Relativistic energy loss in a dispersive medium
Houlrik, Jens Madsen
2002-01-01
The electron energy loss in a dispersive medium is obtained using macroscopic electrodynamics taking advantage of a static frame of reference. Relativistic corrections are described in terms of a dispersive Lorentz factor obtained by replacing the vacuum velocity c by the characteristic phase...
Relativistic energy loss in a dispersive medium
Houlrik, Jens Madsen
2002-01-01
The electron energy loss in a dispersive medium is obtained using macroscopic electrodynamics taking advantage of a static frame of reference. Relativistic corrections are described in terms of a dispersive Lorentz factor obtained by replacing the vacuum velocity c by the characteristic phase...
Holographic energy loss in non-relativistic backgrounds
Atashi, Mahdi; Farahbodnia, Mitra
2016-01-01
In this paper, we study some aspects of energy loss in non-relativistic theories from holography. We analyze the energy lost by a rotating heavy point particle along a circle of radius $l$ with angular velocity $\\omega$ in theories with general dynamical exponent $z$ and hyperscaling violation exponent $\\theta$. It is shown that this problem provides a novel perspective on the energy loss in such theories. A general computation at zero and finite temperature is done and it is shown that how the total energy loss rate depends non-trivially on two characteristic exponents $(z,\\theta)$. We find that at zero temperature there is a special radius $l_c$ where the energy loss is independent of different values of $(z,\\theta)$. Also, there is a crossover between a regime in which the energy loss is dominated by the linear drag force and by the radiation because of the acceleration of the rotating particle. We discover different behaviors at finite temperature case.
Energy loss and longitudinal wakefield of relativistic short proton bunches in electron clouds
O. Boine-Frankenheim
2012-05-01
Full Text Available The aim of our study is the numerical computation of the wakefield and energy loss per unit length for relativistic, short (<10 ns proton bunches interacting with an electron cloud inside the beam pipe. We present analytical expressions for the energy loss in the impulse kick approximation. For the simulation of the wakefields a 2D self-consistent, electrostatic particle-in-cell (PIC code is employed. Results for the energy loss and for the wakefields are presented for the parameter scope of the CERN LHC and SPS. For selected parameters the results are compared to a three-dimensional (3D electromagnetic PIC code.
Enhanced relativistic-electron-beam energy loss in warm dense aluminum.
Vaisseau, X; Debayle, A; Honrubia, J J; Hulin, S; Morace, A; Nicolaï, Ph; Sawada, H; Vauzour, B; Batani, D; Beg, F N; Davies, J R; Fedosejevs, R; Gray, R J; Kemp, G E; Kerr, S; Li, K; Link, A; McKenna, P; McLean, H S; Mo, M; Patel, P K; Park, J; Peebles, J; Rhee, Y J; Sorokovikova, A; Tikhonchuk, V T; Volpe, L; Wei, M; Santos, J J
2015-03-01
Energy loss in the transport of a beam of relativistic electrons in warm dense aluminum is measured in the regime of ultrahigh electron beam current density over 2×10^{11} A/cm^{2} (time averaged). The samples are heated by shock compression. Comparing to undriven cold solid targets, the roles of the different initial resistivity and of the transient resistivity (upon target heating during electron transport) are directly observable in the experimental data, and are reproduced by a comprehensive set of simulations describing the hydrodynamics of the shock compression and electron beam generation and transport. We measured a 19% increase in electron resistive energy loss in warm dense compared to cold solid samples of identical areal mass.
Energy loss distributions of relativistic protons axially channeled in a bent silicon crystal
Stojanov, Nace; Petrović, Srdjan; Nešković, Nebojša
2013-05-01
A detailed study of the energy loss distributions of the relativistic protons axially channeled in the bent Si crystals is presented in this work. The bending angle was varied from 0 to 20 μrad, while the crystal thickness was equal to 1 mm. The proton energy was chosen to be 7 TeV in accordance with the Large Hadron Collider (LHC) project, at the European Organization for Nuclear Research (CERN), in Geneva, Switzerland. The energy loss distributions of the channeled protons were generated using the numerical solution of the proton equations of motion in the transverse plane and the computer simulation method. An accurate energy loss model was used, which takes into account the trajectory dependence of the energy loss of protons during their motion through the crystal channels. Further, the dispersion of the proton's scattering angle caused by its collisions with the electrons of the crystal and the divergence of the proton beam were taken into account. The calculated dependence of the number of dechanneled protons on the bending angle was excellently fitted by the Gompertz type dechanneling function.
Energy loss distributions of relativistic protons axially channeled in a bent silicon crystal
Stojanov, Nace, E-mail: nacestoj@pmf.ukim.mk [Institute of Physics, Faculty of Natural Sciences and Mathematics, Sts. Cyril and Methodius University, P.O. Box 162, 1000 Skopje (Macedonia, The Former Yugoslav Republic of); Petrović, Srdjan; Nešković, Nebojša [Laboratory of Physics (010), Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia)
2013-05-01
A detailed study of the energy loss distributions of the relativistic protons axially channeled in the bent < 100 > Si crystals is presented in this work. The bending angle was varied from 0 to 20 μrad, while the crystal thickness was equal to 1 mm. The proton energy was chosen to be 7 TeV in accordance with the Large Hadron Collider (LHC) project, at the European Organization for Nuclear Research (CERN), in Geneva, Switzerland. The energy loss distributions of the channeled protons were generated using the numerical solution of the proton equations of motion in the transverse plane and the computer simulation method. An accurate energy loss model was used, which takes into account the trajectory dependence of the energy loss of protons during their motion through the crystal channels. Further, the dispersion of the proton’s scattering angle caused by its collisions with the electrons of the crystal and the divergence of the proton beam were taken into account. The calculated dependence of the number of dechanneled protons on the bending angle was excellently fitted by the Gompertz type dechanneling function.
Cao, Shanshan; Bass, Steffen A
2015-01-01
We construct a theoretical framework to describe the evolution of heavy flavors produced in relativistic heavy-ion collisions. The in-medium energy loss of heavy quarks is described using our modified Langevin equation that incorporates both quasi-elastic scatterings and the medium-induced gluon radiation. The space-time profiles of the fireball is described by a (2+1)-dimensional hydrodynamics simulation. A hybrid model of fragmentation and coalescence is utilized for heavy quark hadronization, after which the produced heavy mesons together with the soft hadrons produced from the bulk QGP are fed into the hadron cascade UrQMD model to simulate the subsequent hadronic interactions. We find that the medium-induced gluon radiation contributes significantly to heavy quark energy loss at high $p_\\mathrm{T}$; heavy-light quark coalescence enhances heavy meson production at intermediate $p_\\mathrm{T}$; and scatterings inside the hadron gas further suppress the $D$ meson $R_\\mathrm{AA}$ at large $p_\\mathrm{T}$ and e...
Calibration of ionization energy loss at relativistic rise with STAR Time Projection Chamber
Xu, Yichun; Bichsel, Hans; Dong, Xin; Fachini, Patricia; Fisyak, Yuri; Kocolosky, Adam; Mohanty, Bedanga; Netrakanti, Pawan; Ruan, Lijuan; Suarez, Maria Cristina; Tang, Zebo; van Buren, Gene; Xu, Zhangbu
2008-01-01
We derive a method to improve particle identification (PID) at high transverse momentum ($p_T$) using the relativistic rise of the ionization energy loss ($rdE/dx$) when charged particles traverse the Time Projection Chamber (TPC) at STAR. Electrons triggered and identified by the Barrel Electro-Magnetic Calorimeter (BEMC), pure protons and pions from $\\Lambda\\to p+\\pi^{-}$ ($\\bar{\\Lambda}\\to \\bar{p}+\\pi^{+}$), and $K^{0}_{S}\\to\\pi^{+}+\\pi^{-}$ decays are used to obtain the $dE/dx$ value and its width at given $\\beta\\gamma=p/m$. We found that the deviation of the $dE/dx$ from the Bichsel function can be up to $0.4\\sigma$ ($\\sim3%$) in p+p collisions at $\\sqrt{s_{NN}}=200$ GeV taken and subsequently calibrated in year 2005. The deviation is approximately a function of $\\beta\\gamma$ independent of particle species and can be described with a function of $f(x) = A+\\frac{B}{C+x^{2}}$. The deviations obtained with this method are used to re-calibrate the data sample from p+p collision for physics analysis of ident...
The Beam-Density Effect on Energy Loss of a Relativistic Charged Particle Beam.
1983-09-01
media. t iU NSWC TR 83-348 Folloving the method developed by Sternheimer 24 in his calculations of the Fermi density effect, i l L2 -2in.v-v 2 (2.16...where Z 2v 2 + f.. The Sternheimer factor P is chosen so that the i i i value of the Bethe logarithm, InI, obtained in non-relativistic experiments, is...first three eigenfrequencies were taken from Reference 25. A more recent set has been given by Sternheimer and Peierls,2 6 but the ones of Reference 25
Radiative Energy Loss of Heavy Quark and Dead Cone Effect in Ultra-relativistic Heavy Ion Collisions
XIANG Wen-Chang; DING Heng-Tong; ZHOU Dai-Cui
2005-01-01
@@ The lowest-order heavy quark radiative energy loss has been analysed to quantify the dead cone effect. The medium-induced gluon radiation is found to fill the dead cone, it is reduced at large gluon energies compared to the radiation of light quarks. We calculate the radiative energy loss of heavy quarks in the condition of dead cone effect. It is found that the radiative energy loss with dead cone effect is smaller than that without the dead cone effect.
Boschini, M.J.
2012-01-01
The treatment of the electron-nucleus interaction based on the Mott differential cross section was extended to account for effects due to screened Coulomb potentials, finite sizes and finite rest masses of nuclei for electrons above 200 keV and up to ultra high energies. This treatment allows one to determine both the total and differential cross sections, thus, subsequently to calculate the resulting nuclear and non-ionizing stopping powers. Above a few hundreds of MeV, neglecting the effect due to finite rest masses of recoil nuclei the stopping power and NIEL result to be largely underestimated; while, above a few tens of MeV the finite size of the nuclear target prevents a further large increase of stopping powers which approach almost constant values.
