a transition towards Sweet-Parker configuration in the late non-linear evolution has immediate consequences for the efficiency of magnetic energy dissipation and non-thermal particle generation. Ceasing dissipation rates directly affect our present understanding of non-linear RCS evolution in conventional striped wind scenarios. (author)
International Nuclear Information System (INIS)
Bornapour, Mosayeb; Hooshmand, Rahmat-Allah; Khodabakhshian, Amin; Parastegari, Moein
2017-01-01
Highlights: •Stochastic model is proposed for coordinated scheduling of renewable energy sources. •The effect of combined heat and power is considered. •Hydrogen storage is considered for fuel cells. •Maximizing profits of micro grid is considered as objective function. •Considering the uncertainties of problem lead to profit increasing. -- Abstract: Nowadays, renewable energy sources and combined heat and power units are extremely used in micro grids, so it is necessary to schedule these units to improve the performance of the system. In this regard, a stochastic model is proposed in this paper to schedule proton exchange membrane fuel cell-combined heat and power, wind turbines, and photovoltaic units coordinately in a micro grid while considering hydrogen storage. Hydrogen storage strategy is considered for the operation of proton exchange membrane fuel cell-combined heat and power units. To consider stochastic generation of renewable energy source units in this paper, a scenario-based method is used. In this method, the uncertainties of electrical market price, the wind speed, and solar irradiance are considered. This stochastic scheduling problem is a mixed integer- nonlinear programming which considers the proposed objective function and variables of coordinated scheduling of PEMFC-CHP, wind turbines and photovoltaic units. It also considers hydrogen storage strategy and converts it to a mixed integer nonlinear problem. In this study a modified firefly algorithm is used to solve the problem. This method is examined on modified 33-bus distributed network as a MG for its performance.
International Nuclear Information System (INIS)
Allen, M.A.; Azuma, O.; Callin, R.S.
1989-03-01
Experimental work is underway by a SLAC-LLNL-LBL collaboration to investigate the feasibility of using relativistic klystrons as a power source for future high gradient accelerators. Two different relativistic klystron configurations have been built and tested to date: a high grain multicavity klystron at 11.4 GHz and a low gain two cavity subharmonic buncher driven at 5.7 GHz. In both configurations power is extracted at 11.4 GHz. In order to understand the basic physics issues involved in extracting RF from a high power beam, we have used both a single resonant cavity and a multi-cell traveling wave structure for energy extraction. We have learned how to overcome our previously reported problem of high power RF pulse shortening, and have achieved peak RF power levels of 170 MW with the RF pulse of the same duration as the beam current pulse. 6 refs., 3 figs., 3 tabs
Hakim, Rémi
1994-01-01
Il existe à l'heure actuelle un certain nombre de théories relativistes de la gravitation compatibles avec l'expérience et l'observation. Toutefois, la relativité générale d'Einstein fut historiquement la première à fournir des résultats théoriques corrects en accord précis avec les faits.
International Nuclear Information System (INIS)
Marks, R.
1985-09-01
Theoretical analysis is presented of a relativisic klystron; i.e. a high-relativistic bunched electron beam which is sent through a succession of tuned cavities and has its energy replenished by periodic induction accelerator units. Parameters are given for a full-size device and for an experimental device using the FEL at the ETA; namely the ELF Facility. 6 refs., 2 figs
A new class of galactic discrete gamma ray sources: Chaotic winds of massive stars
Chen, Wan; White, Richard L.
1992-01-01
We propose a new class of galactic discrete gamma-ray sources, the chaotic, high mass-loss-rate winds from luminous early-type stars. Early-type stellar winds are highly unstable due to intrinsic line-driven instabilities, and so are permeated by numerous strong shocks. These shocks can accelerate a small fraction of thermal electrons and ions to relativistic energies via the first-order Fermi mechanism. A power-law-like photon spectrum extending from keV to above 10 MeV energies is produced by inverse Compton scattering of the extremely abundant stellar UV photons by the relativistic electrons. In addition, a typical pi(sup 0)-decay gamma-ray spectrum is generated by proton-ion interactions in the densest part of the winds.
Maneva, Y. G.; Poedts, S.
2017-12-01
Non-thermal kinetic components such as deformed velocity distributions, temperature anisotropies and relative drifts between the multiple ion populations are frequently observed features in the collisionless fast solar wind streams near the Earth whose origin is still to be better understood. Some of the traditional models consider the formation of the temperature anisotropies through the effect of the solar wind expansion, while others assume in situ heating and particle acceleration by local fluctuations, such as plasma waves, or by spacial structures, such as advected or locally generated current sheets. In this study we consider the evolution of initial ion temperature anisotropies and relative drifts in the presence of plasma oscillations, such as ion-cyclotron and kinetic Alfven waves. We perform 2.5D hybrid simulations to study the evolution of observed fast solar wind plasma parcels, including the development of the plasma micro-instabilities, the field-particle correlations and the energy transfer between the multiple ion species. We consider two distinct cases of highly anisotropic and quickly drifting protons which excite ion-cyclotron waves and of moderately anisotropic slower protons, which co-exist with kinetic Alfven waves. The alpha particles for both cases are slightly anisotropic in the beginning and remain anisotropic throughout the simulation time. Both the imposed magnetic fluctuations and the initial differential streaming decrease in time for both cases, while the minor ions are getting heated. Finally we study the effects of the solar wind expansion and discuss its implications for the nonlinear evolution of the system.
International Nuclear Information System (INIS)
Key, M H; Freeman, R R; Hatchett, S P; MacKinnon, A J; Patel, P K; Snavely, R A; Stephens, R B
2006-04-01
Fast ignition (FI) by a laser generated ballistically focused proton beam is a more recently proposed alternative to the original concept of FI by a laser generated beam of relativistic electrons. It has potential advantages in less complex energy transport into dense plasma. Recent successful target heating experiments motivate further investigation of the feasibility of proton fast ignition. The concept, the physics and characteristics of the proton beams, the recent experimental work on focusing of the beams and heating of solid targets and the overall prospects for proton FI are discussed
International Nuclear Information System (INIS)
Zander, A.R.; Lapicki, G.
1981-01-01
When Z 1 2 , inner-shell ionization of a target atom of atomic number Z 2 by a projectile of atomic number Z 1 occurs predominately via removal of an inner-shell electron to the target atom continuum (direct ionization). Electron capture contributes then insignificantly to the ionization, and thus the predictions of perturbativein-Z 1 /Z 2 theories of direct ionization can be tested through comparison with measured ionization cross sections. We present such a comparison with the recently reported data for K-shell ionization of the Z 2 =22, 26, 28, and 30 elements by 60-150 keV protons (Z 1 =1). These ionization cross sections were inferred from x-ray production measurements using Krause's fluorescence yields
Slowly rotating general relativistic superfluid neutron stars with relativistic entrainment
International Nuclear Information System (INIS)
Comer, G.L.
2004-01-01
Neutron stars that are cold enough should have two or more superfluids or supercondutors in their inner crusts and cores. The implication of superfluidity or superconductivity for equilibrium and dynamical neutron star states is that each individual particle species that forms a condensate must have its own, independent number density current and equation of motion that determines that current. An important consequence of the quasiparticle nature of each condensate is the so-called entrainment effect; i.e., the momentum of a condensate is a linear combination of its own current and those of the other condensates. We present here the first fully relativistic modeling of slowly rotating superfluid neutron stars with entrainment that is accurate to the second-order in the rotation rates. The stars consist of superfluid neutrons, superconducting protons, and a highly degenerate, relativistic gas of electrons. We use a relativistic σ-ω mean field model for the equation of state of the matter and the entrainment. We determine the effect of a relative rotation between the neutrons and protons on a star's total mass, shape, and Kepler, mass-shedding limit
Relativistic Outflows from ADAFs
Becker, Peter; Subramanian, Prasad; Kazanas, Demosthenes
2001-04-01
Advection-dominated accretion flows (ADAFs) have a positive Bernoulli parameter, and are therefore gravitationally bound. The Newtonian ADAF model has been generalized recently to obtain the ADIOS model that includes outflows of energy and angular momentum, thereby allowing accretion to proceed self-consistently. However, the utilization of a Newtonian gravitational potential limits the ability of this model to describe the inner region of the disk, where any relativistic outflows are likely to originate. In this paper we modify the ADIOS scenario to incorporate a seudo - Newtonian potential, which approximates the effects of general relativity. The analysis yields a unique, self - similar solution for the structure of the coupled disk/wind system. Interesting features of the new solution include the relativistic character of the outflow in the vicinity of the radius of marginal stability, which represents the inner edge of the quasi-Keplerian disk in our model. Our self - similar model may therefore help to explain the origin of relativistic jets in active galaxies. At large distances the radial dependence of the accretion rate approachs the unique form dot M ∝ r^1/2, with an associated density variation given by ρ ∝ r-1. This density variation agrees with that implied by the dependence of the X-ray hard time lags on the Fourier frequency for a number of accreting galactic black hole candidates. While intriguing, the results of our self-similar model need to be confirmed in the future by incorporating a detailed physical description of the energization mechanism that drives the outflow, which is likely to be powered by the shear of the underlying accretion disk.
Zhang, Bing; Li, Kunyang
2018-02-01
The “Breakthrough Starshot” aims at sending near-speed-of-light cameras to nearby stellar systems in the future. Due to the relativistic effects, a transrelativistic camera naturally serves as a spectrograph, a lens, and a wide-field camera. We demonstrate this through a simulation of the optical-band image of the nearby galaxy M51 in the rest frame of the transrelativistic camera. We suggest that observing celestial objects using a transrelativistic camera may allow one to study the astronomical objects in a special way, and to perform unique tests on the principles of special relativity. We outline several examples that suggest transrelativistic cameras may make important contributions to astrophysics and suggest that the Breakthrough Starshot cameras may be launched in any direction to serve as a unique astronomical observatory.
Relativistic magnetohydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Hernandez, Juan; Kovtun, Pavel [Department of Physics and Astronomy, University of Victoria,Victoria, BC, V8P 5C2 (Canada)
2017-05-02
We present the equations of relativistic hydrodynamics coupled to dynamical electromagnetic fields, including the effects of polarization, electric fields, and the derivative expansion. We enumerate the transport coefficients at leading order in derivatives, including electrical conductivities, viscosities, and thermodynamic coefficients. We find the constraints on transport coefficients due to the positivity of entropy production, and derive the corresponding Kubo formulas. For the neutral state in a magnetic field, small fluctuations include Alfvén waves, magnetosonic waves, and the dissipative modes. For the state with a non-zero dynamical charge density in a magnetic field, plasma oscillations gap out all propagating modes, except for Alfvén-like waves with a quadratic dispersion relation. We relate the transport coefficients in the “conventional” magnetohydrodynamics (formulated using Maxwell’s equations in matter) to those in the “dual” version of magnetohydrodynamics (formulated using the conserved magnetic flux).
Directory of Open Access Journals (Sweden)
Richard Anantua
2018-03-01
Full Text Available This work summarizes a program intended to unify three burgeoning branches of the high-energy astrophysics of relativistic jets: general relativistic magnetohydrodynamic (GRMHD simulations of ever-increasing dynamical range, the microphysical theory of particle acceleration under relativistic conditions, and multiwavelength observations resolving ever-decreasing spatiotemporal scales. The process, which involves converting simulation output into time series of images and polarization maps that can be directly compared to observations, is performed by (1 self-consistently prescribing models for emission, absorption, and particle acceleration and (2 performing time-dependent polarized radiative transfer. M87 serves as an exemplary prototype for this investigation due to its prominent and well-studied jet and the imminent prospect of learning much more from Event Horizon Telescope (EHT observations this year. Synthetic observations can be directly compared with real observations for observational signatures such as jet instabilities, collimation, relativistic beaming, and polarization. The simplest models described adopt the standard equipartition hypothesis; other models calculate emission by relating it to current density or shear. These models are intended for application to the radio jet instead of the higher frequency emission, the disk and the wind, which will be subjects of future investigations.
Energy Technology Data Exchange (ETDEWEB)
Kocharov, Leon; Usoskin, Ilya [Sodankylä Geophysical Observatory/Oulu Unit, University of Oulu, P.O.B. 3000, Oulu FI-90014 (Finland); Pohjolainen, Silja [Tuorla Observatory, University of Turku, Piikkiö FI-21500 (Finland); Mishev, Alexander [Space Climate Research Unit, University of Oulu, Oulu FI-90014 (Finland); Reiner, Mike J. [The Catholic University of America, Washington, DC, and NASA/Goddard Space Flight Center, Greenbelt, MD (United States); Lee, Jeongwoo [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Laitinen, Timo [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Didkovsky, Leonid V. [University of Southern California Space Sciences Center, 835 Bloom Walk, Los Angeles CA 90089 (United States); Pizzo, Victor J. [NOAA Space Weather Prediction Center, Boulder, CO 80305 (United States); Kim, Roksoon; Cho, Kyung-Suk [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Klassen, Andreas [Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, Kiel D-24118 (Germany); Karlicky, Marian [Astronomical Institute of the Czech Academy of Sciences, Fričova 258, Ondřejov 251 65 (Czech Republic); Gary, Dale E. [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark NJ 07102-1982 (United States); Valtonen, Eino; Vainio, Rami [Space Research Laboratory, University of Turku, Turku FI-20014 (Finland)
2017-04-20
We analyze the high-energy particle emission from the Sun in two extreme solar particle events in which protons are accelerated to relativistic energies and can cause a significant signal even in the ground-based particle detectors. Analysis of a relativistic proton event is based on modeling of the particle transport and interaction, from a near-Sun source through the solar wind and the Earth’s magnetosphere and atmosphere to a detector on the ground. This allows us to deduce the time profile of the proton source at the Sun and compare it with observed electromagnetic emissions. The 1998 May 2 event is associated with a flare and a coronal mass ejection (CME), which were well observed by the Nançay Radioheliograph, thus the images of the radio sources are available. For the 2003 November 2 event, the low corona images of the CME liftoff obtained at the Mauna Loa Solar Observatory are available. Those complementary data sets are analyzed jointly with the broadband dynamic radio spectra, EUV images, and other data available for both events. We find a common scenario for both eruptions, including the flare’s dual impulsive phase, the CME-launch-associated decimetric-continuum burst, and the late, low-frequency type III radio bursts at the time of the relativistic proton injection into the interplanetary medium. The analysis supports the idea that the two considered events start with emission of relativistic protons previously accelerated during the flare and CME launch, then trapped in large-scale magnetic loops and later released by the expanding CME.
Relativistic shocks and particle acceleration
International Nuclear Information System (INIS)
Heavens, A.F.
1988-01-01
In this paper, we investigate the fluid dynamics of relativistic shock waves, and use the results to calculate the spectral index of particles accelerated by the Fermi process in such shocks. We have calculated the distributions of Fermi-accelerated particles at shocks propagating into cold proton-electron plasma and also cold electron-positron plasma. We have considered two different power spectra for the scattering waves, and find, in contrast to the non-relativistic case, that the spectral index of the accelerated particles depends on the wave power spectrum. On the assumption of thermal equilibrium both upstream and downstream, we present some useful fits for the compression ratio of shocks propagating at arbitrary speeds into gas of any temperature. (author)
Maslennikova, N V; Melnichuk, T A; Tretakova, M I
1972-01-01
Full account of experiments with the photo-emulsion G5 being irradiated by pi /sup -/ mesons by the CERN accelerator and the photo- emulsions BR-2 and BRx4y being irradiated by protons by the Serpukhov accelerator is presented, supported by tables and histograms. Nuclear interactions, discovered along the trace, and the division criteria between interactions of light nuclei (CNO) and heavy nuclei (AgBr) are studied. All interactions are grouped under quasi-nuclear, light nuclei and heavy nuclei, and their distribution with differing quantities of relativistic particles n/sub s/ and heavily ionized particles N/sub h/ is explained and discussed. (5 refs).
Wang, X.; Tu, C. Y.; He, J.; Wang, L.
2017-12-01
The spectrum break at the ion scale of the solar wind magnetic fluctuations are considered to give important clue on the turbulence dissipation mechanism. Among several possible mechanisms, the most notable ones are the two mechanisms that related respectively with proton thermal gyro-radius and proton inertial length. However, no definite conclusion has been given for which one is more reasonable because the two parameters have similar values in the normal plasma beta range. Here we do a statistical study for the first time to see if the two mechanism predictions have different dependence on the solar wind velocity and on the plasma beta in the normal plasma beta range in the solar wind at 1 AU. From magnetic measurements by Wind, Ulysses and Messenger, we select 60 data sets with duration longer than 8 hours. We found that the ratio between the proton inertial scale and the spectrum break scale do not change considerably with both varying the solar wind speed from 300km/s to 800km/s and varying the plasma beta from 0.2 to 1.4. The average value of the ratio times 2pi is 0.46 ± 0.08. However, the ratio between the proton gyro-radius and the break scale changes clearly. This new result shows that the proton inertial scale could be a single factor that determines the break length scale and hence gives a strong evidence to support the dissipation mechanism related to it in the normal plasma beta range. The value of the constant ratio may relate with the dissipation mechanism, but it needs further theoretical study to give detailed explanation.
International Nuclear Information System (INIS)
He Jiansen; Tu Chuanyi; Marsch, Eckart; Yao Shuo
2012-01-01
To determine the wave modes prevailing in solar wind turbulence at kinetic scales, we study the magnetic polarization of small-scale fluctuations in the plane perpendicular to the data sampling direction (namely, the solar wind flow direction, V SW ) and analyze its orientation with respect to the local background magnetic field B 0,local . As an example, we take only measurements made in an outward magnetic sector. When B 0,local is quasi-perpendicular to V SW , we find that the small-scale magnetic-field fluctuations, which have periods from about 1 to 3 s and are extracted from a wavelet decomposition of the original time series, show a polarization ellipse with right-handed orientation. This is consistent with a positive reduced magnetic helicity, as previously reported. Moreover, for the first time we find that the major axis of the ellipse is perpendicular to B 0,local , a property that is characteristic of an oblique Alfvén wave rather than oblique whistler wave. For an oblique whistler wave, the major axis of the magnetic ellipse is expected to be aligned with B 0,local , thus indicating significant magnetic compressibility, and the polarization turns from right to left handedness as the wave propagation angle (θ kB ) increases toward 90°. Therefore, we conclude that the observation of a right-handed polarization ellipse with orientation perpendicular to B 0,local seems to indicate that oblique Alfvén/ion-cyclotron waves rather than oblique fast-mode/whistler waves dominate in the 'dissipation' range near the break of solar wind turbulence spectra occurring around the proton inertial length.
The relativistic virial theorem
International Nuclear Information System (INIS)
Lucha, W.; Schoeberl, F.F.
1989-11-01
The relativistic generalization of the quantum-mechanical virial theorem is derived and used to clarify the connection between the nonrelativistic and (semi-)relativistic treatment of bound states. 12 refs. (Authors)
Energy Dependence of Near-relativistic Electron Spectrum at ...
Indian Academy of Sciences (India)
chronous altitudes during solar energetic proton events of 2005. ... discussed the radiation belt electron drop outs with respect to their local time, radial and ... number density (Nsw), solar wind speed (Vsw), solar wind pressure (Psw), average.
International Nuclear Information System (INIS)
Chen Baoqiu; Ma Zhongyu
1992-01-01
Relativistic microscopic optical potential of nucleon-nucleus is derived from the relativistic Brueckner-Bethe-Goldstone (RBBG) equation. The complex effective mass of a nucleon is determined by a fit to 200 MeV p- 40 Ca scattering data. The relativistic microscopic optical potentials with this effective mass are obtained from RBBG for p- 16O , 40 Ca, 90 Zr and 208 Pb scattering in energy range from 160 to 800 MeV. The microscopic optical potential is used to study the proton- 40 Ca scattering problem at 200 MeV. The results, such as differential cross section, analyzing power and spin rotation function are compared with those calculated from phenomenological relativistic optical potential
The investigation of relativistic microscopic optical potential based on RBBG equation
International Nuclear Information System (INIS)
Chen Baoqiu; Ma Zhongyu
1992-01-01
The relativistic microscopic optical potential is derived from the RBBG equation. The nucleon complex effective mass is determined phenomenologically by a fit to 200 MeV proton-nucleus scattering data. Then the relativistic microscopic optical potentials of proton scattered from different targets: 16 O, 40 Ca, 90 Zr and 208 Pb in the energies range from 160 to 800 MeV have been got. The relativistic microscopic optical potentials have been used to study proton- 40 Ca scattering at 200 MeV. Theoretical predictions for cross section and spin observables are compared with experimental data and phenomenological Dirac optical potential
Stopping power of K electrons at extreme relativistic energies
International Nuclear Information System (INIS)
Leung, P.T.; Rustgi, M.L.
1983-01-01
The recent work of Anholt on K-vacancy production by relativistic projectiles has been applied to calculate the stopping power of the K electrons. The results show that for protons of energy approx.10 3 GeV and heavy target elements, the relativistic contributions to the stopping power amount to several times the resuls due to the longitudinal terms obtained from Walske's work
Relativistic mean field model for entrainment in general relativistic superfluid neutron stars
International Nuclear Information System (INIS)
Comer, G.L.; Joynt, R.
2003-01-01
General relativistic superfluid neutron stars have a significantly more intricate dynamics than their ordinary fluid counterparts. Superfluidity allows different superfluid (and superconducting) species of particles to have independent fluid flows, a consequence of which is that the fluid equations of motion contain as many fluid element velocities as superfluid species. Whenever the particles of one superfluid interact with those of another, the momentum of each superfluid will be a linear combination of both superfluid velocities. This leads to the so-called entrainment effect whereby the motion of one superfluid will induce a momentum in the other superfluid. We have constructed a fully relativistic model for entrainment between superfluid neutrons and superconducting protons using a relativistic σ-ω mean field model for the nucleons and their interactions. In this context there are two notions of 'relativistic': relativistic motion of the individual nucleons with respect to a local region of the star (i.e. a fluid element containing, say, an Avogadro's number of particles), and the motion of fluid elements with respect to the rest of the star. While it is the case that the fluid elements will typically maintain average speeds at a fraction of that of light, the supranuclear densities in the core of a neutron star can make the nucleons themselves have quite high average speeds within each fluid element. The formalism is applied to the problem of slowly rotating superfluid neutron star configurations, a distinguishing characteristic being that the neutrons can rotate at a rate different from that of the protons
Relativistic impulse approximation and deuteron spin structure
International Nuclear Information System (INIS)
Tokarev, M.V.
1992-01-01
The fragmentation processes were considered of tensor- and vector-polarized deuterons to protons in the framework of the covariant approach in the light cone variables on the basis of the relativistic deuteron wave function with one nucleon on-mass shell. The experimental verification of predicted dependences of T 20 and K is of interest for the research of the momentum and spin distributions of high momentum deuteron constituents. 21 refs.; 6 figs
Is the relativistic approach really useful to nuclear reactions?
Miyazaki, K
2003-01-01
We have reconsidered the non-relativistic distorted-wave t-matrix approximation (NR-DWTA) for proton knockout (p,2p) reaction using modern high-quality phenomenological optical potentials and NN t-matrix. We have calculated 40Ca(p,2p) reactions at T_LAB=200MeV and compared the results with the relativistic distorted-wave impulse approximation (RDWIA) calculations. It is found that the NR-DWTA is superior to the RDWIA in consistent description of the cross section and the analyzing power. An immediate relativistic extension of the DWIA to the nuclear reaction has a problem.
Giannini, M. M.; Santopinto, E.
2013-01-01
The recent values of the proton charge radius obtained by means of muonic-hydrogen laser spectroscopy are about $4\\%$ different from the electron scattering data. It has been suggested that the proton radius is actually measured in different frames and that, starting from a non relativistic quark model calculation, the Lorentz transformation of the form factors accounts properly for the discepancy. We shall show that the relation between the charge radii measured in different frames can be de...
Relativistic Linear Restoring Force
Clark, D.; Franklin, J.; Mann, N.
2012-01-01
We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…
International Nuclear Information System (INIS)
Mittelstaedt, P.
1983-01-01
on the basis of the well-known quantum logic and quantum probability a formal language of relativistic quantum physics is developed. This language incorporates quantum logical as well as relativistic restrictions. It is shown that relativity imposes serious restrictions on the validity regions of propositions in space-time. By an additional postulate this relativistic quantum logic can be made consistent. The results of this paper are derived exclusively within the formal quantum language; they are, however, in accordance with well-known facts of relativistic quantum physics in Hilbert space. (author)
International Nuclear Information System (INIS)
Fearing, H.W.
1990-01-01
We summarize some of the information about the nucleon-nucleon force which has been obtained by comparing recent calculations of proton-proton bremsstrahlung with cross section and analyzing power data from the new TRIUMF bremsstrahlung experiment. Some comments are made as to how these results can be extended to neutron-proton bremsstrahlung. (Author) 17 refs., 6 figs
Relativistic quantum mechanics; Mecanique quantique relativiste
Energy Technology Data Exchange (ETDEWEB)
Ollitrault, J.Y. [CEA Saclay, 91 - Gif-sur-Yvette (France). Service de Physique Theorique]|[Universite Pierre et Marie Curie, 75 - Paris (France)
1998-12-01
These notes form an introduction to relativistic quantum mechanics. The mathematical formalism has been reduced to the minimum in order to enable the reader to calculate elementary physical processes. The second quantification and the field theory are the logical followings of this course. The reader is expected to know analytical mechanics (Lagrangian and Hamiltonian), non-relativistic quantum mechanics and some basis of restricted relativity. The purpose of the first 3 chapters is to define the quantum mechanics framework for already known notions about rotation transformations, wave propagation and restricted theory of relativity. The next 3 chapters are devoted to the application of relativistic quantum mechanics to a particle with 0,1/5 and 1 spin value. The last chapter deals with the processes involving several particles, these processes require field theory framework to be thoroughly described. (A.C.) 2 refs.
Ultra-relativistic heavy-ion physics with AFTER@LHC
DEFF Research Database (Denmark)
Rakotozafindrabe, A.; Arnaldi, R.; Brodsky, Stanley
2013-01-01
We outline the opportunities for ultra-relativistic heavy–ion physics which are offered by a next generation and multi-purpose fixed-target experiment exploiting the proton and ion LHC beams extracted by a bent crystal.......We outline the opportunities for ultra-relativistic heavy–ion physics which are offered by a next generation and multi-purpose fixed-target experiment exploiting the proton and ion LHC beams extracted by a bent crystal....
Towards relativistic quantum geometry
Energy Technology Data Exchange (ETDEWEB)
Ridao, Luis Santiago [Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina); Bellini, Mauricio, E-mail: mbellini@mdp.edu.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, C.P. 7600, Mar del Plata (Argentina); Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina)
2015-12-17
We obtain a gauge-invariant relativistic quantum geometry by using a Weylian-like manifold with a geometric scalar field which provides a gauge-invariant relativistic quantum theory in which the algebra of the Weylian-like field depends on observers. An example for a Reissner–Nordström black-hole is studied.
Norbury, John W.
1992-01-01
Nuclear fission reactions induced by the electromagnetic field of relativistic nuclei are studied for energies relevant to present and future relativistic heavy ion accelerators. Cross sections are calculated for U-238 and Pu-239 fission induced by C-12, Si-28, Au-197, and U-238 projectiles. It is found that some of the cross sections can exceed 10 b.
Relativistic Shock Acceleration
International Nuclear Information System (INIS)
Duffy, P.; Downes, T.P.; Gallant, Y.A.; Kirk, J.G.
1999-01-01
In this paper we briefly review the basic theory of shock waves in relativistic hydrodynamics and magneto-hydrodynamics, emphasising some astrophysically interesting cases. We then present an overview of the theory of particle acceleration at such shocks describing the methods used to calculate the spectral indices of energetic particles. Recent results on acceleration at ultra-relativistic shocks are discussed. (author)
Elliptic flow based on a relativistic hydrodynamic model
Energy Technology Data Exchange (ETDEWEB)
Hirano, Tetsufumi [Department of Physics, Waseda Univ., Tokyo (Japan)
1999-08-01
Based on the (3+1)-dimensional hydrodynamic model, the space-time evolution of hot and dense nuclear matter produced in non-central relativistic heavy-ion collisions is discussed. The elliptic flow parameter v{sub 2} is obtained by Fourier analysis of the azimuthal distribution of pions and protons which are emitted from the freeze-out hypersurface. As a function of rapidity, the pion and proton elliptic flow parameters both have a peak at midrapidity. (author)
ACCELERATION OF POLARIZED PROTONS AT RHIC
International Nuclear Information System (INIS)
HUANG, H.
2002-01-01
Relativistic Heavy Ion Collider (RHIC) ended its second year of operation in January 2002 with five weeks of polarized proton collisions. Polarized protons were successfully injected in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. This is the first time that polarized protons have been accelerated to 100 GeV. The machine performance and accomplishments during the polarized proton run will be reviewed. The plans for the next polarized proton run will be outlined
Interplanetary Magnetic Field Guiding Relativistic Particles
Masson, S.; Demoulin, P.; Dasso, S.; Klein, K. L.
2011-01-01
The origin and the propagation of relativistic solar particles (0.5 to few Ge V) in the interplanetary medium remains a debated topic. These relativistic particles, detected at the Earth by neutron monitors have been previously accelerated close to the Sun and are guided by the interplanetary magnetic field (IMF) lines, connecting the acceleration site and the Earth. Usually, the nominal Parker spiral is considered for ensuring the magnetic connection to the Earth. However, in most GLEs the IMF is highly disturbed, and the active regions associated to the GLEs are not always located close to the solar footprint of the nominal Parker spiral. A possible explanation is that relativistic particles are propagating in transient magnetic structures, such as Interplanetary Coronal Mass Ejections (ICMEs). In order to check this interpretation, we studied in detail the interplanetary medium where the particles propagate for 10 GLEs of the last solar cycle. Using the magnetic field and the plasma parameter measurements (ACE/MAG and ACE/SWEPAM), we found widely different IMF configurations. In an independent approach we develop and apply an improved method of the velocity dispersion analysis to energetic protons measured by SoHO/ERNE. We determined the effective path length and the solar release time of protons from these data and also combined them with the neutron monitor data. We found that in most of the GLEs, protons propagate in transient magnetic structures. Moreover, the comparison between the interplanetary magnetic structure and the interplanetary length suggest that the timing of particle arrival at Earth is dominantly determined by the type of IMF in which high energetic particles are propagating. Finally we find that these energetic protons are not significantly scattered during their transport to Earth.
Pauli principle in the soft-photon approach to proton-proton bremsstrahlung
Liou, MK; Timmermans, R; Gibson, BF
1996-01-01
A relativistic and manifestly gauge-invariant soft-photon amplitude, which is consistent with the soft-photon theorem and satisfies the Pauli principle, is derived for the proton-proton bremsstrahlung process. This soft-photon amplitude is the first two-u-two-t special amplitude to satisfy all
Scaling phenomenon in relativistic nucleus-nucleus collisions
International Nuclear Information System (INIS)
Wong, C.Y.; Blankenbecler, R.
1980-01-01
New scaling variables for proton and pion production in relativistic nucleus-nucleus collisions are introduced which are the generalizations of the Feynmann scaling variable. They allow a simple description of the cross sections at forward and backward angles. 2 figures
Isospin-dependent term in the relativistic microscopic optical potential
International Nuclear Information System (INIS)
Rong Jian; Ma Zhongyu; National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou; Chinese Academy of Sciences, Beijing
2005-01-01
The isospin-dependence of the relativistic microscopic optical potential is investigated in the Dirac Brueckner-Hartree-Fock approach. The isospin part of the microscopic optical potential is emphasized. A local density approximation is adopted for finite nuclei. Taking 208 Pb as example, the difference between proton and neutron optical potentials is studied and compared with the phenomenological Lane Model potential. (authors)
Vereshchagin, Gregory V.; Aksenov, Alexey G.
2017-02-01
Preface; Acknowledgements; Acronyms and definitions; Introduction; Part I. Theoretical Foundations: 1. Basic concepts; 2. Kinetic equation; 3. Averaging; 4. Conservation laws and equilibrium; 5. Relativistic BBGKY hierarchy; 6. Basic parameters in gases and plasmas; Part II. Numerical Methods: 7. The basics of computational physics; 8. Direct integration of Boltzmann equations; 9. Multidimensional hydrodynamics; Part III. Applications: 10. Wave dispersion in relativistic plasma; 11. Thermalization in relativistic plasma; 12. Kinetics of particles in strong fields; 13. Compton scattering in astrophysics and cosmology; 14. Self-gravitating systems; 15. Neutrinos, gravitational collapse and supernovae; Appendices; Bibliography; Index.
Recent progresses in relativistic beam-plasma instability theory
Directory of Open Access Journals (Sweden)
A. Bret
2010-11-01
Full Text Available Beam-plasma instabilities are a key physical process in many astrophysical phenomena. Within the fireball model of Gamma ray bursts, they first mediate a relativistic collisionless shock before they produce upstream the turbulence needed for the Fermi acceleration process. While non-relativistic systems are usually governed by flow-aligned unstable modes, relativistic ones are likely to be dominated by normally or even obliquely propagating waves. After reviewing the basis of the theory, results related to the relativistic kinetic regime of the poorly-known oblique unstable modes will be presented. Relevant systems besides the well-known electron beam-plasma interaction are presented, and it is shown how the concept of modes hierarchy yields a criterion to assess the proton to electron mass ratio in Particle in cell simulations.
Directory of Open Access Journals (Sweden)
Y. Shi
2009-02-01
Full Text Available Determination of the radial profile of phase space density of relativistic electrons at constant adiabatic invariants is crucial for identifying the source for them within the outer radiation belt. The commonly used method is to convert flux observed at fixed energy to phase space density at constant first, second and third adiabatic invariants, which requires an empirical global magnetic field model and thus might produce some uncertainties in the final results. From a different perspective, in this paper we indirectly infer the shape of the radial profile of phase space density of relativistic electrons near the geosynchronous region by statistically examining the geosynchronous energetic flux response to 128 solar wind dynamic pressure enhancements during the years 2000 to 2003. We thus avoid the disadvantage of using empirical magnetic field models. Our results show that the flux response is species and energy dependent. For protons and low-energy electrons, the primary response to magnetospheric compression is an increase in flux at geosynchronous orbit. For relativistic electrons, the dominant response is a decrease in flux, which implies that the phase space density decreases toward increasing radial distance at geosynchronous orbit and leads to a local peak inside of geosynchronous orbit. The flux response of protons and non-relativistic electrons could result from a phase density that increases toward increasing radial distance, but this cannot be determined for sure due to the particle energization associated with pressure enhancements. Our results for relativistic electrons are consistent with previous results obtained using magnetic field models, thus providing additional confirmation that these results are correct and indicating that they are not the result of errors in their selected magnetic field model.
Relativistic finite-temperature Thomas-Fermi model
Faussurier, Gérald
2017-11-01
We investigate the relativistic finite-temperature Thomas-Fermi model, which has been proposed recently in an astrophysical context. Assuming a constant distribution of protons inside the nucleus of finite size avoids severe divergence of the electron density with respect to a point-like nucleus. A formula for the nuclear radius is chosen to treat any element. The relativistic finite-temperature Thomas-Fermi model matches the two asymptotic regimes, i.e., the non-relativistic and the ultra-relativistic finite-temperature Thomas-Fermi models. The equation of state is considered in detail. For each version of the finite-temperature Thomas-Fermi model, the pressure, the kinetic energy, and the entropy are calculated. The internal energy and free energy are also considered. The thermodynamic consistency of the three models is considered by working from the free energy. The virial question is also studied in the three cases as well as the relationship with the density functional theory. The relativistic finite-temperature Thomas-Fermi model is far more involved than the non-relativistic and ultra-relativistic finite-temperature Thomas-Fermi models that are very close to each other from a mathematical point of view.
Thermalization in high energy proton-nucleus collisions
International Nuclear Information System (INIS)
Wedemann, R.S.
1988-03-01
A relativistic proton-nucleus collision using the intranuclear cascade model is studied. The purpose is to verify the equilibration hypothesis at fragmentation time made by many nuclear fragmentation models. (author)
Plasma relativistic microwave electronics
International Nuclear Information System (INIS)
Kuzelev, M.V.; Loza, O.T.; Rukhadze, A.A.; Strelkov, P.S.; Shkvarunets, A.G.
2001-01-01
One formulated the principles of plasma relativistic microwave electronics based on the induced Cherenkov radiation of electromagnetic waves at interaction of a relativistic electron beam with plasma. One developed the theory of plasma relativistic generators and accelerators of microwave radiation, designed and studied the prototypes of such devices. One studied theoretically the mechanisms of radiation, calculated the efficiencies and the frequency spectra of plasma relativistic microwave generators and accelerators. The theory findings are proved by the experiment: intensity of the designed sources of microwave radiation is equal to 500 μW, the frequency of microwave radiation is increased by 7 times (from 4 up to 28 GHz), the width of radiation frequency band may vary from several up to 100%. The designed sources of microwave radiation are no else compared in the electronics [ru
Energy Technology Data Exchange (ETDEWEB)
Antippa, Adel F [Departement de Physique, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, Quebec G9A 5H7 (Canada)
2009-05-15
We solve the problem of the relativistic rocket by making use of the relation between Lorentzian and Galilean velocities, as well as the laws of superposition of successive collinear Lorentz boosts in the limit of infinitesimal boosts. The solution is conceptually simple, and technically straightforward, and provides an example of a powerful method that can be applied to a wide range of special relativistic problems of linear acceleration.
Exact Relativistic `Antigravity' Propulsion
Felber, Franklin S.
2006-01-01
The Schwarzschild solution is used to find the exact relativistic motion of a payload in the gravitational field of a mass moving with constant velocity. At radial approach or recession speeds faster than 3-1/2 times the speed of light, even a small mass gravitationally repels a payload. At relativistic speeds, a suitable mass can quickly propel a heavy payload from rest nearly to the speed of light with negligible stresses on the payload.
International Nuclear Information System (INIS)
Strange, P.
2010-01-01
Quantum revivals are now a well-known phenomena within nonrelativistic quantum theory. In this Letter we display the effects of relativity on revivals and quantum carpets. It is generally believed that revivals do not occur within a relativistic regime. Here we show that while this is generally true, it is possible, in principle, to set up wave packets with specific mathematical properties that do exhibit exact revivals within a fully relativistic theory.
Polarized Proton Collisions at RHIC
Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y
2005-01-01
The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...
Relativistic viscoelastic fluid mechanics
International Nuclear Information System (INIS)
Fukuma, Masafumi; Sakatani, Yuho
2011-01-01
A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.
Relativistic viscoelastic fluid mechanics.
Fukuma, Masafumi; Sakatani, Yuho
2011-08-01
A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.
Dissipative relativistic hydrodynamics
International Nuclear Information System (INIS)
Imshennik, V.S.; Morozov, Yu.I.