Turner, Drew; Gkioulidou, Matina; Ukhorskiy, Aleksandr; Gabrielse, Christine; Runov, Andrei; Angelopoulos, Vassilis
2014-05-01
Earth's radiation belts provide a natural laboratory to study a variety of physical mechanisms important for understanding the nature of energetic particles throughout the Universe. The outer electron belt is a particularly variable population, with drastic changes in relativistic electron intensities occurring on a variety of timescales ranging from seconds to decades. Outer belt variability ultimately results from the complex interplay between different source, loss, and transport processes, and all of these processes are related to the dynamics of the inner magnetosphere. Currently, an unprecedented number of spacecraft are providing in situ observations of the inner magnetospheric environment, including missions such as NASA's THEMIS and Van Allen Probes and ESA's Cluster and operational monitors such as NOAA's GOES and POES constellations. From a sampling of case studies using multi-point observations, we present examples showcasing the significant importance of two processes to outer belt dynamics: energetic particle injections and wave-particle interactions. Energetic particle injections are transient events that tie the inner magnetosphere to the near-Earth magnetotail; they involve the rapid inward transport of plasmasheet particles into the trapping zone in the inner magnetosphere. We briefly review key concepts and present new evidence from Van Allen Probes, GOES, and THEMIS of how these injections provide: 1. the seed population of electrons that are subsequently accelerated locally to relativistic energies in the outer belt and 2. the source populations of ions and electrons that produce a variety of ULF and VLF waves, which are also important for driving outer belt dynamics via wave-particle interactions. Cases of electron acceleration by chorus waves, losses by plasmaspheric hiss and EMIC waves, and radial transport driven by ULF waves will also be presented. Finally, we discuss the implications of this developing picture of the system, namely how
Schofield, Jennifer, E-mail: Jennifer.schofield@postgrad.manchester.ac.uk [School of Chemistry, The University of Manchester, Oxford Road, M13 9PL (United Kingdom); Pimblott, Simon M. [School of Chemistry, The University of Manchester, Oxford Road, M13 9PL (United Kingdom); The University of Manchester Dalton Cumbrian Facility, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3HA (United Kingdom)
2016-04-01
A formalism for the inelastic cross-section for electronic collisions of protons and heavier ions in a material is developed based on a quadratic extrapolation of the experimentally based dipole oscillator strength distribution (DOSD) of the material into the energy momentum plane. The approach is tested by calculating various energy loss properties in zirconium dioxide. Mean free path, stopping power and continuous slowing down approximation (csda) range are predicted as a function of ion energy for various incident ions, with the stopping powers compared to experimental data to assess the effectiveness of the methodology. The DOSD is straightforwardly obtained from the experimentally measured energy loss function data below 80 eV and atomic photo-absorption cross-section data above 100 eV. Agreement between the results of the calculation for stopping power and the experimental data is within 10% for all ions when compared for energies greater than the Bragg peak. The discrepancy is larger below the peak due to limitations in the methodology, especially the failure to make corrections for the Barkas and higher order effects and the lack of charge cycling cross-section data.
Senzel, Florian; Xu, Zhe; Greiner, Carsten
2016-01-01
The phenomenon of jet quenching provides essential information about the properties of hot and dense matter created in ultra-relativistic heavy-ion collisions. Recent results from experiments at the Large Hadron Collider (LHC) show evidence for an unexpectedly similar suppression of both light and heavy flavor jets. Furthermore, the role of radiative energy loss of heavy quarks is still under active discussion within the theoretical community. By employing the parton cascade BAMPS (Boltzmann Approach to Multi-Parton Scatterings), which numerically solves the 3+1D Boltzmann equation both for light and heavy flavor partons, we calculate the nuclear modification factor of inclusive and b-tagged reconstructed jets in 0-10% central $\\sqrt{s}$ = 2.76 ATeV Pb+Pb collisions. Based on perturbative QCD cross sections we find a rather similar suppression of light and heavy flavor jets. To further investigate light and heavy flavor energy loss we predict a different $R$ dependence of the suppression of inclusive and b-ta...
Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts
Shprits, Yuri Y.; Drozdov, Alexander Y.; Spasojevic, Maria; Kellerman, Adam C.; Usanova, Maria E.; Engebretson, Mark J.; Agapitov, Oleksiy V.; Zhelavskaya, Irina S.; Raita, Tero J.; Spence, Harlan E.; Baker, Daniel N.; Zhu, Hui; Aseev, Nikita A.
2016-01-01
The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) distribution of electrons up to ultra-relativistic energies. Here we show that although relativistic electrons are enhanced, ultra-relativistic electrons become depleted and distributions of particles show very clear telltale signatures of electromagnetic ion cyclotron wave-induced loss. Comparisons between observations and modelling of the evolution of the electron flux and pitch angle show that electromagnetic ion cyclotron waves provide the dominant loss mechanism at ultra-relativistic energies and produce a profound dropout of the ultra-relativistic radiation belt fluxes. PMID:27678050
Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts.
Shprits, Yuri Y; Drozdov, Alexander Y; Spasojevic, Maria; Kellerman, Adam C; Usanova, Maria E; Engebretson, Mark J; Agapitov, Oleksiy V; Zhelavskaya, Irina S; Raita, Tero J; Spence, Harlan E; Baker, Daniel N; Zhu, Hui; Aseev, Nikita A
2016-09-28
The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) distribution of electrons up to ultra-relativistic energies. Here we show that although relativistic electrons are enhanced, ultra-relativistic electrons become depleted and distributions of particles show very clear telltale signatures of electromagnetic ion cyclotron wave-induced loss. Comparisons between observations and modelling of the evolution of the electron flux and pitch angle show that electromagnetic ion cyclotron waves provide the dominant loss mechanism at ultra-relativistic energies and produce a profound dropout of the ultra-relativistic radiation belt fluxes.
Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts
Shprits, Yuri Y.; Drozdov, Alexander Y.; Spasojevic, Maria; Kellerman, Adam C.; Usanova, Maria E.; Engebretson, Mark J.; Agapitov, Oleksiy V.; Zhelavskaya, Irina S.; Raita, Tero J.; Spence, Harlan E.; Baker, Daniel N.; Zhu, Hui; Aseev, Nikita A.
2016-09-01
The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) distribution of electrons up to ultra-relativistic energies. Here we show that although relativistic electrons are enhanced, ultra-relativistic electrons become depleted and distributions of particles show very clear telltale signatures of electromagnetic ion cyclotron wave-induced loss. Comparisons between observations and modelling of the evolution of the electron flux and pitch angle show that electromagnetic ion cyclotron waves provide the dominant loss mechanism at ultra-relativistic energies and produce a profound dropout of the ultra-relativistic radiation belt fluxes.
Precipitation of Relativistic Electrons from the Drift Loss Cone
Lorentzen, K. R.; Looper, M. D.; Blake, J. B.; Millan, R. M.; Smith, D. M.; Lin, R. P.
2001-12-01
On Jan. 22, 2000, the MAXIS (MeV Auroral X-ray and Spectroscopy) experiment observed a relativistic electron precipitation event using balloon-borne X-ray detectors. The X-ray spectrum from this event is consistent with atmospheric bremsstrahlung from precipitating electrons peaked between 2 and 3 MeV. This event occurred at L =3.8 in the duskside southern hemisphere, near the western edge of the South Atlantic Anomaly. Several minutes before the start of the balloon event, the SAMPEX satellite observed an intense relativistic electron microburst event in the dawnside northern hemisphere. Tracing the mirror point of electrons observed by SAMPEX indicates that some of these microburst electrons were located in the drift loss cone, and would have precipitated near the location of the balloon measurement. We model the electron drift and scatter in order to examine how the temporal structure and energy spectrum of the precipitating particles change as they drift around the Earth. These observations have implications for quantifying the loss of relativistic electrons from the radiation belts.
Beam loss mechanisms in relativistic heavy-ion colliders
Bruce, Roderik; Gilardoni, S; Wallén, E
2009-01-01
The Large Hadron Collider (LHC), the largest particle accelerator ever built, is presently under commissioning at the European Organization for Nuclear Research (CERN). It will collide beams of protons, and later Pb82+ ions, at ultrarelativistic energies. Because of its unprecedented energy, the operation of the LHC with heavy ions will present beam physics challenges not encountered in previous colliders. Beam loss processes that are harmless in the presently largest operational heavy-ion collider, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, risk to cause quenches of superconducting magnets in the LHC. Interactions between colliding beams of ultrarelativistic heavy ions, or between beam ions and collimators, give rise to nuclear fragmentation. The resulting isotopes could have a charge-to-mass ratio different from the main beam and therefore follow dispersive orbits until they are lost. Depending on the machine conditions and the ion species, these losses could occur in loca...
RELATIVISTIC ELECTRON LOSSES RELATED TO PROTON PRECIPITATION AND EMIC WAVES
Soraas, F.; Sandanger, M. I.; Aarsnes, K.; Oksavik, K.; Evans, D. S.
2009-12-01
Observations of loss of relativistic electrons to the atmosphere is presented and related to SW parameters. It is shown that the L-region of relativistic electron loss matched the anisotropic proton zone. In this zone the pitch angle distribution of the protons are unstable and can generate/amplify EMIC waves which in turn scatter the electrons into the atmosphere. In spatial limited regions, located close to the plasma pause, there can be enhanced losses of protons (sometime completely filling the loss cone). These regions of proton losses (spikes) are shown to give rise to EMIC waves leading to enhance scattering of the relativistic electrons. In the main phase of the storm the proton spikes are located in the midnight/evening sector, but in the storm recovery phase they are located at all MLTs. The anisotropic proton zone and proton spikes are observed in all storms, but not all storms contain an elevated flux of relativistic electrons.
Energy spectra in relativistic electron precipitation events.
Rosenberg, T. J.; Lanzerotti, L. J.; Bailey, D. K.; Pierson, J. D.
1972-01-01
Two events in August 1967, categorized as relativistic electron precipitation (REP) events by their effect on VHF transmissions propagated via the forward-scatter mode, have been examined with regard to the energy spectra of trapped and precipitated electrons. These two substorm-associated events August 11 and August 25 differ with respect to the relativistic, trapped electron population at synchronous altitude; in the August 25 event there was a nonadiabatic enhancement of relativistic (greater than 400 keV) electrons, while in the August 11 event no relativistic electrons were produced. In both events electron spectra deduced from bremsstrahlung measurements (made on a field line close to that of the satellite) had approximately the same e-folding energies as the trapped electron enhancements. However, the spectrum of electrons in the August 25 event was significantly harder than the spectrum in the event of August 11.
Cherenkov loss factor of short relativistic bunches:general approach
Baturin, S S
2013-01-01
The interaction of short relativistic charged particle bunches with waveguides and other accelerator system components is a critical issue for the development of X-ray FELs (free electron lasers) and linear collider projects. Wakefield Cherenkov losses of short bunches have been studied previously for resistive wall, disk-loaded, corrugated and dielectric loaded waveguides. It was noted in various publications [1] that if the slowdown layer is thin, the Cherenkov loss factor of a short bunch does not depend on the guiding system material and is a constant for any given transverse cross section dimensions of the waveguides. In this paper, we consider a new approach to the analysis of loss factors for relativistic short bunches and formulate a general integral relation that allows calculation of the loss factor for a short relativistic bunch passing an arbitrary waveguide system. The loss factors calculated by this new method for various types of waveguides with arbitrary thickness slowdown layers, including in...
Acceleration and loss of relativistic electrons during small geomagnetic storms.
Anderson, B R; Millan, R M; Reeves, G D; Friedel, R H W
2015-12-16
Past studies of radiation belt relativistic electrons have favored active storm time periods, while the effects of small geomagnetic storms (Dst > -50 nT) have not been statistically characterized. In this timely study, given the current weak solar cycle, we identify 342 small storms from 1989 through 2000 and quantify the corresponding change in relativistic electron flux at geosynchronous orbit. Surprisingly, small storms can be equally as effective as large storms at enhancing and depleting fluxes. Slight differences exist, as small storms are 10% less likely to result in flux enhancement and 10% more likely to result in flux depletion than large storms. Nevertheless, it is clear that neither acceleration nor loss mechanisms scale with storm drivers as would be expected. Small geomagnetic storms play a significant role in radiation belt relativistic electron dynamics and provide opportunities to gain new insights into the complex balance of acceleration and loss processes.
Relativistic propulsion using directed energy
Bible, Johanna; Johansson, Isabella; Hughes, Gary B.; Lubin, Philip M.