1989-01-01
Using the comoving reference frame in the general non-inertial case, the relativistic hydrodynamics equations are derived with an account for dissipative effects in the matter. From the entropy production equation, the exact from for the dissipative tensor components is obtained. As a result, the closed system of equations of dissipative relativistic hydrodynamics is obtained in the comoving reference frame as a relativistic generalization of the known Navier-Stokes equations for Lagrange coordinates. Equations of relativistic hydrodynamics with account for dissipative effects in the matter are derived using the assocoated reference system in general non-inertial case. True form of the dissipative tensor components is obtained from entropy production equation. Closed system of equations for dissipative relativistic hydrodynamics is obtained as a result in the assocoated reference system (ARS) - relativistic generalization of well-known Navier-Stokes equations for Lagrange coordinates. Equation system, obtained in this paper for ARS, may be effectively used in numerical models of explosive processes with 10 51 erg energy releases which are characteristic for flashes of supernovae, if white dwarf type compact target suggested as presupernova
Relativistic and non-relativistic studies of nuclear matter
Banerjee, MK; Tjon, JA
2002-01-01
We point out that the differences between the results of the non-relativistic lowest order Brueckner theory (LOBT) and the relativistic Dirac-Brueckner analysis predominantly arise from two sources. Besides effects from a nucleon mass modification M* in nuclear medium we have in a relativistic
Relativistic mean field calculations in neutron-rich nuclei
Energy Technology Data Exchange (ETDEWEB)
Gangopadhyay, G.; Bhattacharya, Madhubrata [Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700 009 (India); Roy, Subinit [Saha Institute of Nuclear Physics, Block AF, Sector 1, Kolkata- 700 064 (India)
2014-08-14
Relativistic mean field calculations have been employed to study neutron rich nuclei. The Lagrange's equations have been solved in the co-ordinate space. The effect of the continuum has been effectively taken into account through the method of resonant continuum. It is found that BCS approximation performs as well as a more involved Relativistic Continuum Hartree Bogoliubov approach. Calculations reveal the possibility of modification of magic numbers in neutron rich nuclei. Calculation for low energy proton scattering cross sections shows that the present approach reproduces the density in very light neutron rich nuclei.
Relativistic quantum mechanics
International Nuclear Information System (INIS)
Ollitrault, J.Y.
1998-12-01
These notes form an introduction to relativistic quantum mechanics. The mathematical formalism has been reduced to the minimum in order to enable the reader to calculate elementary physical processes. The second quantification and the field theory are the logical followings of this course. The reader is expected to know analytical mechanics (Lagrangian and Hamiltonian), non-relativistic quantum mechanics and some basis of restricted relativity. The purpose of the first 3 chapters is to define the quantum mechanics framework for already known notions about rotation transformations, wave propagation and restricted theory of relativity. The next 3 chapters are devoted to the application of relativistic quantum mechanics to a particle with 0,1/5 and 1 spin value. The last chapter deals with the processes involving several particles, these processes require field theory framework to be thoroughly described. (A.C.)
Relativistic solitons and pulsars
Energy Technology Data Exchange (ETDEWEB)
Karpman, V I [Inst. of Terrestrial Magnetism, Ionosphere, and Radio-Wave Propagation, Moscow; Norman, C A; ter Haar, D; Tsytovich, V N
1975-05-01
A production mechanism for stable electron bunches or sheets of localized electric fields is investigated which may account for pulsar radio emission. Possible soliton phenomena in a one-dimensional relativistic plasma are analyzed, and it is suggested that the motion of a relativistic soliton, or ''relaton'', along a curved magnetic-field line may produce radio emission with the correct polarization properties. A general MHD solution is obtained for relatons, the radiation produced by a relativistic particle colliding with a soliton is evaluated, and the emission by a soliton moving along a curved field line is estimated. It is noted that due to a number of severe physical restrictions, curvature radiation is not a very likely solution to the problem of pulsar radio emission. (IAA)
Relativistic quantum mechanics
Horwitz, Lawrence P
2015-01-01
This book describes a relativistic quantum theory developed by the author starting from the E.C.G. Stueckelberg approach proposed in the early 40s. In this framework a universal invariant evolution parameter (corresponding to the time originally postulated by Newton) is introduced to describe dynamical evolution. This theory is able to provide solutions for some of the fundamental problems encountered in early attempts to construct a relativistic quantum theory. A relativistically covariant construction is given for which particle spins and angular momenta can be combined through the usual rotation group Clebsch-Gordan coefficients. Solutions are defined for both the classical and quantum two body bound state and scattering problems. The recently developed quantum Lax-Phillips theory of semigroup evolution of resonant states is described. The experiment of Lindner and coworkers on interference in time is discussed showing how the property of coherence in time provides a simple understanding of the results. Th...
Relativistic theories of materials
Bressan, Aldo
1978-01-01
The theory of relativity was created in 1905 to solve a problem concerning electromagnetic fields. That solution was reached by means of profound changes in fundamental concepts and ideas that considerably affected the whole of physics. Moreover, when Einstein took gravitation into account, he was forced to develop radical changes also in our space-time concepts (1916). Relativistic works on heat, thermodynamics, and elasticity appeared as early as 1911. However, general theories having a thermodynamic basis, including heat conduction and constitutive equations, did not appear in general relativity until about 1955 for fluids and appeared only after 1960 for elastic or more general finitely deformed materials. These theories dealt with materials with memory, and in this connection some relativistic versions of the principle of material indifference were considered. Even more recently, relativistic theories incorporating finite deformations for polarizable and magnetizable materials and those in which couple s...
Handbook of relativistic quantum chemistry
International Nuclear Information System (INIS)
Liu, Wenjian
2017-01-01
This handbook focuses on the foundations of relativistic quantum mechanics and addresses a number of fundamental issues never covered before in a book. For instance: How can many-body theory be combined with quantum electrodynamics? How can quantum electrodynamics be interfaced with relativistic quantum chemistry? What is the most appropriate relativistic many-electron Hamiltonian? How can we achieve relativistic explicit correlation? How can we formulate relativistic properties? - just to name a few. Since relativistic quantum chemistry is an integral component of computational chemistry, this handbook also supplements the ''Handbook of Computational Chemistry''. Generally speaking, it aims to establish the 'big picture' of relativistic molecular quantum mechanics as the union of quantum electrodynamics and relativistic quantum chemistry. Accordingly, it provides an accessible introduction for readers new to the field, presents advanced methodologies for experts, and discusses possible future perspectives, helping readers understand when/how to apply/develop the methodologies.
Handbook of relativistic quantum chemistry
Energy Technology Data Exchange (ETDEWEB)
Liu, Wenjian (ed.) [Peking Univ., Beijing (China). Center for Computational Science and Engineering
2017-03-01
This handbook focuses on the foundations of relativistic quantum mechanics and addresses a number of fundamental issues never covered before in a book. For instance: How can many-body theory be combined with quantum electrodynamics? How can quantum electrodynamics be interfaced with relativistic quantum chemistry? What is the most appropriate relativistic many-electron Hamiltonian? How can we achieve relativistic explicit correlation? How can we formulate relativistic properties? - just to name a few. Since relativistic quantum chemistry is an integral component of computational chemistry, this handbook also supplements the ''Handbook of Computational Chemistry''. Generally speaking, it aims to establish the 'big picture' of relativistic molecular quantum mechanics as the union of quantum electrodynamics and relativistic quantum chemistry. Accordingly, it provides an accessible introduction for readers new to the field, presents advanced methodologies for experts, and discusses possible future perspectives, helping readers understand when/how to apply/develop the methodologies.
Open heavy-flavor measurements in ultra-relativistic nuclear collisions
Energy Technology Data Exchange (ETDEWEB)
Averbeck, Ralf
2016-12-15
Recent results from open heavy-flavor measurements in proton-proton (pp), proton/deuteron-nucleus (p/d-A), and nucleus-nucleus collisions (A-A) at RHIC and at the LHC are presented. Predictions from theoretical models are compared with the data, and implications for the properties of the hot and dense medium produced in ultra-relativistic heavy-ion collisions are discussed.
Biquaternions and relativistic kinematics
International Nuclear Information System (INIS)
Bogush, A.A.; Kurochkin, Yu.A.; Fedorov, F.I.
1979-01-01
The problems concerning the use of quaternion interpretation of the Lorentz group vector parametrization are considered for solving relativistic kinematics problems. A vector theory convenient for describing the characteristic features of the Lobachevsky space is suggested. The kinematics of elementary particle scattering is investigated on the basis of this theory. A synthesis of vector parametrization and of quaternion calculation has been shown to lead to natural formulation of the theory of vectors in the three-dimensional Lobachevsky space, realized on mass hyperboloids of relativistic particles
Relativistic heavy ion collisions
International Nuclear Information System (INIS)
Barz, H.W.; Kaempfer, B.; Schulz, H.
1984-12-01
An elementary introduction is given into the scenario of relativistic heavy ion collisions. It deals with relativistic kinematics and estimates of energy densities, extrapolations of the present knowledge of hadron-hadron and hadron-nuleus to nucleus-nucleus collisions, the properties of the quark-gluon plasma and the formation of the plasma and possible experimental signatures. Comments are made on a cosmic ray experiment which could be interpreted as a first indication of the quark-gluon phase of the matter. (author)
Relativistic particle in a box
Alberto, P.; Fiolhais, Carlos; Gil, Victor
1996-01-01
The problem of a relativistic spin 1/2 particle confined to a one-dimensional box is solved in a way that resembles closely the solution of the well known quantum-mechanical textbook problem of a non-relativistic particle in a box. The energy levels and probability density are computed and compared with the non-relativistic case
Relativistic mean field theory for unstable nuclei
International Nuclear Information System (INIS)
Toki, Hiroshi
2000-01-01
We discuss the properties of unstable nuclei in the framework of the relativistic mean field (RMF) theory. We take the RMF theory as a phenomenological theory with several parameters, whose form is constrained by the successful microscopic theory (RBHF), and whose values are extracted from the experimental values of unstable nuclei. We find the outcome with the newly obtained parameter sets (TM1 and TMA) is promising in comparison with various experimental data. We calculate systematically the ground state properties of even-even nuclei up to the drip lines; about 2000 nuclei. We find that the neutron magic shells (N=82, 128) at the standard magic numbers stay at the same numbers even far from the stability line and hence provide the feature of the r-process nuclei. However, many proton magic numbers disappear at the neutron numbers far away from the magic numbers due to the deformations. We discuss how to describe giant resonances for the case of the non-linear coupling terms for the sigma and omega mesons in the relativistic RPA. We mention also the importance of the relativistic effect on the spin observables as the Gamow-Teller strength and the longitudinal and transverse spin responses. (author)
Development of the relativistic impulse approximation
International Nuclear Information System (INIS)
Wallace, S.J.
1985-01-01
This talk contains three parts. Part I reviews the developments which led to the relativistic impulse approximation for proton-nucleus scattering. In Part II, problems with the impulse approximation in its original form - principally the low energy problem - are discussed and traced to pionic contributions. Use of pseudovector covariants in place of pseudoscalar ones in the NN amplitude provides more satisfactory low energy results, however, the difference between pseudovector and pseudoscalar results is ambiguous in the sense that it is not controlled by NN data. Only with further theoretical input can the ambiguity be removed. Part III of the talk presents a new development of the relativistic impulse approximation which is the result of work done in the past year and a half in collaboration with J.A. Tjon. A complete NN amplitude representation is developed and a complete set of Lorentz invariant amplitudes are calculated based on a one-meson exchange model and appropriate integral equations. A meson theoretical basis for the important pair contributions to proton-nucleus scattering is established by the new developments. 28 references
Relativistic impulse dynamics.
Swanson, Stanley M
2011-08-01
Classical electrodynamics has some annoying rough edges. The self-energy of charges is infinite without a cutoff. The calculation of relativistic trajectories is difficult because of retardation and an average radiation reaction term. By reconceptuallizing electrodynamics in terms of exchanges of impulses rather than describing it by forces and potentials, we eliminate these problems. A fully relativistic theory using photonlike null impulses is developed. Numerical calculations for a two-body, one-impulse-in-transit model are discussed. A simple relationship between center-of-mass scattering angle and angular momentum was found. It reproduces the Rutherford cross section at low velocities and agrees with the leading term of relativistic distinguishable-particle quantum cross sections (Møller, Mott) when the distance of closest approach is larger than the Compton wavelength of the particle. Magnetism emerges as a consequence of viewing retarded and advanced interactions from the vantage point of an instantaneous radius vector. Radiation reaction becomes the local conservation of energy-momentum between the radiating particle and the emitted impulse. A net action is defined that could be used in developing quantum dynamics without potentials. A reinterpretation of Newton's laws extends them to relativistic motion.
Non-relativistic supersymmetry
International Nuclear Information System (INIS)
Clark, T.E.; Love, S.T.
1984-01-01
The most general one- and two-body hamiltonian invariant under galilean supersymmetry is constructed in superspace. The corresponding Feynman rules are given for the superfield Green functions. As demonstrated by a simple example, it is straightforward to construct models in which the supersymmetry is spontaneously broken by the non-relativistic vacuum. (orig.)
International Nuclear Information System (INIS)
Contopoulos, G.
1983-01-01
In this paper, three main areas of relativistic stellar dynamics are reviewed: (a) The dynamics of clusters, or nuclei of galaxies, of very high density; (b) The dynamics of systems containing a massive black hole; and (c) The dynamics of particles (and photons) in an expanding Universe. The emphasis is on the use of orbit perturbations. (Auth.)
Directory of Open Access Journals (Sweden)
Bialynicki-Birula Iwo
2014-01-01
Full Text Available Original definition of the Wigner function can be extended in a natural manner to relativistic domain in the framework of quantum field theory. Three such generalizations are described. They cover the cases of the Dirac particles, the photon, and the full electromagnetic field.
Antippa, Adel F.
2009-01-01
We solve the problem of the relativistic rocket by making use of the relation between Lorentzian and Galilean velocities, as well as the laws of superposition of successive collinear Lorentz boosts in the limit of infinitesimal boosts. The solution is conceptually simple, and technically straightforward, and provides an example of a powerful…
Relativistic few body calculations
International Nuclear Information System (INIS)
Gross, F.
1988-01-01
A modern treatment of the nuclear few-body problem must take into account both the quark structure of baryons and mesons, which should be important at short range, and the relativistic exchange of mesons, which describes the long range, peripheral interactions. A way to model both of these aspects is described. The long range, peripheral interactions are calculated using the spectator model, a general approach in which the spectators to nucleon interactions are put on their mass-shell. Recent numerical results for a relativistic OBE model of the NN interaction, obtained by solving a relativistic equation with one-particle on mass-shell, will be presented and discussed. Two meson exchange models, one with only four mesons (π,σ,/rho/,ω) but with a 25% admixture of γ 5 coupling for the pion, and a second with six mesons (π,σ,/rho/,ω,δ,/eta/) but pure γ 5 γ/sup μ/ pion coupling, are shown to give very good quantitative fits to the NN scattering phase shifts below 400 MeV, and also a good description of the /rvec p/ 40 Ca elastic scattering observables. Applications of this model to electromagnetic interactions of the two body system, with emphasis on the determination of relativistic current operators consistent with the dynamics and the exact treatment of current conservation in the presence of phenomenological form factors, will be described. 18 refs., 8 figs
Relativistic Polarizable Embedding
DEFF Research Database (Denmark)
Hedegård, Erik Donovan; Bast, Radovan; Kongsted, Jacob
2017-01-01
Most chemistry, including chemistry where relativistic effects are important, occurs in an environment, and in many cases, this environment has a significant effect on the chemistry. In nonrelativistic quantum chemistry, a lot of progress has been achieved with respect to including environments s...
Relativistic length agony continued
Directory of Open Access Journals (Sweden)
Redžić D.V.
2014-01-01
Full Text Available We made an attempt to remedy recent confusing treatments of some basic relativistic concepts and results. Following the argument presented in an earlier paper (Redžić 2008b, we discussed the misconceptions that are recurrent points in the literature devoted to teaching relativity such as: there is no change in the object in Special Relativity, illusory character of relativistic length contraction, stresses and strains induced by Lorentz contraction, and related issues. We gave several examples of the traps of everyday language that lurk in Special Relativity. To remove a possible conceptual and terminological muddle, we made a distinction between the relativistic length reduction and relativistic FitzGerald-Lorentz contraction, corresponding to a passive and an active aspect of length contraction, respectively; we pointed out that both aspects have fundamental dynamical contents. As an illustration of our considerations, we discussed briefly the Dewan-Beran-Bell spaceship paradox and the ‘pole in a barn’ paradox. [Projekat Ministarstva nauke Republike Srbije, br. 171028
Relativistic Coulomb excitation
International Nuclear Information System (INIS)
Winther, A.; Alder, K.
1979-01-01
Coulomb excitation of both target and projectile in relativistic heavy ion collisions is evaluated including the lowest order correction for the deviation from a straight line trajectory. Explicit results for differential and total cross sections are given in the form of tables and figures. (Auth.)
Fundamental Relativistic Rotator
International Nuclear Information System (INIS)
Staruszkiewicz, A.
2008-01-01
Professor Jan Weyssenhoff was Myron Mathisson's sponsor and collaborator. He introduced a class of objects known in Cracow as '' kreciolki Weyssenhoffa '', '' Weyssenhoff's rotating little beasts ''. The Author describes a particularly simple object from this class. The relativistic rotator described in the paper is such that its both Casimir invariants are parameters rather than constants of motion. (author)
Relativistic Quantum Mechanics
International Nuclear Information System (INIS)
Antoine, J-P
2004-01-01
The aim of relativistic quantum mechanics is to describe the finer details of the structure of atoms and molecules, where relativistic effects become nonnegligible. It is a sort of intermediate realm, between the familiar nonrelativistic quantum mechanics and fully relativistic quantum field theory, and thus it lacks the simplicity and elegance of both. Yet it is a necessary tool, mostly for quantum chemists. Pilkuhn's book offers to this audience an up-to-date survey of these methods, which is quite welcome since most previous textbooks are at least ten years old. The point of view of the author is to start immediately in the relativistic domain, following the lead of Maxwell's equations rather than classical mechanics, and thus to treat the nonrelativistic version as an approximation. Thus Chapter 1 takes off from Maxwell's equations (in the noncovariant Coulomb gauge) and gradually derives the basic aspects of Quantum Mechanics in a rather pedestrian way (states and observables, Hilbert space, operators, quantum measurement, scattering,. Chapter 2 starts with the Lorentz transformations, then continues with the Pauli spin equation and the Dirac equation and some of their applications (notably the hydrogen atom). Chapter 3 is entitled 'Quantum fields and particles', but falls short of treating quantum field theory properly: only creation/annihilation operators are considered, for a particle in a box. The emphasis is on two-electron states (the Pauli principle, the Foldy--Wouthuysen elimination of small components of Dirac spinors, Breit projection operators. Chapter 4 is devoted to scattering theory and the description of relativistic bound states. Chapter 5, finally, covers hyperfine interactions and radiative corrections. As we said above, relativistic quantum mechanics is by nature limited in scope and rather inelegant and Pilkuhn's book is no exception. The notation is often heavy (mostly noncovariant) and the mathematical level rather low. The central topic
Pinto, V. A.; Bortnik, J.; Moya, P. S.; Lyons, L. R.; Sibeck, D. G.; Kanekal, S. G.
2017-12-01
Using Van Allen Probes Relativistic Electron-Proton Telescope (REPT) instrument we have identified 73 relativistic electron enhancement events in the outer radiation belt that occurred at different L values between L = 2.5 and L = 6.0. To determine an enhancement, we have used three different identification methods. We then determine the radial location, MLT location, timing and strength of those enhancements. We discuss the differences of each of the methods and test them to pinpoint the origin and spatial propagation of each enhancement. We have classified the events based on the radial propagation, speed of enhancement and intensity of fluxes and response for energy channels ranging from 1.8 MeV to 6.3 MeV. In addition, we have used OMNI data to study the statistical properties of the solar wind during each event and have classified similarities and differences that might be relevant for each group of enhancements and help us determine the physical process responsible for different types of enhancements. Additionally, we have used >2 MeV electron fluxes at geostationary orbit as measured by the GOES 13 and 15 Energetic Particle Sensor (EPS) instrument to compare our results with the geostationary orbit. Our results suggest that under certain conditions GOES data can be used to predict fluxes at the core of the radiation belt and vice-versa.
New approximation for Glauber theory on stripping of relativistic deuterons
International Nuclear Information System (INIS)
Nissen-Meyer, S.A.
1978-03-01
The momentum distribution of forward protons from relativistic collisions of deuterons with nuclei is computed from a Glauber theoretical Ansatz of Bertocchi and Tekou. The outgoing proton-neutron scattering state (disintegrated deuteron) with a plane wave minus the components of this plane wave along the deuteron bound state vector is approximated. With no fitted parameters good agreement is found with data from the reaction d + C 12 → p + X in the region corresponding to nonrelativistic Fermi momenta in the forward direction. At more relativistic Fermi momenta, the model deviates more from the data, which can be due to incorrect choice of the short distance part of the deuteron wave function as well as off-shell effects in the deuteron
The relativistic gravity train
Seel, Max
2018-05-01
The gravity train that takes 42.2 min from any point A to any other point B that is connected by a straight-line tunnel through Earth has captured the imagination more than most other applications in calculus or introductory physics courses. Brachystochron and, most recently, nonlinear density solutions have been discussed. Here relativistic corrections are presented. It is discussed how the corrections affect the time to fall through Earth, the Sun, a white dwarf, a neutron star, and—the ultimate limit—the difference in time measured by a moving, a stationary and the fiducial observer at infinity if the density of the sphere approaches the density of a black hole. The relativistic gravity train can serve as a problem with approximate and exact analytic solutions and as numerical exercise in any introductory course on relativity.
Relativistic gravitational instabilities
International Nuclear Information System (INIS)
Schutz, B.F.
1987-01-01
The purpose of these lectures is to review and explain what is known about the stability of relativistic stars and black holes, with particular emphases on two instabilities which are due entirely to relativistic effects. The first of these is the post-Newtonian pulsational instability discovered independently by Chandrasekhar (1964) and Fowler (1964). This effectively ruled out the then-popular supermassive star model for quasars, and it sets a limit to the central density of white dwarfs. The second instability was also discovered by Chandrasekhar (1970): the gravitational wave induced instability. This sets an upper bound on the rotation rate of neutron stars, which is near that of the millisecond pulsar PSR 1937+214, and which is beginning to constrain the equation of state of neutron matter. 111 references, 5 figures
Relativistic studies in actinides
International Nuclear Information System (INIS)
Weinberger, P.; Gonis, A.
1987-01-01
In this review the theoretical background is given for a relativistic description for actinide systems. A short introduction is given of the density functional theory which forms the basis for a fully relativistic single-particle theory. A section on the Dirac Hamiltonian is followed by a brief summary on group theoretical concepts. Single site scattering is presented such that formal extensions to the case of the presence of an internal (external) magnetic field and/or anisotropic scattering are evident. Multiple scattering is discussed such that it can readily be applied also to the problem of dislocations. In connection with the problem of selfconsistency particular attention is drawn to the use of complex energies. Finally the various theoretical aspects discussed are illustrated through the results of numerical calculations. 101 refs.; 37 figs.; 5 tabs
Relativistic heavy ion experiments at BNL-AGS
International Nuclear Information System (INIS)
Miake, Yasuo
1992-01-01
Relativistic heavy ion program at BNL started in 1986. Already a few experiments have achieved their first goals. Several interesting features reported among which are: The black nuclear transparency, the enhanced K + /π + ratio and the larger t > for K + and proton in central Si+Au collisions. Comparisons of m t and dn/dy distributions between pp, pA and AA are discussed together with various model calculations. (orig.)
Cluster approach to intranuclear cascade for relativistic heavy ion colisions
International Nuclear Information System (INIS)
Kodama, T.; Duarte, S.B.; Chung, K.C.; Nazareth, R.A.M.S.
1982-01-01
A new approach to the intranuclear cascade model for relativistic heavy ion reaction is presented. The effect of nucleon conventration on the collision process is explicitly included. It is found that the contributions from the non-binary processes are far from being negligible. Such processes are shown to broaden the angular distribution of inclusive proton spectra for 20 Ne + 238 U head-on collisions. (Author) [pt
RPA correlations and nuclear densities in relativistic mean field approach
International Nuclear Information System (INIS)
Van Giai, N.; Liang, H.Z.; Meng, J.
2007-02-01
The relativistic mean field approach (RMF) is well known for describing accurately binding energies and nucleon distributions in atomic nuclei throughout the nuclear chart. The random phase approximation (RPA) built on top of the RMF is also a good framework for the study of nuclear excitations. Here, we examine the consequences of long range correlations brought about by the RPA on the neutron and proton densities as given by the RMF approach. (authors)
Relativistic Calculations and Measurements of Energies, Auger Rates, and Lifetimes.
1982-12-01
Research and Industry, Denton, Texas, 8-10 November 1982. 7. B. Crasemann: "Efectos Relativ’sticos y de QED Sobre las Transiciones Rayos - X y Auger Entre...INNER-SHELL IONIZATION BY PROTONS X -RAY EMISSION BREIT INTERACTION AUGER TRANSITIONS DIRAC-HARTREE-SLATER COMPUTATIONS SYNCHROTRON RADIATION RESONANT...computations, including relativistic and quantum- electrodynamic effects, of atomic energy levels and of x -ray and Auger transitions in atoms with one or
International Nuclear Information System (INIS)
Hines, D.F.; Frankel, N.E.
1979-01-01
The charged Bose has been previously studied as a many body problem of great intrinsic interest which can also serve as a model of some real physical systems, for example, superconductors, white dwarf stars and neutron stars. In this article the excitation spectrum of a relativistic spin-zero charged Bose gas is obtained in a dielectric response formulation. Relativity introduces a dip in the spectrum and consequences of this dip for the thermodynamic functions are discussed
Relativistic heavy ion reactions
Energy Technology Data Exchange (ETDEWEB)
Brink, D M
1989-08-01
The theory of quantum chromodynamics predicts that if nuclear matter is heated to a sufficiently high temperature then quarks might become deconfined and a quark-gluon plasma could be produced. One of the aims of relativistic heavy ion experiments is to search for this new state of matter. These lectures survey some of the new experimental results and give an introduction to the theories used to interpret them. 48 refs., 4 tabs., 11 figs.
Bratek, Łukasz
2015-01-01
Two particularly simple ideal clocks exhibiting intrinsic circular motion with the speed of light and opposite spin alignment are described. The clocks are singled out by singularities of an inverse Legendre transformation for relativistic rotators of which mass and spin are fixed parameters. Such clocks work always the same way, no matter how they move. When subject to high accelerations or falling in strong gravitational fields of black holes, the clocks could be used to test the clock hypo...
Relativistic heavy ion reactions
International Nuclear Information System (INIS)
Brink, D.M.
1989-08-01
The theory of quantum chromodynamics predicts that if nuclear matter is heated to a sufficiently high temperature then quarks might become deconfined and a quark-gluon plasma could be produced. One of the aims of relativistic heavy ion experiments is to search for this new state of matter. These lectures survey some of the new experimental results and give an introduction to the theories used to interpret them. 48 refs., 4 tabs., 11 figs
Gravitationally confined relativistic neutrinos
Vayenas, C. G.; Fokas, A. S.; Grigoriou, D.
2017-09-01
Combining special relativity, the equivalence principle, and Newton’s universal gravitational law with gravitational rather than rest masses, one finds that gravitational interactions between relativistic neutrinos with kinetic energies above 50 MeV are very strong and can lead to the formation of gravitationally confined composite structures with the mass and other properties of hadrons. One may model such structures by considering three neutrinos moving symmetrically on a circular orbit under the influence of their gravitational attraction, and by assuming quantization of their angular momentum, as in the Bohr model of the H atom. The model contains no adjustable parameters and its solution, using a neutrino rest mass of 0.05 eV/c2, leads to composite state radii close to 1 fm and composite state masses close to 1 GeV/c2. Similar models of relativistic rotating electron - neutrino pairs give a mass of 81 GeV/c2, close to that of W bosons. This novel mechanism of generating mass suggests that the Higgs mass generation mechanism can be modeled as a latent gravitational field which gets activated by relativistic neutrinos.
Point form relativistic quantum mechanics and relativistic SU(6)
Klink, W. H.
1993-01-01
The point form is used as a framework for formulating a relativistic quantum mechanics, with the mass operator carrying the interactions of underlying constituents. A symplectic Lie algebra of mass operators is introduced from which a relativistic harmonic oscillator mass operator is formed. Mass splittings within the degenerate harmonic oscillator levels arise from relativistically invariant spin-spin, spin-orbit, and tensor mass operators. Internal flavor (and color) symmetries are introduced which make it possible to formulate a relativistic SU(6) model of baryons (and mesons). Careful attention is paid to the permutation symmetry properties of the hadronic wave functions, which are written as polynomials in Bargmann spaces.
Numerical modeling of the pulsar wind interaction with ISM
Bogovalov, S. V.; Chechetkin, V. M.; Koldoba, A. V.; Ustyugova, G. V.; Battiston, R; Shea, MA; Rakowski, C; Chatterjee, S
2006-01-01
Time dependent numerical simulation of relativistic wind interaction with interstellar medium was performed. The winds are ejected from magnetosphere of rotation powered pulsars. The particle flux in the winds is assumed to be isotropic. The energy flux is taken as strongly anisotropic in accordance
Consequences of Relativistic Neutron Outflow beyond the Accretion Disks of Active Galaxies
Ekejiuba, I. E.; Okeke, P. N.
1993-05-01
Three channels of relativistic electron injection in the jets of extragalactic radio sources (EGRSs) are discussed. With the assumption that an active galactic nucleus (AGN) is powered by a spinning supermassive black hole of mass ~ 10(8) M_⊙ which sits at the center of the nucleus and ingests matter and energy through an accretion disk, a model for extracting relativistic neutrons from the AGN is forged. In this model, the inelastic proton--proton and proton--photon interactions within the accretion disk, of relativistic protons with background thermal protons and photons, respectively, produce copious amounts of relativistic neutrons. These neutrons travel ballistically for ~ 10(3gamma_n ) seconds and escape from the disk before they decay. The secondary particles produced from the neutron decays then interact with the ambient magnetic field and/or other particles to produce the radio emissions observed in the jets of EGRSs. IEE acknowledges the support of the World Bank and the Federal University of Technology, Yola, Nigeria as well as the hospitality of Georgia State University.
International Nuclear Information System (INIS)
Smith, Alfred R
2006-01-01
Proton therapy has become a subject of considerable interest in the radiation oncology community and it is expected that there will be a substantial growth in proton treatment facilities during the next decade. I was asked to write a historical review of proton therapy based on my personal experiences, which have all occurred in the United States, so therefore I have a somewhat parochial point of view. Space requirements did not permit me to mention all of the existing proton therapy facilities or the names of all of those who have contributed to proton therapy. (review)
Relativistic twins or sextuplets?
International Nuclear Information System (INIS)
Sheldon, Eric
2003-01-01
A recent study of the relativistic twin 'paradox' by Soni in this journal affirmed that 'A simple solution of the twin paradox also shows anomalous behaviour of rigidly connected distant clocks' but entailed a pedagogic hurdle which the present treatment aims to surmount. Two scenarios are presented: the first 'flight-plan' is akin to that depicted by Soni, with constant-velocity segments, while the second portrays an alternative mission undertaken with sustained acceleration and deceleration, illustrated quantitatively for a two-way spacecraft flight from Earth to Polaris (465.9 light years distant) and back
Relativistic twins or sextuplets?
Sheldon, E S
2003-01-01
A recent study of the relativistic twin 'paradox' by Soni in this journal affirmed that 'A simple solution of the twin paradox also shows anomalous behaviour of rigidly connected distant clocks' but entailed a pedagogic hurdle which the present treatment aims to surmount. Two scenarios are presented: the first 'flight-plan' is akin to that depicted by Soni, with constant-velocity segments, while the second portrays an alternative mission undertaken with sustained acceleration and deceleration, illustrated quantitatively for a two-way spacecraft flight from Earth to Polaris (465.9 light years distant) and back.
Relativistic quantum cryptography
Kaniewski, Jedrzej
Special relativity states that information cannot travel faster than the speed of light, which means that communication between agents occupying distinct locations incurs some minimal delay. Alternatively, we can see it as temporary communication constraints between distinct agents and such constraints turn out to be useful for cryptographic purposes. In relativistic cryptography we consider protocols in which interactions occur at distinct locations at well-defined times and we investigate why such a setting allows to implement primitives which would not be possible otherwise. (Abstract shortened by UMI.).
Relativistic distances, sizes, lengths
International Nuclear Information System (INIS)
Strel'tsov, V.N.
1992-01-01
Such notion as light or retarded distance, field size, formation way, visible size of a body, relativistic or radar length and wave length of light from a moving atom are considered. The relation between these notions is cleared up, their classification is given. It is stressed that the formation way is defined by the field size of a moving particle. In the case of the electromagnetic field, longitudinal sizes increase proportionally γ 2 with growing charge velocity (γ is the Lorentz-factor). 18 refs
Localization of relativistic particles
International Nuclear Information System (INIS)
Omnes, R.
1997-01-01
In order to discuss localization experiments and also to extend the consistent history interpretation of quantum mechanics to relativistic properties, the techniques introduced in a previous paper [J. Math. Phys. 38, 697 (1997)] are applied to the localization of a photon in a given region of space. An essential requirement is to exclude arbitrarily large wavelengths. The method is valid for a particle with any mass and spin. Though there is no proper position operator for a photon, one never needs one in practice. Causality is valid up to exponentially small corrections. copyright 1997 American Institute of Physics
Corinaldesi, Ernesto
1963-01-01
Geared toward advanced undergraduate and graduate students of physics, this text provides readers with a background in relativistic wave mechanics and prepares them for the study of field theory. The treatment originated as a series of lectures from a course on advanced quantum mechanics that has been further amplified by student contributions.An introductory section related to particles and wave functions precedes the three-part treatment. An examination of particles of spin zero follows, addressing wave equation, Lagrangian formalism, physical quantities as mean values, translation and rotat
Relativistic quarkonium dynamics
International Nuclear Information System (INIS)
Sazdjian, H.
1985-06-01
We present, in the framework of relativistic quantum mechanics of two interacting particles, a general model for quarkonium systems satisfying the following four requirements: confinement, spontaneous breakdown of chiral symmetry, soft explicit chiral symmetry breaking, short distance interactions of the vector type. The model is characterized by two arbitrary scalar functions entering in the large and short distance interaction potentials, respectively. Using relationships with corresponding quantities of the Bethe-Salpeter equation, we also present the normalization condition of the wave functions, as well as the expressions of the meson decay coupling constants. The quark masses appear in this model as free parameters
[Relativistic heavy ion research
International Nuclear Information System (INIS)
1991-01-01
The present document describes our second-year application for a continuation grant on relativistic heavy-ion research at Nevis Laboratories, Columbia University, over the two-year period starting from November 15, 1990. The progress during the current budget year is presented. This year, construction of RHIC officially began. As a result, the entire Nevis nuclear physics group has made a coherent effort to create new proposal for an Open Axially Symmetric Ion Spectrometer (OASIS) proposal. Future perspectives and our plans for this proposal are described
Lamastra, A.; Menci, N.; Fiore, F.; Antonelli, L. A.; Colafrancesco, S.; Guetta, D.; Stamerra, A.
2017-10-01
We derive the contribution to the extragalactic gamma-ray background (EGB) from active galactic nuclei (AGN) winds and star-forming galaxies by including a physical model for the γ-ray emission produced by relativistic protons accelerated by AGN-driven and supernova-driven shocks into a state-of-the-art semi-analytic model of galaxy formation. This is based on galaxy interactions as triggers of AGN accretion and starburst activity and on expanding blast waves as the mechanism to communicate outwards the energy injected into the interstellar medium by the active nucleus. We compare the model predictions with the latest measurement of the EGB spectrum performed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) in the range between 100 MeV and 820 GeV. We find that AGN winds can provide 35 ± 15% of the observed EGB in the energy interval Eγ = 0.1-1 GeV, for 73 ± 15% at Eγ = 1-10 GeV, and for 60 ± 20% at Eγ ≳10 GeV. The AGN wind contribution to the EGB is predicted to be larger by a factor of 3-5 than that provided by star-forming galaxies (quiescent plus starburst) in the hierarchical clustering scenario. The cumulative γ-ray emission from AGN winds and blazars can account for the amplitude and spectral shape of the EGB, assuming the standard acceleration theory, and AGN wind parameters that agree with observations. We also compare the model prediction for the cumulative neutrino background from AGN winds with the most recent IceCube data. We find that for AGN winds with accelerated proton spectral index p = 2.2-2.3, and taking into account internal absorption of γ-rays, the Fermi-LAT and IceCube data could be reproduced simultaneously.
International Nuclear Information System (INIS)
Chultehm, D.; Damdinsurehn, Ts.; D'yachenko, V.M.; Ehnkhzhin, L.; Lomova, L.A.; Perelygin, V.P.; Tolstov, K.D.
1994-01-01
The present paper describes a method of determining the total number of neutrons generated in an extended lead target by relativistic nuclei and protons. It is shown that 101±20 neutrons per proton are produced in the target with the volume of 50x50x80 cm 3 at 3.65 GeV energy of protons. 11 refs., 14 figs., 1 tab
Relativistic approach to nuclear structure
International Nuclear Information System (INIS)
Nguyen Van Giai; Bouyssy, A.
1987-03-01
Some recent works related with relativistic models of nuclear structure are briefly reviewed. The Dirac-Hartree-Fock and Dirac-Brueckner-Hartree-Fock are recalled and illustrated by some examples. The problem of isoscalar current and magnetic moments of odd nuclei is discussed. The application of the relativistic model to the nuclear response function is examined
Relativistic dynamics without conservation laws
Rothenstein, Bernhard; Popescu, Stefan
2006-01-01
We show that relativistic dynamics can be approached without using conservation laws (conservation of momentum, of energy and of the centre of mass). Our approach avoids collisions that are not easy to teach without mnemonic aids. The derivations are based on the principle of relativity and on its direct consequence, the addition law of relativistic velocities.
Relativistic non-Hamiltonian mechanics
International Nuclear Information System (INIS)
Tarasov, Vasily E.
2010-01-01
Relativistic particle subjected to a general four-force is considered as a nonholonomic system. The nonholonomic constraint in four-dimensional space-time represents the relativistic invariance by the equation for four-velocity u μ u μ + c 2 = 0, where c is the speed of light in vacuum. In the general case, four-forces are non-potential, and the relativistic particle is a non-Hamiltonian system in four-dimensional pseudo-Euclidean space-time. We consider non-Hamiltonian and dissipative systems in relativistic mechanics. Covariant forms of the principle of stationary action and the Hamilton's principle for relativistic mechanics of non-Hamiltonian systems are discussed. The equivalence of these principles is considered for relativistic particles subjected to potential and non-potential forces. We note that the equations of motion which follow from the Hamilton's principle are not equivalent to the equations which follow from the variational principle of stationary action. The Hamilton's principle and the principle of stationary action are not compatible in the case of systems with nonholonomic constraint and the potential forces. The principle of stationary action for relativistic particle subjected to non-potential forces can be used if the Helmholtz conditions are satisfied. The Hamilton's principle and the principle of stationary action are equivalent only for a special class of relativistic non-Hamiltonian systems.
Experiments with stored relativistic exotic nuclei
International Nuclear Information System (INIS)
Klepper, O.; Attallah, F.; Beckert, K.; Bosch, F.; Dolinskiy, A.; Eickhoff, H.; Franczak, B.; Franzke, B.; Geissel, H.; Hausmann, M.; Hellstroem, M.; Herfurth, F.; Kluge, H.-J.; Kozhuharov, C.; Muenzenberg, G.; Nolden, F.; Quint, W.; Tradon, T.; Reich, H.; Scheidenberger, C.; Schlitt, B.; Steck, M.; Suemmerer, K.; Vermeeren, L.; Winkler, M.; Winkler, Th.; Falch, M.; Kerscher, Th.; Loebner, K.E.G.; Fujita, Y.; Novikov, Yu.; Patyk, Z.; Stadlmann, J.; Wollnik, H.
1999-01-01
Beams of relativistic exotic nuclei were produced, separated and investigated with the combination of the fragment separator FRS and the storage ring ESR. The following experiments are presented: 1) Direct mass measurements of relativistic nickel and bismuth projectile fragments were performed using Schottky spectrometry. Applying electron cooling, the relative velocity spread of the circulating secondary nuclear beams of low intensity was reduced to below 10 -6 . The achieved mass resolving power of m/Δm = 6.5·10 5 (FWHM) in recent measurements represents an improvement by a factor of two compared to authors' previous experiments. The previously unknown masses of more than 100 proton-rich isotopes have been measured in the range of 54≤Z≤84. The results are compared with mass models and estimated values based on extrapolations of experimental values. 2) Exotic nuclei with half-lives shorter than the time required for electron cooling can be investigated by time-of-flight measurements with the ESR being operated in the isochronous mode. This novel experimental technique has been successfully applied in a first measurement with nickel fragments. A mass resolving power of m/Δm = 1.5·10 5 (FWHM) was achieved in this mode of operation. 3) Nuclear half-lives of stored and cooled bare projectile fragments have been measured to study the influence of the ionic charge state on the beta-decay probability
Contraint's theory and relativistic dynamics
International Nuclear Information System (INIS)
Longhi, G.; Lusanna, L.
1987-01-01
The purpose of this Workshop was to examine the current situation of relativistic dynamics. In particular, Dirac-Bergmann's theory of constraints, which lies at the heart of gauge theories, general relativity, relativistic mechanics and string theories, was chosen as the unifying theoretical framework best suited to investigate such a field. The papers discussed were on general relativity; relativistic mechanics; particle physics and mathematical physics. Also discussed were the problems of classical and quantum level, namely the identification of the classical observables of constrained systems, the equivalence of the nonequivalence of the various ways to quantize such systems; the problem of the anomalies; the best geometrical approach to the theory of constraints; the possibility of unifying all the treatments of relativistic mechanics. This book compiles the papers presented at proceedings of relativistic dynamics and constraints theory
Relativistic centrifugal instability
Gourgouliatos, Konstantinos N.; Komissarov, Serguei S.
2018-03-01
Near the central engine, many astrophysical jets are expected to rotate about their axis. Further out they are expected to go through the processes of reconfinement and recollimation. In both these cases, the flow streams along a concave surface and hence, it is subject to the centrifugal force. It is well known that such flows may experience the centrifugal instability (CFI), to which there are many laboratory examples. The recent computer simulations of relativistic jets from active galactic nuclei undergoing the process of reconfinement show that in such jets CFI may dominate over the Kelvin-Helmholtz instability associated with velocity shear (Gourgouliatos & Komissarov). In this letter, we generalize the Rayleigh criterion for CFI in rotating fluids to relativistic flows using a heuristic analysis. We also present the results of computer simulations which support our analytic criterion for the case of an interface separating two uniformly rotating cylindrical flows. We discuss the difference between CFI and the Rayleigh-Taylor instability in flows with curved streamlines.
Relativistic heavy ion physics
International Nuclear Information System (INIS)
Hill, J.C.; Wohn, F.K.
1992-01-01
In 1992 a proposal by the Iowa State University experimental nuclear physics group entitled ''Relativistic Heavy Ion Physics'' was funded by the US Department of Energy, Office of Energy Research, for a three-year period beginning November 15, 1991. This is a progress report for the first six months of that period but, in order to give a wider perspective, we report here on progress made since the beginning of calendar year 1991. In the first section, entitled ''Purpose and Trends,'' we give some background on the recent trends in our research program and its evolution from an emphasis on nuclear structure physics to its present emphasis on relativistic heavy ion and RHIC physics. The next section, entitled, ''Physics Research Programs,'' is divided into three parts. First, we discuss our participation in the program to develop a large detector named PHENIX for the RHIC accelerator. Second, we outline progress made in the study of electromagnetic dissociation (ED). A highlight of this endeavor is experiments carried out with the 197 Au beam from the AGS accelerator in April 1991. Third, we discuss progress in completion of our nuclear structure studies. In the final section a list of publications, invited talks and contributed talks starting in 1991 is given
Atomic physics using relativistic H- beams
International Nuclear Information System (INIS)
Bryant, H.C.
2005-01-01
Full text: An 8 GeV hydrogen atom can traverse a focused laser beam of width of 1 micron in a time of 353 attoseconds in its rest frame. A design is currently underway at Fermilab for a superconducting linear accelerator that will accelerate H - ions to 8 GeV. This 'Proton Driver' beam is intended to be injected, after stripping down to protons, into the 120 GeV Main Injector for the mass production of neutrinos aimed at a neutrino detector (MINOS) in a mine shaft in Soudan, Minnesota (USA) for the study of neutrino oscillations. It has not passed unnoticed that with some advance planning a few nanoamps from the up-to-250 mA beam could be diverted for atomic physics experiments. Relativistic kinematics enable the creation of extreme conditions for a beam atom. For example, the Doppler shift allows a very large tuning range in the atom's rest frame of a laser beam that is fixed- frequency in the lab. At 8 GeV the rest frame Doppler shift ranges from a factor of 19 in the forward direction to 0.05 backward. The laser intensity is enhanced by the square of the Doppler shift, so that the world's most intense laser beam would be amplified by a factor of 360 in the atom's rest frame. Furthermore, although there are extreme changes in the frequency and intensity in the atom's frame as one changes the intersection angle, the ponderomotive potential remains constant, as it is a relativistic invariant. One of the interesting problems that arises in the planning for this accelerator is the stripping of electrons from the negative ions by photodetachment from Doppler shifted thermal photons. We estimate that, if the transfer lines are kept at 300 K (room temperature), the mean free path at 8 GeV for stripping from collisions with cavity radiation is about 1300 km. The physics of the interactions of such a beam with very thin material foils, again in the attosecond regime, has been treated theoretically, but has not been studied experimentally at such high energies. We will
Energy Technology Data Exchange (ETDEWEB)
Klein, Kristopher G.; Howes, Gregory G. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); TenBarge, Jason M. [IREAP, University of Maryland, College Park, MD 20742 (United States); Podesta, John J., E-mail: kristopher-klein@uiowa.edu [Center for Space Plasma Physics, Space Science Institute, Boulder, CO 80301 (United States)
2014-04-20
Motivated by recent observations of distinct parallel and perpendicular signatures in magnetic helicity measurements segregated by wave period and angle between the local magnetic field and the solar wind velocity, this paper undertakes a comparison of three intervals of Ulysses data with synthetic time series generated from a physically motivated turbulence model. From these comparisons, it is hypothesized that the observed signatures result from a perpendicular cascade of Alfvénic fluctuations and a local, non-turbulent population of ion-cyclotron or whistler waves generated by temperature anisotropy instabilities. By constraining the model's free parameters through comparison to in situ data, it is found that, on average, ∼95% of the power near dissipative scales is contained in a perpendicular Alfvénic cascade and that the parallel fluctuations are propagating nearly unidirectionally. The effects of aliasing on magnetic helicity measurements are considered and shown to be significant near the Nyquist frequency.
International Nuclear Information System (INIS)
Klein, Kristopher G.; Howes, Gregory G.; TenBarge, Jason M.; Podesta, John J.
2014-01-01
Motivated by recent observations of distinct parallel and perpendicular signatures in magnetic helicity measurements segregated by wave period and angle between the local magnetic field and the solar wind velocity, this paper undertakes a comparison of three intervals of Ulysses data with synthetic time series generated from a physically motivated turbulence model. From these comparisons, it is hypothesized that the observed signatures result from a perpendicular cascade of Alfvénic fluctuations and a local, non-turbulent population of ion-cyclotron or whistler waves generated by temperature anisotropy instabilities. By constraining the model's free parameters through comparison to in situ data, it is found that, on average, ∼95% of the power near dissipative scales is contained in a perpendicular Alfvénic cascade and that the parallel fluctuations are propagating nearly unidirectionally. The effects of aliasing on magnetic helicity measurements are considered and shown to be significant near the Nyquist frequency.
CAFE: A NEW RELATIVISTIC MHD CODE
Energy Technology Data Exchange (ETDEWEB)
Lora-Clavijo, F. D.; Cruz-Osorio, A. [Instituto de Astronomía, Universidad Nacional Autónoma de México, AP 70-264, Distrito Federal 04510, México (Mexico); Guzmán, F. S., E-mail: fdlora@astro.unam.mx, E-mail: aosorio@astro.unam.mx, E-mail: guzman@ifm.umich.mx [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio C-3, Cd. Universitaria, 58040 Morelia, Michoacán, México (Mexico)
2015-06-22
We introduce CAFE, a new independent code designed to solve the equations of relativistic ideal magnetohydrodynamics (RMHD) in three dimensions. We present the standard tests for an RMHD code and for the relativistic hydrodynamics regime because we have not reported them before. The tests include the one-dimensional Riemann problems related to blast waves, head-on collisions of streams, and states with transverse velocities, with and without magnetic field, which is aligned or transverse, constant or discontinuous across the initial discontinuity. Among the two-dimensional (2D) and 3D tests without magnetic field, we include the 2D Riemann problem, a one-dimensional shock tube along a diagonal, the high-speed Emery wind tunnel, the Kelvin–Helmholtz (KH) instability, a set of jets, and a 3D spherical blast wave, whereas in the presence of a magnetic field we show the magnetic rotor, the cylindrical explosion, a case of Kelvin–Helmholtz instability, and a 3D magnetic field advection loop. The code uses high-resolution shock-capturing methods, and we present the error analysis for a combination that uses the Harten, Lax, van Leer, and Einfeldt (HLLE) flux formula combined with a linear, piecewise parabolic method and fifth-order weighted essentially nonoscillatory reconstructors. We use the flux-constrained transport and the divergence cleaning methods to control the divergence-free magnetic field constraint.
International Nuclear Information System (INIS)
Nemenov, L.
2001-01-01
The Coulomb interaction which occurs in the final state between two particles with opposite charges allows for creation of the bound state of these particles. In the case when particles are generated with large momentum in lab frame, the Lorentz factors of the bound state will also be much larger than one. The relativistic velocity of the atoms provides the opportunity to observe bound states of (π + μ - ), (π + π - ) and (π + K - ) with a lifetime as short as 10 -16 s, and to measure their parameters. The ultrarelativistic positronium atoms (A 2e ) allow us to observe the e.ect of superpenetration in matter, to study the effects caused by the formation time of A 2e from virtual e + e - pairs and to investigate the process of transformation of two virtual particles into the bound state
Photoionization at relativistic energies
International Nuclear Information System (INIS)
Ionescu, D.C.; Technische Univ. Dresden; Soerensen, A.H.; Belkacem, A.
2000-11-01
At MeV energies and beyond the inner-shell vacancy production cross section associated with the photoelectric and Compton effect decrease with increasing photon energy. However, when the photon energy exceeds twice the rest energy of the electron, ionization of a bound electron may be catalyzed by the creation of an electron-positron pair. Distinctly different from all other known mechanisms for inner-shell vacancy production by photons, we show that the cross section for this ''vacuum-assisted photoionization'' increases with increasing photon energy and then saturates. As a main result, we predict that vacuum-assisted photoionization will dominate the other known photoionization mechanisms in the highly relativistic energy regime. (orig.)
Relativistic thermodynamics of fluids
International Nuclear Information System (INIS)
Souriau, J.-M.
1977-05-01
The relativistic covariant definition of a statistical equilibrium, applied to a perfect gas, involves a 'temperature four-vector', whose direction is the mean velocity of the fluid, and whose length is the reciprocal temperature. The hypothesis of this 'temperature four-vector' being a relevant variable for the description of the dissipative motions of a simple fluid is discussed. The kinematics is defined by using a vector field and measuring the number of molecules. Such a dissipative fluid is subject to motions involving null entropy generation; the 'temperature four-vector' is then a Killing vector; the equations of motion can be completely integrated. Perfect fluids can be studied by this way and the classical results of Lichnerowicz are obtained. In weakly dissipative motions two viscosity coefficient appear together with the heat conductibility coefficient. Two other coefficients perharps measurable on real fluids. Phase transitions and shock waves are described with using the model [fr
Relativistic heavy ion physics
International Nuclear Information System (INIS)
Hill, J.C.; Wohn, F.K.
1993-01-01
This is a progress report for the period May 1992 through April 1993. The first section, entitled ''Purpose and Trends, gives background on the recent trends in the research program and its evolution from an emphasis on nuclear structure physics to its present emphasis on relativistic heavy ion and RHIC physics. The next section, entitled ''Physics Research Progress'', is divided into four parts: participation in the program to develop a large detector named PHENIX for the RHIC accelerator; joining E864 at the AGS accelerator and the role in that experiment; progress made in the study of electromagnetic dissociation highlight of this endeavor is an experiment carried out with the 197 Au beam from the AGS accelerator in April 1992; progress in completion of the nuclear structure studies. In the final section a list of publications, invited talks, and contributed talks is given
Relativistic plasma dispersion functions
International Nuclear Information System (INIS)
Robinson, P.A.
1986-01-01
The known properties of plasma dispersion functions (PDF's) for waves in weakly relativistic, magnetized, thermal plasmas are reviewed and a large number of new results are presented. The PDF's required for the description of waves with small wave number perpendicular to the magnetic field (Dnestrovskii and Shkarofsky functions) are considered in detail; these functions also arise in certain quantum electrodynamical calculations involving strongly magnetized plasmas. Series, asymptotic series, recursion relations, integral forms, derivatives, differential equations, and approximations for these functions are discussed as are their analytic properties and connections with standard transcendental functions. In addition a more general class of PDF's relevant to waves of arbitrary perpendicular wave number is introduced and a range of properties of these functions are derived
Degree of mapping for general relativistic kinks
International Nuclear Information System (INIS)
Harriot, Tina A.; Williams, J.G.
2005-01-01
The Finkelstein-Misner metrical kinks of general relativity are homo topically nontrivial light cone configurations that can occur on space-time hypersurfaces. The number of kinks corresponds to the winding number of a timelike vector field that that is determined from the metric. This paper uses the usual Euclidean integral formula for degree of mapping as a starting point and so produces a covariant formula that can be applied to counting general relativistic kinks in any dimension. The kink number is calculated for some simple-to-visualize examples in 2 + 1 dimensions. These include hypersurfaces of differing topologies and so have relevance to mechanisms of topology change in semi-classical theories of quantum gravity
Test of Relativistic Gravity for Propulsion at the Large Hadron Collider
Felber, Franklin
2010-01-01
A design is presented of a laboratory experiment that could test the suitability of relativistic gravity for propulsion of spacecraft to relativistic speeds. An exact time-dependent solution of Einstein's gravitational field equation confirms that even the weak field of a mass moving at relativistic speeds could serve as a driver to accelerate a much lighter payload from rest to a good fraction of the speed of light. The time-dependent field of ultrarelativistic particles in a collider ring is calculated. An experiment is proposed as the first test of the predictions of general relativity in the ultrarelativistic limit by measuring the repulsive gravitational field of bunches of protons in the Large Hadron Collider (LHC). The estimated `antigravity beam' signal strength at a resonant detector of each proton bunch is 3 nm/s2 for 2 ns during each revolution of the LHC. This experiment can be performed off-line, without interfering with the normal operations of the LHC.
Energy Technology Data Exchange (ETDEWEB)
Kipping, David, E-mail: dkipping@astro.columbia.edu [Department of Astronomy, Columbia University, 550 W. 120th St., New York, NY 10027 (United States)
2017-06-01
One proposed method for spacecraft to reach nearby stars is by accelerating sails using either solar radiation pressure or directed energy. This idea constitutes the thesis behind the Breakthrough Starshot project, which aims to accelerate a gram-mass spacecraft up to one-fifth the speed of light toward Proxima Centauri. For such a case, the combination of the sail’s low mass and relativistic velocity renders previous treatments incorrect at the 10% level, including that of Einstein himself in his seminal 1905 paper introducing special relativity. To address this, we present formulae for a sail’s acceleration, first in response to a single photon and then extended to an ensemble. We show how the sail’s motion in response to an ensemble of incident photons is equivalent to that of a single photon of energy equal to that of the ensemble. We use this principle of ensemble equivalence for both perfect and imperfect mirrors, enabling a simple analytic prediction of the sail’s velocity curve. Using our results and adopting putative parameters for Starshot , we estimate that previous relativistic treatments underestimate the spacecraft’s terminal velocity by ∼10% for the same incident energy. Additionally, we use a simple model to predict the sail’s temperature and diffraction beam losses during the laser firing period; this allows us to estimate that, for firing times of a few minutes and operating temperatures below 300°C (573 K), Starshot will require a sail that absorbs less than one in 260,000 photons.
International Nuclear Information System (INIS)
Kipping, David
2017-01-01
One proposed method for spacecraft to reach nearby stars is by accelerating sails using either solar radiation pressure or directed energy. This idea constitutes the thesis behind the Breakthrough Starshot project, which aims to accelerate a gram-mass spacecraft up to one-fifth the speed of light toward Proxima Centauri. For such a case, the combination of the sail’s low mass and relativistic velocity renders previous treatments incorrect at the 10% level, including that of Einstein himself in his seminal 1905 paper introducing special relativity. To address this, we present formulae for a sail’s acceleration, first in response to a single photon and then extended to an ensemble. We show how the sail’s motion in response to an ensemble of incident photons is equivalent to that of a single photon of energy equal to that of the ensemble. We use this principle of ensemble equivalence for both perfect and imperfect mirrors, enabling a simple analytic prediction of the sail’s velocity curve. Using our results and adopting putative parameters for Starshot , we estimate that previous relativistic treatments underestimate the spacecraft’s terminal velocity by ∼10% for the same incident energy. Additionally, we use a simple model to predict the sail’s temperature and diffraction beam losses during the laser firing period; this allows us to estimate that, for firing times of a few minutes and operating temperatures below 300°C (573 K), Starshot will require a sail that absorbs less than one in 260,000 photons.
Rotating relativistic neutron stars
Energy Technology Data Exchange (ETDEWEB)
Weber, F.; Glendenning, N.K.
1991-07-21
Models of rotating neutron stars are constructed in the framework of Einstein's theory of general relativity. For this purpose a refined version of Hartle's method is applied. The properties of these objects, e.g. gravitational mass, equatorial and polar radius, eccentricity, red- and blueshift, quadrupole moment, are investigated for Kepler frequencies of 4000 s{sup {minus}1} {le} {Omega}{sub K} {le} 9000 s{sup {minus}1}. Therefore a self-consistency problem inherent in the determination of {Omega}{sub K} must be solved. The investigation is based on neutron star matter equations of state derived from the relativistic Martin-Schwinger hierarch of coupled Green's functions. By means of introducing the Hartree, Hartree-Fock, and ladder ({Lambda}) approximations, models of the equation of state derived. A special feature of the latter approximation scheme is the inclusion of dynamical two-particle correlations. These have been calculated from the relativistic T-matrix applying both the HEA and Bonn meson-exchange potentials of the nucleon-nucleon force. The nuclear forces of the former two treatments are those of the standard scalar-vector-isovector model of quantum hadron dynamics, with parameters adjusted to the nuclear matter data. An important aspect of this work consists in testing the compatibility of different competing models of the nuclear equation of state with data on pulsar periods. By this the fundamental problem of nuclear physics concerning the behavior of the equation of state at supernuclear densities can be treated.
Some problems in relativistic thermodynamics
International Nuclear Information System (INIS)
Veitsman, E. V.
2007-01-01
The relativistic equations of state for ideal and real gases, as well as for various interface regions, have been derived. These dependences help to eliminate some controversies in the relativistic thermodynamics based on the special theory of relativity. It is shown, in particular, that the temperature of system whose velocity tends to the velocity of light in vacuum varies in accordance with the Ott law T = T 0 /√1 - v 2 /c 2 . Relativistic dependences for heat and mass transfer, for Ohm's law, and for a viscous flow of a liquid have also been derived
Radiative pion-proton scattering
International Nuclear Information System (INIS)
Ho-Kim, Q.; Lavine, J.P.
1977-01-01
The results are presented of a non-relativistic calculation of the π +- proton bremsstrahlung cross section at the pion kinetic energy of 298 MeV for backward photon angles. The pion-nucleon interaction is given by models that are based on the p-wave Chew-Low theory. An interaction current is included in an attempt to make the overall bremsstrahlung amplitude gauge-invariant. The predicted cross sections show little of the expected resonance, and are in fair agreement with the data. The authors have also calculated the cross sections at other kinetic energies, and have studied effects of the off-mass-shell electromagnetic vertex. (Auth.)
Relativistic shock waves and the excitation of plerions
Energy Technology Data Exchange (ETDEWEB)
Arons, J. (California Univ., Berkeley, CA (USA)); Gallant, Y.A. (California Univ., Berkeley, CA (USA). Dept. of Physics); Hoshino, Masahiro; Max, C.E. (California Univ., Livermore, CA (USA). Inst. of Geophysics and Planetary Physics); Langdon, A.B. (Lawrence Livermore National Lab., CA (USA))
1991-01-07
The shock termination of a relativistic magnetohydrodynamic wind from a pulsar is the most interesting and viable model for the excitation of the synchrotron sources observed in plerionic supernova remnants. We have studied the structure of relativistic magnetosonic shock waves in plasmas composed purely of electrons and positrons, as well as those whose composition includes heavy ions as a minority constituent by number. We find that relativistic shocks in symmetric pair plasmas create fully thermalized distributions of particles and fields downstream. Therefore, such shocks are not good candidates for the mechanism which converts rotational energy lost from a pulsar into the nonthermal synchrotron emission observed in plerions. However, when the upstream wind contains heavy ions which are minority constituent by number density, but carry the bulk of the energy density, much of the energy of the shock goes into a downstream, nonthermal power law distribution of positrons with energy distribution N(E)dE {proportional to}E{sup {minus}s}. In a specific model presented in some detail, s = 3. These characteristics are close to those assumed for the pairs in macroscopic MHD wind models of plerion excitation. The essential mechanism is collective synchrotron emission of left-handed extraordinary modes by the ions in the shock front at high harmonics of the ion cyclotron frequency, with the downstream positrons preferentially absorbing almost all of this radiation, mostly at their fundamental (relativistic) cyclotron frequencies. Possible applications to models of plerions and to constraints on theories of energy loss from pulsars are briefly outlines. 27 refs., 5 figs.
International Nuclear Information System (INIS)
Anon.
1992-01-01
This chapter discusses the role wind energy may have in the energy future of the US. The topics discussed in the chapter include historical aspects of wind energy use, the wind energy resource, wind energy technology including intermediate-size and small wind turbines and intermittency of wind power, public attitudes toward wind power, and environmental, siting and land use issues
Conductivity of a relativistic plasma
Energy Technology Data Exchange (ETDEWEB)
Braams, B.J.; Karney, C.F.F.
1989-03-01
The collision operator for a relativistic plasma is reformulated in terms of an expansion in spherical harmonics. This formulation is used to calculate the electrical conductivity. 13 refs., 1 fig., 1 tab.
Relativistic description of atomic nuclei
International Nuclear Information System (INIS)
Krutov, V.A.
1985-01-01
Papers on the relativistic description of nuclei are reviewed. The Brown and Rho ''small'' bag'' model is accepted for hardrons. Meson exchange potentials of the nucleon-nucleon interaction have been considered. Then the transition from a system of two interacting nucleons has been performed to the relativistic nucleus description as a multinucleon system on the basis of OBEP (one-boson exchange potential). The proboem of OPEP (one-pion-exchange potential) inclusion to a relativistic scheme is discussed. Simplicity of calculations and attractiveness of the Walecka model for specific computations and calculations was noted. The relativistic model of nucleons interacting through ''effective'' scalar and vector boson fields was used in the Walacka model for describing neutronaand nuclear mater matters
Conductivity of a relativistic plasma
International Nuclear Information System (INIS)
Braams, B.J.; Karney, C.F.F.
1989-03-01
The collision operator for a relativistic plasma is reformulated in terms of an expansion in spherical harmonics. This formulation is used to calculate the electrical conductivity. 13 refs., 1 fig., 1 tab
Relativistic heavy-ion physics
Herrera Corral, G
2010-01-01
The study of relativistic heavy-ion collisions is an important part of the LHC research programme at CERN. This emerging field of research focuses on the study of matter under extreme conditions of temperature, density, and pressure. Here we present an introduction to the general aspects of relativistic heavy-ion physics. Afterwards we give an overview of the accelerator facility at CERN and then a quick look at the ALICE project as a dedicated experiment for heavy-ion collisions.
An introduction to relativistic hydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Font, Jose A [Departamento de AstronomIa y AstrofIsica, Universidad de Valencia, Dr. Moliner 50, 46100 Burjassot (Valencia) (Spain)
2007-11-15
We review formulations of the equations of (inviscid) general relativistic hydrodynamics and (ideal) magnetohydrodynamics, along with methods for their numerical solution. Both systems can be cast as first-order, hyperbolic systems of conservation laws, following the explicit choice of an Eulerian observer and suitable fluid and magnetic field variables. During the last fifteen years, the so-called (upwind) high-resolution shock-capturing schemes based on Riemann solvers have been successfully extended from classical to relativistic fluid dynamics, both special and general. Nowadays, general relativistic hydrodynamical simulations in relativistic astrophysics are routinely performed, particularly within the test-fluid approximation but also for dynamical spacetimes. While such advances also hold true in the case of the MHD equations, the astrophysical applications investigated so far are still limited, yet the field is bound to witness major developments in the near future. The article also presents a brief overview of numerical techniques, providing state-of-the-art examples of their applicability to general relativistic fluids and magneto-fluids in characteristic scenarios of relativistic astrophysics.
Superheavy nuclei in the relativistic mean-field theory
International Nuclear Information System (INIS)
Lalazissis, G.A.; Ring, P.; Gambhir, Y.K.
1996-01-01
We have carried out a study of superheavy nuclei in the framework of the relativistic mean-field theory. Relativistic Hartree-Bogoliubov (RHB) calculations have been performed for nuclei with large proton and neutron numbers. A finite-range pairing force of Gogny type has been used in the RHB calculations. The ground-state properties of very heavy nuclei with atomic numbers Z=100-114 and neutron numbers N=154-190 have been obtained. The results show that in addition to N=184 the neutron numbers N=160 and N=166 exhibit an extra stability as compared to their neighbors. For the case of protons the atomic number Z=106 is shown to demonstrate a closed-shell behavior in the region of well deformed nuclei about N=160. The proton number Z=114 also indicates a shell closure. Indications for a doubly magic character at Z=106 and N=160 are observed. Implications of shell closures on a possible synthesis of superheavy nuclei are discussed. (orig.)
On interference of cumulative proton production mechanisms
International Nuclear Information System (INIS)
Braun, M.A.; Vechernin, V.V.
1993-01-01
The dynamical picture of the cumulative proton production in hA-collisions by means of diagram analysis with NN interaction described by a non-relativistic NN potential is considered. The contributions of the various mechanisms (spectator, direct and rescattering) for backward hemisphere proton production within the framework of this common approach is calculated. The emphasis is on the comparison of the relative contributions of these mechanisms for various angles, taking into account the interference of these contributions. Comparison with experimental data is also presented. (author)
Monte Carlo Simulations of Photospheric Emission in Relativistic Outflows
Bhattacharya, Mukul; Lu, Wenbin; Kumar, Pawan; Santana, Rodolfo
2018-01-01
We study the spectra of photospheric emission from highly relativistic gamma-ray burst outflows using a Monte Carlo code. We consider the Comptonization of photons with a fast-cooled synchrotron spectrum in a relativistic jet with a realistic photon-to-electron number ratio {N}γ /{N}{{e}}={10}5, using mono-energetic protons that interact with thermalized electrons through Coulomb interaction. The photons, electrons, and protons are cooled adiabatically as the jet expands outward. We find that the initial energy distributions of the protons and electrons do not have any appreciable effect on the photon peak energy {E}γ ,{peak} and the power-law spectrum above {E}γ ,{peak}. The Coulomb interaction between the electrons and the protons does not affect the output photon spectrum significantly as the energy of the electrons is elevated only marginally. {E}γ ,{peak} and the spectral indices for the low- and high-energy power-law tails of the photon spectrum remain practically unchanged even with electron-proton coupling. Increasing the initial optical depth {τ }{in} results in a slightly shallower photon spectrum below {E}γ ,{peak} and fewer photons at the high-energy tail, although {f}ν \\propto {ν }-0.5 above {E}γ ,{peak} and up to ∼1 MeV, independent of {τ }{in}. We find that {E}γ ,{peak} determines the peak energy and the shape of the output photon spectrum. Finally, we find that our simulation results are quite sensitive to {N}γ /{N}{{e}}, for {N}{{e}}=3× {10}3. For almost all our simulations, we obtain an output photon spectrum with a power-law tail above {E}γ ,{peak} extending up to ∼1 MeV.
Relativistic theory of gravitation
International Nuclear Information System (INIS)
Logunov, A.A.; Mestvirishvili, M.A.
1986-01-01
In the present paper a relativistic theory of gravitation (RTG) is unambiguously constructed on the basis of the special relativity and geometrization principle. In this a gravitational field is treated as the Faraday--Maxwell spin-2 and spin-0 physical field possessing energy and momentum. The source of a gravitational field is the total conserved energy-momentum tensor of matter and of a gravitational field in Minkowski space. In the RTG the conservation laws are strictly fulfilled for the energy-moment and for the angular momentum of matter and a gravitational field. The theory explains the whole available set of experiments on gravity. By virtue of the geometrization principle, the Riemannian space in our theory is of field origin, since it appears as an effective force space due to the action of a gravitational field on matter. The RTG leads to an exceptionally strong prediction: The universe is not closed but just ''flat.'' This suggests that in the universe a ''missing mass'' should exist in a form of matter
Relativistic theory of gravitation
International Nuclear Information System (INIS)
Logunov, A.A.; Mestvirishvilli, M.A.
1985-01-01
In the present paper a relativistic theory of gravitation (RTG) is constructed in a unique way on the basis of the special relativity and geometrization principle. In this, a gravitational field is treated as the Faraday-Maxwell spin-2 and spin-0 physical field possessing energy and momentum. The source of a gravitational field is the total conserved energy-momentum tensor of matter and of a gravitational field in Minkowski space. In the RTG, the conservation laws are strictly fulfilled for the energy-momentum and for the angular momentum of matter and a gravitational field. The theory explains the whole available set of experiments on gravitation. In virtue of the geometrization principle, the Riemannian space in our theory is of field origin, since it appears as an effective force space due to the action of a gravitational field on matter. The RTg leads to an exceptionally strong prediction: The Universe is not closed but just ''flat''. This suggests that in the Universe a ''hidden mass'' should exist in some form of matter
Relativistic gravitation theory
International Nuclear Information System (INIS)
Logunov, A.A.; Mestvirishvili, M.A.
1984-01-01
On the basis of the special relativity and geometrization principle a relativistic gravitation theory (RGT) is unambiguously constructed with the help of a notion of a gravitational field as a physical field in Faraday-Maxwell spirit, which posesses energy momentum and spins 2 and 0. The source of gravitation field is a total conserved energy-momentum tensor for matter and for gravitation field in Minkowski space. In the RGT conservation laws for the energy momentum and angular momentum of matter and gravitational field hold rigorously. The theory explains the whole set of gravitation experiments. Here, due to the geometrization principle the Riemannian space is of a field origin since this space arises effectively as a result of the gravitation field origin since this space arises effectively as a result of the gravitation field action on the matter. The RGT astonishing prediction is that the Universe is not closed but ''flat''. It means that in the Universe there should exist a ''missing'' mass in some form of matter
'Thermal' multifragmentation induced in gold target by relativistic protons
International Nuclear Information System (INIS)
Karnaukhov, V.A.; Avdeev, S.P.; Kuznetsov, V.D.
1996-01-01
Multifragmentation in p+Au collisions at 2.16, 3.6 and 8.1 GeV has been studied with the FASA set-up. The mean IMF-multiplicities (2.0, 2.6 and 3.0) are comparable with those obtained with heavy ions. The modified Glauber approximation, followed by the statistical multifragmentation model, is used to describe the data on the fragment multiplicities and energy spectra. 25 refs., 4 figs., 1 tab
Parametric Model for Astrophysical Proton-Proton Interactions and Applications
Energy Technology Data Exchange (ETDEWEB)
Karlsson, Niklas [KTH Royal Institute of Technology, Stockholm (Sweden)
2007-01-01
Observations of gamma-rays have been made from celestial sources such as active galaxies, gamma-ray bursts and supernova remnants as well as the Galactic ridge. The study of gamma rays can provide information about production mechanisms and cosmic-ray acceleration. In the high-energy regime, one of the dominant mechanisms for gamma-ray production is the decay of neutral pions produced in interactions of ultra-relativistic cosmic-ray nuclei and interstellar matter. Presented here is a parametric model for calculations of inclusive cross sections and transverse momentum distributions for secondary particles--gamma rays, e^{±}, v_{e}, $\\bar{v}$_{e}, v_{μ} and $\\bar{μ}$_{e}--produced in proton-proton interactions. This parametric model is derived on the proton-proton interaction model proposed by Kamae et al.; it includes the diffraction dissociation process, Feynman-scaling violation and the logarithmically rising inelastic proton-proton cross section. To improve fidelity to experimental data for lower energies, two baryon resonance excitation processes were added; one representing the Δ(1232) and the other multiple resonances with masses around 1600 MeV/c^{2}. The model predicts the power-law spectral index for all secondary particle to be about 0.05 lower in absolute value than that of the incident proton and their inclusive cross sections to be larger than those predicted by previous models based on the Feynman-scaling hypothesis. The applications of the presented model in astrophysics are plentiful. It has been implemented into the Galprop code to calculate the contribution due to pion decays in the Galactic plane. The model has also been used to estimate the cosmic-ray flux in the Large Magellanic Cloud based on HI, CO and gamma-ray observations. The transverse momentum distributions enable calculations when the proton distribution is anisotropic. It is shown that the gamma-ray spectrum and flux due to a
Rest frame properties of the proton
International Nuclear Information System (INIS)
Strobel, G.L.
1998-01-01
The proton is modeled as three quarks of small current quark mass. The three-body Dirac equation is solved with spin-independent central diagonal linear confining potentials with an attractive Coulombic term in a relativistic three-quark model. Hyperspherical coordinates are used, and the bound state is found analytically. After integrating over the hyperangles, the Hamiltonian is an 8 by 8 matrix of coupled first-order differential equations in one variable, the hyperradius. These are analytically solved in hypercentral approximation. For the (1/2 + ) 3 ground-state configuration in the nonrelativistic large-quark-mass limit, there are no nodes in the wave function. However, in the extreme relativistic limit of small current quark masses of a few MeV, the expectation value of the number of nodes is about 1.30 when the potential parameters are chosen to reproduce the proton rms charge radius. The quarks are assumed to possess a Pauli anomalous magnetic moment, like that of the electron and muon of (α/2π)(e/m). Assuming all three quarks have equal mass, one can fit the rest energy, magnetic moment, rms charge radius, and axial charge of the proton with this relativistic three-body Dirac equation model. The solution found shows the necessity of including all components of the composite three-quark wave function, as the upper component contributes only 0.585 to the norm
On the proton exchange contribution to electron-hydrogen atom elastic scattering
International Nuclear Information System (INIS)
Mignaco, J.A.; Tort, A.C.
1979-05-01
It is shown that the exchange contribution to the electron-proton potential Born term in elastic electron-hydrogen atom scattering arises as the non relativistic limit from the exchange of a proton between the two participant electrons - calculated from quantum electrodynamics including properly bound states (as solution of Bethe - Salpeter equation). (Author) [pt
Studies of neutron emission from relativistic nuclear interactions
Guo, S L; Wang, Y L; Guo, H Y; Sá Ben-Hao; Zheng, Y M; Brandt, R; Vater, P; Wan, J S; Ochs, M; Kulakov, B A; Sosnin, A N; Krivopustov, M I; Butsev, V S; Bradnova, V
1999-01-01
Studies were carried out on the yields and spatial distributions of secondary neutrons produced in the relativistic nuclear interactions of 1.5 GeV to 14.4 GeV projectiles p, d and alpha-particles with targets Pb and U/Pb. CR-39 track detectors were used to measure the neutrons. It shows that: (1) Secondary neutrons are produced in the whole length of Pb or U targets having a thickness of 20 cm. The neutron intensities produced by proton bombardments are reduced along the proton beam direction in the targets. The higher the energy of protons, the lower the reduction rate of the neutrons. The reduction rate of neutrons in U target is higher than in Pb target for the same energy of protons. (2) The radial intensities of neutrons decrease as the distance increases from the target central line. (3) The neutron yield in U target by proton bombardments is approx 55% higher than in Pb target. (4) The ratio of neutron yield by 14.4 GeV alpha to 7.3 GeV d bombardment in Pb target is 1.74+-0.20.
ρ - ω Mixing Effects in Relativistic Heavy-Ion Collisions
International Nuclear Information System (INIS)
Broniowski, W.; Florkowski, W.
1999-01-01
Full text: We have shown that even moderate excess of neutrons over protons in nuclear matter, such as in 208 Pb, can lead to large ρ - ω mixing at densities of the order of twice the nuclear saturation density and higher. The typical mixing angle is of the order of 10 o . The mixing may result in noticeable shifts of the positions and widths of resonances. We also analyze temperature effects and find that temperatures up to 50 MeV have practically no effect on the mixing. The results have relevance for the explanation of dilepton production in relativistic heavy-ion collisions. (author)
Relativistic positioning systems: perspectives and prospects
Coll Bartolomé
2013-11-01
Relativistic positioning systems are interesting technical objects for applications around the Earth and in the Solar system. But above all else, they are basic scientific objects allowing developing relativity from its own concepts. Some past and future features of relativistic positioning sys- tems, with special attention to the developments that they suggest for an epistemic relativity (relativistic experimental approach to physics), are analyzed. This includes relativistic stereometry, which, together with relativistic positioning systems, allows to introduce the general relativistic notion of (finite) laboratory (space-time region able to perform experiments of finite size).
Czech Academy of Sciences Publication Activity Database
Hajra, R.; Tsurutani, B. T.; Echer, E.; Gonzalez, W. D.; Brum, Ch. G. M.; Antunes Vieira, L. E.; Santolík, Ondřej
2015-01-01
Roč. 67, Article Number 109 (2015), 109/1-109/11 ISSN 1880-5981 R&D Projects: GA MŠk LH12231 Institutional support: RVO:68378289 Keywords : HILDCAAs * high-speed streams * CIRs * chorus plasma waves * radiation belt * magnetospheric relativistic electrons * solar wind * geomagnetic storms Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.871, year: 2015
Relativistic theory of gravity
International Nuclear Information System (INIS)
Logunov, A.A.; Mestvirishvili, M.A.
1985-01-01
This work presents an unambiguous construction of the relativistic theory of gravity (RTG) in the framework of relativity and the geometrization principle. The gauge principle has been formulated, and the Lagrangian density of the gravitational field has thus been constructed. This theory explains the totality of the available experimental data on the solar system and predicts the existence of gravitational waves of the Faraday-Maxwell type. According to the RTG, the Universe is infinite and ''flat'', hence it follows that its matter density should be equal to its critical density. Therefore, an appreciable ''hidden mass'' exceeding the presently observed mass of the matter almost 40-fold should exist in the Universe in some form of the matter or other. In accordance with the RTG, a massive body having a finite density ceases to contract under gravitational forces within a finite interval of proper time. From the viewpoint of an external reference frame, the brightness of the body decreases exponentially (it is getting darker), but nothing extraordinary happens in this case because its density always remains finite and, for example, for a body with the mass of about 10 8 M 0 it is equal to 2 g/cm 3 . That is why it follows from the RTG that there could be no object whatsoever (black holes) in which gravitational collapse of matter develops to an infinite density. As has been shown, the presence of a cosmological term necessarily requires the introduction of a term with an explicit dependence on the Minkowski metrics. For the long-range gravitational forces the cosmological constant vanishes
Scattering in relativistic particle mechanics
International Nuclear Information System (INIS)
De Bievre, S.