2013-09-01
We propose a directed energy orbital planetary defense system capable of heating the surface of potentially hazardous objects to the evaporation point as a futuristic but feasible approach to impact risk mitigation. The system is based on recent advances in high efficiency photonic systems. The system could also be used for propulsion of kinetic or nuclear tipped asteroid interceptors or other interplanetary spacecraft. A photon drive is possible using direct photon pressure on a spacecraft similar to a solar sail. Given a laser power of 70GW, a 100 kg craft can be propelled to 1AU in approximately 3 days achieving a speed of 0.4% the speed of light, and a 10,000 kg craft in approximately 30 days. We call the system DE-STAR for Directed Energy System for Targeting of Asteroids and exploRation. DE-STAR is a modular phased array of solid-state lasers, powered by photovoltaic conversion of sunlight. The system is scalable and completely modular so that sub elements can be built and tested as the technology matures. The sub elements can be immediately utilized for testing as well as other applications including space debris mitigation. The ultimate objective of DE-STAR would be to begin direct asteroid vaporization and orbital modification starting at distances beyond 1 AU. Using phased array technology to focus the beam, the surface spot temperature on the asteroid can be raised to more than 3000K, allowing evaporation of all known substances. Additional scientific uses of DE-STAR are also possible.
Martin, T.H.; Seamen, J.F.; Jobe, D.O.
1993-07-01
The authors experiments show energy losses between 2 and 10 times that of the resistive time predictions. The experiments used hydrogen, helium, air, nitrogen, SF{sub 6} polyethylene, and water for the switching dielectric. Previously underestimated switch losses have caused over predicting the accelerator outputs. Accurate estimation of these losses is now necessary for new high-efficiency pulsed power devices where the switching losses constitute the major portion of the total energy loss. They found that the switch energy losses scale as (V{sub peak}I{sub peak}){sup 1.1846}. When using this scaling, the energy losses in any of the tested dielectrics are almost the same. This relationship is valid for several orders of magnitude and suggested a theoretical basis for these results. Currents up to .65 MA, with voltages to 3 MV were applied to various gaps during these experiments. The authors data and the developed theory indicates that the switch power loss continues for a much longer time than the resistive time, with peak power loss generally occurring at peak current in a ranging discharge instead of the early current time. All of the experiments were circuit code modeled after developing a new switch loss version based on the theory. The circuit code predicts switch energy loss and peak currents as a function of time. During analysis of the data they noticed slight constant offsets between the theory and data that depended on the dielectric. They modified the plasma conductivity for each tested dielectric to lessen this offset.
Higher-order perturbative relativistic corrections to energies and properties
Stopkowicz, Stella
2011-01-01
Relativistic effects need to be considered in quantum-chemical calculations on systems including heavy elements or when aiming at high accuracy for molecules containing only lighter elements. In the latter case, consideration of relativistic effects via perturbation theory is an attractive option. Among the available techniques, Direct Perturbation Theory (DPT) in its lowest order (DPT2) has become a standard tool for the calculation of relativistic corrections to energies and properties.In t...
Dependence of bunch energy loss in cavities on beam velocity
Kurennoy, Sergey S.
1999-03-01
Beam energy loss in a cavity can be easily computed for a relativistic bunch using time-domain codes like MAFIA or ABCI. However, for nonrelativistic beams the problem is more complicated because of difficulties with its numerical formulation in the time domain. We calculate the cavity loss factors for a bunch in frequency domain as a function of its velocity and compare results with the relativistic case.
$\\Lambda$ polarization in peripheral collisions at moderate relativistic energies
Xie, Y L; Stöcker, H; Wang, D J; Csernai, L P
2016-01-01
The polarization of $\\Lambda$ hyperons from relativistic flow vorticity is studied in peripheral heavy ion reactions at FAIR and NICA energies, just above the threshold of the transition to the Quark-Gluon Plasma. Previous calculations at higher energies with larger initial angular momentum, predicted significant $\\Lambda$ polarization based on the classical vorticity term in the polarization, while relativistic modifications decreased the polarization and changed its structure in the momentum space. At the lower energies studied here, we see the same effect namely that the relativistic modifications decrease the polarization arising from the initial shear flow vorticity.
Dark Energy Coupled with Relativistic Dark Matter in Accelerating Universe
张杨
2003-01-01
Recent observations favour an accelerating Universe dominated by the dark energy. We take the effective YangMills condensate as the dark energy and couple it to a relativistic matter which is created by the decaying condensate. The dynamic evolution has asymptotic behaviour with finite constant energy densities, and the fractional densities Ω∧～ 0.7 for dark energy and Ωm ～ 0.3 for relativistic matter are achieved at proper values of the decay rate. The resulting expansion of the Universe is in the de Sitter acceleration.
Nucleon self-energy in the relativistic Brueckner theory
Waindzoch, T.; Fuchs, C.; Faessler, A. [Inst. fuer Theoretische Physik, Univ. Tuebingen (Germany)
1998-06-01
The self-energy of the nucleon in nuclear matter is calculated in the relativistic Brueckner theory. We solve the Thompson equation for the two nucleon scattering in the medium using different Bonn potentials. The self-energy has a rather strong momentum dependence while the equation of state compares well with previous calculations. (orig.)
THEORETICAL CALCULATION OF THE RELATIVISTIC SUBCONFIGURATION-AVERAGED TRANSITION ENERGIES
张继彦; 杨向东; 杨国洪; 张保汉; 雷安乐; 刘宏杰; 李军
2001-01-01
A method for calculating the average energies of relativistic subconfigurations in highly ionized heavy atoms has been developed in the framework of the multiconfigurational Dirac-Fock theory. The method is then used to calculate the average transition energies of the spin-orbit-split 3d-4p transition of Co-like tungsten, the 3d-5f transition of Cu-like tantalum, and the 3d-5f transitions of Cu-like and Zn-like gold samples. The calculated results are in good agreement with those calculated with the relativistic parametric potential method and also with the experimental results.
Energy Extraction from Spinning Black Holes via Relativistic Jets
Narayan, Ramesh; Tchekhovskoy, Alexander
2013-01-01
It has for long been an article of faith among astrophysicists that black hole spin energy is responsible for powering the relativistic jets seen in accreting black holes. Two recent advances have strengthened the case. First, numerical general relativistic magnetohydrodynamic simulations of accreting spinning black holes show that relativistic jets form spontaneously. In at least some cases, there is unambiguous evidence that much of the jet energy comes from the black hole, not the disk. Second, spin parameters of a number of accreting stellar-mass black holes have been measured. For ballistic jets from these systems, it is found that the radio luminosity of the jet correlates with the spin of the black hole. This suggests a causal relationship between black hole spin and jet power, presumably due to a generalized Penrose process.
Mass, Momentum and Kinetic Energy of a Relativistic Particle
Zanchini, Enzo
2010-01-01
A rigorous definition of mass in special relativity, proposed in a recent paper, is recalled and employed to obtain simple and rigorous deductions of the expressions of momentum and kinetic energy for a relativistic particle. The whole logical framework appears as the natural extension of the classical one. Only the first, second and third laws of…
Losing energy in classical, relativistic and quantum mechanics
Atkinson, David
2007-01-01
A Zenonian supertask involving an infinite number of colliding balls is considered, under the restriction that the total mass of all the balls is finite. Classical mechanics leads to the conclusion that momentum, but not necessarily energy, must be conserved. In relativistic mechanics, however, neit
Relativistic energies for the SiC radical
Jia, Chun-Sheng [Southwest Petroleum University, State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu (China); Shui, Zheng-Wei [Southwest Petroleum University, School of Vocational and Technical Education, Nanchong (China)
2015-11-15
The analytical solutions of the Dirac equation with the modified Rosen-Morse potential energy model have been explored. Under the condition of the spin symmetry, we present the bound state energy equation. In the nonrelativistic limit, the relativistic energy equation becomes the nonrelativistic energy form deduced within the framework of the Schroedinger equation. We find that the relativistic effect of the relative motion of the ions leads to a little decrease in the vibrational energies when the vector potential is equal to the scalar potential for the electronic ground state of the SiC radical, while to an increase in those if the vector potential is greater than the scalar potential. (orig.)
Relativistic calculation of the triton binding energy and its implications
Stadler, A; Stadler, Alfred; Gross, Franz
1996-01-01
First results for the triton binding energy obtained from the relativistic spectator or Gross equation are reported. The Dirac structure of the nucleons is taken into account. Numerical results are presented for a family of realistic OBE models with off-shell scalar couplings. It is shown that these off-shell couplings improve both the fits to the two-body data and the predictions for the binding energy.
Proton induced fission of 181-Ta at relativistic energies
Ayyad, Y; Casarejos, E; Álvarez-Pol, H; Bacquias, A; Boudard, A; Caamaño, M; Enqvist, T; Föhr, V; Kelić-Heil, A; Kezzar, K; Leray, S; Paradela, C; Pérez-Loureiro, D; Pleskač, R; Tarrío, D
2012-01-01
Total fission cross sections of 181-Ta induced by protons at different relativistic energies have been measured at GSI, Darmstadt. The inverse kinematics technique used together with a dedicated set-up, made it possible to determine these cross sections with high accuracy. The new data obtained in this experiment will contribute to the understanding of the fission process at high excitation energies. The results are compared with data from previous experiments and systematics for proton-induced fission cross sections.
Bering, E. A.; Kokorowski, M.; Holzworth, R. H.; Sample, J. G.; McCarthy, M. P.; Smith, D. M.; Parks, G. K.; Millan, R. M.; Woodger, L.; Reddell, B. D.; Lay, E.; Bale, S. D.; Pulupa, M.; O'Brien, T. P.; Blake, J. B.; Lin, R. P.; Moraal, H.; Stoker, P.; Hughes, A. R.; Collier, A. B.
2005-05-01
The MINIS balloon campaign was successfully conducted in January 2005 to investigate relativistic electron loss mechanisms. Quantifying and understanding losses is an integral part of understanding the variability of relativistic electrons in the radiation belts. Balloon-based experiments directly measure precipitation and thus provide a method for quantifying losses, while the nearly stationary platform allows for the separation of temporal and spatial variations. A new class of precipitation event, characterized by extremely hard spectra, short durations, and complex temporal structure, occurring in the evening to midnight sector, was discovered by the INTERBOA balloon in 1996 and studied further by the MAXIS balloon in 2000. The MINIS campaign provided the first opportunities for multi-point measurements of electron precipitation up to MeV energies, including simultaneous measurements at different longitudes and at near-conjugate locations. Two balloons, each carrying an X-ray spectrometer for measuring the bremsstrahlung produced as electrons precipitate into the atmosphere, were launched from Churchill, Manitoba at 0850 UT on 21 January 2005 and 0140 UT on 25 January 2005. Four balloons, each carrying an X-ray spectrometer, a Z-axis search coil magnetometer, and a 3-axis electric field instrument providing DC electric field and VLF measurements in 3 frequency bands, were launched from the South African Antarctic Station (SANAE IV). The Southern launches took place at 1400 UT on 17 January, 1309 UT on 19 January, 2115 UT on 20 January, and 0950 UT on 24 January 2005. In this paper, we present the preliminary results from the MINIS South electric field instrumentation. We have good DC and VLF electric field data from all payloads, and the payload rotation mechanism worked in all four as well. The campaign began with two large solar flares. In the post-flare environment, some very magnetospherically active periods are included in our data, with strong and
Preliminary X-ray Results From A Multiple Balloon Campaign to Study Relativistic Electron Loss
Sample, J. G.; Kokorowski, M.; Millan, R. M.; McCarthy, M.; Holzworth, R. H.; Bering, E. A.; Parks, G. K.; Woodger, L.; Reddell, B. D.; Lay, E.; Pulupa, M.; Bale, S.; O'Brien, T. P.; Blake, J. B.; Lin, R. P.; Moraal, H.; Stoker, P.; Hughes, A. R.; Collier Cameron, A.; Smith, D. M.