1986-01-01
The problem of direct interaction in relativistic particle mechanics has been extensively studied and a variety of models has been proposed avoiding the conclusions of the so-called no-interaction theorems. In this thesis the authors studied scattering in the relativistic two-body problem. He uses the results to analyze gauge invariance in Hamiltonian constraint models and the uniqueness of the symplectic structure in manifestly covariant relativistic particle mechanics. A general geometric framework that underlies approaches to relativistic particle mechanics is presented and the kinematic properties of the scattering transformation, i.e., those properties that arise solely from the invariance of the theory under the Poincare group are studied. The second part of the analysis of the relativistic two-body scattering problem is devoted to the dynamical properties of the scattering process. Using general geometric arguments, gauge invariance of the scattering transformation in the Todorov-Komar Hamiltonian constraint model is proved. Finally, quantization of the models is discussed
International Nuclear Information System (INIS)
Cameron, A.
2005-01-01
The June 2005 edition of 'Wind Force 12' suggests that wind could generate 12% of global electricity requirements by 2020. But what moves a potential market into an emerging one? Geographical factors include a good wind resource, plenty of open space and the ability to get the generated electricity to end-users. A country's political framework is equally important, with fixed price systems, renewable quota systems and political will all playing a part. Some potential wind markets around the world are thought to have the conditions necessary to become key players in the wind industry. The emerging markets in countries such as Australia, Brazil, Canada, France, Japan and the Philippines are highlighted as examples
Proton-rich nuclear statistical equilibrium
International Nuclear Information System (INIS)
Seitenzahl, I.R.; Timmes, F.X.; Marin-Lafleche, A.; Brown, E.; Magkotsios, G.; Truran, J.
2008-01-01
Proton-rich material in a state of nuclear statistical equilibrium (NSE) is one of the least studied regimes of nucleosynthesis. One reason for this is that after hydrogen burning, stellar evolution proceeds at conditions of an equal number of neutrons and protons or at a slight degree of neutron-richness. Proton-rich nucleosynthesis in stars tends to occur only when hydrogen-rich material that accretes onto a white dwarf or a neutron star explodes, or when neutrino interactions in the winds from a nascent proto-neutron star or collapsar disk drive the matter proton-rich prior to or during the nucleosynthesis. In this Letter we solve the NSE equations for a range of proton-rich thermodynamic conditions. We show that cold proton-rich NSE is qualitatively different from neutron-rich NSE. Instead of being dominated by the Fe-peak nuclei with the largest binding energy per nucleon that have a proton-to-nucleon ratio close to the prescribed electron fraction, NSE for proton-rich material near freezeout temperature is mainly composed of 56Ni and free protons. Previous results of nuclear reaction network calculations rely on this nonintuitive high-proton abundance, which this Letter explains. We show how the differences and especially the large fraction of free protons arises from the minimization of the free energy as a result of a delicate competition between the entropy and nuclear binding energy.
Simulating three-dimensional nonthermal high-energy photon emission in colliding-wind binaries
Energy Technology Data Exchange (ETDEWEB)
Reitberger, K.; Kissmann, R.; Reimer, A.; Reimer, O., E-mail: klaus.reitberger@uibk.ac.at [Institut für Astro- und Teilchenphysik and Institut für Theoretische Physik, Leopold-Franzens-Universität Innsbruck, A-6020 Innsbruck (Austria)
2014-07-01
Massive stars in binary systems have long been regarded as potential sources of high-energy γ rays. The emission is principally thought to arise in the region where the stellar winds collide and accelerate relativistic particles which subsequently emit γ rays. On the basis of a three-dimensional distribution function of high-energy particles in the wind collision region—as obtained by a numerical hydrodynamics and particle transport model—we present the computation of the three-dimensional nonthermal photon emission for a given line of sight. Anisotropic inverse Compton emission is modeled using the target radiation field of both stars. Photons from relativistic bremsstrahlung and neutral pion decay are computed on the basis of local wind plasma densities. We also consider photon-photon opacity effects due to the dense radiation fields of the stars. Results are shown for different stellar separations of a given binary system comprising of a B star and a Wolf-Rayet star. The influence of orbital orientation with respect to the line of sight is also studied by using different orbital viewing angles. For the chosen electron-proton injection ratio of 10{sup –2}, we present the ensuing photon emission in terms of two-dimensional projections maps, spectral energy distributions, and integrated photon flux values in various energy bands. Here, we find a transition from hadron-dominated to lepton-dominated high-energy emission with increasing stellar separations. In addition, we confirm findings from previous analytic modeling that the spectral energy distribution varies significantly with orbital orientation.
Relativistic Few-Body Hadronic Physics Calculations
Energy Technology Data Exchange (ETDEWEB)
Polyzou, Wayne [Univ. of Iowa, Iowa City, IA (United States)
2016-06-20
The goal of this research proposal was to use ``few-body'' methods to understand the structure and reactions of systems of interacting hadrons (neutrons, protons, mesons, quarks) over a broad range of energy scales. Realistic mathematical models of few-hadron systems have the advantage that they are sufficiently simple that they can be solved with mathematically controlled errors. These systems are also simple enough that it is possible to perform complete accurate experimental measurements on these systems. Comparison between theory and experiment puts strong constraints on the structure of the models. Even though these systems are ``simple'', both the experiments and computations push the limits of technology. The important property of ``few-body'' systems is that the ``cluster property'' implies that the interactions that appear in few-body systems are identical to the interactions that appear in complicated many-body systems. Of particular interest are models that correctly describe physics at distance scales that are sensitive to the internal structure of the individual nucleons. The Heisenberg uncertainty principle implies that in order to be sensitive to physics on distance scales that are a fraction of the proton or neutron radius, a relativistic treatment of quantum mechanics is necessary. The research supported by this grant involved 30 years of effort devoted to studying all aspects of interacting two and three-body systems. Realistic interactions were used to compute bound states of two- and three-nucleon, and two- and three-quark systems. Scattering observables for these systems were computed for a broad range of energies - from zero energy scattering to few GeV scattering, where experimental evidence of sub-nucleon degrees of freedom is beginning to appear. Benchmark calculations were produced, which when compared with calculations of other groups provided an essential check on these complicated calculations. In
Photon production in relativistic nuclear collisions at SPS and RHIC energies
Turbide, S; Rapp, R; 10.1142/S0217751X0402258X
2004-01-01
Chiral Lagrangians are used to compute the production rate of photons from the hadronic phase of relativistic nuclear collisions. Special attention is paid to the role of the a/sub 1/ pseudovector. Calculations that include strange meson reactions, form factors, the use of consistent vector spectral densities, the emission from a quark-gluon plasma, and primordial nucleon-nucleon collisions reproduce the photon spectra measured at the Super Proton Synchrotron (SPS). Some predictions for the Relativistic Heavy Ion Collider (RHIC) are made.
Relativistic QRPA Calculation of β-Decay Rates of r-process Nuclei
International Nuclear Information System (INIS)
Marketin, T.; Paar, N.; Niksic, T.; Vretenar, D.; Ring, P.
2009-01-01
A systematic, fully self-consistent calculation of β-decay rates is presented, based on a microscopic theoretical framework. Analysis is performed on a large number of nuclei from the valley of β stability towards the neutron drip-line. Nuclear ground state is determined using the Relativistic Hartree-Bogoliubov (RHB) model with density-dependent meson-nucleon coupling constants. Transition rates are calculated within the proton-neutron relativistic quasiparticle RPA (pn-RQRPA) using the same interaction that was used in the RHB equations.
Beam-beam observations in the Relativistic Heavy Ion Collider
Energy Technology Data Exchange (ETDEWEB)
Luo, Y. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Laboratory (BNL), Upton, NY (United States); White, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States)
2015-06-24
The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.
Proton-proton and neutron-proton bremsstrahlung in the potential model
International Nuclear Information System (INIS)
Herrmann, V.
1993-11-01
The nucleon-nucleon (NN) bremsstrahlung reaction is studied in the framework of a potential model. We investigate and explain the behavior of the most important corrections to the purely non-relativistic model considering only the external current; i.e. we include the relativistic spin correction, the one-body rescattering contribution and the Coulomb-effect, where it is needed. The important contribution of the two-body or meson-exchange current is treated in the soft-photon-approximation. In addition to the usual coplanar NNγ cross section we also study non-coplanar cross sections and spin observables like the analyzing power and spin correlation coefficients. It is shown that the behavior of the relativistic spin correction is governed by the 1 S 0 partial-wave state, is almost energy independent and reduces the NNγ cross section by roughly 20 - 30%. The one-body rescattering contribution enhances the ppγ cross section for the geometry of the last TRIUMF experiment by about 20% and thus almost compensates the effect of the relativistic spin corrections. The effects of each part of the NN interaction on the ppγ observables is studied in the coplanar geometry. We find that these effects depend on the proton scattering angles as well as on the considered observable. However, the tensor component of the NN interaction is important in all geometries. The comparison of different NN potential models yields that the NNγ reaction is not able to discriminate these potentials in their off-shell behavior, although the corresponding T-matrices deviate from each other off the energy shell. It is concluded that the occuring differences originate already from deviations on the energy shell or from the fact that the approximations made in the calculations for the two-body current are not of the same quality for all NN potential models. (orig.)
International Nuclear Information System (INIS)
Nottale, Laurent
2003-01-01
The principle of relativity, when it is applied to scale transformations, leads to the suggestion of a generalization of fundamental dilations laws. These new special scale-relativistic resolution transformations involve log-Lorentz factors and lead to the occurrence of a minimal and of a maximal length-scale in nature, which are invariant under dilations. The minimal length-scale, that replaces the zero from the viewpoint of its physical properties, is identified with the Planck length l P , and the maximal scale, that replaces infinity, is identified with the cosmic scale L=Λ -1/2 , where Λ is the cosmological constant.The new interpretation of the Planck scale has several implications for the structure and history of the early Universe: we consider the questions of the origin, of the status of physical laws at very early times, of the horizon/causality problem and of fluctuations at recombination epoch.The new interpretation of the cosmic scale has consequences for our knowledge of the present universe, concerning in particular Mach's principle, the large number coincidence, the problem of the vacuum energy density, the nature and the value of the cosmological constant. The value (theoretically predicted ten years ago) of the scaled cosmological constant Ω Λ =0.75+/-0.15 is now supported by several different experiments (Hubble diagram of Supernovae, Boomerang measurements, gravitational lensing by clusters of galaxies).The scale-relativity framework also allows one to suggest a solution to the missing mass problem, and to make theoretical predictions of fundamental energy scales, thanks to the interpretation of new structures in scale space: fractal/classical transitions as Compton lengths, mass-coupling relations and critical value 4π 2 of inverse couplings. Among them, we find a structure at 3.27+/-0.26x10 20 eV, which agrees closely with the observed highest energy cosmic rays at 3.2+/-0.9x10 20 eV, and another at 5.3x10 -3 eV, which corresponds to the
SPECIAL RELATIVISTIC HYDRODYNAMICS WITH GRAVITATION
Energy Technology Data Exchange (ETDEWEB)
Hwang, Jai-chan [Department of Astronomy and Atmospheric Sciences, Kyungpook National University, Daegu (Korea, Republic of); Noh, Hyerim [Korea Astronomy and Space Science Institute, Daejon (Korea, Republic of)
2016-12-20
Special relativistic hydrodynamics with weak gravity has hitherto been unknown in the literature. Whether such an asymmetric combination is possible has been unclear. Here, the hydrodynamic equations with Poisson-type gravity, considering fully relativistic velocity and pressure under the weak gravity and the action-at-a-distance limit, are consistently derived from Einstein’s theory of general relativity. An analysis is made in the maximal slicing, where the Poisson’s equation becomes much simpler than our previous study in the zero-shear gauge. Also presented is the hydrodynamic equations in the first post-Newtonian approximation, now under the general hypersurface condition. Our formulation includes the anisotropic stress.
Methods in relativistic nuclear physics
International Nuclear Information System (INIS)
Danos, M.; Gillet, V.; Cauvin, M.
1984-01-01
This book is intended to provide the methods and tools for performing actual calculations for finite many-body systems of bound relativistic constituent particles. The aim is to cover thoroughly the methodological aspects of the relativistic many-body problem for bound states while avoiding the presentation of specific models. The many examples contained in the later part of the work are meant to give concrete illustrations of how to actually apply the methods which are given in the first part. The basic framework of the approach is the lagrangian field theory solved in the time-independent Schroedinger picture. (Auth.)
Frontiers in relativistic celestial mechanics
2014-01-01
Relativistic celestial mechanics – investigating the motion celestial bodies under the influence of general relativity – is a major tool of modern experimental gravitational physics. With a wide range of prominent authors from the field, this two-volume series consists of reviews on a multitude of advanced topics in the area of relativistic celestial mechanics – starting from more classical topics such as the regime of asymptotically-flat spacetime, light propagation and celestial ephemerides, but also including its role in cosmology and alternative theories of gravity as well as modern experiments in this area.
Recircular accelerator to proton ocular therapy
Energy Technology Data Exchange (ETDEWEB)
Rabelo, Luisa A.; Campos, Tarcisio P.R., E-mail: luisarabelo88@gmail.com, E-mail: tprcampos@pq.cnpq.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear
2013-07-01
Proton therapy has been used for the treatment of Ocular Tumors, showing control in most cases as well as conservation of the eyeball, avoiding the enucleation. The protons provide higher energetic deposition in depth with reduced lateral spread, compared to the beam of photons and electrons, with characteristic dose deposition peak (Bragg peak). This technique requires large particle accelerators hampering the deployment a Proton Therapy Center in some countries due to the need for an investment of millions of dollars. This study is related to a new project of an electromagnetic unit of proton circular accelerator to be coupled to the national radiopharmaceutical production cyclotrons, to attend ocular therapy. This project evaluated physical parameters of proton beam circulating through classical and relativistic mechanical formulations and simulations based on an ion transport code in electromagnetic fields namely CST (Computer Simulation Technology). The structure is differentiated from other circular accelerations (patent CTIT/UFMG NRI research group/UFMG). The results show the feasibility of developing compact proton therapy equipment that works like pre-accelerator or post-accelerator to cyclotrons, satisfying the interval energy of 15 MeV to 64 MeV. Methods of reducing costs of manufacture, installation and operation of this equipment will facilitate the dissemination of the proton treatment in Brazil and consequently advances in fighting cancer. (author)
Recircular accelerator to proton ocular therapy
International Nuclear Information System (INIS)
Rabelo, Luisa A.; Campos, Tarcisio P.R.
2013-01-01
Proton therapy has been used for the treatment of Ocular Tumors, showing control in most cases as well as conservation of the eyeball, avoiding the enucleation. The protons provide higher energetic deposition in depth with reduced lateral spread, compared to the beam of photons and electrons, with characteristic dose deposition peak (Bragg peak). This technique requires large particle accelerators hampering the deployment a Proton Therapy Center in some countries due to the need for an investment of millions of dollars. This study is related to a new project of an electromagnetic unit of proton circular accelerator to be coupled to the national radiopharmaceutical production cyclotrons, to attend ocular therapy. This project evaluated physical parameters of proton beam circulating through classical and relativistic mechanical formulations and simulations based on an ion transport code in electromagnetic fields namely CST (Computer Simulation Technology). The structure is differentiated from other circular accelerations (patent CTIT/UFMG NRI research group/UFMG). The results show the feasibility of developing compact proton therapy equipment that works like pre-accelerator or post-accelerator to cyclotrons, satisfying the interval energy of 15 MeV to 64 MeV. Methods of reducing costs of manufacture, installation and operation of this equipment will facilitate the dissemination of the proton treatment in Brazil and consequently advances in fighting cancer. (author)
Apparent unambiguousness of relativistic time dilation
International Nuclear Information System (INIS)
Strel'tsov, V.N.
1992-01-01
It is indicated on the definite analogy between the dependence of visible sizes of relativistic objects and period of the wave, emitted by the moving source from the observation conditions ('retradition factor'). It is noted that the definition of time for moving extended objects, led to relativistic dilation, corresponds to the definition of the relativistic (radar) length led to the 'elongation formula'. 10 refs
Relativistic generalization of strong plasma turbulence
International Nuclear Information System (INIS)
Chian, A.C.-L.
1982-01-01
Two fundamental electrostatic modes of an unmagnetized plasma, namely, ion acoustic mode and Langumir mode are studied. Previous theories are generalized to include the effect of relativistic mass variations. The existence of relativistic ion acoustic solitons is demonstrated. In addition, it is shown that simple, relativistic Langumir solitons do not exist in a infinite plasma. (L.C.) [pt
Quantum gates via relativistic remote control
Energy Technology Data Exchange (ETDEWEB)
Martín-Martínez, Eduardo, E-mail: emartinm@uwaterloo.ca [Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Dept. Applied Math., University of Waterloo, Ontario, N2L 3G1 (Canada); Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada); Sutherland, Chris [Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)
2014-12-12
We harness relativistic effects to gain quantum control on a stationary qubit in an optical cavity by controlling the non-inertial motion of a different probe atom. Furthermore, we show that by considering relativistic trajectories of the probe, we enhance the efficiency of the quantum control. We explore the possible use of these relativistic techniques to build 1-qubit quantum gates.
Relativistic electron dropout echoes induced by interplanetary shocks
Schiller, Q.; Kanekal, S. G.; Boyd, A. J.; Baker, D. N.; Blake, J. B.; Spence, H. E.
2017-12-01
Interplanetary shocks that impact Earth's magnetosphere can produce immediate and dramatic responses in the trapped relativistic electron population. One well-studied response is a prompt injection capable of transporting relativistic electrons deep into the magnetosphere and accelerating them to multi-MeV energies. The converse effect, electron dropout echoes, are observations of a sudden dropout of electron fluxes observed after the interplanetary shock arrival. Like the injection echo signatures, dropout echoes can also show clear energy dispersion signals. They are of particular interest because they have only recently been observed and their causal mechanism is not well understood. In the analysis presented here, we show observations of electron drift echo signatures from the Relativistic Electron-Proton Telescope (REPT) and Magnetic Electron and Ion Sensors (MagEIS) onboard NASA's Van Allen Probes mission, which show simultaneous prompt enhancements and dropouts within minutes of the associated with shock impact. We show that the observations associated with both enhancements and dropouts are explained by the inward motion caused by the electric field impulse induced by the interplanetary shock, and either energization to cause the enhancement, or lack of a seed population to cause the dropout.
Nuclei at extreme conditions. A relativistic study
Energy Technology Data Exchange (ETDEWEB)
Afanasjev, Anatoli [Mississippi State Univ., Mississippi State, MS (United States)
2014-11-14
The major goals of the current project were further development of covariant density functional theory (CDFT), better understanding of its features, its application to different nuclear structure and nuclear astrophysics phenomena and training of graduate and undergraduate students. The investigations have proceeded in a number of directions which are discussed in detail in the part “Accomplishments” of this report. We have studied the role of isovector and isoscalar proton-neutron pairings in rotating nuclei; based on available experimental data it was concluded that there are no evidences for the existence of isoscalar proton-neutron pairing. Generalized theoretical approach has been developed for pycnonuclear reaction rates in the crust of neutron stars and interior of white dwarfs. Using this approach, extensive database for considerable number of pycnonuclear reactions involving stable and neutron-rich light nuclei has been created; it can be used in future for the study of various nuclear burning phenomena in different environments. Time-odd mean fields and their manifestations in terminating states, non-rotating and rotating nuclei have been studied in the framework of covariant density functional theory. Contrary to non-relativistic density functional theories these fields, which are important for a proper description of nuclear systems with broken time-reversal symmetry, are uniquely defined in the CDFT framework. Hyperdeformed nuclear shapes (with semi-axis ratio 2.5:1 and larger) have been studied in the Z = 40-58 part of nuclear chart. We strongly believe that such shapes could be studied experimentally in the future with full scale GRETA detector.
On a method for high-energy electron beam production in proton synchrotrons
International Nuclear Information System (INIS)
Bessonov, E.G.; Vazdik, Ya.A.
1979-01-01
It is suggested to produce high-energy electron beams in such a way that the ultrarelativistic protons give an amount of their kinetic energy to the electrons of a thin target, placed inside the working volume of the proton synchrotron. The kinematics of the elastic scattering of relativistic protons on electrons at rest is treated. Evaluation of a number of elastically-scattered electrons by 1000 GeV and 3000 GeV proton beams is presented. The method under consideration is of certain practical interest and may appear to be preferable in a definite energy range of protons and electrons
Instability in relativistic nuclear matter
International Nuclear Information System (INIS)
Tezuka, Hirokazu.
1979-11-01
The stability of the Fermi gas state in the nuclear matter which satisfies the saturation property is considered relativistically. It is shown that the Fermi gas state is stable at very low density and at high density, but it is unstable for density fluctuation in the intermediate density region including the normal density. (author)
Cyberinfrastructure for Computational Relativistic Astrophysics
Ott, Christian
2012-01-01
Poster presented at the NSF Office of Cyberinfrastructure CyberBridges CAREER PI workshop. This poster discusses the computational challenges involved in the modeling of complex relativistic astrophysical systems. The Einstein Toolkit is introduced. It is an open-source community infrastructure for numerical relativity and computational astrophysics.
Future relativistic heavy ion experiments
International Nuclear Information System (INIS)
Pugh, H.G.
1980-12-01
Equations of state for nuclear matter and ongoing experimental studies are discussed. Relativistic heavy ion physics is the only opportunity to study in the laboratory the properties of extended multiquark systems under conditions such that quarks might run together into new arrangements previously unobserved. Several lines of further study are mentioned
A relativistic radiation transfer benchmark
International Nuclear Information System (INIS)
Munier, A.
1988-01-01
We use the integral form of the radiation transfer equation in an one dimensional slab to determine the time-dependent propagation of the radiation energy, flux and pressure in a collisionless homogeneous medium. First order v/c relativistic terms are included and the solution is given in the fluid frame and the laboratory frame
Relativistic models of nuclear structure
International Nuclear Information System (INIS)
Gillet, V.; Kim, E.J.; Cauvin, M.; Kohmura, T.; Ohnaka, S.
1991-01-01
The introduction of the relativistic field formalism for the description of nuclear structure has improved our understanding of fundamental nuclear mechanisms such as saturation or many body forces. We discuss some of these progresses, both in the semi-classical mean field approximation and in a quantized meson field approach. (author)
Fundamental length and relativistic length
International Nuclear Information System (INIS)
Strel'tsov, V.N.
1988-01-01
It si noted that the introduction of fundamental length contradicts the conventional representations concerning the contraction of the longitudinal size of fast-moving objects. The use of the concept of relativistic length and the following ''elongation formula'' permits one to solve this problem
Studies of relativistic heavy ion collisions
International Nuclear Information System (INIS)
Madansky, L.
1989-01-01
This report presents the progress in our program of Relativistic Heavy Ion studies. The first phase of experiments on lepton pairs is almost complete and the results from the initial part of this program are presented in copies of three publications. It appears that the origin of lepton pairs is the annihilation of pions. The evidence for this seems to be the shape of the dilepton mass spectrum, the cross-section as a function of energy which seems to scale with pion production, and the general kinematic behavior of the lepton pairs themselves. We present progress on the development of Ring Imaging Cerenkov counters for dilepton observations in general, and a short report on a high resolution method counter proposal that could be adapted to RHIC counters in general. Publication of results on hyperon polarization with incident polarized proton beams is also presented. These results use the phenomenological approach that could be useful in understanding hyperon production in heavy ion collisions. In this connection, a proposal for studying high density nuclear matter with incident antiprotons is presented. Progress on the TPC detectors developed by the BNL group for heavy ion research is reported, along with recent analysis of polarization with incident silicon beams. Finally, the most recent results on subthreshold antiproton production is presented. These latter results are several orders of magnitude more than expected and they point to some kind of coherent hadronic phenomena even at extremely low energies
Fundamentals of relativistic particle beam optics
International Nuclear Information System (INIS)
Cornacchia, M.
1995-12-01
This lecture introduces the nonaccelerator-specialist to the motion of charged particles in a Storage Ring. The topics of discussion are restricted to the linear and nonlinear dynamics of a single particle in the transverse plane, i.e., the plane perpendicular to the direction of motion. The major omissions for a complete review of accelerator theory, for which a considerable literature exists, are the energy and phase oscillations (1). Other important accelerator physics aspects not treated here are the collective instabilities (2), the role of synchrotron radiation in electron storage rings (3), scattering processes (4), and beam-beam effects in colliding beam facilities (5). Much of the discussion that follows applies equally well to relativistic electron, proton, or ion synchrotrons. In this narrative, we refer to the particle as electron. After a broad overview, the magnetic forces acting on the electrons and the associated differential equations of motion are discussed. Solutions of the equations are given without derivation; the method of solution is outlined. and references for deeper studies are given. In this paper, the word electron is used to signify electron or positron. The dynamics of a single particle are not affected by the sign of its charge when the magnetic field direction is changed accordingly
Relativistic corrections to the elastic electron scattering from 208Pb
International Nuclear Information System (INIS)
Chandra, H.; Sauer, G.
1976-01-01
In the present work we have calculated the differential cross sections for the elastic electron scattering from 208 Pb using the charge distributions resulting from various corrections. The point proton and neutron mass distributions have been calculated from the spherical wave functions for 208 Pb obtained by Kolb et al. The relativistic correction to the nuclear charge distribution coming from the electromagnetic structure of the nucleon has been accomplished by assuming a linear superposition of Gaussian shapes for the proton and the neutron charge form factor. Results of this calculation are quite similar to an earlier calculation by Bertozzi et al., who have used a different wave function for 208 Pb and have assumed exponential smearing for the proton corresponding to the dipole fit for the form factor. Also in the present work, reason for the small spin orbit contribution to the effective charge distribution is discussed in some detail. It is also shown that the use of a single Gaussian shape for the proton smearing usually underestimates the actual theoretical cross section
Solar wind classification from a machine learning perspective
Heidrich-Meisner, V.; Wimmer-Schweingruber, R. F.
2017-12-01
It is a very well known fact that the ubiquitous solar wind comes in at least two varieties, the slow solar wind and the coronal hole wind. The simplified view of two solar wind types has been frequently challenged. Existing solar wind categorization schemes rely mainly on different combinations of the solar wind proton speed, the O and C charge state ratios, the Alfvén speed, the expected proton temperature and the specific proton entropy. In available solar wind classification schemes, solar wind from stream interaction regimes is often considered either as coronal hole wind or slow solar wind, although their plasma properties are different compared to "pure" coronal hole or slow solar wind. As shown in Neugebauer et al. (2016), even if only two solar wind types are assumed, available solar wind categorization schemes differ considerably for intermediate solar wind speeds. Thus, the decision boundary between the coronal hole and the slow solar wind is so far not well defined.In this situation, a machine learning approach to solar wind classification can provide an additional perspective.We apply a well-known machine learning method, k-means, to the task of solar wind classification in order to answer the following questions: (1) How many solar wind types can reliably be identified in our data set comprised of ten years of solar wind observations from the Advanced Composition Explorer (ACE)? (2) Which combinations of solar wind parameters are particularly useful for solar wind classification?Potential subtypes of slow solar wind are of particular interest because they can provide hints of respective different source regions or release mechanisms of slow solar wind.
International Nuclear Information System (INIS)
Marciano, W.J.
1983-01-01
Topics include minimal SU(5) predictions, gauge boson mediated proton decay, uncertainties in tau/sub p/, Higgs scalar effects, proton decay via Higgs scalars, supersymmetric SU(5), dimension 5 operators and proton decay, and Higgs scalars and proton decay
RHIC spin: The first polarized proton collider
International Nuclear Information System (INIS)
Roser, T.
1994-01-01
The very successful program of QCD and electroweak tests at the high energy hadron colliders have shown that the perturbative QCD has progressed towards becoming a ''precision'' theory. At the same time, it has been shown that with the help of Siberian Snakes it is feasible to accelerate polarized protons to high enough energies where the proven methods of collider physics can be used to probe the spin content of the proton but also where fundamental tests of the spin effects in the standard model are possible. With Siberian Snakes the Relativistic Heavy Ion Collider (RHIC) will be the first collider to allow for 250 GeV on 250 GeV polarized proton collisions
Relativistic Descriptions of Few-Body Systems
International Nuclear Information System (INIS)
Karmanov, V. A.
2011-01-01
A brief review of relativistic effects in few-body systems, of theoretical approaches, recent developments and applications is given. Manifestations of relativistic effects in the binding energies, in the electromagnetic form factors and in three-body observables are demonstrated. The three-body forces of relativistic origin are also discussed. We conclude that relativistic effects in nuclei can be important in spite of small binding energy. At high momenta they clearly manifest themselves and are necessary to describe the deuteron e.m. form factors. At the same time, there is still a discrepancy in three-body observables which might be a result of less clarity in understanding the corresponding relativistic effects, the relativistic NN kernel and the three-body forces. Relativistic few-body physics remains to be a field of very intensive and fruitful researches. (author)
International Nuclear Information System (INIS)
Jongen, Y.
1995-01-01
Ideal radiotherapy deposits a large amount of energy in the tumour volume, and none in the surrounding healthy tissues. Proton therapy comes closer to this goal because of a greater concentration of dose, well defined proton ranges and points of energy release which are precisely known - the Bragg peak1. In the past, the development of clinical proton therapy has been hampered by complexity, size, and cost. To be clinically effective, energies of several hundred MeV are required; these were previously unavailable for hospital installations, and pioneering institutions had to work with complex, inadequate equipment originally intended for nuclear physics research. Recently a number of specialist organizations and commercial companies have been working on dedicated systems for proton therapy. One, IBA of Belgium, has equipment for inhouse hospital operation which encompasses a complete therapy centre, delivered as a turnkey package and incorporating a compact, automated, higher energy cyclotron with isocentric gantries. Their system will be installed at Massachusetts General Hospital, Boston. The proton therapy system comprises: - a 235 MeV isochronous cyclotron to deliver beams of up to 1.5 microamps, but with a hardware limitation to restrict the maximum possible dose; - variable energy beam (235 to 70 MeV ) with energy spread and emittance verification; - a beam transport and switching system to connect the exit of the energy selection system to the entrances of a number of gantries and fixed beamlines. Along the beam transport system, the beam characteristics are monitored with non-interceptive multiwire ionization chambers for automatic tuning; - gantries fitted with nozzles and beamline elements for beam control; both beam scattering and beam wobbling techniques are available for shaping the beam;
International Nuclear Information System (INIS)
Rodriguez D, J.M.
1998-01-01
The general theory of the wind energy conversion systems is presented. The availability of the wind resource in Colombia and the ranges of the speed of the wind in those which is possible economically to use the wind turbines are described. It is continued with a description of the principal technological characteristics of the wind turbines and are split into wind power and wind-powered pumps; and its use in large quantities grouped in wind farms or in autonomous systems. Finally, its costs and its environmental impact are presented
Recent development of relativistic molecular theory
International Nuclear Information System (INIS)
Takahito, Nakajima; Kimihiko, Hirao
2005-01-01
Today it is common knowledge that relativistic effects are important in the heavy-element chemistry. The continuing development of the relativistic molecular theory is opening up rows of the periodic table that are impossible to treat with the non-relativistic approach. The most straightforward way to treat relativistic effects on heavy-element systems is to use the four-component Dirac-Hartree-Fock approach and its electron-correlation methods based on the Dirac-Coulomb(-Breit) Hamiltonian. The Dirac-Hartree-Fock (DHF) or Dirac-Kohn-Sham (DKS) equation with the four-component spinors composed of the large- and small-components demands severe computational efforts to solve, and its applications to molecules including heavy elements have been limited to small- to medium-size systems. Recently, we have developed a very efficient algorithm for the four-component DHF and DKS approaches. As an alternative approach, several quasi-relativistic approximations have also been proposed instead of explicitly solving the four-component relativistic equation. We have developed the relativistic elimination of small components (RESC) and higher-order Douglas-Kroll (DK) Hamiltonians within the framework of the two-component quasi-relativistic approach. The developing four-component relativistic and approximate quasi-relativistic methods have been implemented into a program suite named REL4D. In this article, we will introduce the efficient relativistic molecular theories to treat heavy-atomic molecular systems accurately via the four-component relativistic and the two-component quasi-relativistic approaches. We will also show several chemical applications including heavy-element systems with our relativistic molecular approaches. (author)
Relativistic quantum mechanics an introduction to relativistic quantum fields
Maiani, Luciano
2016-01-01
Written by two of the world's leading experts on particle physics and the standard model - including an award-winning former Director General of CERN - this textbook provides a completely up-to-date account of relativistic quantum mechanics and quantum field theory. It describes the formal and phenomenological aspects of the standard model of particle physics, and is suitable for advanced undergraduate and graduate students studying both theoretical and experimental physics.
β-decay rates of r-process nuclei in the relativistic quasiparticle random phase approximation
International Nuclear Information System (INIS)
Niksic, T.; Marketin, T.; Vretenar, D.; Paar, N.; Ring, P.
2004-01-01
The fully consistent relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is employed in the calculation of β-decay half-lives of neutron-rich nuclei in the N∼50 and N∼82 regions. A new density-dependent effective interaction, with an enhanced value of the nucleon effective mass, is used in relativistic Hartree-Bogolyubov calculation of nuclear ground states and in the particle-hole channel of the PN-RQRPA. The finite range Gogny D1S interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The theoretical half-lives reproduce the experimental data for the Fe, Zn, Cd, and Te isotopic chains, but overestimate the lifetimes of Ni isotopes and predict a stable 132 Sn. (orig.)
β-decay rates of r-process nuclei in the relativistic quasiparticle random phase approximation
International Nuclear Information System (INIS)
Niksic, T.; Marketin, T.; Vretenar, D.; Paar, N.; Ring, P.
2005-01-01
The fully consistent relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is employed in the calculation of β-decay half-lives of neutron-rich nuclei in the N≅50 and N≅82 regions. A new density-dependent effective interaction, with an enhanced value of the nucleon effective mass, is used in relativistic Hartree-Bogoliubov calculation of nuclear ground states and in the particle-hole channel of the PN-RQRPA. The finite range Gogny D1S interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The theoretical half-lives reproduce the experimental data for the Fe, Zn, Cd, and Te isotopic chains but overestimate the lifetimes of Ni isotopes and predict a stable 132 Sn
{beta}-decay rates of r-process nuclei in the relativistic quasiparticle random phase approximation
Energy Technology Data Exchange (ETDEWEB)
Niksic, T.; Marketin, T.; Vretenar, D. [Zagreb Univ. (Croatia). Faculty of Science, Physics Dept.; Paar, N. [Technische Univ. Darmstadt (Germany). Inst. fuer Kernphysik; Ring, P. [Technische Univ. Muenchen, Garching (Germany). Physik-Department
2004-12-08
The fully consistent relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is employed in the calculation of {beta}-decay half-lives of neutron-rich nuclei in the N{approx}50 and N{approx}82 regions. A new density-dependent effective interaction, with an enhanced value of the nucleon effective mass, is used in relativistic Hartree-Bogolyubov calculation of nuclear ground states and in the particle-hole channel of the PN-RQRPA. The finite range Gogny D1S interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The theoretical half-lives reproduce the experimental data for the Fe, Zn, Cd, and Te isotopic chains, but overestimate the lifetimes of Ni isotopes and predict a stable {sup 132}Sn. (orig.)
Perpendicular relativistic shocks in magnetized pair plasma
Plotnikov, Illya; Grassi, Anna; Grech, Mickael
2018-04-01
Perpendicular relativistic (γ0 = 10) shocks in magnetized pair plasmas are investigated using two dimensional Particle-in-Cell simulations. A systematic survey, from unmagnetized to strongly magnetized shocks, is presented accurately capturing the transition from Weibel-mediated to magnetic-reflection-shaped shocks. This transition is found to occur for upstream flow magnetizations 10-3 10-2, it leaves place to a purely electromagnetic precursor following from the strong emission of electromagnetic waves at the shock front. Particle acceleration is found to be efficient in weakly magnetized perpendicular shocks in agreement with previous works, and is fully suppressed for σ > 10-2. Diffusive Shock Acceleration is observed only in weakly magnetized shocks, while a dominant contribution of Shock Drift Acceleration is evidenced at intermediate magnetizations. The spatial diffusion coefficients are extracted from the simulations allowing for a deeper insight into the self-consistent particle kinematics and scale with the square of the particle energy in weakly magnetized shocks. These results have implications for particle acceleration in the internal shocks of AGN jets and in the termination shocks of Pulsar Wind Nebulae.
International Nuclear Information System (INIS)
Gos, H.P.
2007-01-01
The analysis of two-particle correlations provides a powerful tool to study the properties of hot and dense matter created in heavy-ion collisions at ultra-relativistic energies. Applied to identical and non-identical hadron pairs, it makes the study of space-time evolution of the source in femtoscopic scale possible. Baryon femtoscopy allows extraction of the radii of produced sources which can be compared to those deduced from identical pion studies, providing complete information about the source characteristics. In this paper we present the correlation functions obtained for identical and non-identical baryon pairs of protons and anti-protons. The data were collected recently in Au+Au collisions at √(s NN )=62 GeV and √(s NN )=200 GeV by the STAR detector at the RHIC accelerator. We introduce corrections to the baryon-baryon correlations taking into account: residual correlations from weak decays, particle identification probability and the fraction of primary baryons. Finally we compare our results to theoretical predictions. (orig.)
Examining Relativistic Electron Loss in the Outer Radiation Belt
Green, J. C.; Onsager, T. G.; O'Brien, P.
2003-12-01
Since the discovery of earth's radiation belts researchers have sought to identify the mechanisms that dictate the seemingly erratic relativistic electron flux levels in the outer belt. Contrary to intuition, relativistic electron flux levels do not always increase during geomagnetic storms even though these storms signify enhanced energy input from the solar wind to the magnetosphere [Reeves et al., 2003; O'Brien et al., 2001]. The fickle response of the radiation belt electrons to geomagnetic activity suggests that flux levels are determined by the outcome of a continuous competition between acceleration and loss. Some progress has been made developing and testing acceleration mechanisms but little is known about how relativistic electrons are lost. We examine relativistic electron losses in the outer belt focusing our attention on flux decrease events of the type first described by Onsager et al. [2002]. The study showed a sudden decrease of geosynchronous >2MeV electron flux occurring simultaneously with local stretching of the magnetic field. The decrease was first observed near 15:00 MLT and progressed to all local times after a period of ˜10 hours. Expanding on the work of Onsager et al. [2002], we have identified ˜ 51 such flux decrease events in the GOES and LANL data and present the results of a superposed epoch analysis of solar wind data, geomagnetic activity indicators, and locally measured magnetic field and plasma data. The analysis shows that flux decreases occur after 1-2 days of quiet condition. They begin when either the solar wind dynamic pressure increases or Bz turns southward pushing hot dense plasma earthward to form a partial ring current and stretched magnetic field at dusk. Adiabatic electron motion in response to the stretched magnetic field may explain the initial flux reduction; however, often the flux does not recover with the magnetic field recovery, indicating that true loss from the magnetosphere is occurring. Using Polar and
Proton radiography to improve proton therapy treatment
Takatsu, J.; van der Graaf, E. R.; van Goethem, Marc-Jan; van Beuzekom, M.; Klaver, T.; Visser, Jan; Brandenburg, S.; Biegun, A. K.
The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT)
Prediction Model for Relativistic Electrons at Geostationary Orbit
Khazanov, George V.; Lyatsky, Wladislaw
2008-01-01
We developed a new prediction model for forecasting relativistic (greater than 2MeV) electrons, which provides a VERY HIGH correlation between predicted and actually measured electron fluxes at geostationary orbit. This model implies the multi-step particle acceleration and is based on numerical integrating two linked continuity equations for primarily accelerated particles and relativistic electrons. The model includes a source and losses, and used solar wind data as only input parameters. We used the coupling function which is a best-fit combination of solar wind/interplanetary magnetic field parameters, responsible for the generation of geomagnetic activity, as a source. The loss function was derived from experimental data. We tested the model for four year period 2004-2007. The correlation coefficient between predicted and actual values of the electron fluxes for whole four year period as well as for each of these years is stable and incredibly high (about 0.9). The high and stable correlation between the computed and actual electron fluxes shows that the reliable forecasting these electrons at geostationary orbit is possible.
International Nuclear Information System (INIS)
Key, M.H.; Campbell, E.M.; Cowan, T.E.; Hatchett, S.P.; Henry, E.A.; Koch, J.A.; Landgon, A.B.; Lasinski, B.F.; Lee, R.W.; MacKinnon, A.; Offenberger, A.; Pennington, D.M.; Perry, M.D.; Sangster, T.C.; Yasuike, K.; Snavely, R.; Roth, M.; Phillips, T.W.; Stoyer, M.A.; Wilks, S.C.; Singh, M.S.
1999-01-01
The interaction of laser radiation with solid targets at 1 petawatt power and intensity up to 3x10 20 Wcm -2 has been studied with emphasis on relativistic electrons and high energy ions. Secondary effects including Bremsstrahlung radiation, nuclear interactions and heating have been characterized. A collimated beam of protons with up to 55 MeV energy is emitted normal to the rear surface of thin targets and its characteristics and origin are discussed. The significance of the data for radiography, fast ignition and proton beam applications is summarized
International Nuclear Information System (INIS)
Napolitani, P.; Tassan-Got, L.; Bernas, M.; Armbruster, P.
2003-04-01
Secondary reactions induced by relativistic beams in inverse kinematics in a thick target are relevant in several fields of experimental physics and technology, like secondary radioactive beams, production of exotic nuclei close to the proton drip line, and cross-section measurements for applications of spallation reactions for energy production and incineration of nuclear wastes. A general mathematical formulation is presented and successively applied as a tool to disentangle the primary reaction yields from the secondary production in the measurement of fission of a 238 U projectile impinging on a proton target at the energy of 1 A GeV. (orig.)
Relativistic quantum mechanics of bosons
International Nuclear Information System (INIS)
Ghose, P.; Home, D.; Sinha Roy, M.N.
1993-01-01
We show that it is possible to use the Klein-Gordon, Proca and Maxwell formulations to construct multi-component relativistic configuration space wavefunctions of spin-0 and spin-1 bosons in an external field. These wavefunctions satisfy the first-order Kemmer-Duffin equation. The crucial ingredient is the use of the future-causal normal n μ (n μ n μ =1, n 0 >0) to the space-like hypersurfaces foliating space-time, inherent in the concept of a relativistic wavefunction, to construct a conserved future-causal probability current four-vector from the second-rank energy-momentum tensor, following Holland's prescription. The existence of a Hermitian position operator, localized solutions, compatibility with the second quantized theories and the question of interpretation are discussed. (orig.)
Kinetic approach to relativistic dissipation
Gabbana, A.; Mendoza, M.; Succi, S.; Tripiccione, R.
2017-08-01
Despite a long record of intense effort, the basic mechanisms by which dissipation emerges from the microscopic dynamics of a relativistic fluid still elude complete understanding. In particular, several details must still be finalized in the pathway from kinetic theory to hydrodynamics mainly in the derivation of the values of the transport coefficients. In this paper, we approach the problem by matching data from lattice-kinetic simulations with analytical predictions. Our numerical results provide neat evidence in favor of the Chapman-Enskog [The Mathematical Theory of Non-Uniform Gases, 3rd ed. (Cambridge University Press, Cambridge, U.K., 1970)] procedure as suggested by recent theoretical analyses along with qualitative hints at the basic reasons why the Chapman-Enskog expansion might be better suited than Grad's method [Commun. Pure Appl. Math. 2, 331 (1949), 10.1002/cpa.3160020403] to capture the emergence of dissipative effects in relativistic fluids.
Relativistic electron beams above thunderclouds
DEFF Research Database (Denmark)
Füellekrug, M.; Roussel-Dupre, R.; Symbalisty, E. M. D.
2011-01-01
Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency similar to 40-400 kHz which they radiate. The electron beams occur similar to 2-9 ms after positive cloud-to-ground lightning discharges at heights between similar to 22-72 km above...... thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron beam. One electron beam was detected without any luminous sprite which suggests that electron beams may also occur independently of sprites. Numerical simulations show that beams...... of electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of similar to 7MeV to transport a total charge of similar to-10mC upwards. The impulsive current similar to 3 x 10(-3) Am-2 associated with relativistic electron beams above thunderclouds...
The relativistic electron wave equation
International Nuclear Information System (INIS)
Dirac, P.A.M.
1977-08-01
The paper was presented at the European Conference on Particle Physics held in Budapest between the 4th and 9th July of 1977. A short review is given on the birth of the relativistic electron wave equation. After Schroedinger has shown the equivalence of his wave mechanics and the matrix mechanics of Heisenberg, a general transformation theory was developed by the author. This theory required a relativistic wave equation linear in delta/delta t. As the Klein--Gordon equation available at this time did not satisfy this condition the development of a new equation became necessary. The equation which was found gave the value of the electron spin and magnetic moment automatically. (D.P.)
Diffraction radiation from relativistic particles
Potylitsyn, Alexander Petrovich; Strikhanov, Mikhail Nikolaevich; Tishchenko, Alexey Alexandrovich
2010-01-01
This book deals with diffraction radiation, which implies the boundary problems of electromagnetic radiation theory. Diffraction radiation is generated when a charged particle moves in a vacuum near a target edge. Diffraction radiation of non-relativistic particles is widely used to design intense emitters in the cm wavelength range. Diffraction radiation from relativistic charged particles is important for noninvasive beam diagnostics and design of free electron lasers based on Smith-Purcell radiation which is diffraction radiation from periodic structures. Different analytical models of diffraction radiation and results of recent experimental studies are presented in this book. The book may also serve as guide to classical electrodynamics applications in beam physics and electrodynamics. It can be of great use for young researchers to develop skills and for experienced scientists to obtain new results.
Volatility smile as relativistic effect
Kakushadze, Zura
2017-06-01
We give an explicit formula for the probability distribution based on a relativistic extension of Brownian motion. The distribution (1) is properly normalized and (2) obeys the tower law (semigroup property), so we can construct martingales and self-financing hedging strategies and price claims (options). This model is a 1-constant-parameter extension of the Black-Scholes-Merton model. The new parameter is the analog of the speed of light in Special Relativity. However, in the financial context there is no ;speed limit; and the new parameter has the meaning of a characteristic diffusion speed at which relativistic effects become important and lead to a much softer asymptotic behavior, i.e., fat tails, giving rise to volatility smiles. We argue that a nonlocal stochastic description of such (Lévy) processes is inadequate and discuss a local description from physics. The presentation is intended to be pedagogical.
Double Relativistic Electron Accelerating Mirror
Directory of Open Access Journals (Sweden)
Saltanat Sadykova
2013-02-01
Full Text Available In the present paper, the possibility of generation of thin dense relativistic electron layers is shown using the analytical and numerical modeling of laser pulse interaction with ultra-thin layers. It was shown that the maximum electron energy can be gained by optimal tuning between the target width, intensity and laser pulse duration. The optimal parameters were obtained from a self-consistent system of Maxwell equations and the equation of motion of electron layer. For thin relativistic electron layers, the gaining of maximum electron energies requires a second additional overdense plasma layer, thus cutting the laser radiation off the plasma screen at the instant of gaining the maximum energy (DREAM-schema.
Diffraction radiation from relativistic particles
International Nuclear Information System (INIS)
Potylitsyn, Alexander Petrovich; Ryazanov, Mikhail Ivanovich; Strikhanov, Mikhail Nikolaevich; Tishchenko, Alexey Alexandrovich
2010-01-01
This book deals with diffraction radiation, which implies the boundary problems of electromagnetic radiation theory. Diffraction radiation is generated when a charged particle moves in a vacuum near a target edge. Diffraction radiation of non-relativistic particles is widely used to design intense emitters in the cm wavelength range. Diffraction radiation from relativistic charged particles is important for noninvasive beam diagnostics and design of free electron lasers based on Smith-Purcell radiation which is diffraction radiation from periodic structures. Different analytical models of diffraction radiation and results of recent experimental studies are presented in this book. The book may also serve as guide to classical electrodynamics applications in beam physics and electrodynamics. It can be of great use for young researchers to develop skills and for experienced scientists to obtain new results. (orig.)
Mechanism of disintegration of sup 2 sup 3 sup 8 U nuclei by relativistic projectiles
Andronenko, L N; Kravtsov, A V; Solyakin, G E
2002-01-01
The sup 2 sup 3 sup 8 U nuclei disintegration through the 16 GeV energy protons and sup 3 He 2 GeV energy nuclei are considered. The pulse mechanism compensation is proposed to explain the formation of collinear mass fragments accompanied by a large amount of charged secondaries and neutrons flying on the m sub 1 relativistic particle heavy nuclei on the account of the particle emission with the mass m sub 2 > m sub 1
Asymptotics of relativistic spin networks
International Nuclear Information System (INIS)
Barrett, John W; Steele, Christopher M
2003-01-01
The stationary phase technique is used to calculate asymptotic formulae for SO(4) relativistic spin networks. For the tetrahedral spin network this gives the square of the Ponzano-Regge asymptotic formula for the SU(2) 6j-symbol. For the 4-simplex (10j-symbol) the asymptotic formula is compared with numerical calculations of the spin network evaluation. Finally, we discuss the asymptotics of the SO(3, 1) 10j-symbol
Analytic approaches to relativistic hydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Hatta, Yoshitaka
2016-12-15
I summarize our recent work towards finding and utilizing analytic solutions of relativistic hydrodynamic. In the first part I discuss various exact solutions of the second-order conformal hydrodynamics. In the second part I compute flow harmonics v{sub n} analytically using the anisotropically deformed Gubser flow and discuss its dependence on n, p{sub T}, viscosity, the chemical potential and the charge.
Pythagoras Theorem and Relativistic Kinematics
Mulaj, Zenun; Dhoqina, Polikron
2010-01-01
In two inertial frames that move in a particular direction, may be registered a light signal that propagates in an angle with this direction. Applying Pythagoras theorem and principles of STR in both systems, we can derive all relativistic kinematics relations like the relativity of simultaneity of events, of the time interval, of the length of objects, of the velocity of the material point, Lorentz transformations, Doppler effect and stellar aberration.
Characteristic manifolds in relativistic hypoelasticity
Energy Technology Data Exchange (ETDEWEB)
Giambo, S [Messina Univ. (Italy). Istituto di Matematica
1978-10-02
The relativistic hypoelasticity is considered and the characteristic manifolds are determined by using the Cauchy-Kovalevski theorem for the Cauchy problem with analytic initial conditions. Taking into account that the characteristic manifold represents the image of the front-wave in the space-time, it is possible to determine the velocities of propagation. Three wave-species are obtained: material waves, longitudinal waves and transverse waves.
A relativistic quarkonium potential model
International Nuclear Information System (INIS)
Klima, B.; Maor, U.
1984-04-01
We review a recently developed relativistic quark-antiquark bound state equation using the expansion in intermediate states. Using a QCD motivated potential we succeeded very well to fit both the heavy systems (banti b, canti c) and the light systems (santi s, uanti u and danti d). Here we emphasize our results on heavy-light sustems and on the possible (tanti t) family. (orig.)
Coordinates in relativistic Hamiltonian mechanics
International Nuclear Information System (INIS)
Sokolov, S.N.
1984-01-01
The physical (covariant and measurable) coordinates of free particles and covariant coordinates of the center of inertia are found for three main forms of relativistic dynamics. In the point form of dynamics, the covariant coordinates of two directly interacting particles are found, and the equations of motion are brought to the explicitly covariant form. These equations are generalized to the case of interaction with an external electromagnetic field
Relativistic mechanics with reduced fields
International Nuclear Information System (INIS)
Sokolov, S.N.
1996-01-01
A new relativistic classical mechanics of interacting particles using a concept of a reduced field (RF) os proposed. RF is a mediator of interactions, the state of which is described by a finite number of two-argument functions. Ten of these functions correspond to the generators of the Poincare group. Equations of motion contain the retardation of interactions required by the causality principle and have form of a finite system of ordinary hereditary differential equations [ru
Theory of a relativistic peniotron
International Nuclear Information System (INIS)
Zhurakhovskii, V.A.
1986-01-01
A normalized mathematical model for describing the motion of electrons in a relativistic peniotron with smoothly varying magnetostatic field, which provides a state of exact gyroresonance along the entire length of the device, is constructed. The results of computer calculations of the energetics of this device are presented and an example of an effective choice of its parameterse corresponding to high electronic efficiency of a one-velocity flow are presented
Relativistic beaming and quasar statistics
International Nuclear Information System (INIS)
Orr, M.J.L.; Browne, I.W.A.
1982-01-01
The statistical predictions of a unified scheme for the radio emission from quasars are explored. This scheme attributes the observed differences between flat- and steep-spectrum quasars to projection and the effects of relativistic beaming of the emission from the nuclear components. We use a simple quasar model consisting of a compact relativistically beamed core with spectral index zero and unbeamed lobes, spectral index - 1, to predict the proportion of flat-spectrum sources in flux-limited samples selected at different frequencies. In our model this fraction depends on the core Lorentz factor, γ and we find that a value of approximately 5 gives satisfactory agreement with observation. In a similar way the model is used to construct the expected number/flux density counts for flat-spectrum quasars from the observed steep-spectrum counts. Again, good agreement with the observations is obtained if the average core Lorentz factor is about 5. Independent estimates of γ from observations of superluminal motion in quasars are of the same order of magnitude. We conclude that the statistical properties of quasars are entirely consistent with the predictions of simple relativistic-beam models. (author)
Relativistic Binaries in Globular Clusters
Directory of Open Access Journals (Sweden)
Matthew J. Benacquista
2013-03-01
Full Text Available Galactic globular clusters are old, dense star systems typically containing 10^4 – 10^6 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker–Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.
Pulsar Magnetohydrodynamic Winds
Okamoto, Isao; Sigalo, Friday B.
2006-12-01
The acceleration and collimation/decollimation of relativistic magnetocentrifugal winds are discussed concerning a cold plasma from a strongly magnetized, rapidly rotating neutron star in a steady axisymmetric state based on ideal magnetohydrodynamics. There exist unipolar inductors associated with the field line angular frequency, α, at the magnetospheric base surface, SB, with a huge potential difference between the poles and the equator, which drive electric current through the pulsar magnetosphere. Any ``current line'' must emanate from one terminal of the unipolar inductor and return to the other, converting the Poynting flux to the kinetic flux of the wind at finite distances. In a plausible field structure satisfying the transfield force-balance equation, the fast surface, SF, must exist somewhere between the subasymptotic and asymptotic domains, i.e., at the innermost point along each field line of the asymptotic domain of \\varpaA2/\\varpi2 ≪ 1, where \\varpiA is the Alfvénic axial distance. The criticality condition at SF yields the Lorentz factor, γF = μ\\varepsilon1/3, and the angular momentum flux, β, as the eigenvalues in terms of the field line angular velocity, α, the mass flux per unit flux tube, η, and one of the Bernoulli integrals, μδ, which are assumed to be specifiable as the boundary conditions at SB. The other Bernoulli integral, μɛ, is related to μδ as μɛ = μδ[1-(α2\\varpiA2/c2)]-1, and both μɛ and \\varpiA2 are eigenvalues to be determined by the criticality condition at SF. Ongoing MHD acceleration is possible in the superfast domain. This fact may be helpful in resolving a discrepancy between the wind theory and the Crab-nebula model. It is argued that the ``anti-collimation theorem'' holds for relativistic winds, based on the curvature of field streamlines determined by the transfield force balance. The ``theorem'' combines with the ``current-closure condition'' as a global condition in the wind zone to produce a
Nonlinear dynamics of the relativistic standard map
International Nuclear Information System (INIS)
Nomura, Y.; Ichikawa, Y.H.; Horton, W.
1991-04-01
Heating and acceleration of charged particles by RF fields have been extensively investigated by the standard map. The question arises as to how the relativistic effects change the nonlinear dynamical behavior described by the classical standard map. The relativistic standard map is a two parameter (K, Β = ω/kc) family of dynamical systems reducing to the standard map when Β → 0. For Β ≠ 0 the relativistic mass increase suppresses the onset of stochasticity. It shown that the speed of light limits the rate of advance of the phase in the relativistic standard map and introduces KAM surfaces persisting in the high momentum region. An intricate structure of mixing in the higher order periodic orbits and chaotic orbits is analyzed using the symmetry properties of the relativistic standard map. The interchange of the stability of the periodic orbits in the relativistic standard map is also observed and is explained by the local linear stability of the orbits. 12 refs., 16 figs
Relativistic bound state wave functions
International Nuclear Information System (INIS)
Micu, L.
2005-01-01
A particular method of writing the bound state wave functions in relativistic form is applied to the solutions of the Dirac equation with confining potentials in order to obtain a relativistic description of a quark antiquark bound system representing a given meson. Concerning the role of the effective constituent in the present approach we first observe that without this additional constituent we couldn't expand the bound state wave function in terms of products of free states. Indeed, we notice that if the wave function depends on the relative coordinates only, all the expansion coefficients would be infinite. Secondly we remark that the effective constituent enabled us to give a Lorentz covariant meaning to the potential energy of the bound system which is now seen as the 4th component of a 4-momentum. On the other side, by relating the effective constituent to the quantum fluctuations of the background field which generate the binding, we provided a justification for the existence of some spatial degrees of freedom accompanying the interaction potential. These ones, which are quite unusual in quantum mechanics, in our model are the natural consequence of the the independence of the quarks and can be seen as the effect of the imperfect cancellation of the vector momenta during the quantum fluctuations. Related with all these we remark that the adequate representation for the relativistic description of a bound system is the momentum representation, because of the transparent and easy way of writing the conservation laws and the transformation properties of the wave functions. The only condition to be fulfilled is to find a suitable way to take into account the potential energy of the bound system. A particular feature of the present approach is that the confining forces are due to a kind of glue where both quarks are embedded. This recalls other bound state models where the wave function is factorized in terms of constituent wave functions and the confinement is
Relativistic neoclassical transport coefficients with momentum correction
International Nuclear Information System (INIS)
Marushchenko, I.; Azarenkov, N.A.
2016-01-01
The parallel momentum correction technique is generalized for relativistic approach. It is required for proper calculation of the parallel neoclassical flows and, in particular, for the bootstrap current at fusion temperatures. It is shown that the obtained system of linear algebraic equations for parallel fluxes can be solved directly without calculation of the distribution function if the relativistic mono-energetic transport coefficients are already known. The first relativistic correction terms for Braginskii matrix coefficients are calculated.
Loading relativistic Maxwell distributions in particle simulations
International Nuclear Information System (INIS)
Zenitani, Seiji
2015-01-01
Numerical algorithms to load relativistic Maxwell distributions in particle-in-cell (PIC) and Monte-Carlo simulations are presented. For stationary relativistic Maxwellian, the inverse transform method and the Sobol algorithm are reviewed. To boost particles to obtain relativistic shifted-Maxwellian, two rejection methods are proposed in a physically transparent manner. Their acceptance efficiencies are ≈50% for generic cases and 100% for symmetric distributions. They can be combined with arbitrary base algorithms
Loading relativistic Maxwell distributions in particle simulations
Energy Technology Data Exchange (ETDEWEB)
Zenitani, Seiji, E-mail: seiji.zenitani@nao.ac.jp [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
2015-04-15
Numerical algorithms to load relativistic Maxwell distributions in particle-in-cell (PIC) and Monte-Carlo simulations are presented. For stationary relativistic Maxwellian, the inverse transform method and the Sobol algorithm are reviewed. To boost particles to obtain relativistic shifted-Maxwellian, two rejection methods are proposed in a physically transparent manner. Their acceptance efficiencies are ≈50% for generic cases and 100% for symmetric distributions. They can be combined with arbitrary base algorithms.
Kutateladze, Andrei G; Mukhina, Olga A
2014-09-05
Spin-spin coupling constants in (1)H NMR carry a wealth of structural information and offer a powerful tool for deciphering molecular structures. However, accurate ab initio or DFT calculations of spin-spin coupling constants have been very challenging and expensive. Scaling of (easy) Fermi contacts, fc, especially in the context of recent findings by Bally and Rablen (Bally, T.; Rablen, P. R. J. Org. Chem. 2011, 76, 4818), offers a framework for achieving practical evaluation of spin-spin coupling constants. We report a faster and more precise parametrization approach utilizing a new basis set for hydrogen atoms optimized in conjunction with (i) inexpensive B3LYP/6-31G(d) molecular geometries, (ii) inexpensive 4-31G basis set for carbon atoms in fc calculations, and (iii) individual parametrization for different atom types/hybridizations, not unlike a force field in molecular mechanics, but designed for the fc's. With the training set of 608 experimental constants we achieved rmsd <0.19 Hz. The methodology performs very well as we illustrate with a set of complex organic natural products, including strychnine (rmsd 0.19 Hz), morphine (rmsd 0.24 Hz), etc. This precision is achieved with much shorter computational times: accurate spin-spin coupling constants for the two conformers of strychnine were computed in parallel on two 16-core nodes of a Linux cluster within 10 min.
Relativistic fluids in spherically symmetric space
International Nuclear Information System (INIS)
Dipankar, R.
1977-12-01
Some of McVittie and Wiltshire's (1977) solutions of Walker's (1935) isotropy conditions for relativistic perfect fluid spheres are generalized. Solutions are spherically symmetric and conformally flat
RELATIVISTIC CYCLOTRON INSTABILITY IN ANISOTROPIC PLASMAS
Energy Technology Data Exchange (ETDEWEB)
López, Rodrigo A.; Moya, Pablo S.; Muñoz, Víctor; Valdivia, J. Alejandro [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Navarro, Roberto E.; Araneda, Jaime A. [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Viñas, Adolfo F., E-mail: rlopez186@gmail.com [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, MD 20771 (United States)
2016-11-20
A sufficiently large temperature anisotropy can sometimes drive various types of electromagnetic plasma micro-instabilities, which can play an important role in the dynamics of relativistic pair plasmas in space, astrophysics, and laboratory environments. Here, we provide a detailed description of the cyclotron instability of parallel propagating electromagnetic waves in relativistic pair plasmas on the basis of a relativistic anisotropic distribution function. Using plasma kinetic theory and particle-in-cell simulations, we study the influence of the relativistic temperature and the temperature anisotropy on the collective and noncollective modes of these plasmas. Growth rates and dispersion curves from the linear theory show a good agreement with simulations results.
The first SEPServer event catalogue ~68-MeV solar proton events observed at 1 AU in 1996–2010
Directory of Open Access Journals (Sweden)
Rodríguez-Gasén Rosa
2013-03-01
Full Text Available SEPServer is a three-year collaborative project funded by the seventh framework programme (FP7-SPACE of the European Union. The objective of the project is to provide access to state-of-the-art observations and analysis tools for the scientific community on solar energetic particle (SEP events and related electromagnetic (EM emissions. The project will eventually lead to better understanding of the particle acceleration and transport processes at the Sun and in the inner heliosphere. These processes lead to SEP events that form one of the key elements of space weather. In this paper we present the first results from the systematic analysis work performed on the following datasets: SOHO/ERNE, SOHO/EPHIN, ACE/EPAM, Wind/WAVES and GOES X-rays. A catalogue of SEP events at 1 AU, with complete coverage over solar cycle 23, based on high-energy (~68-MeV protons from SOHO/ERNE and electron recordings of the events by SOHO/EPHIN and ACE/EPAM are presented. A total of 115 energetic particle events have been identified and analysed using velocity dispersion analysis (VDA for protons and time-shifting analysis (TSA for electrons and protons in order to infer the SEP release times at the Sun. EM observations during the times of the SEP event onset have been gathered and compared to the release time estimates of particles. Data from those events that occurred during the European day-time, i.e., those that also have observations from ground-based observatories included in SEPServer, are listed and a preliminary analysis of their associations is presented. We find that VDA results for protons can be a useful tool for the analysis of proton release times, but if the derived proton path length is out of a range of 1 AU < s ≲ 3 AU, the result of the analysis may be compromised, as indicated by the anti-correlation of the derived path length and release time delay from the associated X-ray flare. The average path length derived from VDA is about 1.9 times
Pulsar magnetosphere-wind or wave
International Nuclear Information System (INIS)
Kennel, C.F.
1979-01-01
The structure of both the interior and exterior pulsar magnetosphere depends upon the strength of its plasma source near the surface of the star. We review wave models of exterior pulsar magnetospheres in the light of a vacuum pair-production source model proposed by Sturrock, and Ruderman and Sutherland. This model predicts the existence of a cutoff, determined by the neutron star's spin rate and magnetic field strenght, beyond which coherent radio emission is no longer possible. Since the observed distribution of pulsar spin periods and period derivatives, and the distribution of pulsars with missing radio pulses, is consistent with the pair production threshold, those neutron stars observed as radio pulsars can have relativistic magnetohydrodynamic wind exterior magnetospheres, and cannot have relativistic plasma wave exterior magnetospheres. On the other hand, most erstwhile pulsars in the galaxy are probably halo objects that emit weak fluxes of energetic photons that can have relativistic wave exterior magnetospheres. Extinct pulsars have not been yet observed
Electromagnetic Cyclotron Waves in the Solar Wind: Wind Observation and Wave Dispersion Analysis
Jian, L. K.; Moya, P. S.; Vinas, A. F.; Stevens, M.
2016-01-01
Wind observed long-lasting electromagnetic cyclotron waves near the proton cyclotron frequency on 11 March 2005, in the descending part of a fast wind stream. Bi-Maxwellian velocity distributions are fitted for core protons, beam protons, and alpha-particles. Using the fitted plasma parameters we conduct kinetic linear dispersion analysis and find ion cyclotron and/or firehose instabilities grow in six of 10 wave intervals. After Doppler shift, some of the waves have frequency and polarization consistent with observation, thus may be correspondence to the cyclotron waves observed.
High luminosity polarized proton collisions at RHIC
International Nuclear Information System (INIS)
Roser, T.
2001-01-01
The Brookhaven Relativistic Heavy Ion Collider (RHIC) provides the unique opportunity to collide polarized proton beams at a center-of-mass energy of up to 500 GeV and luminosities of up to 2 x 10 32 cm -2 s -1 . Such high luminosity and high energy polarized proton collisions will open up the possibility of studying spin effects in hard processes. However, the acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial Siberian snake and a rf dipole that ensure stable adiabatic spin motion during acceleration has made it possible to accelerate polarized protons to 25 GeV at the Brookhaven AGS. After successful operation of RHIC with gold beams polarized protons from the AGS have been successfully injected into RHIC and accelerated using a full Siberian snakes built from four superconducting helical dipoles. A new high energy proton polarimeter was also successfully commissioned. Operation with two snakes per RHIC ring is planned for next year
International Nuclear Information System (INIS)
Den Besten, J.L.; Jamieson, D.N.; Allen, L.J.
1998-01-01
The Lindhard theory on ion channeling in crystals has been widely accepted throughout ion beam analysis for use in simulating such experiments. The simulations use a Monte Carlo method developed by Barret, which utilises the classical 'billiard ball' theory of ions 'bouncing' between planes or tubes of atoms in the crystal. This theory is not valid for 'thin' crystals where the planes or strings of atoms can no longer be assumed to be of infinite proportions. We propose that a theory similar to that used for high energy electron diffraction can be applied to MeV ions, especially protons, in thin crystals to simulate the intensities of transmission channeling and of RBS spectra. The diffraction theory is based on a Bloch wave solution of the Schroedinger equation for an ion passing through the periodic crystal potential. The widely used universal potential for proton-nucleus scattering is used to construct the crystal potential. Absorption due to thermal diffuse scattering is included. Experimental parameters such as convergence angle, beam tilt and scanning directions are considered in our calculations. Comparison between theory and experiment is encouraging and suggests that further work is justified. (authors)
Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process
Vlasov, Andrey D.; Metzger, Brian D.; Lippuner, Jonas; Roberts, Luke F.; Thompson, Todd A.
2017-06-01
We explore heavy element nucleosynthesis in neutrino-driven winds from rapidly rotating, strongly magnetized protoneutron stars ('millisecond protomagnetars') for which the magnetic dipole is aligned with the rotation axis, and the field is assumed to be a static force-free configuration. We process the protomagnetar wind trajectories calculated by Vlasov, Metzger & Thompson through the r-process nuclear reaction network SkyNet using contemporary models for the evolution of the wind electron fraction during the protoneutron star cooling phase. Although we do not find a successful second or third-peak r-process for any rotation period P, we show that protomagnetars with P ˜ 1-5 ms produce heavy element abundance distributions that extend to higher nuclear mass number than from otherwise equivalent spherical winds (with the mass fractions of some elements enhanced by factors of ≳100-1000). The heaviest elements are synthesized by outflows emerging along flux tubes that graze the closed zone and pass near the equatorial plane outside the light cylinder. Due to dependence of the nucleosynthesis pattern on the magnetic field strength and rotation rate of the protoneutron star, natural variations in these quantities between core collapse events could contribute to the observed diversity of the abundances of weak r-process nuclei in metal-poor stars. Further diversity, including possibly even a successful third-peak r-process, could be achieved for misaligned rotators with non-zero magnetic inclination with respect to the rotation axis. If protomagnetars are central engines for GRBs, their relativistic jets should contain a high-mass fraction of heavy nuclei of characteristic mass number \\bar{A}≈ 100, providing a possible source for ultrahigh energy cosmic rays comprised of heavy nuclei with an energy spectrum that extends beyond the nominal Grezin-Zatsepin-Kuzmin cut-off for protons or iron nuclei.
Relativistic many-body theory of atomic transitions: the relativistic equation-of-motion approach
International Nuclear Information System (INIS)
Huang, K.N.
1981-01-01
An equation-of-motion approach is used to develop the relativistic many-body theory of atomic transitions. The relativistic equations of motion for transition matrices are formulated using techniques of quantum field theory. To reduce the equation of motion to a tractable form which is appropriate for numerical calculations, a graphical method is employed to resolve the complication arising from the antisymmetrization and angular momentum coupling. The relativistic equation-of-motion method allows an ab initio treatment of correlation and relativistic effects in both closed- and open-shell many-body systems. A special case of the present formulation reduces to the relativistic random-phase approximation
Wind and IMP 8 Solar Wind, Magnetosheath and Shock Data
2004-01-01
The purpose of this project was to provide the community access to magnetosheath data near Earth. We provided 27 years of IMP 8 magnetosheath proton velocities, densities, and temperatures with our best (usually 1-min.) time resolution. IMP 8 crosses the magnetosheath twice each 125 day orbit, and we provided magnetosheath data for the roughly 27 years of data for which magnetometer data are also available (which are needed to reliably pick boundaries). We provided this 27 years of IMP 8 magnetosheath data to the NSSDC; this data is now integrated with the IMP 8 solar wind data with flags indicating whether each data point is in the solar wind, magnetosheath, or at the boundary between the two regions. The plasma speed, density, and temperature are provided for each magnetosheath point. These data are also available on the MIT web site ftp://space .mit.edu/pub/plasma/imp/www/imp.html. We provide ASCII time-ordered rows of data giving the observation time, the spacecraft position in GSE, the velocity is GSE, the density and temperature for protons. We also have analyzed and archived on our web site the Wind magnetosheath plasma parameters. These consist of ascii files of the proton and alpha densities, speeds, and thermal speeds. These data are available at ftp://space.mit.edu/pub/plasma/wind/sheath These are the two products promised in the work statement and they have been completed in full.
Thermodynamics of polarized relativistic matter
Energy Technology Data Exchange (ETDEWEB)
Kovtun, Pavel [Department of Physics and Astronomy, University of Victoria,PO Box 1700 STN CSC, Victoria BC, V8W 2Y2 (Canada)
2016-07-05
We give the free energy of equilibrium relativistic matter subject to external gravitational and electromagnetic fields, to one-derivative order in the gradients of the external fields. The free energy allows for a straightforward derivation of bound currents and bound momenta in equilibrium. At leading order, the energy-momentum tensor admits a simple expression in terms of the polarization tensor. Beyond the leading order, electric and magnetic polarization vectors are intrinsically ambiguous. The physical effects of polarization, such as the correlation between the magneto-vortically induced surface charge and the electro-vortically induced surface current, are not ambiguous.
Observation of relativistic antihydrogen atoms
International Nuclear Information System (INIS)
Blanford, Glenn DelFosse
1998-01-01
An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 0 production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e + e - pair creation near a nucleus with the e + being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure
Similarity flows in relativistic hydrodynamics
International Nuclear Information System (INIS)
Blaizot, J.P.; Ollitrault, J.Y.
1986-01-01
In ultra-relativistic heavy ion collisions, one expects in particular to observe a deconfinement transition leading to a formation of quark gluon plasma. In the framework of the hydrodynamic model, experimental signatures of such a plasma may be looked for as observable consequences of a first order transition on the evolution of the system. In most of the possible scenario, the phase transition is accompanied with discontinuities in the hydrodynamic flow, such as shock waves. The method presented in this paper has been developed to treat without too much numerical effort such discontinuous flow. It relies heavily on the use of similarity solutions of the hydrodynamic equations
Relativistic heavy ion facilities: worldwide
International Nuclear Information System (INIS)
Schroeder, L.S.
1986-05-01
A review of relativistic heavy ion facilities which exist, are in a construction phase, or are on the drawing boards as proposals is presented. These facilities span the energy range from fixed target machines in the 1 to 2 GeV/nucleon regime, up to heavy ion colliders of 100 GeV/nucleon on 100 GeV/nucleon. In addition to specifying the general features of such machines, an outline of the central physics themes to be carried out at these facilities is given, along with a sampling of the detectors which will be used to extract the physics. 22 refs., 17 figs., 3 tabs
Unlimited Relativistic Shock Surfing Acceleration
International Nuclear Information System (INIS)
Ucer, D.; Shapiro, V. D.
2001-01-01
Nonrelativistic shock surfing acceleration at quasiperpendicular shocks is usually considered to be a preacceleration mechanism for slow pickup ions to initiate diffusive shock acceleration. In shock surfing, the particle accelerates along the shock front under the action of the convective electric field of the plasma flow. However, the particle also gains kinetic energy normal to the shock and eventually escapes downstream. We consider the case when ions are accelerated to relativistic velocities. In this case, the ions are likely to be trapped for infinitely long times, because the energy of bounce oscillations tends to decrease during acceleration. This suggests the possibility of unlimited acceleration by shock surfing
The magnetosphere in relativistic physics
International Nuclear Information System (INIS)
Zapffe, C.A.
1982-01-01
The present paper takes off from the author's earlier epistemological analysis and criticism of the Special Theory of Relativity, identifies the problem as lying in Einstein's choice of the inertial frame of Newtonian mechanics rather than the electromagnetic frame of the locally embedding Maxwellian field when discussing electrodynamics, then proposes this Maxwellian field of the magnetosphere as the specific rest frame proper to all experimentation of optical or electromagnetic sort conducted within its bounds. The result is shown to remove all paradoxes from relativistic physics. (author)
International Nuclear Information System (INIS)
Kotevski, Darko
2003-01-01
Wind is not only free, it is inexhaustible. Wind energy has come a very long way since the prototypes of just 20 years ago. today's wind turbines are state-of-the-art technology - modular and quick to install anywhere where there is sufficient wind potential to provide secure, centralised or distributed generation. It is a global phenomenon, the world's fastest growing energy sector, a clean and effective modern technology that completely avoids pollution and thus reducing the 'green house' effect. (Original)
Liu, Ruo-Yu; Murase, Kohta; Inoue, Susumu; Ge, Chong; Wang, Xiang-Yu
2018-05-01
Various observations are revealing the widespread occurrence of fast and powerful winds in active galactic nuclei (AGNs) that are distinct from relativistic jets, likely launched from accretion disks and interacting strongly with the gas of their host galaxies. During the interaction, strong shocks are expected to form that can accelerate nonthermal particles to high energies. Such winds have been suggested to be responsible for a large fraction of the observed extragalactic gamma-ray background (EGB) and the diffuse neutrino background, via the decay of neutral and charged pions generated in inelastic pp collisions between protons accelerated by the forward shock and the ambient gas. However, previous studies did not properly account for processes such as adiabatic losses that may reduce the gamma-ray and neutrino fluxes significantly. We evaluate the production of gamma rays and neutrinos by AGN-driven winds in detail by modeling their hydrodynamic and thermal evolution, including the effects of their two-temperature structure. We find that they can only account for less than ∼30% of the EGB flux, as otherwise the model would violate the independent upper limit derived from the diffuse isotropic gamma-ray background. If the neutrino spectral index is steep with Γ ≳ 2.2, a severe tension with the isotropic gamma-ray background would arise as long as the winds contribute more than 20% of the IceCube neutrino flux in the 10–100 TeV range. At energies ≳ 100 TeV, we find that the IceCube neutrino flux may still be accountable by AGN-driven winds if the spectral index is as small as Γ ∼ 2.0–2.1.
Relativistic mean field theory for deformed nuclei with pairing correlations
International Nuclear Information System (INIS)
Geng, Lisheng; Toki, Hiroshi; Sugimoto, Satoru; Meng, Jie
2003-01-01
We develop a relativistic mean field (RMF) description of deformed nuclei with pairing correlations in the BCS approximation. The treatment of the pairing correlations for nuclei whose Fermi surfaces are close to the threshold of unbound states needs special attention. With this in mind, we use a delta function interaction for the pairing interaction to pick up those states whose wave functions are concentrated in the nuclear region and employ the standard BCS approximation for the single-particle states obtained from the BMF theory with deformation. We apply the RMF + BCS method to the Zr isotopes and obtain a good description of the binding energies and the nuclear radii of nuclei from the proton drip line to the neutron drip line. (author)
Response of the GLAST LAT calorimeter to relativistic heavy ions
International Nuclear Information System (INIS)
Lott, B.; Piron, F.; Blank, B.; Bogaert, G.; Bregeon, J.; Canchel, G.; Chekhtman, A.; D'Avezac, P.; Dumora, D.; Giovinazzo, J.; Grove, J.E.; Hellstroem, M.; Jacholkowska, A.; Johnson, W.N.; Nuss, E.; Reposeur, Th.; Smith, D.A.; Suemmerer, K.