2005-05-01
The MINIS balloon campaign was successfully conducted in January 2005 to investigate relativistic electron loss mechanisms. Quantifying and understanding losses is an integral part of understanding the variability of relativistic electrons in the radiation belts. Balloon-based experiments directly measure precipitation and thus provide a method for quantifying losses, while the nearly stationary platform allows for the separation of temporal and spatial variations. A new class of precipitation event, characterized by extremely hard spectra, short durations, and complex temporal structure, occurring in the evening to midnight sector, was discovered by the INTERBOA balloon in 1996 and studied further by the MAXIS balloon in 2000. The MINIS campaign provided the first opportunities for multi-point measurements of electron precipitation up to MeV energies, including simultaneous measurements at different longitudes and at near-conjugate locations. Two balloons, each carrying an X-ray spectrometer for measuring the bremsstrahlung produced as electrons precipitate into the atmosphere, were launched from Churchill, Manitoba at 0850 UT on 21 January 2005 and 0140 UT on 25 January 2005. Four balloons, each carrying an X-ray spectrometer, a Z-axis search coil magnetometer, and a 3-axis electric field instrument providing DC electric field and VLF measurements in 3 frequency bands, were launched from the South African Antarctic Station (SANAE IV). The Southern launches took place at 1400 UT on 17 January, 1309 UT on 19 January, 2115 UT on 20 January, and 0950 UT on 24 January 24 2005. In this paper, we present the preliminary results from the MINIS North and South X-ray data. The first and second Southern payloads observed a rarely-seen phenomenon: gamma-ray line emission from nuclear interactions of solar protons in the Earth's atmosphere. When the solar particles abated, there were numerous opportunities for simultaneous observations of MeV precipitation from multiple
Aurenche, P. [LAPTH, Universite de Savoie, CNRS, BP 110, F-74941, Annecy-le-Vieux Cedex (France); Zakharov, B.G. [L.D. Landau Institute for Theoretical Physics, GSP-1, 117940, Kosygina Str. 2, 117334 Moscow (Russian Federation)
2013-01-08
We study the synchrotron-like gluon emission in AA-collisions from fast partons due to interaction with the coherent glasma color fields. Our results show that for RHIC and LHC conditions the contribution of this mechanism to parton energy loss is much smaller than the radiative energy loss in the plasma phase.
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
Loveland, W.D.
1991-08-01
The work described herein is part of a project involving the study of low energy (< 10 MeV/A), intermediate energy (10--100 MeV/A) and relativistic (> 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of best'' semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon {sup 129}Xe with {sup 197}Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon {sup 12}C with {sup 197}Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated.
Shprits, Yuri Y.; Elkington, Scot R.; Meredith, Nigel P.; Subbotin, Dmitriy A.
2008-11-01
In this paper, we focus on the modeling of radial transport in the Earth's outer radiation belt. A historical overview of the first observations of the radiation belts is presented, followed by a brief description of radial diffusion. We describe how resonant interactions with poloidal and toroidal components of the ULF waves can change the electron's energy and provide radial displacements. We also present radial diffusion and guiding center simulations that show the importance of radial transport in redistributing relativistic electron fluxes and also in accelerating and decelerating radiation belt electrons. We conclude by presenting guiding center simulations of the coupled particle tracing and magnetohydrodynamic (MHD) codes and by discussing the origin of relativistic electrons at geosynchronous orbit. Local acceleration and losses and 3D simulations of the dynamics of the radiation belt fluxes are discussed in the companion paper [Shprits, Y.Y., Subbotin, D.A., Meredith, N.P., Elkington, S.R., 2008. Review of modeling of losses and sources of relativistic electrons in the outer radiation belt II: Local acceleration and loss. Journal of Atmospheric and Solar-Terrestrial Physics, this issue. doi:10.1016/j.jastp.2008.06.014].
Fundamental channeling questions at ultra relativistic energies
Carrigan, Richard A., Jr.; /Fermilab
2006-08-01
TeV-range bent crystal channeling has interesting advantages for several applications at high energy accelerators. Observations of enhanced deflection over the whole arc of a bent crystal at RHIC and recently at the Tevatron may be due to a process called ''volume reflection''. More investigations of volume reflection and of the complimentary process, volume capture, are needed. So-called quasimosaic bending processes also deserve additional study. Negative particle channeling may be relevant to channeling collimation for electron machines. Electron and positron channeling and channeling radiation are interwoven so that the impact of channeling radiation on applications needs to be better understood. Beams in the 0.1 to 1 GeV range may be useful for some of these investigations. Finally there has been little or no study of positive and negative muon channeling. The current understanding of these topics and the desirability of further work is reviewed.
Exact two-component relativistic energy band theory and application
Zhao, Rundong; Zhang, Yong; Xiao, Yunlong; Liu, Wenjian, E-mail: liuwj@pku.edu.cn [Beijing National Laboratory for Molecular Sciences, Institute of Theoretical and Computational Chemistry, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, and Center for Computational Science and Engineering, Peking University, Beijing 100871 (China)
2016-01-28
An exact two-component (X2C) relativistic density functional theory in terms of atom-centered basis functions is proposed for relativistic calculations of band structures and structural properties of periodic systems containing heavy elements. Due to finite radial extensions of the local basis functions, the periodic calculation is very much the same as a molecular calculation, except only for an Ewald summation for the Coulomb potential of fluctuating periodic monopoles. For comparison, the nonrelativistic and spin-free X2C counterparts are also implemented in parallel. As a first and pilot application, the band gaps, lattice constants, cohesive energies, and bulk moduli of AgX (X = Cl, Br, I) are calculated to compare with other theoretical results.
Exact two-component relativistic energy band theory and application.
Zhao, Rundong; Zhang, Yong; Xiao, Yunlong; Liu, Wenjian
2016-01-28
An exact two-component (X2C) relativistic density functional theory in terms of atom-centered basis functions is proposed for relativistic calculations of band structures and structural properties of periodic systems containing heavy elements. Due to finite radial extensions of the local basis functions, the periodic calculation is very much the same as a molecular calculation, except only for an Ewald summation for the Coulomb potential of fluctuating periodic monopoles. For comparison, the nonrelativistic and spin-free X2C counterparts are also implemented in parallel. As a first and pilot application, the band gaps, lattice constants, cohesive energies, and bulk moduli of AgX (X = Cl, Br, I) are calculated to compare with other theoretical results.
Energy losses in photovoltaic systems
Anis, Wagdy R.; Nour, M. Abdulsadek
1994-10-01
The maximum power generated by photovoltaic (PV) arrays is not fully used. During summer, the main cause for the energy loss is the system design that necessitates an oversizing of the PV array to supply the load during the winter season when the solar energy is limited. Other reasons that cause energy loss are: the mismatch between the array and the load or battery, the loss in the batteries, and the loss due to the PV array disconnect. The array disconnect loss takes place during summer season when the battery is fully charged. To avoid the disconnect loss, a novel battery voltage regulator (BVR) is used. This supplies the load directly from the array when the battery is fully charged. Energy losses have been analyzed and divided into fundamental (unavoidable) and non-fundamental losses. Both conventional (using a conventional BVR) and new (using a novel BVR) PV systems are studied. A load that consumes constant power for 24 h a day through the year is considered. The climatic condition of Cairo city is taken as the test case.
Thermodynamics of relativistic quantum fields: extracting energy from gravitational waves
Bruschi, David Edward
2016-01-01
We investigate the quantum thermodynamical properties of localised relativistic quantum fields that can be used as quantum thermal machines. We study the efficiency and power of energy transfer between the classical degrees of freedom, such as the energy input due to motion or to an impinging gravitational wave, and the excitations of the confined quantum field. We find that the efficiency of energy transfer depends dramatically on the input initial state of the system. Furthermore, we investigate the ability to extract the energy and to store it in a battery. This process is inefficient in optical cavities but is significantly enhanced when employing trapped Bose Einstein Condensates. Finally, we apply our techniques to a setup where an impinging gravitational wave excites the phononic modes of a Bose Einstein Condensate. We find that, in this case, the amount of energy transfer to the phonons increases with time and quickly approaches unity. These results suggest that, in the future, it might be possible to...
Li, En-Kun; Geng, Jin-Ling
2014-01-01
The modified holographic Ricci dark energy coupled to interacting relativistic and non-relativistic dark matter is considered in the nonflat Friedmann-Robertson-Walker universe. Through examining the deceleration parameter, one can find that the transition time of the Universe from decelerating to accelerating phase in the interacting holographic Ricci dark energy model is close to that in the $\\Lambda$ cold dark matter model. The evolution of modified holographic Ricci dark energy's state parameter and the evolution of dark matter and dark energy's densities shows that the dark energy holds the dominant position from the near past to the future. By studying the statefinder diagnostic and the evolution of the total pressure, one can find that this model could explain the Universe's transition from the radiation to accelerating expansion stage through the dust stage. According to the $Om$ diagnostic, it is easy to find that when the interaction is weak and the proportion of relativistic dark matter in total da...
Evaluating the Role and Effects of Precipitation on Relativistic Electron Losses during Storms
Chen, Y.; Fu, X.
2016-12-01
Theoretic studies have suggested that during storm times various waves (e.g., whistler-mode chorus and electromagnetic ion cyclotron waves) can cause significant precipitation of relativistic ( MeV) electrons that are originally trapped inside the outer radiation belt. However, the role of precipitation and its quantitative contribution to the losses of outer-belt electrons remain open questions. In this study, we tackle these questions by systemically examining the latest wave and electron in-situ, simultaneous observations made at different altitudes by Van Allen Probes from near equator, NOAA POES at low Earth orbits near/across electron loss cone, and BARREL under the mesosphere. After calibrating with DEMTER observations, we first confirm and quantify the response of POES MEPED proton channels to MeV electrons. Next, we identify a list of precipitation events from BARREL and POES measurements, examine the temporal adn spatial relation between the two data sets, and estimate the intensities of electron precipitation with ascertained uncertainties. Then, from Van Allen Probes data, we select another list of dropout events during storms. By cross checking the above two lists, we are able to determine the causal relation between precipitation and dropouts through individual case as well as statistical studies so as to quantify the contributions from precipitation. This study mainly focuses on the relatively small L-shells with positive phase space density radial gradient in order to alleviate the impacts from outward radial diffusion and adiabatic effects. Based upon the recent discovery of cross-energy cross-pitch angle coherence, we pay particular attention to the cross-term diffusions which may account for the extra "loss" needed by observed MeV electron dropouts. Results from this observational study will advance our knowledge on the loss mechanism of outer-belt electrons, and thus lay down another stepping stone towards high-fidelity physics-based models for
Parton-Hadron-String Dynamics at Relativistic Collider Energies
Bratkovskaya, E L; Konchakovski, V P; Linnyk, O
2011-01-01
The novel Parton-Hadron-String Dynamics (PHSD) transport approach is applied to nucleus-nucleus collisions at RHIC energies with respect to differential hadronic spectra in comparison to available data. The PHSD approach is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results from the Wuppertal-Budapest group in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current-conservation, color neutrality as well as energy-momentum conservation. Our dynamical studies for heavy-ion collisions at relativistic collider energies are compared to earlier results from the Hadron-String Dynamics (HSD) approach - incorporating no explicit dynamical partonic phase - as well as to experimental data from the STAR, PHENIX, BRAHMS and PHOBOS collaborations for Au+Au collisions at the top RHIC energy...