2006-01-01
The CsI calorimeter of the Gamma-Ray Large-Area Space Telescope (GLAST) will be calibrated in flight with cosmic-ray heavy ions. In order to determine the response of the calorimeter to relativistic heavy ions lighter than Fe, an experiment was carried out at the GSI heavy ion facility using the Fragment Separator (FRS). The measured response exhibits an unexpected feature for light ions, opposite to that observed at low incident energy: for a given deposited energy, the observed signal is greater for these ions than for protons (or more generally Z=1 minimum ionizing particles). Pulse shapes are found to be almost identical for carbon ions and Z=1 particles, with a significant slow scintillation component, which constitutes another departure from the low-energy behavior. Data on the energy resolution for the individual CsI crystals and on the loss of ions due to nuclear reactions in the calorimeter are also presented
Incident energy dependence of pt correlations at relativistic energies
Adams, J; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Berger, J; Bezverkhny, B I; Bharadwaj, S; Bhasin, A; Bhati, A K; Bhatia, V S; Bichsel, H; Bielcik, J; Bielcikova, J; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Bouchet, J; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Daugherity, M; De Moura, M M; Dedovich, T G; Derevshchikov, A A; Didenko, L; Dietel, T; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta, M R; Mazumdar; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faivre, J; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Yu; Fu, J; Gagliardi, C A; Gaillard, L; Gans, J; Ganti, M S; Geurts, F; Ghazikhanian, V; Ghosh, P; González, J E; Gos, H; Grachov, O; Grebenyuk, O; Grosnick, D P; Guertin, S M; Guo, Y; Sen-Gupta, A; Gutíerrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Jedynak, M; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Kislov, E M; Klay, J; Klein, S R; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kowalik, K L; Krämer, M; Kravtsov, P; Kravtsov, V I; Krüger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kutuev, R K; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lehocka, S; Le Vine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahajan, S; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J N; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnik, Yu M; Meschanin, A; Miller, M L; Minaev, N G; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnár, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pal, S K; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevozchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M V; Potrebenikova, E V; Potukuchi, B V K S; Prindle, D; Pruneau, C A; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J G; Reinnarth, J; Renault, G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Sarsour, M; Savin, I; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shen, W Q; Shestermanov, K E; Shimansky, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sørensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Suaide, A A P; Sugarbaker, E R; Suire, C; Sumbera, M; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T J; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; Van Leeuwen, M; Van der Molen, A M; Varma, R; Vasilevski, I M; Vasilev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, X L; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Zborovský, I; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N
2005-01-01
We present results for two-particle transverse momentum correlations, , as a function of event centrality for Au+Au collisions at sqrt(sNN) = 20, 62, 130, and 200 GeV at the Relativistic Heavy Ion Collider. We observe correlations decreasing with centrality that are similar at all four incident energies. The correlations multiplied by the multiplicity density increase with incident energy and the centrality dependence may show evidence of processes such as thermalization, minijet production, or the saturation of transverse flow. The square root of the correlations divided by the event-wise average transverse momentum per event shows little or no beam energy dependence and generally agrees with previous measurements at the Super Proton Synchrotron.
Tailoring of silicon crystals for relativistic-particle channeling
International Nuclear Information System (INIS)
Guidi, V.; Antonini, A.; Baricordi, S.; Logallo, F.; Malagu, C.; Milan, E.; Ronzoni, A.; Stefancich, M.; Martinelli, G.; Vomiero, A.
2005-01-01
In the last years, the research on channeling of relativistic particles has progressed considerably. A significant contribution has been provided by the development of techniques for quality improvement of the crystals. In particular, a planar etching of the surfaces of the silicon crystals proved useful to remove the superficial layer, which is a region very rich in imperfections, in turn leading to greater channeling efficiency. Micro-fabrication techniques, borrowed from silicon technology, may also be useful: micro-indentation and deposition of tensile or compressive layers onto silicon samples allow one to impart an even curvature to the samples. In this way, different topologies may be envisaged, such as a bent crystal for deflection of protons and ions or an undulator to force coherent oscillations of positrons and electrons
Momentum distributions in nuclei measured with relativistic heavy ions
International Nuclear Information System (INIS)
Hiller, B.; Huefner, J.; Heidelberg Univ.
1982-01-01
In a peripheral reaction between relativistic heavy ions, where one nucleon is knocked out of the projektile, the momentum distribution of the remaining fragment reflects the momentum distribution of the knocked out nucleon. This has been proven in a previous paper. Here we study how the final-state interaction between the knocked out nucleon and the observed fragment influences the result: The real part of the optical potential which describes the final-state interaction shifts the experimental momentum distribution by a value [ksub(||)] of a few tens of MeV/c and the imaginary part reduces the cross sections by a factor 2 roughly. We also derive the cross section for a proton as target. (orig.)
Relativistic Quantum Transport in Graphene Systems
2015-07-09
dimensional Dirac material systems. 2 List of Publications 1. X. Ni, L. Huang, Y.-C. Lai, and L. M. Pecora, “Effect of chaos on relativistic quantum...development of relativistic quantum devices based on graphene or alternative two-dimensional Dirac material systems. In the project period, we studied
Relativistic calculations of coalescing binary neutron stars
Indian Academy of Sciences (India)
We have designed and tested a new relativistic Lagrangian hydrodynamics code, which treats gravity in the conformally flat approximation to general relativity. We have tested the resulting code extensively, finding that it performs well for calculations of equilibrium single-star models, collapsing relativistic dust clouds, and ...
Relativistic corrections to molecular dynamic dipole polarizabilities
DEFF Research Database (Denmark)
Kirpekar, Sheela; Oddershede, Jens; Jensen, Hans Jørgen Aagaard
1995-01-01
obtained from the use of the Darwin and mass-velocity operators to first order are included at both levels of approximation. We find that correlation and relativistic contributions are not even approximately additive for the two molecules. The importance of the relativistic corrections is smallest...
A Primer to Relativistic MOND Theory
Bekenstein, J.D..; Sanders, R.H.
2005-01-01
Abstract: We first review the nonrelativistic lagrangian theory as a framework for the MOND equation. Obstructions to a relativistic version of it are discussed leading up to TeVeS, a relativistic tensor-vector-scalar field theory which displays both MOND and Newtonian limits. The whys for its
Relativistic astrophysics and theory of gravity
International Nuclear Information System (INIS)
Zel'dovich, Ya.B.
1982-01-01
A brief historical review of the development of astrophysical science in the State Astrophysical Institute named after Shternberg (SAISh) has been given in a popular form. The main directions of the SAISh astrophysical investigations have been presented: relativistic theory of gravity, relativistic astrophysics of interplanetary medium and cosmology
Einstein Never Approved of Relativistic Mass
Hecht, Eugene
2009-01-01
During much of the 20th century it was widely believed that one of the significant insights of special relativity was "relativistic mass." Today there are two schools on that issue: the traditional view that embraces speed-dependent "relativistic mass," and the more modern position that rejects it, maintaining that there is only one mass and it's…
Relativistic ion collisions as the source of hypernuclei
Energy Technology Data Exchange (ETDEWEB)
Botvina, A.S. [J.W. Goethe University, Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Russian Academy of Sciences, Institute for Nuclear Research, Moscow (Russian Federation); Bleicher, M.; Steinheimer, J. [J.W. Goethe University, Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Pochodzalla, J. [J. Gutenberg-Universitaet, Helmholtz-Institut Mainz, Mainz (Germany); J. Gutenberg-Universitaet Mainz, Institut fuer Kernphysik and PRISMA Cluster of Excellence, Mainz (Germany)
2016-08-15
We shortly review the theory of hypernuclei production in relativistic ion collisions, that is adequate to future experiments at BM rate at N, NICA, and FAIR. Within a hybrid approach we use transport, coalescence and statistical models to describe the whole process. We demonstrate that the origin of hypernuclei can be explained by typical baryon interactions, that is similar to the production of conventional nuclei. In particular, heavy hypernuclei are coming mostly from projectile and target residues, whereas light hypernuclei can be produced at all rapidities. The yields of hypernuclei increase considerably above the energy threshold for Λ hyperon production, and there is a tendency to saturation of yields of hypernuclei with increasing the beam energy up to few TeV. There are unique opportunities in relativistic ion collisions which are difficult to realize in traditional hypernuclear experiments: The produced hypernuclei have a broad distribution in masses and isospin. They can even reach beyond the neutron and proton drip-lines and that opens a chance to investigate properties of exotic hypernuclei. One finds also the abundant production of multi-strange nuclei, of bound and unbound hypernuclear states with new decay modes. In addition, we can directly get an information on the hypermatter both at high and low temperatures. (orig.)
Proton imaging apparatus for proton therapy application
International Nuclear Information System (INIS)
Sipala, V.; Lo Presti, D.; Brianzi, M.; Civinini, C.; Bruzzi, M.; Scaringella, M.; Talamonti, C.; Bucciolini, M.; Cirrone, G.A.P.; Cuttone, G.; Randazzo, N.; Stancampiano, C.; Tesi, M.
2011-01-01
Radiotherapy with protons, due to the physical properties of these particles, offers several advantages for cancer therapy as compared to the traditional radiotherapy and photons. In the clinical use of proton beams, a p CT (Proton Computer Tomography) apparatus can contribute to improve the accuracy of the patient positioning and dose distribution calculation. In this paper a p CT apparatus built by the Prima (Proton Imaging) Italian Collaboration will be presented and the preliminary results will be discussed.
Proton radioactivity from proton-rich nuclei
International Nuclear Information System (INIS)
Guzman, F.; Goncalves, M.; Tavares, O.A.P.; Duarte, S.B.; Garcia, F.; Rodriguez, O.
1999-03-01
Half-lives for proton emission from proton-rich nuclei have been calculated by using the effective liquid drop model of heavy-particle decay of nuclei. It is shown that this model is able to offer results or spontaneous proton-emission half-life-values in excellent agreement with the existing experimental data. Predictions of half-life-values for other possible proton-emission cases are present for null orbital angular momentum. (author)
Random phase approximation in relativistic approach
International Nuclear Information System (INIS)
Ma Zhongyu; Yang Ding; Tian Yuan; Cao Ligang
2009-01-01
Some special issues of the random phase approximation(RPA) in the relativistic approach are reviewed. A full consistency and proper treatment of coupling to the continuum are responsible for the successful application of the RPA in the description of dynamical properties of finite nuclei. The fully consistent relativistic RPA(RRPA) requires that the relativistic mean filed (RMF) wave function of the nucleus and the RRPA correlations are calculated in a same effective Lagrangian and the consistent treatment of the Dirac sea of negative energy states. The proper treatment of the single particle continuum with scattering asymptotic conditions in the RMF and RRPA is discussed. The full continuum spectrum can be described by the single particle Green's function and the relativistic continuum RPA is established. A separable form of the paring force is introduced in the relativistic quasi-particle RPA. (authors)
Loading relativistic Maxwell distributions in particle simulations
Zenitani, S.
2015-12-01
In order to study energetic plasma phenomena by using particle-in-cell (PIC) and Monte-Carlo simulations, we need to deal with relativistic velocity distributions in these simulations. However, numerical algorithms to deal with relativistic distributions are not well known. In this contribution, we overview basic algorithms to load relativistic Maxwell distributions in PIC and Monte-Carlo simulations. For stationary relativistic Maxwellian, the inverse transform method and the Sobol algorithm are reviewed. To boost particles to obtain relativistic shifted-Maxwellian, two rejection methods are newly proposed in a physically transparent manner. Their acceptance efficiencies are 50% for generic cases and 100% for symmetric distributions. They can be combined with arbitrary base algorithms.
Relativistic theory of spontaneous emission
International Nuclear Information System (INIS)
Barut, A.O.; Salamin, Y.I.
1987-06-01
We derive a formula for the relativistic decay rates in atoms in a formulation of Quantum Electrodynamics based upon the electron's self energy. Relativistic Coulomb wavefunctions are used, the full spin calculation is carried out and the dipole approximation is not employed. The formula has the correct nonrelativistic limit and is used here for calculating the decay rates in Hydrogen and Muonium for the transitions 2P → 1S 1/2 and 2S 1/2 → 1S 1/2 . The results for Hydrogen are: Γ(2P → 1S 1/2 )=6.2649x10 8 s -1 and Γ(2S 1/2 → 1S 1/2 )=2.4946x10 -6 s -1 . Our result for the 2P → 1S 1/2 transition rate is in perfect agreement with the best nonrelativistic calculations as well as with the results obtained from the best known radiative decay lifetime measurements. As for the Hydrogen 2S 1/2 → 1S 1/2 decay rate, the result obtained here is also in good agreement with the best known magnetic dipole calculations. For Muonium we get: Γ(2P → 1S 1/2 )=6.2382x10 8 s -1 and Γ(2S 1/2 → 1S 1/2 )=2.3997x10 -6 s -1 . (author). 23 refs, 4 tabs
Physical processes in relativistic plasmas
International Nuclear Information System (INIS)
Svensson, R.
1984-01-01
The continuum emission in many active galactic nuclei (AGNs) extend to 100 keV and beyond (e.g. Rothschild et al. 1983). In thermal models of the continuum emission this implies temperatures above 10 9 K or kT of order mc 2 . In such a plasma the electrons are at least mildly relativistic and furthermore the particles and the photons are energetic enough to produce electron-positron pairs. The physics of such hot plasmas has only recently been studied in any detail and here we review the results of those studies. Significant electron-positron pair production may also occur in non-thermal models of the continuum emission if the optical depth to photon-photon pair production is greater than unity. We review the few results obtained regarding this interesting but not very well studied possibility. First, however, we briefly discuss the processes taking place in relativistic plasmas and the standard models for the continuum emission from AGNs. We then summarize the effects pair production have on these models and the observational implications of the presence of electron-positron pairs. (orig./WL)
24-Hour Relativistic Bit Commitment.
Verbanis, Ephanielle; Martin, Anthony; Houlmann, Raphaël; Boso, Gianluca; Bussières, Félix; Zbinden, Hugo
2016-09-30
Bit commitment is a fundamental cryptographic primitive in which a party wishes to commit a secret bit to another party. Perfect security between mistrustful parties is unfortunately impossible to achieve through the asynchronous exchange of classical and quantum messages. Perfect security can nonetheless be achieved if each party splits into two agents exchanging classical information at times and locations satisfying strict relativistic constraints. A relativistic multiround protocol to achieve this was previously proposed and used to implement a 2-millisecond commitment time. Much longer durations were initially thought to be insecure, but recent theoretical progress showed that this is not so. In this Letter, we report on the implementation of a 24-hour bit commitment solely based on timed high-speed optical communication and fast data processing, with all agents located within the city of Geneva. This duration is more than 6 orders of magnitude longer than before, and we argue that it could be extended to one year and allow much more flexibility on the locations of the agents. Our implementation offers a practical and viable solution for use in applications such as digital signatures, secure voting and honesty-preserving auctions.
Coherent production of {epsilon}{sup +} particles in crystal using proton beam from SSC
Energy Technology Data Exchange (ETDEWEB)
Okorokov, V.V.; Dubin, A.Yu. [ITER, Moscow, (Russian Federation)
1995-05-01
The unique possibilities of the SSC can be ideally used for a new generation of coherent generation experiments with relativistic protons which require 20 Tev energy of the incident beam. The availability of 20 Tev proton beam at SSC allows new experiments on coherent production of {var_epsilon}{sup +} particle by relativistic proton in crystal. Experiment carried out at low energies can now be extended with protons in very narrow energy region (resonance energy, which easy can be calculated) using the new accelerator facilities at SSC. We propose to study coherent production via the Coulomb field of the cristal atoms to excite the transition p + {gamma}{implies} {var_epsilon} {sup +} (1189).
Development of circular protons accelerator for ocular teletherapy
International Nuclear Information System (INIS)
Rabelo, L. A.; Campos, T.P.R.
2011-01-01
The proton therapy has been used for ocular tumors providing tumor control in most cases and vision preservations. The protons show high doses in depth depict lower scattering from beam than other particles, electrons and photons. The cyclotron is a type of accelerator that increases the kinetic energy of the charged particle, recirculating it on a magnetic field and crossing an accelerating electrical field. It can be used to produce radioisotopes to hospitals. The goal of this study is to investigate a unit of circular accelerator to be coupled in existing national cyclotrons to generate a proton beams suitable to ocular therapy. Herein, physical parameters are evaluable, including relativistic corrections. That result shows the viability of developing an accelerator unit to ocular proton therapy. (author)
Proton beam generation of whistler waves in the earth's foreshock
Wong, H. K.; Goldstein, M. L.
1987-01-01
It is shown that proton beams, often observed upstream of the earth's bow shock and associated with the generation of low-frequency hydromagnetic fluctuations, are also capable of generating whistler waves. The waves can be excited by an instability driven by two-temperature streaming Maxwellian proton distributions which have T (perpendicular)/T(parallel) much greater than 1. It can also be excited by gyrating proton beam distributions. These distributions generate whistler waves with frequencies ranging from 10 to 100 times the proton cyclotron frequency (in the solar wind reference frame) and provide another mechanism for generating the '1-Hz' waves often seen in the earth's foreshock.
Proton beam generation of whistler waves in the Earth's foreshock
International Nuclear Information System (INIS)
Wong, H.K.; Goldstein, M.L.
1987-01-01
We show that proton beams, often observed upstream of the Earth's bow shock and associated with the generation of low-frequency hydromagnetic fluctuations, are also capable of generating whistler waves. The waves can be excited by an instability driven by two-temperature streaming Maxwellian proton distributions which have T/sub perpendicular//T/sub parallel/>>1. It can also be excited by gyrating proton beam distributions. These distributions generate whistler waves with frequencies ranging from 10 to 100 times the proton cyclotron frequency (in the solar wind reference frame) and provide another mechanism for generating the ''1-Hz'' waves often seen in the Earth's foreshock
Wind Structure and Wind Loading
DEFF Research Database (Denmark)
Brorsen, Michael
The purpose of this note is to provide a short description of wind, i.e. of the flow in the atmosphere of the Earth and the loading caused by wind on structures. The description comprises: causes to the generation of windhe interaction between wind and the surface of the Earthhe stochastic nature...
Dynamical or static radio halo - Is there a galactic wind
International Nuclear Information System (INIS)
Lerche, I.; Schlickeiser, R.
1981-01-01
The effect of a galactic wind on a radio halo can be best observed at frequencies smaller than about 1 GHz. At higher frequencies static halo models predict the same features as dynamical halo models. External galaxies, which exhibit a break by 0.5 in their high frequency nonthermal integral flux spectrum, are the best candidates for studying the influence of galactic winds on the formation of relativistic electron haloes around these systems. Several such cases are presented
International Nuclear Information System (INIS)
Gipe, P.
2007-01-01
This book is a translation of the edition published in the USA under the title of ''wind power: renewable energy for home, farm and business''. In the wake of mass blackouts and energy crises, wind power remains a largely untapped resource of renewable energy. It is a booming worldwide industry whose technology, under the collective wing of aficionados like author Paul Gipe, is coming of age. Wind Power guides us through the emergent, sometimes daunting discourse on wind technology, giving frank explanations of how to use wind technology wisely and sound advice on how to avoid common mistakes. Since the mid-1970's, Paul Gipe has played a part in nearly every aspect of wind energy development from installing small turbines to promoting wind energy worldwide. As an American proponent of renewable energy, Gipe has earned the acclaim and respect of European energy specialists for years, but his arguments have often fallen on deaf ears at home. Today, the topic of wind power is cropping up everywhere from the beaches of Cape Cod to the Oregon-Washington border, and one wind turbine is capable of producing enough electricity per year to run 200 average American households. Now, Paul Gipe is back to shed light on this increasingly important energy source with a revised edition of Wind Power. Over the course of his career, Paul Gipe has been a proponent, participant, observer, and critic of the wind industry. His experience with wind has given rise to two previous books on the subject, Wind Energy Basics and Wind Power for Home and Business, which have sold over 50,000 copies. Wind Power for Home and Business has become a staple for both homeowners and professionals interested in the subject, and now, with energy prices soaring, interest in wind power is hitting an all-time high. With chapters on output and economics, Wind Power discloses how much you can expect from each method of wind technology, both in terms of energy and financial savings. The book updated models
Supernova and r-process simulations with relativistic EOS table
International Nuclear Information System (INIS)
Sumiyoshi, Kohsuke
2000-01-01
We study the neutrino-driven wind from the proto-neutron star by the general relativistic hydrodynamical simulations. We examine the properties of the neutrino-driven wind to explore the possibility of the r-process nucleosynthesis. The numerical simulations with the neutrino heating and cooling processes are performed with the assumption of the constant neutrino luminosity by using realistic profiles of the proto-neutron star (PNS) as well as simplified models. The dependence on the mass of PNS and the neutrino luminosity is studied systematically. Comparisons with the analytic treatment in the previous studies are also done. In the cases with the realistic PNS, we found that the entropy per baryon and the expansion time scale are neither high nor short enough for the r-process within the current assumptions. On the other hand, we found that the expansion time scale obtained by the hydrodynamical simulations is systematically shorter than that in the analytic solutions due to our proper treatment of the equation of state. This fact might lead to the increase of the neutron-to-seed ratio, which is suitable for the r-process in the neutrino-driven wind. Indeed, in the case of massive and compact proto-neutron stars with high neutrino luminosities, the expansion time scale is found short enough in the hydrodynamical simulations and the r-process elements up to A ∼ 200 are produced in the r-process network calculation. (author)
DISCOVERY OF RELATIVISTIC OUTFLOW IN THE SEYFERT GALAXY Ark 564
International Nuclear Information System (INIS)
Gupta, A.; Mathur, S.; Krongold, Y.; Nicastro, F.
2013-01-01
We present Chandra High Energy Transmission Grating Spectra of the narrow-line Seyfert-1 galaxy Ark 564. The spectrum shows numerous absorption lines which are well modeled with low-velocity outflow components usually observed in Seyfert galaxies. There are, however, some residual absorption lines which are not accounted for by low-velocity outflows. Here, we present identifications of the strongest lines as Kα transitions of O VII (two lines) and O VI at outflow velocities of ∼0.1c. These lines are detected at 6.9σ, 6.2σ, and 4.7σ, respectively, and cannot be due to chance statistical fluctuations. Photoionization models with ultra-high velocity components improve the spectral fit significantly, providing further support for the presence of relativistic outflow in this source. Without knowing the location of the absorber, its mass and energy outflow rates cannot be well constrained; we find E-dot (outflow)/L bol lower limit of ≥0.006% assuming a bi-conical wind geometry. This is the first time that absorption lines with ultra-high velocities are unambiguously detected in the soft X-ray band. The presence of outflows with relativistic velocities in active galactic nuclei (AGNs) with Seyfert-type luminosities is hard to understand and provides valuable constraints to models of AGN outflows. Radiation pressure is unlikely to be the driving mechanism for such outflows and magnetohydrodynamic may be involved
2009-01-01
A humorous short film made by three secondary school students received an award at a Geneva film festival. Even without millions of dollars or Hollywood stars at your disposal, it is still possible to make a good science fiction film about CERN. That is what three students from the Collège Madame de Staël in Carouge, near Geneva, demonstrated. For their amateur short film on the LHC, they were commended by the jury of the video and multimedia festival for schools organised by the "Media in education" service of the Canton of Geneva’s Public Education Department. The film is a spoof of a television news report on the LHC start-up. In sequences full of humour and imagination, the reporter conducts interviews with a very serious "Professor Sairne", some protons preparing for their voyage and even the neutrons that were rejected by the LHC. "We got the idea of making a film about CERN at the end of the summer," explains Lucinda Päsche, one of the three students. "We did o...
Energy Technology Data Exchange (ETDEWEB)
Robin, Caroline; Litvinova, Elena [Western Michigan University, Department of Physics, Kalamazoo, MI (United States)
2016-07-15
A new theoretical approach to spin-isospin excitations in open-shell nuclei is presented. The developed method is based on the relativistic meson-exchange nuclear Lagrangian of Quantum Hadrodynamics and extends the response theory for superfluid nuclear systems beyond relativistic quasiparticle random phase approximation in the proton-neutron channel (pn-RQRPA). The coupling between quasiparticle degrees of freedom and collective vibrations (phonons) introduces a time-dependent effective interaction, in addition to the exchange of pion and ρ-meson taken into account without retardation. The time-dependent contributions are treated in the resonant time-blocking approximation, in analogy to the previously developed relativistic quasiparticle time-blocking approximation (RQTBA) in the neutral (non-isospin-flip) channel. The new method is called proton-neutron RQTBA (pn-RQTBA) and is applied to the Gamow-Teller resonance in a chain of neutron-rich nickel isotopes {sup 68-78}Ni. A strong fragmentation of the resonance along with quenching of the strength, as compared to pn-RQRPA, is obtained. Based on the calculated strength distribution, beta-decay half-lives of the considered isotopes are computed and compared to pn-RQRPA half-lives and to experimental data. It is shown that a considerable improvement of the half-life description is obtained in pn-RQTBA because of the spreading effects, which bring the lifetimes to a very good quantitative agreement with data. (orig.)
Thermodynamic laws and equipartition theorem in relativistic Brownian motion.
Koide, T; Kodama, T
2011-06-01
We extend the stochastic energetics to a relativistic system. The thermodynamic laws and equipartition theorem are discussed for a relativistic Brownian particle and the first and the second law of thermodynamics in this formalism are derived. The relation between the relativistic equipartition relation and the rate of heat transfer is discussed in the relativistic case together with the nature of the noise term.
Relativistic effects in resonance absorption
International Nuclear Information System (INIS)
Drake, J.F.; Lee, Y.C.
1976-01-01
The role of the relativistic-electron-mass variation in the generation of plasma waves by the linear mode conversion of intense electromagnetic waves is investigated. The increase in the electron mass in high intensity regions of the mode-converted wave reduces the local plasma frequency and thereby strongly modifies the plasma-driver resonance. A spatial discontinuity in the structure of the mode-converted wave results and causes the wave to break. Under rather modest restrictions, the wave breaking resulting from these effects occurs before the wave amplitude is limited either by thermal convection or by breaking caused by previously investigated nonrelativistic effects. Consequently, the amplitude of the mode-converted plasma wave should saturate at a much lower level than previously predicted. For simplicity, the analysis is limited to the initial stages of mode conversion where the ion dynamics can be neglected. The validity of this approximation is discussed
Parton distribution in relativistic hadrons
International Nuclear Information System (INIS)
Kopeliovich, B.Z.; Lapidus, L.I.; Zamolodchikov, Al.B.
1979-01-01
The distribution in the slow-parton number in the relativistic hadron is considered as a function of its rapidity (y). Neglecting corrections due to the tarton chain recombination the equation is derived and its explicit solution is found. It describes this distribution depending on the initial distribution at y approximately 1. Comparison with the reggeon diagrams results in relations between the parton model and the regaeon field theory parameters. The interpretation of the cutting rules in the framework of the parton model is presented. The numerical estimation of the parton model parameters is performed. It is shown that the slow-parton density corresponding to accessible energies seems to be close to the saturated density. Therefore, the enhanced graphs contributions turn out to be of considerable importance
Relativistic three-particle theory
International Nuclear Information System (INIS)
Hochauser, S.
1979-01-01
In keeping with recent developments in experimental nuclear physics, a formalism is developed to treat interactions between three relativistic nuclear particles. The concept of unitarity and a simple form of analyticity are used to construct coupled, integral, Faddeev-type equations and, with the help of analytic separable potentials, these are cast in simple, one-dimensional form. Energy-dependent potentials are introduced so as to take into account the sign-change of some phase shifts in the nucleon-nucleon interaction and parameters for these potentials are obtained. With regard to the success of such local potentials as the Yukawa potential, a recently developed method for expanding these in separable form is discussed. Finally, a new method for the numerical integration of the Faddeev equations along the real axis is introduced, thus avoiding the traditional need for contour rotations into the complex plane. (author)
Relativistic thermodynamics of Fluids. l
International Nuclear Information System (INIS)
Havas, P.; Swenson, R.J.
1979-01-01
In 1953, Stueckelberg and Wanders derived the basic laws of relativistic linear nonequilibrium thermodynamics for chemically reacting fluids from the relativistic local conservation laws for energy-momentum and the local laws of production of substances and of nonnegative entropy production by the requirement that the corresponding currents (assumed to depend linearly on the derivatives of the state variables) should not be independent. Generalizing their method, we determine the most general allowed form of the energy-momentum tensor T/sup alphabeta/ and of the corresponding rate of entropy production under the same restriction on the currents. The problem of expressing this rate in terms of thermodynamic forces and fluxes is discussed in detail; it is shown that the number of independent forces is not uniquely determined by the theory, and seven possibilities are explored. A number of possible new cross effects are found, all of which persist in the Newtonian (low-velocity) limit. The treatment of chemical reactions is incorporated into the formalism in a consistent manner, resulting in a derivation of the law for rate of production, and in relating this law to transport processes differently than suggested previously. The Newtonian limit is discussed in detail to establish the physical interpretation of the various terms of T/sup alphabeta/. In this limit, the interpretation hinges on that of the velocity field characterizing the fluid. If it is identified with the average matter velocity following from a consideration of the number densities, the usual local conservation laws of Newtonian nonequilibrium thermodynamics are obtained, including that of mass. However, a slightly different identification allows conversion of mass into energy even in this limit, and thus a macroscopic treatment of nuclear or elementary particle reactions. The relation of our results to previous work is discussed in some detail
International Nuclear Information System (INIS)
Paar, N.; Niksic, T.; Marketin, T.; Vretenar, D.; Ring, P.
2005-01-01
The excitation phenomena in unstable nuclei are investigated in the framework of the relativistic quasiparticle random-phase approximation (RQRPA) in the relativistic Hartree-Bogolyubov model (RHB) which is extended to include effective interactions with explicit density-dependent meson-nucleon couplings. The properties of the pygmy dipole resonance (PDR) are examined in 132 Sn and within isotopic chains, showing that already at moderate proton-neutron asymmetry the PDR peak energy is located above the neutron emission threshold. A method is suggested for determining the size of the neutron skin within an isotopic chain, based on the measurement of the excitation energies of the Gamow-Teller resonance relative to the isobaric analog state. In addition, for the first time the relativistic RHB+RQRPA model, with tensor ω meson-nucleon couplings, is employed in calculations of β-decay half-lives of nuclei of the relevance for the r-process. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Paar, N. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); University of Zagreb, Physics Department, Faculty of Science (Croatia); University of Washington, Institute for Nuclear Theory, Seattle (United States); Niksic, T. [University of Zagreb, Physics Department, Faculty of Science (Croatia); University of Washington, Institute for Nuclear Theory, Seattle (United States); Marketin, T.; Vretenar, D. [University of Zagreb, Physics Department, Faculty of Science (Croatia); Ring, P. [Physik-Department der Technischen Universitaet Muenchen, Garching (Germany)
2005-09-01
The excitation phenomena in unstable nuclei are investigated in the framework of the relativistic quasiparticle random-phase approximation (RQRPA) in the relativistic Hartree-Bogolyubov model (RHB) which is extended to include effective interactions with explicit density-dependent meson-nucleon couplings. The properties of the pygmy dipole resonance (PDR) are examined in {sup 132}Sn and within isotopic chains, showing that already at moderate proton-neutron asymmetry the PDR peak energy is located above the neutron emission threshold. A method is suggested for determining the size of the neutron skin within an isotopic chain, based on the measurement of the excitation energies of the Gamow-Teller resonance relative to the isobaric analog state. In addition, for the first time the relativistic RHB+RQRPA model, with tensor {omega} meson-nucleon couplings, is employed in calculations of {beta}-decay half-lives of nuclei of the relevance for the r-process. (orig.)
Relativistic klystron research for linear colliders
International Nuclear Information System (INIS)
Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Hoag, H.A.; Koontz, R.F.; Lavine, T.L.; Lee, T.G.; Loew, G.A.; Miller, R.H.; Morton, P.L.; Palmer, R.B.; Paterson, J.M.; Ruth, R.D.; Schwarz, H.D.; Vlieks, A.E.; Wilson, P.B.
1989-01-01
Relativistic klystrons are being developed as a power source for high gradient accelerator applications which include large linear electron-positron colliders, compact accelerators, and FEL sources. The authors have attained 200 MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. In this paper the authors report on the design of our relativistic klystrons, the results of our experiments so far, and some of our plans for the near future
Relativistic klystron research for linear colliders
International Nuclear Information System (INIS)
Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Herrmannesfeldt, W.B.; Higo, T.; Hoag, H.A.; Koontz, R.F.; Lavine, T.L.; Lee, T.G.; Loew, G.A.; Miller, R.H.; Morton, P.L.; Palmer, R.B.; Paterson, J.M.; Ruth, R.D.; Schwarz, H.D.; Takeuchi, Y.; Vlieks, A.E.; Wang, J.W.; Wilson, P.B.; Hopkins, D.B.; Sessler, A.M.; Ryne, R.D.; Westenskow, G.A.; Yu, S.S.
1989-01-01
Relativistic klystrons are being developed as a power source for high gradient accelerator applications which include large linear electron-positron colliders, compact accelerators, and FEL sources. The authors have attained 200MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. They report here on the design of our relativistic klystrons, the results of our experiments so far, and some of our plans for the near future. 5 refs., 9 figs., 1 tab
New derivation of relativistic dissipative fluid dynamics
International Nuclear Information System (INIS)
Jaiswal, Amaresh; Bhalerao, Rajeev S.; Pal, Subrata
2012-01-01
Relativistic dissipative hydrodynamics has been quite successful in explaining the spectra and azimuthal anisotropy of particles produced in heavy-ion collisions at the RHIC and recently at the LHC. The first-order dissipative fluid dynamics or the relativistic Navier-Stokes (NS) theory involves parabolic differential equations and suffers from a causality and instability. The second-order or Israel-Stewart (IS) theory with its hyperbolic equations restores causality but may not guarantee stability. The correct formulation of relativistic viscous fluid dynamics is far from settled and is under intense investigation
Relativistic Theory of Few Body Systems
Energy Technology Data Exchange (ETDEWEB)
Franz Gross
2002-11-01
Very significant advances have been made in the relativistic theory of few body systems since I visited Peter Sauer and his group in Hannover in 1983. This talk provides an opportunity to review the progress in this field since then. Different methods for the relativistic calculation of few nucleon systems are briefly described. As an example, seven relativistic calculations of the deuteron elastic structure functions, A, B, and T{sub 20}, are compared. The covariant SPECTATOR {copyright} theory, among the more successful and complete of these methods, is described in more detail.
Penetration of relativistic heavy ions through matter
International Nuclear Information System (INIS)
Scheidenberger, C.; Geissel, H.
1997-07-01
New heavy-ion accelerators covering the relativistic and ultra-relativistic energy regime allow to study atomic collisions with bare and few-electron projectiles. High-resolution magnetic spectrometers are used for precise stopping-power and energy-loss straggling measurements. Refined theories beyond the Born approximation have been developed and are confirmed by experiments. This paper summarizes the large progress in the understanding of relativistic heavy-ion penetration through matter, which has been achieved in the last few years. (orig.)
Relativistic klystron research for linear colliders
International Nuclear Information System (INIS)
Allen, M.A.; Callin, R.S.; Deruyter, H.
1988-09-01
Relativistic klystrons are being developed as a power source for high gradient accelerator applications which include large linear electron-positron colliders, compact accelerators, and FEL sources. We have attained 200 MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We report here on the design of our relativistic klystrons, the results of our experiments so far, and some of our plans for the near future. 5 refs., 9 figs., 1 tab
Whispering gallery effect in relativistic optics
Abe, Y.; Law, K. F. F.; Korneev, Ph.; Fujioka, S.; Kojima, S.; Lee, S.-H.; Sakata, S.; Matsuo, K.; Oshima, A.; Morace, A.; Arikawa, Y.; Yogo, A.; Nakai, M.; Norimatsu, T.; d'Humières, E.; Santos, J. J.; Kondo, K.; Sunahara, A.; Gus'kov, S.; Tikhonchuk, V.
2018-03-01
relativistic laser pulse, confined in a cylindrical-like target, under specific conditions may perform multiple scattering along the internal target surface. This results in the confinement of the laser light, leading to a very efficient interaction. The demonstrated propagation of the laser pulse along the curved surface is just yet another example of the "whispering gallery" effect, although nonideal due to laser-plasma coupling. In the relativistic domain its important feature is a gradual intensity decrease, leading to changes in the interaction conditions. The proccess may pronounce itself in plenty of physical phenomena, including very efficient electron acceleration and generation of relativistic magnetized plasma structures.
Holographic Aspects of a Relativistic Nonconformal Theory
Directory of Open Access Journals (Sweden)
Chanyong Park
2013-01-01
Full Text Available We study a general D-dimensional Schwarzschild-type black brane solution of the Einstein-dilaton theory and derive, by using the holographic renormalization, its thermodynamics consistent with the geometric results. Using the membrane paradigm, we calculate the several hydrodynamic transport coefficients and compare them with the results obtained by the Kubo formula, which shows the self-consistency of the gauge/gravity duality in the relativistic nonconformal theory. In order to understand more about the relativistic non-conformal theory, we further investigate the binding energy, drag force, and holographic entanglement entropy of the relativistic non-conformal theory.
The de Sitter relativistic top theory
International Nuclear Information System (INIS)
Armenta, J.; Nieto, J.A.
2005-01-01
We discuss the relativistic top theory from the point of view of the de Sitter (or anti-de Sitter) group. Our treatment rests on the Hanson-Regge spherical relativistic top Lagrangian formulation. We propose an alternative method for studying spinning objects via Kaluza-Klein theory. In particular, we derive the relativistic top equations of motion starting with the geodesic equation for a point particle in 4+N dimensions. We compare our approach with Fukuyama's formulation of spinning objects, which is also based on Kaluza-Klein theory. We also report a generalization of our approach to a 4+N+D dimensional theory
The ionisation equation in a relativistic gas
International Nuclear Information System (INIS)
Kichenassamy, S.; Krikorian, R.A.
1983-01-01
By deriving the relativistic form of the ionisation equation for a perfect gas it is shown that the usual Saha equation is valid to 3% for temperatures below one hundred million Kelvin. Beyond 10 9 K, the regular Saha equation is seriously incorrect and a relativistic distribution function for electrons must be taken into account. Approximate forms are derived when only the electrons are relativistic (appropriate up to 10 12 K) and also for the ultrarelativistic case (temperatures greater than 10 15 K). (author)
On the physics of relativistic double layers
International Nuclear Information System (INIS)
Carlqvist, P.
1982-06-01
A model of a strong, time-independent, and relativistic double layer is studied. Besides double layers having the electric field parallel to the current the model also describes a certain type of oblique double layers. The 'Langmuir condition' (ratio of ion current density to electron current density) as well as an expression for the potential drop of the double layer are derived. Furthermore, the distribution of charged particles, electric field, and potential within the double layer are clarified and discussed. It is found that the properties of relativistic double layers differ substantially from the properties of corresponding non-relativistic double layers. (Author)
Local density approximations for relativistic exchange energies
International Nuclear Information System (INIS)
MacDonald, A.H.
1986-01-01
The use of local density approximations to approximate exchange interactions in relativistic electron systems is reviewed. Particular attention is paid to the physical content of these exchange energies by discussing results for the uniform relativistic electron gas from a new point of view. Work on applying these local density approximations in atoms and solids is reviewed and it is concluded that good accuracy is usually possible provided self-interaction corrections are applied. The local density approximations necessary for spin-polarized relativistic systems are discussed and some new results are presented
Radiative pion-proton scattering in the static Chew-Low model
International Nuclear Information System (INIS)
Ho-Kim, Q.; Lavine, J.P.
1976-01-01
The results of a non-relativistic calculation of π +- -proton bremsstrahlung cross-sections at the pion laboratory kinetic energy of 298 MeV for backward photon angles are presented. The πp interaction is described by the static Chew-Low model. (Auth.)
Directory of Open Access Journals (Sweden)
L.S. Ferreira
2016-02-01
Full Text Available Proton radioactivity from deformed nuclei is described for the first time by a self-consistent calculation based on covariant relativistic density functionals derived from meson exchange and point coupling models. The calculation provides an important new test to these interactions at the limits of stability, since the mixing of different angular momenta in the single particle wave functions is probed.
Electronic structure of FeTiSb using relativistic and scalar-relativistic approaches
Energy Technology Data Exchange (ETDEWEB)
Sahariya, Jagrati [Department of Physics, Manipal University Jaipur, Jaipur-303007, Rajasthan (India); Mund, H. S., E-mail: hmoond@gmail.com [Department of Physics, M. L. Sukhadia University, Udaipur-313001, Rajasthan (India)
2016-05-06
Electronic and magnetic properties of FeTiSb have been reported. The calculations are performed using spin polarized relativistic Korringa-Kohn-Rostoker scheme based on Green’s function method. Within SPR-KKR a fully relativistic and scalar-relativistic approaches have been used to investigate electronic structure of FeTiSb. Energy bands, total and partial density of states, atom specific magnetic moment along with total moment of FeTiSb alloys are presented.
The Wigner function in the relativistic quantum mechanics
Energy Technology Data Exchange (ETDEWEB)
Kowalski, K., E-mail: kowalski@uni.lodz.pl; Rembieliński, J.