Classical and relativistic flux of energy conservation in astrophysical jets
Zaninetti, L
2016-01-01
The conservation of the energy flux in turbulent jets which propagate in the intergalactic medium (IGM) allows deducing the law of motion in the classical and relativistic cases. Three types of IGM are considered: constant density, hyperbolic and inverse power law decrease of density. An analytical law for the evolution of the magnetic field along the radio-jets is deduced using a linear relation between the magnetic pressure and the rest density. Astrophysical applications are made to the centerline intensity of synchrotron emission in NGC315 and to the magnetic field of 3C273.
Bremsstrahlung Energy Losses for Cosmic Ray Electrons and Positrons
Widom, A; Srivastava, R
2015-01-01
Recently cosmic ray electrons and positrons, i.e. cosmic ray charged leptons, have been observed. To understand the distances from our solar system to the sources of such lepton cosmic rays, it is important to understand energy losses from cosmic electrodynamic fields. Energy losses for ultra-relativistic electrons and/or positrons due to classical electrodynamic bremsstrahlung are computed. The energy losses considered are (i) due to Thompson scattering from fluctuating electromagnetic fields in the background cosmic thermal black body radiation and (ii) due to the synchrotron radiation losses from quasi-static domains of cosmic magnetic fields. For distances to sources of galactic length proportions, the lepton cosmic ray energy must be lass than about a TeV.
THE MAXIMUM ENERGY OF ACCELERATED PARTICLES IN RELATIVISTIC COLLISIONLESS SHOCKS
Sironi, Lorenzo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spitkovsky, Anatoly [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544-1001 (United States); Arons, Jonathan, E-mail: lsironi@cfa.harvard.edu [Department of Astronomy, Department of Physics, and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States)
2013-07-01
The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from electrons accelerated at the GRB external shock that propagates with relativistic velocities into the magnetized interstellar medium. By means of multi-dimensional particle-in-cell simulations, we investigate the acceleration performance of weakly magnetized relativistic shocks, in the magnetization range 0 {approx}< {sigma} {approx}< 10{sup -1}. The pre-shock magnetic field is orthogonal to the flow, as generically expected for relativistic shocks. We find that relativistic perpendicular shocks propagating in electron-positron plasmas are efficient particle accelerators if the magnetization is {sigma} {approx}< 10{sup -3}. For electron-ion plasmas, the transition to efficient acceleration occurs for {sigma} {approx}< 3 Multiplication-Sign 10{sup -5}. Here, the acceleration process proceeds similarly for the two species, since the electrons enter the shock nearly in equipartition with the ions, as a result of strong pre-heating in the self-generated upstream turbulence. In both electron-positron and electron-ion shocks, we find that the maximum energy of the accelerated particles scales in time as {epsilon}{sub max}{proportional_to}t {sup 1/2}. This scaling is shallower than the so-called (and commonly assumed) Bohm limit {epsilon}{sub max}{proportional_to}t, and it naturally results from the small-scale nature of the Weibel turbulence generated in the shock layer. In magnetized plasmas, the energy of the accelerated particles increases until it reaches a saturation value {epsilon}{sub sat}/{gamma}{sub 0} m{sub i}c {sup 2} {approx} {sigma}{sup -1/4}, where {gamma}{sub 0} m{sub i}c {sup 2} is the mean energy per particle in the upstream bulk flow. Further energization is prevented by the fact that the self-generated turbulence is confined within a finite region of thickness {proportional_to}{sigma}{sup -1/2} around the shock. Our results can provide physically
Parton energy loss in a classical strongly coupled QGP
Dusling, Kevin; Zahed, Ismail
2009-01-01
We investigate the energy loss of heavy quarks in the gas, liquid and solid phase of a classical quark-gluon plasma (cQGP) using molecular dynamics simulations. The model consists of massive quarks and gluons interacting as a classical non-relativistic colored Coulomb gas. We show that the electric force decorrelates on a short time scale causing the energy loss to be mostly diffusive and langevin-like in the cQGP. We find that the drag coefficient changes with the heavy quark mass, while the...
Turner, Drew; Mann, Ian; Usanova, Maria; Rodriguez, Juan; Henderson, Mike; Angelopoulos, Vassilis; Morley, Steven; Claudepierre, Seth; Li, Wen; Kellerman, Adam; Boyd, Alexander; Kim, Kyung-Chan
source in the plasma sheet, and chorus waves. We show how sudden losses during outer belt dropout events are dominated at higher L-shells (L>~4) by magnetopause shadowing and outward radial transport, which is effective over the full ranges of energy and equatorial pitch angle of outer belt electrons, but at lower L-shells near the plasmapause, energy and pitch angle dependent losses can also occur and are consistent with rapid scattering by interactions between relativistic electrons and EMIC waves. We show cases demonstrating how these different processes occur simultaneously during active periods, with relative effects that vary as a function of L-shell and electron energy and pitch angle. Ultimately, our results highlight the complexity of competing source/acceleration, loss, and transport processes in Earth’s outer radiation belt and the necessity of using multipoint observations to disambiguate between them for future studies.
Relativistic Momentum and Kinetic Energy, and E = mc[superscript 2
Hu, Ben Yu-Kuang
2009-01-01
Based on relativistic velocity addition and the conservation of momentum and energy, I present simple derivations of the expressions for the relativistic momentum and kinetic energy of a particle, and for the formula E = mc[superscript 2]. (Contains 5 footnotes and 2 figures.)
Uniqueness of Landau-Lifshitz energy frame in relativistic dissipative hydrodynamics.
Tsumura, Kyosuke; Kunihiro, Teiji
2013-05-01
We show that the relativistic dissipative hydrodynamic equation derived from the relativistic Boltzmann equation by the renormalization-group method uniquely leads to the one in the energy frame proposed by Landau and Lifshitz, provided that the macroscopic-frame vector, which defines the local rest frame of the flow velocity, is independent of the momenta of constituent particles, as it should. We argue that the relativistic hydrodynamic equations for viscous fluids must be defined on the energy frame if consistent with the underlying relativistic kinetic equation.
Relativistic Killingbeck energy states under external magnetic fields
Eshghi, M. [Islamic Azad University, Researchers and Elite Club, Central Tehran Branch, Tehran (Iran, Islamic Republic of); Mehraban, H. [Semnan University, Faculty of Physics, Semnan (Iran, Islamic Republic of); Ikhdair, S.M. [An-Najah National University, Department of Physics, Faculty of Science, Nablus, West Bank, Palestine (Country Unknown); Near East University, Department of Electrical Engineering, Nicosia, Northern Cyprus (Turkey)
2016-07-15
We address the behavior of the Dirac equation with the Killingbeck radial potential including the external magnetic and Aharonov-Bohm (AB) flux fields. The spin and pseudo-spin symmetries are considered. The correct bound state spectra and their corresponding wave functions are obtained. We seek such a solution using the biconfluent Heun's differential equation method. Further, we give some of our results at the end of this study. Our final results can be reduced to their non-relativistic forms by simply using some appropriate transformations. The spectra, in the spin and pseudo-spin symmetries, are very similar with a slight difference in energy spacing between different states. (orig.)
The Earth's Electron Radiation Belts Modeling: from the Source Population to Relativistic Energies
Aseev, N.; Shprits, Y. Y.; Kellerman, A. C.; Drozdov, A.; Zhu, H.
2016-12-01
The dynamics of the Earth's electron radiation belts is characterized by intricate interactions of different particle populations. During the main phase of a geomagnetic storm, electron source (tens keV) and seed (hundreds keV) populations are injected from the plasma sheet to the outer belt region. The source population transfers energy to electromagnetic waves, while the seed population can be accelerated locally by interaction with chorus waves. Electrons can also be lost by scattering into the loss cone due to wave-particle interaction and by magnetopause shadowing due to outward radial motion. In this work, we present results of simulations of the dynamics of electron fluxes in the inner magnetosphere from a few keV to relativistic energies of several MeV using the VERB-4D code. The code includes radial, energy and pitch angle diffusion, convection and adiabatic effects due to compression or expansion of the magnetic field. We extended the spatial outer boundary of the computational domain to 10-15 RE which allow us to study, how the source and seed population particles are convected from the plasma sheet, accelerated to relativistic energies and lost to the atmosphere or the magnetopause. The results of simulations reproduce Van Allen Probes, GOES and THEMIS observations, indicating that magnetospheric convection is the main driver of electron dynamics above the GEO, while radial diffusion and local diffusion are the most important processes in the outer belt region.
Parton-Hadron-String Dynamics at relativistic collider energies
Bratkovskaya, E. L.; Cassing, W.; Konchakovski, V. P.; Linnyk, O.
2011-04-01
The novel Parton-Hadron-String Dynamics (PHSD) transport approach is applied to nucleus-nucleus collisions at RHIC energies with respect to differential hadronic spectra in comparison to available data. The PHSD approach is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results from the Wuppertal-Budapest group in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current-conservation, color neutrality as well as energy-momentum conservation. Our dynamical studies for heavy-ion collisions at relativistic collider energies are compared to earlier results from the Hadron-String Dynamics (HSD) approach - incorporating no explicit dynamical partonic phase - as well as to experimental data from the STAR, PHENIX, BRAHMS and PHOBOS Collaborations for Au + Au collisions at the top RHIC energy of √{s}=200 GeV. We find a reasonable reproduction of hadron rapidity distributions and transverse mass spectra and also a fair description of the elliptic flow of charged hadrons as a function of the centrality of the reaction and the transverse momentum p. Furthermore, an approximate quark-number scaling of the elliptic flow v of hadrons is observed in the PHSD results, too.
Parton-Hadron-String Dynamics at relativistic collider energies
Bratkovskaya, E.L., E-mail: Elena.Bratkovskaya@th.physik.uni-frankfurt.d [Institut fuer Theoretische Physik, JWG Universitaet Frankfurt, D-60438 Frankfurt am Main (Germany); Frankfurt Institut for Advanced Studies, Frankfurt University, D-60438 Frankfurt-am-Main (Germany); Cassing, W.; Konchakovski, V.P. [Institut fuer Theoretische Physik, Universitaet Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Linnyk, O. [Frankfurt Institut for Advanced Studies, Frankfurt University, D-60438 Frankfurt-am-Main (Germany)
2011-04-15
The novel Parton-Hadron-String Dynamics (PHSD) transport approach is applied to nucleus-nucleus collisions at RHIC energies with respect to differential hadronic spectra in comparison to available data. The PHSD approach is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results from the Wuppertal-Budapest group in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current-conservation, color neutrality as well as energy-momentum conservation. Our dynamical studies for heavy-ion collisions at relativistic collider energies are compared to earlier results from the Hadron-String Dynamics (HSD) approach - incorporating no explicit dynamical partonic phase - as well as to experimental data from the STAR, PHENIX, BRAHMS and PHOBOS Collaborations for Au + Au collisions at the top RHIC energy of {radical}(s)=200 GeV. We find a reasonable reproduction of hadron rapidity distributions and transverse mass spectra and also a fair description of the elliptic flow of charged hadrons as a function of the centrality of the reaction and the transverse momentum p{sub T}. Furthermore, an approximate quark-number scaling of the elliptic flow v{sub 2} of hadrons is observed in the PHSD results, too.
Dynamical Effects on Jet Energy Loss in QCD Medium
Djordjevic, Magdalena
2009-01-01
Computation of radiative energy loss in a finite size dynamically screened QCD medium is a key ingredient for obtaining reliable predictions for jet quenching in ultra-relativistic heavy ion collisions. We develop a theory which allows calculating, to first order in the number of scattering centers, the energy loss of a heavy quark traveling through a finite size dynamical QCD medium. We show that the result for a dynamical medium is significantly larger compared to a medium consisting of randomly distributed static scattering centers. Therefore, a quantitative description of jet suppression at RHIC and LHC experiments must correctly account for the dynamics of the medium's constituents. Furthermore, qualitative predictions that come from this energy loss formalism are also presented.
Energy and Centrality Dependences of Charged Multiplicity Density in Relativistic Nuclear Collisions
SA; Ben-hao; Bonasera; A; TAI; An
2002-01-01
Using a hadron and string cascade model, JPCIAE, the energy and centrality dependences of chargedparticle pseudo rapidity density in relativistic nuclear collisions were studied. Within the framework ofthis model, both the relativistic p + p experimental data and the PHOBOS and PHENIX Au + Au data at
Energy eigenvalues of spherical symmetric potentials with relativistic corrections: analytic results
Dineykhan, M; Zhaugasheva, S A [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Toinbaeva, N Sh [al-Farabi Kazak National University, Almaty (Kazakhstan)
2010-01-14
Based on the investigation of the asymptotic behaviour of the polarization loop function for charged n scalar particles in an external gauge field, we determine the interaction Hamiltonian including the relativistic corrections. The energy eigenvalues of spherical symmetric potentials for two-particle bound state systems with relativistic corrections are analytically derived. The energy spectra of linear and funnel potentials with orbital and radial excitations are determined. The energy spectrum of a superposition of Coulomb and Yukawa potentials is also determined. Our result shows that the energy spectrum with the relativistic corrections for the linear, harmonic oscillator and funnel potentials is smaller than the upper boundaries for the energy spectrum established in the framework of the spinless Salpeter equation for the orbital and radial excited states. The relativistic corrections to the energy spectrum of a superposition of the attractive Coulomb potential and the Yukawa (exponentially screened Coulomb) potentials are very small.
Stephan, Karl D
2016-01-01
After centuries, the long-standing problem of the nature of ball lightning may be closer to a solution. The relativistic-microwave theory of ball lightning recently proposed by Wu accounts for many of the leading characteristics of ball lightning, which most previous theories have failed to do. It involves the impact of a lightning-caused relativistic electron bunch to soil, producing an EM pulse that forms a plasma bubble. While the theory presents a plausible account of ball-lightning formation, storing electromagnetic energy long enough to account for the observed lifetime of such objects was not demonstrated. Here we show how such a structure can develop the high Q factor (~10^10) needed for the observed lifetimes of ~seconds for ball lightning, and show that the structure is radially stable, given certain assumptions.
Energy dependence of resonance production in relativistic heavy ion collisions
Shao, Feng-lan; Wang, Rui-qin; Zhang, Mao-sheng
2016-01-01
The production of hadronic resonances $K^{*}(892)$, $\\phi(1020)$, $\\Sigma^{*}(1385)$, and $\\Xi^{*}(1530)$ in central AA collisions at $\\sqrt{s_{NN}}=$ 17.3, 200, and 2760 GeV are systematically studied. The direct production of these resonances at system hadronization are described by the quark combination model and the effects of hadron multiple-scattering stage are dealt with by a ultra-relativistic quantum molecular dynamics model (UrQMD). We study the contribution of these two production sources to final observation and compare the final spectra with the available experimental data. The $p_T$ spectra of $K^{*}(892)$ calculated directly by quark combination model are explicitly higher than the data at low $p_T \\lesssim 1.5$ GeV and taking into account the modification of rescattering effects the resulting final spectra well agree with the data at all three collision energies. The rescattering effect on $\\phi(1020)$ production is weak and including it can slightly improve our description at low $p_T$ on the...
Energy dependence of resonance production in relativistic heavy ion collisions
Shao, Feng-Lan; Song, Jun; Wang, Rui-Qin; Zhang, Mao-Sheng
2017-01-01
The production of the hadronic resonances K*0(892), ϕ(1020), Σ*(1385), and Ξ*(1530) in central AA collisions at , 200, and 2760 GeV is systematically studied. The direct production of these resonances at system hadronization is described by the quark combination model and the effects of hadron multiple-scattering stage are dealt with by a ultra-relativistic quantum molecular dynamics model (UrQMD). We study the contribution of these two production sources to final observation and compare the final spectra with the available experimental data. The p T spectra of K*0(892) calculated directly by quark combination model are explicitly higher than the data at low p T ≲ 1.5 GeV, and taking into account the modification of rescattering effects, the resulting final spectra well agree with the data at all three collision energies. The rescattering effect on ϕ(1020) production is weak and including it can slightly improve our description at low p T on the basis of overall agreement with the data. We also predict the p T spectra of Σ*(1385) and Ξ*(1530), to be tested by the future experimental data. Supported by National Natural Science Foundation of China (11575100, 11305076, 11505104)
Generalization of radiative jet energy loss to non-zero magnetic mass
Djordjevic, Magdalena, E-mail: magda@ipb.ac.rs [Institute of Physics Belgrade, University of Belgrade (Serbia); Djordjevic, Marko [Faculty of Biology, University of Belgrade (Serbia)
2012-03-19
Reliable predictions for jet quenching in ultra-relativistic heavy ion collisions require accurate computation of radiative energy loss. While all available energy loss formalisms assume zero magnetic mass - in accordance with the one-loop perturbative calculations - different non-perturbative approaches report a non-zero magnetic mass at RHIC and LHC. We here generalize a recently developed energy loss formalism in a realistic finite size QCD medium, to consistently include a possibility for existence of non-zero magnetic screening. We also present how the inclusion of finite magnetic mass changes the energy loss results. Our analysis suggests a fundamental constraint on magnetic to electric mass ratio.
The Maximum Energy of Accelerated Particles in Relativistic Collisionless Shocks
Sironi, Lorenzo; Arons, Jonathan
2013-01-01
The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from electrons accelerated at the GRB external shock, that propagates with relativistic velocities into the magnetized interstellar medium. By means of multi-dimensional particle-in-cell simulations, we investigate the acceleration performance of weakly magnetized relativistic shocks, in the magnetization range 0
Physical stress, mass, and energy for non-relativistic spinful matter
Geracie, Michael; Roberts, Matthew M
2016-01-01
For theories of relativistic matter fields with spin there exist two possible definitions of the stress-energy tensor, one defined by a variation of the action with the coframes at fixed connection, and the other at fixed torsion. These two stress-energy tensors do not necessarily coincide and it is the latter that corresponds to the Cauchy stress measured in the lab. In this note we discuss the corresponding issue for non-relativistic matter theories. We point out that while the physical non-relativistic stress, momentum, and mass currents are defined by a variation of the action at fixed torsion, the energy current does not admit such a description and is naturally defined at fixed connection. Any attempt to define an energy current at fixed torsion results in an ambiguity which cannot be resolved from the background spacetime data or conservation laws. We also provide computations of these quantities for some simple non-relativistic actions.
Quantum Geometry: Relativistic energy approach to cooperative electron-nucleary-transition spectrum
Ольга Юрьевна Хецелиус
2014-11-01
Full Text Available An advanced relativistic energy approach is presented and applied to calculating parameters of electron-nuclear 7-transition spectra of nucleus in the atom. The intensities of the spectral satellites are defined in the relativistic version of the energy approach (S-matrix formalism, and gauge-invariant quantum-electrodynamical perturbation theory with the Dirac-Kohn-Sham density-functional zeroth approximation.
On origin and destruction of relativistic dust and its implication for ultrahigh energy cosmic rays
Hoang, Thiem; Schlickeiser, R
2014-01-01
Dust grains may be accelerated to relativistic speeds by radiation pressure of luminous sources, diffusive shocks, and other acceleration mechanisms. Such relativistic grains have been suggested as potential primary particles of ultrahigh energy cosmic rays (UHECRs). In this paper, we reexamine this idea by studying in detail different destruction mechanisms for relativistic grains moving with Lorentz factor $\\gamma$ through a variety of environment conditions. For the solar radiation field, we find that sublimation/melting is a dominant destruction mechanism for silicate grains and large graphite grains. Using an improved treatment of photoelectric emission, we calculate the closest distance that relativistic grains can approach the Sun before destroyed by Coulomb explosions. A range of survival parameters for relativistic grains (size $a$ and $\\gamma$) against both sublimation and Coulomb explosions by the solar radiation field is identified. We also study collisional destruction mechanisms, consisting of e...
Energy losses of positive and negative charged particles in electron gas
Diachenko, M. M.; Kholodov, R. I.
2017-02-01
A heavy charged particle propagation through electron gas has been studied using combination of non-relativistic quantum mechanics and the Green’s functions method. The energy loss of a charged particle has been found in the case of large transferred momentum taking into account the interference term in the expression for the rate. The dependence of the energy loss of a charged particles in electron gas with nonzero temperature on the sign of the charge has been obtained.
A simple method for realistic estimation of the most probable energy loss in thin gas layers
Grishin, V. M.; Merson, G. I.
1989-01-01
A simple method for the estimation of the relativistic rise of the most probable ionisation loss in thin gas layers is suggested. The method is based on the similarity of the most probable and restricted energy loss of relativistic charged particles in matter. This allows to correct the Landau-Sternheimer theory taking into account the fact that particle collisions with internal atomic electrons do not influence the most probable value of the ionisation loss. The effective values of the charge number and average ionisation potential which are simple to calculate are used for this correction. A similarity of the energy loss distributions for various gases and gas layers is found. This similarity is expressed in a constant fraction of the ionisation loss distribution tail area ( ˜ 1:3.5). It is the value which was used for correction of the Landau-Sternheimer formula.
Energy-loss distributions of fission fragments
Demidovich, N.N.; Nakhutin, I.E.; Shatunov, V.G.
1976-03-05
The f-f coincidence method was used to investigate the change in the form of the energy-loss distributions of Cf/sup 252/ fission fragments in air, down to fragment energies approx.0.8 MeV. A theoretical model is considered for the estimate of the mean-squared deviations of the fragment energy-loss distributions. (AIP)
Illustrations of the Relativistic Conservation Law for the Center of Energy
Boyer, T H
2005-01-01
The relativistic conservation law involving the center of energy is reviewed and illustrated using simple examples from classical electromagnetic theory. It is emphasized that this conservation law is parallel to the conservation laws for energy, linear momentum, and energy, in arising from the generators of the Poincare group for electromagnetic theory; yet this relativistic law reflecting the continuous flow of energy goes virtually unmentioned in the text books. The illustrations here present situations both where external forces are present and are absent. The cases of a parallel plate capacitor, a flattened slip-joint solenoid, and two interacting charges are included.