2016-12-15
A detailed study is presented of the relativistic Wigner function for a quantum spinless particle evolving in time according to the Salpeter equation. - Highlights: • We study the Wigner function for a quantum spinless relativistic particle. • We discuss the relativistic Wigner function introduced by Zavialov and Malokostov. • We introduce relativistic Wigner function based on the standard definition. • We find analytic expressions for relativistic Wigner functions.
New relativistic generalization of the Heisenberg commutation relations
International Nuclear Information System (INIS)
Bohm, A.; Loewe, M.; Magnollay, P.; Tarlini, M.; Aldinger, R.R.; Kielanowski, P.
1984-01-01
A relativistic generalization of the Heisenberg commutation relations is suggested which is different from the conventional ones used for the intrinsic coordinates and momenta in the relativistic oscillator model and the relativistic string. This new quantum relativistic oscillator model is determined by the requirement that it gives a unified description of relativistic vibrations and rotations and contracts in the nonrelativistic limit c -1 →0 into the usual nonrelativistic harmonic oscillator
A unified treatment of the non-relativistic and relativistic hydrogen atom: Pt. 2
International Nuclear Information System (INIS)
Swainson, R.A.; Drake, G.W.F.
1991-01-01
This is the second in a series of three papers in which it is shown how the radial part of non-relativistic and relativistic hydrogenic bound-state calculations involving the Green functions can be presented in a unified manner. In this paper the non-relativistic Green function is examined in detail; new functional forms are presented and a clear mathematical progression is show to link these and most other known forms. A linear transformation of the four radial parts of the relativistic Green function is given which allows for the presentation of this function as a simple generalization of the non-relativistic Green function. Thus, many properties of the non-relativistic Green function are shown to have simple relativistic generalizations. In particular, new recursion relations of the radial parts of both the non-relativistic and relativistic Green functions are presented, along with new expressions for the double Laplace transforms and recursion relations between the radial matrix elements. (author)
Energy loss distributions of 7 TeV protons channeled in a bent silicon crystals
Directory of Open Access Journals (Sweden)
Stojanov Nace
2013-01-01
Full Text Available The energy loss distributions of relativistic protons axially channeled through the bent Si crystals, with the constant curvature radius, R = 50 m, are studied here. The proton energy is 7 TeV and the thickness of the crystal is varied from 1 mm to 5 mm, which corresponds to the reduced crystal thickness, L, from 2.1 to 10.6, respectively. The proton energy was chosen in accordance with the large hadron collider project, at the European Organization for Nuclear Research, in Geneva, Switzerland. The energy loss distributions of the channeled protons were generated by the computer simulation method using the numerical solution of the proton equations of motion in the transverse plane. Dispersion of the proton scattering angle caused by its collisions with the crystal’s electrons was taken into account. [Projekat Ministarstva nauke Republike Srbije, br. III 45006
Energy Technology Data Exchange (ETDEWEB)
Anon.
1984-03-15
The seventeenth annual Users' Group Meeting of the Los Alamos Meson Physics Facility (LAMPF) felt the winds of change. LAMPF Director Louis Rosen noted that recent progress at the 800 MeV proton linac should not hide the fact that these are difficult times. Extra funding for operations together with good luck in sustaining 800-900 μA beam for lengthy operating cycles have resulted in high utilization and effective running for difficult experiments such as neutrino scattering and the 'Crystal Box' measurement of rare muon decays. New impetus has been given to nuclear spectroscopy with the incorporation of a polarized target (partly from KEK) on the proton spectrometer, while the proton storage ring and beam areas will extend the LAMPF programme in 1985.
Proton-air and proton-proton cross sections
Directory of Open Access Journals (Sweden)
Ulrich Ralf
2013-06-01
Full Text Available Different attempts to measure hadronic cross sections with cosmic ray data are reviewed. The major results are compared to each other and the differences in the corresponding analyses are discussed. Besides some important differences, it is crucial to see that all analyses are based on the same fundamental relation of longitudinal air shower development to the observed fluctuation of experimental observables. Furthermore, the relation of the measured proton-air to the more fundamental proton-proton cross section is discussed. The current global picture combines hadronic proton-proton cross section data from accelerator and cosmic ray measurements and indicates a good consistency with predictions of models up to the highest energies.
Time Operator in Relativistic Quantum Mechanics
Khorasani, Sina
2017-07-01
It is first shown that the Dirac’s equation in a relativistic frame could be modified to allow discrete time, in agreement to a recently published upper bound. Next, an exact self-adjoint 4 × 4 relativistic time operator for spin-1/2 particles is found and the time eigenstates for the non-relativistic case are obtained and discussed. Results confirm the quantum mechanical speculation that particles can indeed occupy negative energy levels with vanishingly small but non-zero probablity, contrary to the general expectation from classical physics. Hence, Wolfgang Pauli’s objection regarding the existence of a self-adjoint time operator is fully resolved. It is shown that using the time operator, a bosonic field referred here to as energons may be created, whose number state representations in non-relativistic momentum space can be explicitly found.
On quantization of relativistic string theory
International Nuclear Information System (INIS)
Isaev, A.P.
1982-01-01
Quantization of the relativistic string theory based on methods of the constrained Hamiltonian systems quantization is considered. Connections of this approach and Polyakov's quantization are looked. New representation of a loop heat kernel is obtained
Fourth sound in relativistic superfluidity theory
International Nuclear Information System (INIS)
Vil'chinskij, S.I.; Fomin, P.I.
1995-01-01
The Lorentz-covariant equations describing propagation of the fourth sound in the relativistic theory of superfluidity are derived. The expressions for the velocity of the fourth sound are obtained. The character of oscillation in sound is determined
Relativistic Boltzmann theory for a plasma
International Nuclear Information System (INIS)
Erkelens, H. van.
1984-01-01
This thesis gives a self-contained treatment of the relativistic Boltzmann theory for a plasma. Here plasma means any mixture containing electrically charged particles. The relativistic Boltzmann equation is linearized for the case of a plasma. The Chapman-Enskog method is elaborated further for transport phenomena. Linear laws for viscous phenomena are derived. Then the collision term in the Boltzmann theory is dealt with. Using the transport equation, a kinetic theory of wave phenomena is developed and the dissipation of hydromagnetic waves in a relativistic plasma is investigated. In the final chapter, it is demonstrated how the relativistic Boltzmann theory can be applied in cosmology. In doing so, expressions are derived for the electric conductivity of the cosmological plasma in the lepton era, the plasma era and the annihilation era. (Auth.)
Relativistic nuclear physics and quantum chromodynamics. Abstracts
International Nuclear Information System (INIS)
1994-01-01
The data of investigations on problems of high energy physics are given. Special attention pays to quantum chromodynamics at large distances, cumulative processes, multiquark states and relativistic nuclear collisions
ULTRA-RELATIVISTIC NUCLEI: A NEW FRONTIER
International Nuclear Information System (INIS)
MCLERRAN, L.
1999-01-01
The collisions of ultra-relativistic nuclei provide a window on the behavior of strong interactions at asymptotically high energies. They also will allow the authors to study the bulk properties of hadronic matter at very high densities
Electrodisintegration of relativistic nuclei by a periodic crystal field in channeling
International Nuclear Information System (INIS)
Pivovarov, Yu.L.; Vorob'ev, S.A.
1981-01-01
Processes on channeled relativistic nuclei with transition into a continuous spectrum (electrodisintegration of nuclei with emission of neutron, proton, photon and etc.) are considered. A case of plane channeling is considered. The equivalent photon method is used for calculating the disintegration cross section. The beryllium disintegration cross section in the system of tungsten crystal (100) planes is calculated. At the γ=10 2 Lorentz factor the cross section value is 5.27 mb. The process considered is of interest from the viewpoint of production of monoenergy neutrons of high energies and γ quanta of excited nuclei. The channeling effect gives the possibility to study electromagnetic interactions of relativistic nuclei under suppre--ssion conditions of the nuclear interaction channel [ru
Beta decay and muon capture rates in a self-consistent relativistic framework
Energy Technology Data Exchange (ETDEWEB)
Marketin, Tomislav; Paar, Nils; Niksic, Tamara; Vretenar, Dario [Physics Department, Faculty of Science, University of Zagreb (Croatia); Ring, Peter [Physik-Department, Technische Universitaet Muenchen, D-85748 Muenchen (Germany)
2009-07-01
A fully consistent calculation of muon capture and beta decay rates is presented, based on a microscopic theoretical framework describing the semileptonic weak interaction processes. Nuclear ground state is determined using the Relativistic Hartree-Bogolyubov (RHB) model with density dependent meson-nucleon coupling constants, and transition rates are calculated via proton-neutron relativistic quasiparticle RPA using the same interaction as in the RHB equations. Muon capture rates are calculated for a wide range of nuclei along the valley of stability, from {sup 12}C to {sup 244}Pu, with accuracy of approximately 30%, using the interaction DD-ME2. Previous studies of beta decay rates have only taken into account Gamow-Teller transitions. We extend this approach by including forbidden transitions and systematically study their contribution to decay rates of exotic nuclei along the r-process path, which are important for constraining the conditions in which nucleosynthesis takes place.
Relativistic quasiparticle random-phase approximation calculation of total muon capture rates
International Nuclear Information System (INIS)
Marketin, T.; Paar, N.; Niksic, T.; Vretenar, D.
2009-01-01
The relativistic proton-neutron quasiparticle random phase approximation (pn-RQRPA) is applied in the calculation of total muon capture rates on a large set of nuclei from 12 C to 244 Pu, for which experimental values are available. The microscopic theoretical framework is based on the relativistic Hartree-Bogoliubov (RHB) model for the nuclear ground state, and transitions to excited states are calculated using the pn-RQRPA. The calculation is fully consistent, i.e., the same interactions are used both in the RHB equations that determine the quasiparticle basis, and in the matrix equations of the pn-RQRPA. The calculated capture rates are sensitive to the in-medium quenching of the axial-vector coupling constant. By reducing this constant from its free-nucleon value g A =1.262 by 10% for all multipole transitions, the calculation reproduces the experimental muon capture rates to better than 10% accuracy.
Alterations to the relativistic Love-Franey model and their application to inelastic scattering
International Nuclear Information System (INIS)
Zeile, J.R.
1989-01-01
The fictitious axial-vector and tensor mesons for the real part of the relativistic Love-Franey interaction are removed. In an attempt to make up for this loss, derivative couplings are used for the π and ρ mesons. Such derivative couplings require the introduction of axial-vector and tensor contact term corrections. Meson parameters are then fit to free nucleon-nucleon scattering data. The resulting fits are comparable to those of the relativistic Love-Franey model provided that the contact term corrections are included and the fits are weighted over the physically significant quantity of twice the tensor minus the axial-vector Lorentz invariants. Failure to include contact term corrections leads to poor fits at higher energies. The off-shell behavior of this model is then examined by looking at several applications from inelastic proton-nucleus scattering
Summary of the relativistic heavy ion sessions
International Nuclear Information System (INIS)
Harris, J.W.
1988-01-01
The topics covered in the Relativistic Heavy Ion Sessions span four orders of magnitude in energy in the laboratory and a few more in theory. In the two years since the last Intersections conference, experiments in the field of very high energy heavy ion research have begun at CERN and Brookhaven. The prime motivation for these experiments is the possibility of forming quark matter. This paper is a review of the topics covered in the Relativistic Heavy Ion Sessions
Relativistic charged fluids: hydrodynamic and kinetic approaches
International Nuclear Information System (INIS)
Debbasch, F.; Bonnaud, G.
1991-10-01
This report gives a rigorous and consistent hydrodynamic and kinetic description of a charged fluid and the basis equations, in a relativistic context. This study should lead to a reliable model, as much analytical as numerical, of relativistic plasmas which will appear in the interaction of a strong laser field with a plasma. For simplicity, we limited our study to a perfect fluid or, in other words, we disregarded the energy dissipation processes inside the fluid [fr
On the convexity of relativistic hydrodynamics
International Nuclear Information System (INIS)
Ibáñez, José M; Martí, José M; Cordero-Carrión, Isabel; Miralles, Juan A
2013-01-01
The relativistic hydrodynamic system of equations for a perfect fluid obeying a causal equation of state is hyperbolic (Anile 1989 Relativistic Fluids and Magneto-Fluids (Cambridge: Cambridge University Press)). In this report, we derive the conditions for this system to be convex in terms of the fundamental derivative of the equation of state (Menikoff and Plohr1989 Rev. Mod. Phys. 61 75). The classical limit is recovered. Communicated by L Rezzolla (note)
Chiral quark model with relativistic kinematics
International Nuclear Information System (INIS)
Garcilazo, H.; Valcarce, A.
2003-01-01
The nonstrange baryon spectrum is studied within a three-body model that incorporates relativistic kinematics. We found that the combined effect of relativistic kinematics together with the pion exchange between quarks is able to reverse the order of the first positive- and negative-parity nucleon excited states as observed experimentally. Including the chiral partner of the pion (the σ meson) leads to an overall good description of the spectrum
Chiral quark model with relativistic kinematics
Garcilazo, H.; Valcarce, A.
2003-01-01
The non-strange baryon spectrum is studied within a three-body model that incorporates relativistic kinematics. We found that the combined effect of relativistic kinematics together with the pion exchange between quarks is able to reverse the order of the first positive- and negative-parity nucleon excited states as observed experimentally. Including the chiral partner of the pion (the $\\sigma$ meson) leads to an overall good description of the spectrum.
Limits and signatures of relativistic spaceflight
Yurtsever, Ulvi; Wilkinson, Steven
2018-01-01
While special relativity imposes an absolute speed limit at the speed of light, our Universe is not empty Minkowski spacetime. The constituents that fill the interstellar/intergalactic vacuum, including the cosmic microwave background photons, impose a lower speed limit on any object travelling at relativistic velocities. Scattering of cosmic microwave photons from an ultra-relativistic object may create radiation with a characteristic signature allowing the detection of such objects at large distances.
Relativistic klystron research at SLAC and LLNL
International Nuclear Information System (INIS)
Allen, M.A.; Callin, R.S.; Deruyter, H.
1988-06-01
We are developing relativistic klystrons as a power source for high gradient accelerator applications such as large linear electron-positron colliders and compact accelerators. We have attained 200 MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We report here briefly on our experiments so far. 5 refs., 1 fig., 1 tab
Fundamental laws of relativistic classical dynamics revisited
International Nuclear Information System (INIS)
Blaquiere, Augustin
1977-01-01
By stating that a linear differential form, whose coefficients are the components of the momentum and the energy of a particle, has an antiderivative, the basic equations of the dynamics of points are obtained, in the relativistic case. From the point of view of optimization theory, a connection between our condition and the Bellman-Isaacs equation of dynamic programming is discussed, with a view to extending the theory to relativistic wave mechanics [fr
Dechanneling function for relativistic axially channeled electrons
International Nuclear Information System (INIS)
Muralev, V.A.; Telegin, V.I.
1981-01-01
Behaviour of the x(t) dechanneling function depending on the depth is theoretically studied. Theoretical consideration of x(t) for axial channeled relativistic electrons in anisotropic medium results in two-dimensional kinetic equation with mixed derivatives of the parabolic type. The kinetic equation in the approximation of the continuous Lindchard model for relativistic axial channeled electrons is numerically solved. The depth dependence of the x(t) dechanneling function is obtained [ru
Relativistic positioning systems: Numerical simulations
Puchades Colmenero, Neus
The position of users located on the Earth's surface or near it may be found with the classic positioning systems (CPS). Certain information broadcast by satellites of global navigation systems, as GPS and GALILEO, may be used for positioning. The CPS are based on the Newtonian formalism, although relativistic post-Newtonian corrections are done when they are necessary. This thesis contributes to the development of a different positioning approach, which is fully relativistic from the beginning. In the relativistic positioning systems (RPS), the space-time position of any user (ship, spacecraft, and so on) can be calculated with the help of four satellites, which broadcast their proper times by means of codified electromagnetic signals. In this thesis, we have simulated satellite 4-tuples of the GPS and GALILEO constellations. If a user receives the signals from four satellites simultaneously, the emission proper times read -after decoding- are the user "emission coordinates". In order to find the user "positioning coordinates", in an appropriate almost inertial reference system, there are two possibilities: (a) the explicit relation between positioning and emission coordinates (broadcast by the satellites) is analytically found or (b) numerical codes are designed to calculate the positioning coordinates from the emission ones. Method (a) is only viable in simple ideal cases, whereas (b) allows us to consider realistic situations. In this thesis, we have designed numerical codes with the essential aim of studying two appropriate RPS, which may be generalized. Sometimes, there are two real users placed in different positions, which receive the same proper times from the same satellites; then, we say that there is bifurcation, and additional data are needed to choose the real user position. In this thesis, bifurcation is studied in detail. We have analyzed in depth two RPS models; in both, it is considered that the satellites move in the Schwarzschild's space
Relativistic gas in a Schwarzschild metric
International Nuclear Information System (INIS)
Kremer, Gilberto M
2013-01-01
A relativistic gas in a Schwarzschild metric is studied within the framework of a relativistic Boltzmann equation in the presence of gravitational fields, where Marle’s model for the collision operator of the Boltzmann equation is employed. The transport coefficients of the bulk and shear viscosities and thermal conductivity are determined from the Chapman–Enskog method. It is shown that the transport coefficients depend on the gravitational potential. Expressions for the transport coefficients in the presence of weak gravitational fields in the non-relativistic (low temperature) and ultra-relativistic (high temperature) limiting cases are given. Apart from the temperature gradient the heat flux has two relativistic terms. The first one, proposed by Eckart, is due to the inertia of energy and represents an isothermal heat flux when matter is accelerated. The other, suggested by Tolman, is proportional to the gravitational potential gradient and indicates that—in the absence of an acceleration field—a state of equilibrium of a relativistic gas in a gravitational field can be attained only if the temperature gradient is counterbalanced by a gravitational potential gradient. (paper)
A Comprehensive Comparison of Relativistic Particle Integrators
Ripperda, B.; Bacchini, F.; Teunissen, J.; Xia, C.; Porth, O.; Sironi, L.; Lapenta, G.; Keppens, R.
2018-03-01
We compare relativistic particle integrators commonly used in plasma physics, showing several test cases relevant for astrophysics. Three explicit particle pushers are considered, namely, the Boris, Vay, and Higuera–Cary schemes. We also present a new relativistic fully implicit particle integrator that is energy conserving. Furthermore, a method based on the relativistic guiding center approximation is included. The algorithms are described such that they can be readily implemented in magnetohydrodynamics codes or Particle-in-Cell codes. Our comparison focuses on the strengths and key features of the particle integrators. We test the conservation of invariants of motion and the accuracy of particle drift dynamics in highly relativistic, mildly relativistic, and non-relativistic settings. The methods are compared in idealized test cases, i.e., without considering feedback onto the electrodynamic fields, collisions, pair creation, or radiation. The test cases include uniform electric and magnetic fields, {\\boldsymbol{E}}× {\\boldsymbol{B}} fields, force-free fields, and setups relevant for high-energy astrophysics, e.g., a magnetic mirror, a magnetic dipole, and a magnetic null. These tests have direct relevance for particle acceleration in shocks and in magnetic reconnection.
International Nuclear Information System (INIS)
Hafeez-Ur-Rehman; Mahmood, S.; Shah, Asif; Haque, Q.
2011-01-01
Two dimensional (2D) solitons are studied in a plasma system comprising of relativistically streaming ions, kappa distributed electrons, and positrons. Kadomtsev-Petviashvili (KP) equation is derived through the reductive perturbation technique. Analytical solution of the KP equation has been studied numerically and graphically. It is noticed that kappa parameters of electrons and positrons as well as the ions relativistic streaming factor have an emphatic influence on the structural as well as propagation characteristics of two dimensional solitons in the considered plasma system. Our results may be helpful in the understanding of soliton propagation in astrophysical and laboratory plasmas, specifically the interaction of pulsar relativistic wind with supernova ejecta and the transfer of energy to plasma by intense electric field of laser beams producing highly energetic superthermal and relativistic particles [L. Arons, Astrophys. Space Sci. Lib. 357, 373 (2009); P. Blasi and E. Amato, Astrophys. Space Sci. Proc. 2011, 623; and A. Shah and R. Saeed, Plasma Phys. Controlled Fusion 53, 095006 (2011)].
Compression-amplified EMIC waves and their effects on relativistic electrons
International Nuclear Information System (INIS)
Li, L. Y.; Yu, J.; Cao, J. B.; Yuan, Z. G.
2016-01-01
During enhancement of solar wind dynamic pressure, we observe the periodic emissions of electromagnetic ion cyclotron (EMIC) waves near the nightside geosynchronous orbit (6.6R E ). In the hydrogen and helium bands, the different polarized EMIC waves have different influences on relativistic electrons (>0.8 MeV). The flux of relativistic electrons is relatively stable if there are only the linearly polarized EMIC waves, but their flux decreases if the left-hand polarized (L-mode) EMIC waves are sufficiently amplified (power spectral density (PSD) ≥ 1 nT 2 /Hz). The larger-amplitude L-mode waves can cause more electron losses. In contrast, the R-mode EMIC waves are very weak (PSD < 1 nT 2 /Hz) during the electron flux dropouts; thus, their influence may be ignored here. During the electron flux dropouts, the relativistic electron precipitation is observed by POES satellite near the foot point (∼850 km) of the wave emission region. The quasi-linear simulation of wave-particle interactions indicates that the L-mode EMIC waves can cause the rapid precipitation loss of relativistic electrons, especially when the initial resonant electrons have a butterfly-like pitch angle distribution.
Compression-amplified EMIC waves and their effects on relativistic electrons
Energy Technology Data Exchange (ETDEWEB)
Li, L. Y., E-mail: lyli-ssri@buaa.edu.cn; Yu, J.; Cao, J. B. [School of Space and Environment, Beihang University, Beijing (China); Yuan, Z. G. [School of Electronic Information, Wuhan University, Wuhan (China)
2016-06-15
During enhancement of solar wind dynamic pressure, we observe the periodic emissions of electromagnetic ion cyclotron (EMIC) waves near the nightside geosynchronous orbit (6.6R{sub E}). In the hydrogen and helium bands, the different polarized EMIC waves have different influences on relativistic electrons (>0.8 MeV). The flux of relativistic electrons is relatively stable if there are only the linearly polarized EMIC waves, but their flux decreases if the left-hand polarized (L-mode) EMIC waves are sufficiently amplified (power spectral density (PSD) ≥ 1 nT{sup 2}/Hz). The larger-amplitude L-mode waves can cause more electron losses. In contrast, the R-mode EMIC waves are very weak (PSD < 1 nT{sup 2}/Hz) during the electron flux dropouts; thus, their influence may be ignored here. During the electron flux dropouts, the relativistic electron precipitation is observed by POES satellite near the foot point (∼850 km) of the wave emission region. The quasi-linear simulation of wave-particle interactions indicates that the L-mode EMIC waves can cause the rapid precipitation loss of relativistic electrons, especially when the initial resonant electrons have a butterfly-like pitch angle distribution.
Baryon-antibaryon dynamics in relativistic heavy-ion collisions
Seifert, E.; Cassing, W.
2018-04-01
The dynamics of baryon-antibaryon annihilation and reproduction (B B ¯↔3 M ) is studied within the Parton-Hadron-String Dynamics (PHSD) transport approach for Pb+Pb and Au+Au collisions as a function of centrality from lower Super Proton Synchrotron (SPS) up to Large Hadron Collider (LHC) energies on the basis of the quark rearrangement model. At Relativistic Heavy-Ion Collider (RHIC) energies we find a small net reduction of baryon-antibaryon (B B ¯ ) pairs while for the LHC energy of √{sN N}=2.76 TeV a small net enhancement is found relative to calculations without annihilation (and reproduction) channels. Accordingly, the sizable difference between data and statistical calculations in Pb+Pb collisions at √{sN N}=2.76 TeV for proton and antiproton yields [ALICE Collaboration, B. Abelev et al., Phys. Rev. C 88, 044910 (2013), 10.1103/PhysRevC.88.044910], where a deviation of 2.7 σ was claimed by the ALICE Collaboration, should not be attributed to a net antiproton annihilation. This is in line with the observation that no substantial deviation between the data and statistical hadronization model (SHM) calculations is seen for antihyperons, since according to the PHSD analysis the antihyperons should be modified by the same amount as antiprotons. As the PHSD results for particle ratios are in line with the ALICE data (within error bars) this might point towards a deviation from statistical equilibrium in the hadronization (at least for protons and antiprotons). Furthermore, we find that the B B ¯↔3 M reactions are more effective at lower SPS energies where a net suppression for antiprotons and antihyperons up to a factor of 2-2.5 can be extracted from the PHSD calculations for central Au+Au collisions.
Chemical freeze-out study in proton-proton collisions at RHIC and LHC energies
International Nuclear Information System (INIS)
Das, Sabita; Mishra, Debadeepti; Mohanty, Bedangadas; Chatterjee, Sandeep
2016-01-01
Particle multiplicities measured at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) facilities can be used to understand the chemical freeze-out dynamics. At chemical freeze-out (CFO), inelastic collisions cease and the freeze-out parameters can be determined using measured particle multiplicities within the framework of a statistical model. The statistical model has proven to be quite successful in describing the particle production from elementary p-p and e"+e"- collisions up to heavy-ion collisions. It helps to do a systematic study of the centrality and energy dependence of freeze-out parameters in heavy-ion collisions from lower SPS to higher LHC energies. The new data at LHC along with the RHIC data can be used to do such a systematic study in proton-proton collisions
Measurement of J/{psi} production in proton-proton collisions by the PHENIX experiment
Energy Technology Data Exchange (ETDEWEB)
Bruner, Nichelle [University of New Mexico, Albuquerque, NM (United States)
2004-07-01
The PHENIX experiment at the Relativistic Heavy Ion Collider has measured J/{psi} production in proton-proton collisions at {radical}(s)= 200 GeV using data from the 2001-2002 collider run. Distributions of rapidity and transverse momentum are presented and compared with theoretical predictions. The total cross section and mean p{sub T} are calculated and compared to fixed-target results. The total J/{psi} cross section is 4.0{+-}0.6(stat){+-}0.6(sys){+-}0.4(abs){mu}b. The mean p{sub T} is 1.80{+-}0.23(stat){+-}0.16(sys) GeV/c. (orig.)
Measurement of J/ψ production in proton-proton collisions by the PHENIX experiment
International Nuclear Information System (INIS)
Bruner, Nichelle
2004-01-01
The PHENIX experiment at the Relativistic Heavy Ion Collider has measured J/ψ production in proton-proton collisions at √(s)= 200 GeV using data from the 2001-2002 collider run. Distributions of rapidity and transverse momentum are presented and compared with theoretical predictions. The total cross section and mean p T are calculated and compared to fixed-target results. The total J/ψ cross section is 4.0±0.6(stat)±0.6(sys)±0.4(abs)μb. The mean p T is 1.80±0.23(stat)±0.16(sys) GeV/c. (orig.)
International Nuclear Information System (INIS)
Tronc, D.
1994-01-01
The invention concerns a proton therapy device using a proton linear accelerator which produces a proton beam with high energies and intensities. The invention lies in actual fact that the proton beam which is produced by the linear accelerator is deflected from 270 deg in its plan by a deflecting magnetic device towards a patient support including a bed the longitudinal axis of which is parallel to the proton beam leaving the linear accelerator. The patient support and the deflecting device turn together around the proton beam axis while the bed stays in an horizontal position. The invention applies to radiotherapy. 6 refs., 5 figs
Leithead, W E
2007-04-15
From its rebirth in the early 1980s, the rate of development of wind energy has been dramatic. Today, other than hydropower, it is the most important of the renewable sources of power. The UK Government and the EU Commission have adopted targets for renewable energy generation of 10 and 12% of consumption, respectively. Much of this, by necessity, must be met by wind energy. The US Department of Energy has set a goal of 6% of electricity supply from wind energy by 2020. For this potential to be fully realized, several aspects, related to public acceptance, and technical issues, related to the expected increase in penetration on the electricity network and the current drive towards larger wind turbines, need to be resolved. Nevertheless, these challenges will be met and wind energy will, very likely, become increasingly important over the next two decades. An overview of the technology is presented.
Magnetic Origin of Black Hole Winds Across the Mass Scale
Fukumura, Keigo; Kazanas, Demosthenes; Shrader, Chris; Behar, Ehud; Tombesi, Francesco; Contopoulos, Ioannis
2017-01-01
Black hole accretion disks appear to produce invariably plasma outflows that result in blue-shifted absorption features in their spectra. The X-ray absorption-line properties of these outflows are quite diverse, ranging in velocity from non-relativistic (approx. 300 km/sec) to sub-relativistic (approx. 0.1c where c is the speed of light) and a similarly broad range in the ionization states of the wind plasma. We report here that semi-analytic, self-similar magnetohydrodynamic (MHD) wind models that have successfully accounted for the X-ray absorber properties of supermassive black holes, also fit well the high-resolution X-ray spectrum of the accreting stellar-mass black hole, GRO J1655-40. This provides an explicit theoretical argument of their MHD origin (aligned with earlier observational claims) and supports the notion of a universal magnetic structure of the observed winds across all known black hole sizes.
Relativistic mechanics, time and inertia
International Nuclear Information System (INIS)
Kilmister, C.W.; Tocaci, E.
1985-01-01
This book offers a thought-provoking approach to the fundamentals of relativity, and is structured to provide a clear-cut introduction to the essentials of relativistic mechanics. It seeks to emphasize the sensible content of concepts, to improve on their inherent or often forgotten fuzziness, and to explore prospects for their further exploitation. The work also provides an analysis conducive to a rigorous, normative definition of Time, which is seen as a synthesis of universal motion, instrumental in defining a general measure to transformations, and as a sufficient reason to suppose that the speed of light must be the same in all inertial reference frames - hence showing this cardinal postulate to be a demonstrable truth. Moreover it provides an augmented perception of what inertial vs. non-inertial systems are. In addition, the book offers a natural, time-like interpretation of Space that departs from the usual converse approach; it offers a self-consistent proposal to rationalize the axiomatic grounds of mechanics, based on a single postulate in conjunction with the overall approach developed. (author). refs.; figs.; tabs
Canonical formalism for relativistic dynamics
International Nuclear Information System (INIS)
Penafiel-Nava, V.M.
1982-01-01
The possibility of a canonical formalism appropriate for a dynamical theory of isolated relativistic multiparticle systems involving scalar interactions is studied. It is shown that a single time-parameter structure satisfying the requirements of Poincare invariance and simultaneity of the constituents (global tranversality) can not be derived from a homogeneous Lagrangian. The dynamics is deduced initially from a non-homogeneous but singular Lagrangian designed to accommodate the global tranversality constraints with the equaltime plane associated to the total momentum of the system. An equivalent standard Lagrangian is used to generalize the parametrization procedure which is referred to an arbitrary geodesic in Minkowski space. The equations of motion and the definition of center of momentum are invariant with respect to the choice of geodesic and the entire formalism becomes separable. In the original 8N-dimensional phase-space, the symmetries of the Lagrangian give rise to a canonical realization of a fifteen-generator Lie algebra which is projected in the 6N dimensional hypersurface of dynamical motions. The time-component of the total momentum is thus reduced to a neutral element and the canonical Hamiltonian survives as the only generator for time-translations so that the no-interaction theorem becomes inapplicable
Elastic proton-proton scattering at RHIC
Energy Technology Data Exchange (ETDEWEB)
Yip, K.
2011-09-03
Here we describe elastic proton+proton (p+p) scattering measurements at RHIC in p+p collisions with a special optics run of {beta}* {approx} 21 m at STAR, at the center-of-mass energy {radical}s = 200 GeV during the last week of the RHIC 2009 run. We present preliminary results of single and double spin asymmetries.
Baryon production in proton-proton collisions
International Nuclear Information System (INIS)
Liu, F.M.; Werner, K.
2002-01-01
Motivated by the recent rapidity spectra of baryons and antibaryons in pp collisions at 158 GeV and the Ω-bar/Ω ratio discussion, we reviewed string formation mechanism and some string models. This investigation told us how color strings are formed in ultrarelativistic proton-proton collisions
1S0 proton superfluidity in neutron star matter: Impact of bulk properties
International Nuclear Information System (INIS)
Tanigawa, Tomonori; Matsuzaki, Masayuki; Chiba, Satoshi
2004-01-01
We study the 1 S 0 proton pairing gap in neutron star matter putting emphasis on influence of the Dirac effective mass and the proton fraction on the gap within the relativistic Hartree-Bogoliubov model. The gap equation is solved using the Bonn-B potential as a particle-particle channel interaction. It is found that the maximal pairing gap Δ max is 1-2 MeV, which has a strong correlation with the Dirac effective mass. Hence we suggest that it serves as a guide to narrow down parameter sets of the relativistic effective field theory. Furthermore, the more slowly protons increase with density in the core region of neutron stars, the wider the superfluid range and the slightly lower the peak of the gap become
Sombun, S.; Steinheimer, J.; Herold, C.; Limphirat, A.; Yan, Y.; Bleicher, M.
2018-02-01
We study the dependence of the normalized moments of the net-proton multiplicity distributions on the definition of centrality in relativistic nuclear collisions at a beam energy of \\sqrt{{s}{NN}}=7.7 {GeV}. Using the ultra relativistic quantum molecular dynamics model as event generator we find that the centrality definition has a large effect on the extracted cumulant ratios. Furthermore we find that the finite efficiency for the determination of the centrality introduces an additional systematic uncertainty. Finally, we quantitatively investigate the effects of event-pile up and other possible spurious effects which may change the measured proton number. We find that pile-up alone is not sufficient to describe the data and show that a random double counting of events, adding significantly to the measured proton number, affects mainly the higher order cumulants in most central collisions.
Grid Integration of Offshore Wind | Wind | NREL
Grid Integration of Offshore Wind Grid Integration of Offshore Wind Much can be learned from the existing land-based integration research for handling the variability and uncertainty of the wind resource Arklow Bank offshore wind park consists of seven GE Wind 3.6-MW wind turbines. Integration and
Relativistic many-body theory of atomic transitions. The relativistic equation-of-motion approach
International Nuclear Information System (INIS)
Huang, K.
1982-01-01
An equation-of-motion approach is used to develop the relativistic many-body theory of atomic transitions. The relativistic equations of motion for transition matrices are formulated with the use of techniques of quantum-field theory. To reduce the equations of motion to a tractable form which is appropriate for numerical calculations, a graphical method to resolve the complication arising from the antisymmetrization and angular-momentum coupling is employed. The relativistic equation-of-motion method allows an ab initio treatment of correlation and relativistic effects in both closed- and open-shell many-body systems. A special case of the present formulation reduces to the relativistic random-phase approximation
International Nuclear Information System (INIS)
Lusanna, Luca
2011-01-01
After a review of the problems induced by the Lorentz signature of Minkowski space-time, like the need of a clock synchronization convention for the definition of 3-space and the complexity of the notion of relativistic center of mass, there is the introduction of a new formulation of relativistic quantum mechanics compatible with the theory of relativistic bound states. In it the zeroth postulate of non-relativistic quantum mechanics is not valid and the physics is described in the rest frame by a Hilbert space containing only relative variables. The non-locality of the Poincare' generators imply a kinematical non-locality and non-separability influencing the theory of relativistic entanglement and not connected with the standard quantum non-locality.
Beam dynamics simulation of a double pass proton linear accelerator
Directory of Open Access Journals (Sweden)
Kilean Hwang
2017-04-01
Full Text Available A recirculating superconducting linear accelerator with the advantage of both straight and circular accelerator has been demonstrated with relativistic electron beams. The acceleration concept of a recirculating proton beam was recently proposed [J. Qiang, Nucl. Instrum. Methods Phys. Res., Sect. A 795, 77 (2015NIMAER0168-900210.1016/j.nima.2015.05.056] and is currently under study. In order to further support the concept, the beam dynamics study on a recirculating proton linear accelerator has to be carried out. In this paper, we study the feasibility of a two-pass recirculating proton linear accelerator through the direct numerical beam dynamics design optimization and the start-to-end simulation. This study shows that the two-pass simultaneous focusing without particle losses is attainable including fully 3D space-charge effects through the entire accelerator system.
Suit, Herman
2013-11-01
The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter. Copyright © 2013 Elsevier Inc. All
Energy Technology Data Exchange (ETDEWEB)
Suit, Herman
2013-11-01
The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10{sup 80}. Protons were created at 10{sup −6} –1 second after the Big Bang at ≈1.37 × 10{sup 10} years beforethe present. Proton life span has been experimentally determined to be ≥10{sup 34} years; that is, the age of the universe is 10{sup −24}th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W{sup +}, W{sup −}, Z{sup 0}, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.
Energy Technology Data Exchange (ETDEWEB)
Beurskens, H.J.M. [SET Analysis, Kievitlaan 26, 1742 AD Schagen (Netherlands); Brand, A.J. [Energy research Centre of the Netherlands ECN, Unit Wind Energy, P.O. Box 1, 1755 ZG Petten (Netherlands)
2013-02-15
Over the years, wind energy has become a major source of renewable energy worldwide. The present chapter addresses the wind resource, which is available for exploitation for large-scale electricity production, and its specific physical properties. Furthermore, the technical options available to convert the energy of the air flow into mechanical energy and electricity are described. Specific problems of large-scale integration of wind energy into the grid as well as the present and future market developments are described in this chapter. Finally, environmental aspects are discussed briefly.
Re-hardening of hadron transverse mass spectra in relativistic heavy-ion collisions
International Nuclear Information System (INIS)
Ohnishi, A.; Otuka, N.; Sahu, P.K.; Isse, M.; Nara, Y.
2001-01-01
We analyze the spectra of pions and protons in heavy-ion collisions at relativistic energies from 2 A GeV to 65 + 65 A GeV by using a jet-implemented hadron-string cascade model. In this energy region, hadron transverse mass spectra first show softening until SPS energies, and re-hardening may emerge at RHIC energies. Since hadronic matter is expected to show only softening at higher energy densities, this re-hardening of spectra can be interpreted as a good signature of the quark-gluon plasma formation. (author)
Neutron fraction and neutrino mean free path predictions in relativistic mean field models
International Nuclear Information System (INIS)
Hutauruk, P.T.P.; Williams, C.K.; Sulaksono, A.; Mart, T.
2004-01-01
The equation of state (EOS) of dense matter and neutrino mean free path (NMFP) in a neutron star have been studied by using relativistic mean field models motivated by effective field theory. It is found that the models predict too large proton fractions, although one of the models (G2) predicts an acceptable EOS. This is caused by the isovector terms. Except G2, the other two models predict anomalous NMFP's. In order to minimize the anomaly, besides an acceptable EOS, a large M* is favorable. A model with large M* retains the regularity in the NMFP even for a small neutron fraction
Spin rotation function in a microscopic non-relativistic optical model
International Nuclear Information System (INIS)
Bauhoff, W.
1984-01-01
A microscopic optical potential, which is calculated non-relativistically with a density-dependent effective force, is used to calculate cross-section, polarization and spin-rotation function for elastic proton scattering from 40 Ca at 160 MeV and 497 MeV. At 160 MeV, the agreement to the data is comparable to phenomenological fits, and the spin-rotation can be used to distinguish between microscopic and Woods-Saxon potentials. A good fit to the spin-rotation function results at 497 MeV, whereas the polarization data are not well reproduced
Prompt double J/ψ production in proton-proton collisions at the LHC
International Nuclear Information System (INIS)
Baranov, S.P.; Rezaeian, Amir H.