Mass Hierarchy of Collisional Energy Loss
Kolevatov, Rodion
2008-01-01
Collisional parton energy loss is revisited within a simple model assuming incoherent elastic scattering of on-shell projectile partons on partonic constituents of the QGP with HTL screening. The thermal motion of plasma particles is carefully taken into account. Results on $dE/dx$ are found to be consistent with other authors. There is a significant discrepancy in the energy loss pattern for the cases with thermal motion on and off, which illustrates the importance of taking the kinematics into account exactly. The dependence on the mass of the partons forming the plasma is included in the calculations and its influence on the collisional energy loss is studied. The mass hierarchy of collisional energy loss is found to have a strong dependence on the mass introduced for plasma particles. Due to difference in the mass hierarchy with radiative energy loss, the collisional one when included increases the relative suppression of heavy quarks compared to light quarks.
Relativistic and Radiative Energy Shifts for Rydberg States
Jentschura, U D; Evers, J; Mohr, P J; Keitel, C H
2004-01-01
We investigate relativistic and quantum electrodynamic effects for highly-excited bound states in hydrogenlike systems (Rydberg states). In particular, hydrogenic one-loop Bethe logarithms are calculated for all circular states (l = n-1) in the range 20 20 to an accuracy of five to seven decimal digits, within the specified manifolds of atomic states. Within the numerical accuracy, the results constitute unified, general formulas for quantum electrodynamic corrections whose validity is not restricted to a single atomic state. The results are relevant for accurate predictions of radiative shifts of Rydberg states and for the description of the recently investigated laser-dressed Lamb shift, which is observable in a strong coherent-wave light field.
Energy Loss of Proton in Extraction Window
LIU; Bao-jie; ZENG; Zi-qiang
2015-01-01
The particle is transported in vacuum in accelerator,and is exported through extraction windows.The Kapton foil is used in a 3 MeV proton accelerator.The energy loss of 3 MeV proton is calculated when it comes through Kapton foil of different thicknesses with Monte Carlo method.The energy loss of 3 MeV proton in
Energy loss of a fast-electron beam due to the excitation of collective oscillation in hot plasma
Ma Jin-Yi; Qiu Xi-Jun; Zhu Zhi-Yuan
2004-01-01
Energy loss due to a fast-electron beam interacting with the hot plasma at a high density is analysed theoretically.By splitting the particle density fluctuations into the individual part due to the random thermal motion of the individual electrons and the collective part due to plasma-wave excitation, we are concerned with the collective interaction of the relativistic plasma electrons resulting from the Coulomb interactions. Consequently, we derive the frequency of the hot plasma and the "Debye length" with the modification of the relativistic effect. And finally we calculate the energy loss of a fast-electron beam due to the excitation of collective oscillation in the hot plasma.
On pseudosupersymmetric oscillators and reality of relativistic energies for vector mesons
Beckers, Jules; Debergh, Nathalie
1995-01-01
Specific oscillators - hereafter called pseudosupersymmetric oscillators - appear as interesting nonrelativistic concepts in connection with the study of relativistic vector mesons interacting with an external constant magnetic field when the real character of the energy eigenvalues is required as expected. A new pseudosupersymmetric quantum mechanics can then be developed and the corresponding pseudosupersymmetries can be pointed out.
On the energy conservation by weak solutions of the relativistic Vlasov-Maxwell system
Sospedra-Alfonso, Reinel
2010-01-01
We show that weak solutions of the relativistic Vlasov-Maxwell system preserve the total energy provided that the electromagnetic field is locally of bounded variation and, for any $\\lambda$> 0, the one-particle distribution function has a square integrable $\\lambda$-moment in the momentum variable.
Spectrum and Composition of Ultra-high Energy Cosmic Rays from Semi-relativistic Hypernovae
Liu, Ruo-Yu
2011-01-01
It has been suggested that hypernova remnants, with a substantial amount of energy in semi-relativistic ejecta, can accelerate intermediate mass or heavy nuclei to ultra-high energies and provide sufficient amount of energy in cosmic rays to account for the observed flux. We here calculate the expected energy spectrum and chemical composition of ultra-high energy cosmic rays from such semi-relativistic hypernovae. With a chemical composition equal to that of the hypernova ejecta and a flat or hard spectrum for cosmic rays at the sources, the spectrum and composition of the propagated cosmic rays observed at the Earth can be compatible with the measurements by the Pierre Auger Observatory.
Relativistic contributions to single and double core electron ionization energies of noble gases.
Niskanen, J; Norman, P; Aksela, H; Agren, H
2011-08-07
We have performed relativistic calculations of single and double core 1s hole states of the noble gas atoms in order to explore the relativistic corrections and their additivity to the ionization potentials. Our study unravels the interplay of progression of relaxation, dominating in the single and double ionization potentials of the light elements, versus relativistic one-electron effects and quantum electrodynamic effects, which dominate toward the heavy end. The degree of direct relative additivity of the relativistic corrections for the single electron ionization potentials to the double electron ionization potentials is found to gradually improve toward the heavy elements. The Dirac-Coulomb Hamiltonian is found to predict a scaling ratio of ∼4 for the relaxation induced relativistic energies between double and single ionization. Z-scaling of the computed quantities were obtained by fitting to power law. The effects of nuclear size and form were also investigated and found to be small. The results indicate that accurate predictions of double core hole ionization potentials can now be made for elements across the full periodic table.
Kholmetskii, Alexander; Missevitch, Oleg; Yarman, Tolga
2016-02-01
We address to the Poynting theorem for the bound (velocity-dependent) electromagnetic field, and demonstrate that the standard expressions for the electromagnetic energy flux and related field momentum, in general, come into the contradiction with the relativistic transformation of four-vector of total energy-momentum. We show that this inconsistency stems from the incorrect application of Poynting theorem to a system of discrete point-like charges, when the terms of self-interaction in the product {\\varvec{j}} \\cdot {\\varvec{E}} (where the current density {\\varvec{j}} and bound electric field {\\varvec{E}} are generated by the same source charge) are exogenously omitted. Implementing a transformation of the Poynting theorem to the form, where the terms of self-interaction are eliminated via Maxwell equations and vector calculus in a mathematically rigorous way (Kholmetskii et al., Phys Scr 83:055406, 2011), we obtained a novel expression for field momentum, which is fully compatible with the Lorentz transformation for total energy-momentum. The results obtained are discussed along with the novel expression for the electromagnetic energy-momentum tensor.
Mueller, Bernhard
2009-05-07
In this thesis, we have presented the first multi-dimensional models of core-collapse supernovae that combine a detailed, up-to-date treatment of neutrino transport, the equation of state, and - in particular - general relativistic gravity. Building on the well-tested neutrino transport code VERTEX and the GR hydrodynamics code CoCoNuT, we developed and implemented a relativistic generalization of a ray-by-ray-plus method for energy-dependent neutrino transport. The result of these effort, the VERTEX-CoCoNuT code, also incorporates a number of improved numerical techniques that have not been used in the code components VERTEX and CoCoNuT before. In order to validate the VERTEX-CoCoNuT code, we conducted several test simulations in spherical symmetry, most notably a comparison with the one-dimensional relativistic supernova code AGILE-BOLTZTRAN and the Newtonian PROMETHEUSVERTEX code. (orig.)
Abstract composition rule for relativistic kinetic energy in the thermodynamical limit
Biro, T S
2008-01-01
We demonstrate by simple mathematical considerations that a power-law tailed distribution in the kinetic energy of relativistic particles can be a limiting distribution seen in relativistic heavy ion experiments. We prove that the infinite repetition of an arbitrary composition rule on an infinitesimal amount leads to a rule with a formal logarithm. As a consequence the stationary distribution of energy in the thermodynamical limit follows the composed function of the Boltzmann-Gibbs exponential with this formal logarithm. In particular, interactions described as solely functions of the relative four-momentum squared lead to kinetic energy distributions of the Tsallis-Pareto (cut power-law) form in the high energy limit.
Anisotropy of low energy direct photons in relativistic heavy ion collisions
Koide, T.; Kodama, T.
2016-09-01
Using the Wigner function approach for electromagnetic radiation fields, we investigate the behavior of low energy photons radiated by the deceleration processes of two colliding nuclei in relativistic heavy ion collisions. The angular distribution reveals information of the initial geometric configurations, which is reflected in the anisotropic parameter v 2, with an increasing v 2 as energy decreases. This behavior is qualitatively different to the v 2 from the hadrons produced in the collisions.
Anisotropicity of Low Energy Direct Photons in Relativistic Heavy Ion Collisions
Koide, T
2016-01-01
We investigate the behavior of low energy photons radiated by deceleration processes of two colliding nuclei in relativistic heavy ion collisions, where their angular distribution reveals information of the initial geometric configurations. Such a property is reflected in the anisotropic parameter v_{2}, showing an increasing v_{2} as energy decreases, which is qualitatively different behavior from v_{2} from hadrons produced in the collisions.
Energy shift of interacting non-relativistic fermions in noncommutative space
A. Jahan
2005-06-01
Full Text Available A local interaction in noncommutative space modifies to a non-local one. For an assembly of particles interacting through the contact potential, formalism of the quantum field theory makes it possible to take into account the effect of modification of the potential on the energy of the system. In this paper we calculate the energy shift of an assembly of non-relativistic fermions, interacting through the contact potential in the presence of the two-dimensional noncommutativity.
Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts
Yuri Shprits; A. Y. Drozdov; M. Spasojevic; A. C. Kellerman; M. E. Usanova; M. J. Engebretson; O. V. Agapitov; K. G. Orlova; I. S. Zhelavskaya; T. Raita; H. E. Spence; D. N. Baker; H. Zhu
2016-01-01
The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) di...
Generalization of radiative jet energy loss to non-zero magnetic mass
Djordjevic, Magdalena
2011-01-01
Reliable predictions for jet quenching in ultra-relativistic heavy ion collisions require accurate computation of radiative energy loss. With this goal, an energy loss formalism in a realistic finite size dynamical QCD medium was recently developed. While this formalism assumes zero magnetic mass - in accordance with the one-loop perturbative calculations - different non-perturbative approaches report a non-zero magnetic mass at RHIC and LHC. We here generalize the energy loss to consistently include a possibility for existence of non-zero magnetic screening. We also present how the inclusion of finite magnetic mass changes the energy loss results. Our analysis indicates a fundamental constraint on magnetic to electric mass ratio.
Energy Loss of a Heavy Fermion in an Anisotropic QED Plasma
Romatschke, P; Romatschke, Paul; Strickland, Michael
2004-01-01
We compute the leading-order collisional energy loss of a heavy fermion propagating in a QED plasma with an electron distribution function which is anisotropic in momentum space. We show that in the presence of such anisotropies there can be a significant directional dependence of the heavy fermion energy loss with the effect being quite large for highly-relativistic velocities. We also repeat the analysis of the isotropic case more carefully and show that the final result depends on the intermediate scale used to separate hard and soft contributions to the energy loss. We then show that the canonical isotropic result is obtained in the weak-coupling limit. For intermediate-coupling we use the residual scale dependence as a measure of our theoretical uncertainty. We also discuss complications which could arise due to the presence of unstable soft photonic modes and demonstrate that the calculation of the energy loss is safe.