2015-11-01
We provide a detailed study of prompt double J/ψ production within the non-relativistic QCD (NRQCD) framework in proton-proton collisions at the LHC.We confront the recent LHC data with the results obtained at leading-order (LO) in the NRQCD framework within two approaches of the collinear factorization and the k T -factorization. We show that the LHCb data can be fairly described within the k T -factorized LO NRQCD, while the collinearly factorized LO NRQCD significantly overshoots the LHCb data at low J/ψ-pair invariant mass. We show that the LO NRQCD formalism cannot describe the recent CMS data, with about one order of magnitude discrepancy. If the CMS data are confirmed, this indicates rather large higher-order corrections for prompt double J/ψ production. We provide various predictions which can further test the NRQCD-based approach at the LHC in a kinematic region that LO contributions dominate. We also investigate long-range in rapidity double J/ψ correlations. We found no evidence of a ridge-like structure for double J/ψ production in proton-proton collisions at the LHC up to subleading α 6 s accuracy.
Timing Comparisons for GLEs and High-energy Proton Events using GPS Proton Measurements
Bernstein, V.; Winter, L. M.; Carver, M.; Morley, S.
2017-12-01
The newly released LANL GPS particle sensor data offers a unique snapshot of access of relativistic particles into the geomagnetic field. Currently, 23 of the 31 operational GPS satellites host energetic particle detectors which can detect the arrival of high-energy solar protons associated with Ground Level Enhancements (GLEs). We compare the timing profiles of solar energetic proton detections from GPS satellites as well as from ground-based Neutron Monitors and GOES spacecraft at geostationary orbit in order to understand how high-energy protons from the Sun enter the geomagnetic field and investigate potential differences in arrival time of energetic protons at GPS satellites as a function of location. Previous studies could only use one or two spacecraft at a similar altitude to track the arrival of energetic particles. With GPS data, we can now test whether the particles arrive isotropically, as assumed, or whether there exist differences in the timing and energetics viewed by each of the individual satellites. Extensions of this work could lead to improvements in space weather forecasting that predict more localized risk estimates for space-based technology.
National Aeronautics and Space Administration — World Wind allows any user to zoom from satellite altitude into any place on Earth, leveraging high resolution LandSat imagery and SRTM elevation data to experience...
International Nuclear Information System (INIS)
2009-01-01
At the end of 2008,the European wind power capacity had risen to 65,247 MW which is a 15,1% increase on 2007. The financial crisis does not appear to have any real consequences of the wind power sector's activity in 2008. At the end of 2008 the European Union accommodated 53,9% of the world's wind power capacity. The top ten countries in terms of installed wind capacities are: 1) Usa with 25,388 MW, 2) Germany with 23,903 MW, 3) Spain with 16,740 MW, 4) China with 12,200 MW, 5) India with 9,645 MW, 6) Italy with 3,736 MW, 7) France with 3,542 MW, 8) U.K. with 3,406 MW, 9) Denmark with 3,166 MW and 10) Portugal with 2,862 MW. (A.C.)
RELATIVISTIC HEAVY ION COLLISIONS: EXPERIMENT
Energy Technology Data Exchange (ETDEWEB)
Friedlander, Erwin M.; Heckman, Harry H.
1982-04-01
Relativistic heavy ion physics began as a 'no man's land' between particle and nuclear physics, with both sides frowning upon it as 'unclean', because on one hand, hadronic interactions and particle production cloud nuclear structure effects, while on the other, the baryonic environment complicates the interpretation of production experiments. They have attempted to review here the experimental evidence on RHI collisions from the point of view that it represents a new endeavor in the understanding of strong interaction physics. Such an approach appears increasingly justified; first, by the accumulation of data and observations of new features of hadronic interactions that could not have been detected outside a baryonic environment; second, by the maturation of the field owing to the advances made over the past several years in experimental inquiries on particle production by RHI, including pions, kaons, hyperons, and searches for antiprotons; and third, by the steady and progressive increase in the energy and mass ranges of light nuclear beams that have become available to the experiment; indeed the energy range has widened from the {approx} 0.2 to 2 AGeV at the Bevalac to {approx}4 AGeV at Dubna and recently, to the quantum jump in energies to {approx} 1000 equivalent AGeV at the CERN PS-ISR. Accompanying these expansions in the energy frontier are the immediate prospects for very heavy ion beams at the Bevalac up to, and including, 1 AGeV {sup 238}U, thereby extending the 'mass frontier' to its ultimate extent.
Relativistic model for statevector reduction
International Nuclear Information System (INIS)
Pearle, P.
1991-04-01
A relativistic quantum field model describing statevector reduction for fermion states is presented. The time evolution of the states is governed by a Schroedinger equation with a Hamiltonian that has a Hermitian and a non-Hermitian part. In addition to the fermions, the Hermitian part describes positive and negative energy mesons of equal mass, analogous to the longitudinal and timelike photons of electromagnetism. The meson-field-sum is coupled to the fermion field. This ''dresses'' each fermion so that, in the extreme nonrelativistic limit (non-moving fermions), a fermion in a position eigenstate is also in an eigenstate of the meson-field-difference with the Yukawa-potential as eigenvalue. However, the fermions do not interact: this is a theory of free dressed fermions. It is possible to obtain a stationary normalized ''vacuum'' state which satisfies two conditions analogous to the gauge conditions of electromagnetism (i.e., that the meson-field-difference, as well as its time derivative, give zero when applied to the vacuum state), to any desired degree of accuracy. The non-Hermitian part of the Hamiltonian contains the coupling of the meson-field-difference to an externally imposed c-number fluctuating white noise field, of the CSL (Continuous Spontaneous Localization) form. This causes statevector reduction, as is shown in the extreme nonrelativistic limit. For example, a superposition of spatially separated wavepackets of a fermion will eventually be reduced to a single wavepacket: the meson-field-difference discriminates among the Yukawa-potential ''handles'' attached to each wavepacket, thereby selecting one wavepacket to survive by the CSL mechanism. Analysis beyond that given in this paper is required to see what happens when the fermions are allowed to move. (It is possible that the ''vacuum'' state becomes involved in the dynamics so that the ''gauge'' conditions can no longer be maintained.) It is shown how to incorporate these ideas into quantum
Opacity Build-up in Impulsive Relativistic Sources
International Nuclear Information System (INIS)
Granot, Jonathan; Cohen-Tanugi, Johann; Silva, Eduardo do Couto e
2007-01-01
Opacity effects in relativistic sources of high-energy gamma-rays, such as gamma-ray bursts (GRBs) or Blazars, can probe the Lorentz factor of the outflow as well as the distance of the emission site from the source, and thus help constrain the composition of the outflow (protons, pairs, magnetic field) and the emission mechanism. Most previous works consider the opacity in steady state. Here we study the effects of the time dependence of the opacity to pair production (γγ → e + e - ) in an impulsive relativistic source, which may be relevant for the prompt gamma-ray emission in GRBs or flares in Blazars. We present a simple, yet rich, semi-analytic model for the time and energy dependence of the optical depth, τγγ, in which a thin spherical shell expands ultra-relativistically and emits isotropically in its own rest frame over a finite range of radii, R 0 (le) R (le) R 0 +ΔR. This is particularly relevant for GRB internal shocks. We find that in an impulsive source (ΔR ∼ 0 ), while the instantaneous spectrum (which is typically hard to measure due to poor photon statistics) has an exponential cutoff above the photon energy (var e psilon)1(T) where tγγ((var e psilon)1) = 1, the time integrated spectrum (which is easier to measure) has a power-law high-energy tail above the photon energy (var e psilon)1* ∼ (var e psilon)1(ΔT) where ΔT is the duration of the emission episode. Furthermore, photons with energies (var e psilon) > (var e psilon)1* are expected to arrive mainly near the onset of the spike in the light curve or flare, which corresponds to the short emission episode. This arises since in such impulsive sources it takes time to build-up the (target) photon field, and thus the optical depth τγγ((var e psilon)) initially increases with time and (var e psilon)1(T) correspondingly decreases with time, so that photons of energy (var e psilon) > (var e psilon)1* are able to escape the source mainly very early on while (var e psilon)1(T) > (var
Energy Technology Data Exchange (ETDEWEB)
1979-01-01
This publication describes some of the technical, economic, safety and institutional considerations involved in the selection, installation and evaluation of a wind generation system. This information is presented, where possible, in practical, non-technical terms. The first four sections provide background information, theory, and general knowledge, while the remaining six sections are of a more specific nature to assist the prospective owner of a wind generator in his calculations and selections. Meteorological information is provided relating to the wind regime in Nova Scotia. The section on cost analysis discusses some of the factors and considerations which must be examined in order to provide a logical comparison between the alternatives of electricity produced from other sources. The final two sections are brief summaries of the regulations and hazards pertaining to the use of wind generators. The cost of wind-generated electricity is high compared to present Nova Scotia Power Corporation rates, even on Sable Island, Nova Scotia's highest wind area. However, it may be observed that Sable Island is one of the areas of Nova Scotia which is not presently supplied through the power grid and, particularly if there was a significant increase in the price of diesel oil, wind-generated electricity may well be the most economical alternative in that area. Generally speaking, however, where a consumer can purchase electricity at the normal domestic rate, wind generators are not economical, and they will not become economical unless there is a great reduction in their cost, an great increase in electricity rates, or both. Includes glossary. 23 figs., 11 tabs.
Chaos and maps in relativistic rynamical systems
Directory of Open Access Journals (Sweden)
L. P. Horwitz
2000-01-01
Full Text Available The basic work of Zaslavskii et al showed that the classical non-relativistic electromagnetically kicked oscillator can be cast into the form of an iterative map on the phase space; the resulting evolution contains a stochastic flow to unbounded energy. Subsequent studies have formulated the problem in terms of a relativistic charged particle in interaction with the electromagnetic field. We review the structure of the covariant Lorentz force used to study this problem. We show that the Lorentz force equation can be derived as well from the manifestly covariant mechanics of Stueckelberg in the presence of a standard Maxwell field, establishing a connection between these equations and mass shell constraints. We argue that these relativistic generalizations of the problem are intrinsically inaccurate due to an inconsistency in the structure of the relativistic Lorentz force, and show that a reformulation of the relativistic problem, permitting variations (classically in both the particle mass and the effective “mass” of the interacting electromagnetic field, provides a consistent system of classical equations for describing such processes.
Composite hadrons and relativistic nuclei
International Nuclear Information System (INIS)
Blankenbecler, R.
1978-01-01
Lectures are presented describing a model of hadronic scattering at large momentum transfer, either transverse or longitudinal. This model emphasizes in this regime the importance of forces involving the interchange of constituents of the hadrons, hence its name, the constituent interchange model CIM. The CIM is a rearrangement of standard perturbation theory to take into account the fact that the binding force is very strong in color singlet states (singlet dominance). The hard scattering expansion, incoherence problems, nuclear wave functions and counting rules, interaction between nuclei, pion and proton yields and form factors, structure functions and nonscaling, massive lepton pairs, hadrons at large transverse momentum, and quark-quark scattering are treated. 49 references
International Nuclear Information System (INIS)
Berg, S.; Semmes, P.B.; Nazarewicz, W.
1997-01-01
Various theoretical approaches to proton emission from spherical nuclei are investigated, and it is found that all the methods employed give very similar results. The calculated decay widths are found to be qualitatively insensitive to the parameters of the proton-nucleus potential, i.e., changing the potential parameters over a fairly large range typically changes the decay width by no more than a factor of ∼3. Proton half-lives of observed heavy proton emitters are, in general, well reproduced by spherical calculations with the spectroscopic factors calculated in the independent quasiparticle approximation. The quantitative agreement with experimental data obtained in our study requires that the parameters of the proton-nucleus potential be chosen carefully. It also suggests that deformed proton emitters will provide invaluable spectroscopic information on the angular momentum decomposition of single-proton orbitals in deformed nuclei. copyright 1997 The American Physical Society
2012-01-01
Proton Therapy Physics goes beyond current books on proton therapy to provide an in-depth overview of the physics aspects of this radiation therapy modality, eliminating the need to dig through information scattered in the medical physics literature. After tracing the history of proton therapy, the book summarizes the atomic and nuclear physics background necessary for understanding proton interactions with tissue. It describes the physics of proton accelerators, the parameters of clinical proton beams, and the mechanisms to generate a conformal dose distribution in a patient. The text then covers detector systems and measuring techniques for reference dosimetry, outlines basic quality assurance and commissioning guidelines, and gives examples of Monte Carlo simulations in proton therapy. The book moves on to discussions of treatment planning for single- and multiple-field uniform doses, dose calculation concepts and algorithms, and precision and uncertainties for nonmoving and moving targets. It also exami...
Variable-Energy Cyclotron for Proton Therapy Application
Alenitsky, Yu G; Vorozhtsov, A S; Glazov, A A; Mytsyn, G V; Molokanov, A G; Onishchenko, L M
2004-01-01
The requirements to characteristics of the beams used for proton therapy are considered. The operation and proposed cyclotrons for proton therapy are briefly described. The technical decisions of creation of the cyclotron with energy variation in the range 70-230 MeV and with current up to 100 nA are estimated. Taking into account the fact, that the size and cost of the cyclotron are approximately determined by the maximum proton energy, it is realistically offered to limit the maximum proton energy to 190 MeV and to elaborate a cyclotron project with a warm winding of the magnet for acceleration of H^{-} ions. The energy of the extracted protons for each run is determined by a stripped target radius in the vacuum chamber of the accelerator, and the radiation dose field for the patient is created by the external devices using the developed techniques.
Ion acceleration from relativistic laser nano-target
Energy Technology Data Exchange (ETDEWEB)
Jung, Daniel
2012-01-06
Laser-ion acceleration has been of particular interest over the last decade for fundamental as well as applied sciences. Remarkable progress has been made in realizing laser-driven accelerators that are cheap and very compact compared with conventional rf-accelerators. Proton and ion beams have been produced with particle energies of up to 50 MeV and several MeV/u, respectively, with outstanding properties in terms of transverse emittance and current. These beams typically exhibit an exponentially decaying energy distribution, but almost all advanced applications, such as oncology, proton imaging or fast ignition, require quasimonoenergetic beams with a low energy spread. The majority of the experiments investigated ion acceleration in the target normal sheath acceleration (TNSA) regime with comparably thick targets in the {mu}m range. In this thesis ion acceleration is investigated from nm-scaled targets, which are partially produced at the University of Munich with thickness as low as 3 nm. Experiments have been carried out at LANL's Trident high-power and high-contrast laser (80 J, 500 fs, {lambda}=1054 nm), where ion acceleration with these nano-targets occurs during the relativistic transparency of the target, in the so-called Breakout afterburner (BOA) regime. With a novel high resolution and high dispersion Thomson parabola and ion wide angle spectrometer, thickness dependencies of the ions angular distribution, particle number, average and maximum energy have been measured. Carbon C{sup 6+} energies reached 650 MeV and 1 GeV for unheated and heated targets, respectively, and proton energies peaked at 75 MeV and 120 MeV for diamond and CH{sub 2} targets. Experimental data is presented, where the conversion efficiency into carbon C{sup 6+} (protons) is investigated and found to have an up to 10fold (5fold) increase over the TNSA regime. With circularly polarized laser light, quasi-monoenergetic carbon ions have been generated from the same nm-scaled foil
Ion acceleration from relativistic laser nano-target interaction
International Nuclear Information System (INIS)
Jung, Daniel
2012-01-01
Laser-ion acceleration has been of particular interest over the last decade for fundamental as well as applied sciences. Remarkable progress has been made in realizing laser-driven accelerators that are cheap and very compact compared with conventional rf-accelerators. Proton and ion beams have been produced with particle energies of up to 50 MeV and several MeV/u, respectively, with outstanding properties in terms of transverse emittance and current. These beams typically exhibit an exponentially decaying energy distribution, but almost all advanced applications, such as oncology, proton imaging or fast ignition, require quasimonoenergetic beams with a low energy spread. The majority of the experiments investigated ion acceleration in the target normal sheath acceleration (TNSA) regime with comparably thick targets in the μm range. In this thesis ion acceleration is investigated from nm-scaled targets, which are partially produced at the University of Munich with thickness as low as 3 nm. Experiments have been carried out at LANL's Trident high-power and high-contrast laser (80 J, 500 fs, λ=1054 nm), where ion acceleration with these nano-targets occurs during the relativistic transparency of the target, in the so-called Breakout afterburner (BOA) regime. With a novel high resolution and high dispersion Thomson parabola and ion wide angle spectrometer, thickness dependencies of the ions angular distribution, particle number, average and maximum energy have been measured. Carbon C 6+ energies reached 650 MeV and 1 GeV for unheated and heated targets, respectively, and proton energies peaked at 75 MeV and 120 MeV for diamond and CH 2 targets. Experimental data is presented, where the conversion efficiency into carbon C 6+ (protons) is investigated and found to have an up to 10fold (5fold) increase over the TNSA regime. With circularly polarized laser light, quasi-monoenergetic carbon ions have been generated from the same nm-scaled foil targets at Trident with an
Energy Technology Data Exchange (ETDEWEB)
Renault, G
2004-09-01
Non-identical correlation functions allow to study the space-time evolution of the source of particles formed in ultra-relativistic heavy ion collisions. The STAR experiment is dedicated to probe the formation of a new state of nuclear matter called Quark Gluon Plasma. The proton - lambda correlation function is supposed to be more sensitive to bigger source sizes than the proton - proton because of the absence of the final state Coulomb interaction. In this thesis, proton - lambda, anti-proton - anti-lambda, anti-proton - lambda and proton - anti-lambda correlation functions are studied in Au+Au collisions at {radical}S{sub NN} = 200 GeV using an analytical model. The proton - lambda and anti-proton - anti-lambda correlation functions exhibit the same behavior as in previous measurements. The anti-proton - lambda and proton - anti-lambda correlation functions, measured for the first time, show a very strong signal corresponding to the baryon - anti-baryon annihilation channel. Parameterizing the correlation functions has allowed to characterize final state interactions. (author)
Proton solvation and proton transfer in chemical and electrochemical processes
International Nuclear Information System (INIS)
Lengyel, S.; Conway, B.E.
1983-01-01
This chapter examines the proton solvation and characterization of the H 3 O + ion, proton transfer in chemical ionization processes in solution, continuous proton transfer in conductance processes, and proton transfer in electrode processes. Topics considered include the condition of the proton in solution, the molecular structure of the H 3 O + ion, thermodynamics of proton solvation, overall hydration energy of the proton, hydration of H 3 O + , deuteron solvation, partial molal entropy and volume and the entropy of proton hydration, proton solvation in alcoholic solutions, analogies to electrons in semiconductors, continuous proton transfer in conductance, definition and phenomenology of the unusual mobility of the proton in solution, solvent structure changes in relation to anomalous proton mobility, the kinetics of the proton-transfer event, theories of abnormal proton conductance, and the general theory of the contribution of transfer reactions to overall transport processes
Nuclear matter in relativistic mean field theory with isovector scalar meson.
Energy Technology Data Exchange (ETDEWEB)
Kubis, S.; Kutschera, M. [Institute of Nuclear Physics, Cracow (Poland)
1996-12-01
Relativistic mean field (RMF) theory of nuclear matter with the isovector scalar mean field corresponding to the {delta}-meson [a{sub 0}(980)] is studied. While the {delta}-meson field vanishes in symmetric nuclear matter, it can influence properties of asymmetric nuclear matter in neutron stars. The RMF contribution due to {delta}-field to the nuclear symmetry energy is negative. To fit the empirical value, E{sub s}{approx}30 MeV, a stronger {rho}-meson coupling is required than in absence of the {delta}-field. The energy per particle of neutron star matter is than larger at high densities than the one with no {delta}-field included. Also, the proton fraction of {beta}-stable matter increases. Splitting of proton and neutron effective masses due to the {delta}-field can affect transport properties of neutron star matter. (author). 4 refs, 6 figs.
Nuclear matter in relativistic mean field theory with isovector scalar meson
International Nuclear Information System (INIS)
Kubis, S.; Kutschera, M.
1996-12-01
Relativistic mean field (RMF) theory of nuclear matter with the isovector scalar mean field corresponding to the δ-meson [a 0 (980)] is studied. While the δ-meson field vanishes in symmetric nuclear matter, it can influence properties of asymmetric nuclear matter in neutron stars. The RMF contribution due to δ-field to the nuclear symmetry energy is negative. To fit the empirical value, E s ∼30 MeV, a stronger ρ-meson coupling is required than in absence of the δ-field. The energy per particle of neutron star matter is than larger at high densities than the one with no δ-field included. Also, the proton fraction of β-stable matter increases. Splitting of proton and neutron effective masses due to the δ-field can affect transport properties of neutron star matter. (author). 4 refs, 6 figs
Exact quantisation of the relativistic Hopfield model
Energy Technology Data Exchange (ETDEWEB)
Belgiorno, F., E-mail: francesco.belgiorno@polimi.it [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo 32, IT-20133 Milano (Italy); INdAM-GNFM (Italy); Cacciatori, S.L., E-mail: sergio.cacciatori@uninsubria.it [Department of Science and High Technology, Università dell’Insubria, Via Valleggio 11, IT-22100 Como (Italy); INFN sezione di Milano, via Celoria 16, IT-20133 Milano (Italy); Dalla Piazza, F., E-mail: f.dallapiazza@gmail.com [Università “La Sapienza”, Dipartimento di Matematica, Piazzale A. Moro 2, I-00185, Roma (Italy); Doronzo, M., E-mail: m.doronzo@uninsubria.it [Department of Science and High Technology, Università dell’Insubria, Via Valleggio 11, IT-22100 Como (Italy)
2016-11-15
We investigate the quantisation in the Heisenberg representation of a relativistically covariant version of the Hopfield model for dielectric media, which entails the interaction of the quantum electromagnetic field with the matter dipole fields, represented by a mesoscopic polarisation field. A full quantisation of the model is provided in a covariant gauge, with the aim of maintaining explicit relativistic covariance. Breaking of the Lorentz invariance due to the intrinsic presence in the model of a preferred reference frame is also taken into account. Relativistic covariance forces us to deal with the unphysical (scalar and longitudinal) components of the fields, furthermore it introduces, in a more tricky form, the well-known dipole ghost of standard QED in a covariant gauge. In order to correctly dispose of this contribution, we implement a generalised Lautrup trick. Furthermore, causality and the relation of the model with the Wightman axioms are also discussed.
Relativistic stars in vector-tensor theories
Kase, Ryotaro; Minamitsuji, Masato; Tsujikawa, Shinji
2018-04-01
We study relativistic star solutions in second-order generalized Proca theories characterized by a U (1 )-breaking vector field with derivative couplings. In the models with cubic and quartic derivative coupling, the mass and radius of stars become larger than those in general relativity for negative derivative coupling constants. This phenomenon is mostly attributed to the increase of star radius induced by a slower decrease of the matter pressure compared to general relativity. There is a tendency that the relativistic star with a smaller mass is not gravitationally bound for a low central density and hence is dynamically unstable, but that with a larger mass is gravitationally bound. On the other hand, we show that the intrinsic vector-mode couplings give rise to general relativistic solutions with a trivial field profile, so the mass and radius are not modified from those in general relativity.
Spinning relativistic particles in external fields
International Nuclear Information System (INIS)
Pomeranskii, Andrei A; Sen'kov, Roman A; Khriplovich, Iosif B
2000-01-01
The motion of spinning relativistic particles in external electromagnetic and gravitational fields is considered. The self-consistent equations of motion are built with the noncovariant description of spin and with the usual, 'naive' definition of the coordinate of a relativistic particle. A simple derivation of the gravitational interaction of first order in spin is presented for a relativistic particle. The approach developed allows one to consider effects of higher order in spin. Concrete calculations are performed for the second order. The gravimagnetic moment is discussed, a special spin effect in general relativity. We also consider the contributions of the spin interactions of first and second order to the gravitational radiation of compact binary stars. (from the current literature)
Nonlinear relativistic plasma resonance: Renormalization group approach
Energy Technology Data Exchange (ETDEWEB)
Metelskii, I. I., E-mail: metelski@lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Kovalev, V. F., E-mail: vfkvvfkv@gmail.com [Dukhov All-Russian Research Institute of Automatics (Russian Federation); Bychenkov, V. Yu., E-mail: bychenk@lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)
2017-02-15
An analytical solution to the nonlinear set of equations describing the electron dynamics and electric field structure in the vicinity of the critical density in a nonuniform plasma is constructed using the renormalization group approach with allowance for relativistic effects of electron motion. It is demonstrated that the obtained solution describes two regimes of plasma oscillations in the vicinity of the plasma resonance— stationary and nonstationary. For the stationary regime, the spatiotemporal and spectral characteristics of the resonantly enhanced electric field are investigated in detail and the effect of the relativistic nonlinearity on the spatial localization of the energy of the plasma relativistic field is considered. The applicability limits of the obtained solution, which are determined by the conditions of plasma wave breaking in the vicinity of the resonance, are established and analyzed in detail for typical laser and plasma parameters. The applicability limits of the earlier developed nonrelativistic theories are refined.
Theory of relativistic radiation reflection from plasmas
Gonoskov, Arkady
2018-01-01
We consider the reflection of relativistically strong radiation from plasma and identify the physical origin of the electrons' tendency to form a thin sheet, which maintains its localisation throughout its motion. Thereby, we justify the principle of relativistic electronic spring (RES) proposed in [Gonoskov et al., Phys. Rev. E 84, 046403 (2011)]. Using the RES principle, we derive a closed set of differential equations that describe the reflection of radiation with arbitrary variation of polarization and intensity from plasma with an arbitrary density profile for an arbitrary angle of incidence. We confirm with ab initio PIC simulations that the developed theory accurately describes laser-plasma interactions in the regime where the reflection of relativistically strong radiation is accompanied by significant, repeated relocation of plasma electrons. In particular, the theory can be applied for the studies of plasma heating and coherent and incoherent emissions in the RES regime of high-intensity laser-plasma interaction.
Relativistic transport theory for cosmic-rays
International Nuclear Information System (INIS)
Webb, G.M.
1985-01-01
Various aspects of the transport of cosmic-rays in a relativistically moving magnetized plasma supporting a spectrum of hydromagnetic waves that scatter the cosmic-rays are presented. A local Lorentz frame moving with the waves or turbulence scattering the cosmic-rays is used to specify the individual particle momentum. The comoving frame is in general a noninertial frame in which the observer's volume element is expanding and shearing, geometric energy change terms appear in the cosmic-ray transport equation which consist of the relativistic generalization of the adiabatic deceleration term and a further term involving the acceleration vector of the scatterers. A relativistic version of the pitch angle evolution equation, including the effects of adiabatic focussing, pitch angle scattering, and energy changes is presented
Relativistic Calculations for Be-like Iron
International Nuclear Information System (INIS)
Yang Jianhui; Zhang Jianping; Li Ping; Li Huili
2008-01-01
Relativistic configuration interaction calculations for the states of 1s 2 2s 2 , 1s 2 2s3l (l = s,p,d) and 1s 2 2p3l (l = s,p,d) configurations of iron are carried out using relativistic configuration interaction (RCI) and multi-configuration Dirac-Fock (MCDF) method in the active interaction approach. In the present calculation, a large-scale configuration expansion was used in describing the target states. These results are extensively compared with other available calculative and experimental and observed values, the corresponding present results are in good agreement with experimental and observed values, and some differences are found with other available calculative values. Because more relativistic effects are considered than before, the present results should be more accurate and reliable
Relativistic Spacecraft Propelled by Directed Energy
Kulkarni, Neeraj; Lubin, Philip; Zhang, Qicheng
2018-04-01
Achieving relativistic flight to enable extrasolar exploration is one of the dreams of humanity and the long-term goal of our NASA Starlight program. We derive a relativistic solution for the motion of a spacecraft propelled by radiation pressure from a directed energy (DE) system. Depending on the system parameters, low-mass spacecraft can achieve relativistic speeds, thus enabling interstellar exploration. The diffraction of the DE system plays an important role and limits the maximum speed of the spacecraft. We consider “photon recycling” as a possible method to achieving higher speeds. We also discuss recent claims that our previous work on this topic is incorrect and show that these claims arise from an improper treatment of causality.
Relativistic dynamical reduction models and nonlocality
International Nuclear Information System (INIS)
Ghirardi, G.C.; Grassi, R.
1990-09-01
We discuss some features of continuous dynamical models yielding state vector reduction and we briefly sketch some recent attempts to get a relativistic generalization of them. Within the relativistic context we analyze in detail the local an nonlocal features of the reduction mechanism and we investigate critically the possibility of attributing objective properties to individual systems in the micro and macroscopic cases. At the nonrelativistic level, two physically equivalent versions of continuous reduction mechanisms have been presented. However, only one of them can be taken as a starting point for the above considered relativistic generalization. By resorting to counterfactual arguments we show that the reason for this lies in the fact that the stochasticity involved in the two approaches has different conceptual implications. (author). 7 refs, 4 figs
Viscous photons in relativistic heavy ion collisions
International Nuclear Information System (INIS)
Dion, Maxime; Paquet, Jean-Francois; Young, Clint; Jeon, Sangyong; Gale, Charles; Schenke, Bjoern
2011-01-01
Theoretical studies of the production of real thermal photons in relativistic heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) are performed. The space-time evolution of the colliding system is modelled using music, a 3+1D relativistic hydrodynamic simulation, using both its ideal and viscous versions. The inclusive spectrum and its azimuthal angular anisotropy are studied separately, and the relative contributions of the different photon sources are highlighted. It is shown that the photon v 2 coefficient is especially sensitive to the details of the microscopic dynamics like the equation of state, the ratio of shear viscosity over entropy density, η/s, and to the morphology of the initial state.
Relativistic spin precession in the double pulsar.
Breton, Rene P; Kaspi, Victoria M; Kramer, Michael; McLaughlin, Maura A; Lyutikov, Maxim; Ransom, Scott M; Stairs, Ingrid H; Ferdman, Robert D; Camilo, Fernando; Possenti, Andrea
2008-07-04
The double pulsar PSR J0737-3039A/B consists of two neutron stars in a highly relativistic orbit that displays a roughly 30-second eclipse when pulsar A passes behind pulsar B. Describing this eclipse of pulsar A as due to absorption occurring in the magnetosphere of pulsar B, we successfully used a simple geometric model to characterize the observed changing eclipse morphology and to measure the relativistic precession of pulsar B's spin axis around the total orbital angular momentum. This provides a test of general relativity and alternative theories of gravity in the strong-field regime. Our measured relativistic spin precession rate of 4.77 degrees (-0 degrees .65)(+0 degrees .66) per year (68% confidence level) is consistent with that predicted by general relativity within an uncertainty of 13%.
Neutron relativistic phenomenological and microscopic optical potential
International Nuclear Information System (INIS)
Shen Qing-biao; Feng Da-chun; Zhuo Yi-zhong
1991-01-01
In this paper, both the phenomenological and microscopic neutron relativistic optical potentials are presented. The global neutron relativistic phenomenological optical potential (RPOP) based on the available experimental data for various nuclei ranging from C to U with incident energies E n =20--1000 MeV has been obtained through an automatic search of the best parameters by computer. Then the nucleon relativistic microscopic optical potential (RMOP) is studied by utilizing the effective Lagrangian based on the popular Walecka model. Through comparison between the theoretical results and experimental data we shed some insight into both the RMOP and RPOP. Further improvement concerning how to combine the phenomenological potential with the microscopic one in order to reduce the number of free parameters appearing in the RPOP is suggested
Relativistic thermodynamics and kinetic theory, with applications to cosmology
International Nuclear Information System (INIS)
Stewart, J.M.
1973-01-01
The discussion of relativistic thermodynamics and kinetic theory with applications to cosmology also covers the fundamentals and nonequilibrium relativistic kinetic theory and applications to cosmology and astrophysics. (U.S.)
Relativistic supersymmetric quantum mechanics based on Klein-Gordon equation
International Nuclear Information System (INIS)
Znojil, Miloslav
2004-01-01
Witten's the non-relativistic formalism of supersymmetric quantum mechanics was based on a factorization and partnership between Schroedinger equations. We show how it accommodates a transition to the partnership between relativistic Klein-Gordon equations
Observational and theoretical aspects of relativistic astrophysics and cosmology
International Nuclear Information System (INIS)
Sanz, J.L.; Goicoechea, L.J.
1985-01-01
The studies of relativistic astrophysics and cosmology in these proceedings include primordial nucleosynthesis, nonluminous matter, star and galaxy evolution, cosmic microwave background, and general relativistic models of the universe
Study of proton radioactivities
Energy Technology Data Exchange (ETDEWEB)
Davids, C.N.; Back, B.B.; Henderson, D.J. [and others
1995-08-01
About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.
Pivotal issues on relativistic electrons in ITER
Boozer, Allen H.
2018-03-01
The transfer of the plasma current from thermal to relativistic electrons is a threat to ITER achieving its mission. This danger is significantly greater in the nuclear than in the non-nuclear phase of ITER operations. Two issues are pivotal. The first is the extent and duration of magnetic surface breaking in conjunction with the thermal quenches. The second is the exponential sensitivity of the current transfer to three quantities: (1) the poloidal flux change required to e-fold the number of relativistic electrons, (2) the time τa after the beginning of the thermal quench before the accelerating electric field exceeds the Connor-Hastie field for runaway, and (3) the duration of the period τ_op in which magnetic surfaces remain open. Adequate knowledge does not exist to devise a reliable strategy for the protection of ITER. Uncertainties are sufficiently large that a transfer of neither a negligible nor the full plasma current to relativistic electrons can be ruled out during the non-nuclear phase of ITER. Tritium decay can provide a sufficiently strong seed for a dangerous relativistic-electron current even if τa and τ_op are sufficiently long to avoid relativistic electrons during non-nuclear operations. The breakup of magnetic surfaces that is associated with thermal quenches occurs on a time scale associated with fast magnetic reconnection, which means reconnection at an Alfvénic rather than a resistive rate. Alfvénic reconnection is well beyond the capabilities of existing computational tools for tokamaks, but its effects can be studied using its property of conserving magnetic helicity. Although the dangers to ITER from relativistic electrons have been known for twenty years, the critical issues have not been defined with sufficient precision to formulate an effective research program. Studies are particularly needed on plasma behavior in existing tokamaks during thermal quenches, behavior which could be clarified using methods developed here.
International Nuclear Information System (INIS)
Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.
1978-01-01
Measurements aboard Imp 6, 7, and 8 reveal that approximately one third of all high-speed solar wind streams observed at 1 AU contain a sharp boundary (of thickness less than approx.4 x 10 4 km) near their leading edge, called a stream interface, which separates plasma of distinctly different properties and origins. Identified as discontinuities across which the density drops abruptly, the proton temperature increases abruptly, and the speed rises, stream interfaces are remarkably similar in character from one stream to the next. A superposed epoch analysis of plasma data has been performed for 23 discontinuous stream interfaces observed during the interval March 1971 through August 1974. Among the results of this analysis are the following: (1) a stream interface separates what was originally thick (i.e., dense) slow gas from what was originally thin (i.e., rare) fast gas; (2) the interface is the site of a discontinuous shear in the solar wind flow in a frame of reference corotating with the sun; (3) stream interfaces occur at speeds less than 450 km s - 1 and close to or at the maximum of the pressure ridge at the leading edges of high-speed streams; (4) a discontinuous rise by approx.40% in electron temperature occurs at the interface; and (5) discontinuous changes (usually rises) in alpha particle abundance and flow speed relative to the protons occur at the interface. Stream interfaces do not generally recur on successive solar rotations, even though the streams in which they are embedded often do. At distances beyond several astronomical units, stream interfaces should be bounded by forward-reverse shock pairs; three of four reverse shocks observed at 1 AU during 1971--1974 were preceded within approx.1 day by stream interfaces. Our observations suggest that many streams close to the sun are bounded on all sides by large radial velocity shears separating rapidly expanding plasma from more slowly expanding plasma
An energy principle for two-dimensional collisionless relativistic plasmas
International Nuclear Information System (INIS)
Otto, A.; Schindler, K.
1984-01-01
Using relativistic Vlasov theory an energy principle for two-dimensional plasmas is derived, which provides a sufficient and necessary criterion for the stability of relativistic plasma equilibria. This energy principle includes charge separating effects since the exact Poisson equation was taken into consideration. Applying the variational principle to the case of the relativistic plane plasma sheet, the same marginal wave length is found as in the non-relativistic case. (author)
General Relativistic Calculations for White Dwarf Stars
Mathew, Arun; Nandy, Malay K.
2014-01-01
The mass-radius relations for white dwarf stars are investigated by solving the Newtonian as well as Tolman-Oppenheimer-Volkoff (TOV) equations for hydrostatic equilibrium assuming the electron gas to be non-interacting. We find that the Newtonian limiting mass of $1.4562M_\\odot$ is modified to $1.4166M_\\odot$ in the general relativistic case for $^4_2$He (and $^{12}_{\\ 6}$C) white dwarf stars. Using the same general relativistic treatment, the critical mass for $^{56}_{26}$Fe white dwarf is ...
Relativistic quantum mechanics of leptons and fields
International Nuclear Information System (INIS)
Grandy, W.T. Jr.
1991-01-01
This book serves as an advanced text on the Dirac theory, and provides a monograph summarizing the description of relativistic quantum mechanics and quantum electrodynamics as classical field theories. It presents a broad, detailed, and up-to-date exposition of relativistic quantum mechanics, including the two-body problem. It also demonstrates the extent to which the behavior of stable particles and their interactions can be understood without introducing operator (second-quantized) fields. The subsequent difficulties are studied in detail and possible resolutions are presented through quantum field theory
The relativistic Brownian motion: Interdisciplinary applications
International Nuclear Information System (INIS)
Aragones-Munoz, A; Sandoval-Villalbazo, A
2010-01-01
Relativistic Brownian motion theory will be applied to the study of analogies between physical and economic systems, emphasizing limiting cases in which Gaussian distributions are no longer valid. The characteristic temperatures of the particles will be associated with the concept of variance, and this will allow us to choose whether the pertinent distribution is classical or relativistic, while working specific situations. The properties of particles can be interpreted as economic variables, in order to study the behavior of markets in terms of Levy financial processes, since markets behave as stochastic systems. As far as we know, the application of the Juettner distribution to the study of economic systems is a new idea.
Relativistic motion in gamma-ray bursts
International Nuclear Information System (INIS)
Krolik, J.H.; Pier, E.A.
1991-01-01
Three fundamental problems affect models of gamma-ray bursts, i.e., the energy source, the ability of high-energy photons to escape the radiation region, and the comparative weakness of X-ray emission. It is indicated that relativistic bulk motion of the gamma-ray-emitting plasma generically provides a solution to all three of these problems. Results show that, if the plasma that produces gamma-ray bursts has a bulk relativistic velocity with Lorentz factor gamma of about 10, several of the most troubling problems having to do with gamma-ray bursts are solved. 42 refs
Path integral for relativistic particle theory
International Nuclear Information System (INIS)
Fradkin, E.S.; Gitman, D.M.; Shvartsman, Sh.M.
1990-06-01
An action for a relativistic spinning particle interacting with external electromagnetic field is considered in reparametrization and local supergauge invariant form. It is shown that various path integral representations derived for the causal Green function correspond to the different forms of the relativistic particle action. The analogy of the path integral derived with the Lagrangian path integral of the field theory is discussed. It is shown that to obtain the causal propagator, the integration over the null mode of the Lagrangian multiplier corresponding to the reparametrization invariance, has to be performed in the (0,+infinity) limits. (author). 23 refs
Relativistic effects in a rotating coordinate system
International Nuclear Information System (INIS)
Chugreev, Y.V.
1989-01-01
The general approach to calculating various physical effects in a rotating, noninertial reference frame based on the tetrad formalism for observables is discussed. It is shown that the method based on the search for the ''true'' coordinate transformation from an inertial to the rotating frame is ill-founded. Most special relativistic effects in a rotating frame have been calculated without any nonrelativistic restrictions. It is shown how simple physical experiments can be used to determine whether a circle is at rest in the equatorial plane of a Kerr--Newman gravitational source in the relativistic theory of gravity or is rotating about an axis through its center