Energy loss of fast quarks in nuclei.
Johnson, M B; Kopeliovich, B Z; Potashnikova, I K; McGaughey, P L; Moss, J M; Peng, J C; Garvey, G T; Leitch, M J; Adams, M R; Alde, D M; Baer, H W; Barlett, M L; Brown, C N; Cooper, W E; Carey, T A; Danner, G; Hoffmann, G W; Hsiung, Y B; Kaplan, D M; Klein, A; Lee, C; Lillberg, J W; McCarthy, R L; Mishra, C S; Wang, M J
2001-05-14
We report an analysis of the nuclear dependence of the yield of Drell-Yan dimuons from the 800 GeV/c proton bombardment of 2H, C, Ca, Fe, and W targets. Employing a new formulation of the Drell-Yan process in the rest frame of the nucleus, this analysis examines the effect of initial-state energy loss and shadowing on the nuclear-dependence ratios versus the incident proton's momentum fraction and dimuon effective mass. The resulting energy loss per unit path length is -dE/dz = 2.32+/-0.52+/-0.5 GeV/fm. This is the first observation of a nonzero energy loss of partons traveling in a nuclear environment.
Energy loss of fast quarks in nuclei
Johnson, M B; Potashnikova, I K; McGaughey, P L; Moss, J M; Peng, J C; Garvey, G T; Leitch, M J; Adams, M R; Alde, D M; Baer, Howard W; Barlett, M L; Brown, C N; Cooper, W E; Carey, T A; Danner, G; Hoffmann, G W; Hsiung, Y B; Kaplan, D M; Klein, A; Lee, C; Lillberg, J W; McCarthy, R L; Mishra, C S; Wang, M J
2001-01-01
We report an analysis of the nuclear dependence of the yield of Drell-Yan dimuons from the 800 GeV/c proton bombardment of $^2H$, C, Ca, Fe, and W targets. Employing a new formulation of the Drell-Yan process in the rest frame of the nucleus, this analysis examines the effect of initial-state energy loss and shadowing on the nuclear-dependence ratios versus the incident proton's momentum fraction and dimuon effective mass. The resulting energy loss per unit path length is $-dE/dz = 2.32 \\pm 0.52\\pm 0.5$ GeV/fm. This is the first observation of a nonzero energy loss of partons traveling in nuclear environment.
Wallin, Erik; Gonoskov, Arkady; Marklund, Mattias
2015-03-01
We model the emission of high energy photons due to relativistic charged particle motion in intense laser-plasma interactions. This is done within a particle-in-cell code, for which high frequency radiation normally cannot be resolved due to finite time steps and grid size. A simple expression for the synchrotron radiation spectra is used together with a Monte-Carlo method for the emittance. We extend previous work by allowing for arbitrary fields, considering the particles to be in instantaneous circular motion due to an effective magnetic field. Furthermore, we implement noise reduction techniques and present validity estimates of the method. Finally, we perform a rigorous comparison to the mechanism of radiation reaction, and find the emitted energy to be in excellent agreement with the losses calculated using radiation reaction.
Wallin, Erik; Marklund, Mattias
2014-01-01
We model the emission of high energy photons due to relativistic particles in a plasma interacting with a super-intense laser. This is done in a particle-in-cell code where the high frequency radiation normally cannot be resolved, due to the unattainable demands it would place on the time and space resolution. A simple expression for the synchrotron radiation spectra is used together with a Monte-Carlo method for the emittance. We extend to previous work by accounting acceleration due to arbitrary fields, considering the particles to be in instantaneous circular motion due to an effective magnetic field. Furthermore we implement noise reduction techniques and present estimations of the validity of the method. Finally we perform a rigorous comparison to the mechanism of radiation reaction, with the emitted energy very well in agreement with the radiation reaction loss.
All-optical time-resolved measurement of laser energy modulation in a relativistic electron beam
D. Xiang
2011-11-01
Full Text Available We propose and demonstrate an all-optical method to measure laser energy modulation in a relativistic electron beam. In this scheme the time-dependent energy modulation generated from the electron-laser interaction in an undulator is converted into time-dependent density modulation with a chicane, which is measured to infer the laser energy modulation. The method, in principle, is capable of simultaneously providing information on femtosecond time scale and 10^{-5} energy scale not accessible with conventional methods. We anticipate that this method may have wide applications in many laser-based advanced beam manipulation techniques.
A new relativistic hydrodynamics code for high-energy heavy-ion collisions
Okamoto, Kazuhisa; Akamatsu, Yukinao; Nonaka, Chiho
2016-10-01
We construct a new Godunov type relativistic hydrodynamics code in Milne coordinates, using a Riemann solver based on the two-shock approximation which is stable under the existence of large shock waves. We check the correctness of the numerical algorithm by comparing numerical calculations and analytical solutions in various problems, such as shock tubes, expansion of matter into the vacuum, the Landau-Khalatnikov solution, and propagation of fluctuations around Bjorken flow and Gubser flow. We investigate the energy and momentum conservation property of our code in a test problem of longitudinal hydrodynamic expansion with an initial condition for high-energy heavy-ion collisions. We also discuss numerical viscosity in the test problems of expansion of matter into the vacuum and conservation properties. Furthermore, we discuss how the numerical stability is affected by the source terms of relativistic numerical hydrodynamics in Milne coordinates.
A new relativistic hydrodynamics code for high-energy heavy-ion collisions
Okamoto, Kazuhisa [Nagoya University, Department of Physics, Nagoya (Japan); Akamatsu, Yukinao [Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya (Japan); Osaka University, Department of Physics, Toyonaka (Japan); Stony Brook University, Department of Physics and Astronomy, Stony Brook, NY (United States); Nonaka, Chiho [Nagoya University, Department of Physics, Nagoya (Japan); Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya (Japan); Duke University, Department of Physics, Durham, NC (United States)
2016-10-15
We construct a new Godunov type relativistic hydrodynamics code in Milne coordinates, using a Riemann solver based on the two-shock approximation which is stable under the existence of large shock waves. We check the correctness of the numerical algorithm by comparing numerical calculations and analytical solutions in various problems, such as shock tubes, expansion of matter into the vacuum, the Landau-Khalatnikov solution, and propagation of fluctuations around Bjorken flow and Gubser flow. We investigate the energy and momentum conservation property of our code in a test problem of longitudinal hydrodynamic expansion with an initial condition for high-energy heavy-ion collisions. We also discuss numerical viscosity in the test problems of expansion of matter into the vacuum and conservation properties. Furthermore, we discuss how the numerical stability is affected by the source terms of relativistic numerical hydrodynamics in Milne coordinates. (orig.)
A new relativistic hydrodynamics code for high-energy heavy-ion collisions
Okamoto, Kazuhisa; Nonaka, Chiho
2016-01-01
We construct a new Godunov type relativistic hydrodynamics code in Milne coordinates, using a Riemann solver based on the two-shock approximation which is stable under existence of large shock waves. We check the correctness of the numerical algorithm by comparing numerical calculations and analytical solutions in various problems, such as shock tubes, expansion of matter into the vacuum, Landau-Khalatnikov solution, propagation of fluctuations around Bjorken flow and Gubser flow. We investigate the energy and momentum conservation property of our code in a test problem of longitudinal hydrodynamic expansion with an initial condition for high-energy heavy-ion collisions.We also discuss numerical viscosity in the test problems of expansion of matter into the vacuum and conservation properties. Furthermore, we discuss how the numerical stability is affected by the source terms of relativistic numerical hydrodynamics in Milne coordinates.
Pion tensor force and nuclear binding energy in the relativistic Hartree-Fock formalism
Marcos, S.; López-Quelle, M.; Niembro, R.; Savushkin, L. N.
2014-03-01
The binding energies of several isotopic families are studied within the relativistic Hartree-Fock approximation with the pseudovector coupling for the πN vertex, to find out a suitable strength for the effective pion tensor force (EPTF). An approximation for determining separately the contributions of the central and tensor forces generated by pion is considered. The results for heavy nuclei indicate that a realistic strength for the EPTF is smaller than a half of that appearing in the OPEP. This conclusion also applies to the results for the single-particle energies. Besides, it has been found that there is a genuine relativistic contribution of the EPTF in nuclear matter which is small but significant.
Geometrical Unification of Gravitation and Dark Energy: The Universe as a Relativistic Particle
Hojman, Sergio A; Rubio, Carlos A
2014-01-01
The Lagrangian, the Hamilton--Jacobi equation and the Schr\\"{o}dinger, Dirac and Klein--Gordon equations for the Friedmann--Robertson--Walker--Quintessence (FRWQ) system are presented and solved exactly for different interesting scenarios. The classical Lagrangian reproduces the usual two (second order) dynamical equations for the radius of the Universe and for the scalar field as well as the (first order) constraint equation. The approach naturally unifies gravity and dark energy, which may be related to the tlaplon (scalar torsion potential). The Lagrangian and the equations of motion are those of a relativistic particle moving on a two dimensional spacetime where the conformal metric factor is related to the dark energy scalar field potential. This allows us to quantize the system, obtaining a Klein-Gordon equation when the Universe is considered as a spinless particle, and a Dirac equation when the Universe is thought as a relativistic spin particle.
Energy loss of fast quarks in nuclei
Moss, J M; Johnson, M B; Leitch, M J; McGaughey, P L; Kopeliovich, B Z; Potashnikova, I K; Peng, J C
2001-01-01
We report an analysis of the nuclear dependence of the yield of Drell-Yan (DY) dimuons from the 800 GeV/c proton bombardment of $^2H$, C, Ca, Fe, and W targets. A light-cone formulation of the DY process is employed in the rest frame of the nucleus. In this frame, for $x_2\\ll x_1$, DY production appears as bremsstrahlung of a virtual photon followed by decay into dileptons. We treat the two sources of nuclear suppression, energy loss and shadowing, in a consistent formulation. Shadowing, involving no free parameters, is calculated within the light-cone dipole formalism. Initial-state energy loss, the only unknown in the problem, is determined from a fit to the nuclear-dependence ratio versus $x_1$. With the assumption of constant energy loss per unit path length, we find $-dE/dz = 2.32 \\pm 0.52\\pm 0.5$ GeV/fm. This is the first observation of a nonzero energy loss of partons traveling in nuclear environment.
Yerokhin, V A; Fritzsche, S
2014-01-01
Relativistic configuration-interaction calculations have been performed for the energy levels of the low-lying and core-excited states of beryllium-like argon, Ar$^{14+}$. These calculations include the one-loop QED effects as obtained by two different methods, the screening-potential approach as well as the model QED operator approach. The calculations are supplemented by a systematic estimation of uncertainties of theoretical predictions.
Measurement of mean excitation energy by energy loss
LiuChang－Shi
1997-01-01
The mean excitation energy(MEE) for Al,Ti,Fe,Cu and Ta has been determined experimentally by the Landan equation,which describes the most probable energy loss of electrons in the incidence direction,and the results are consistent with the values given in the literature,THese provide a quick,easy and accurate evaluation method for the experimental MEE.
Evidence for acceleration of outer zone electrons to relativistic energies by whistler mode chorus
N. P. Meredith
Full Text Available We use plasma wave and electron data from the Combined Release and Radiation Effects Satellite (CRRES to investigate the viability of a local stochastic electron acceleration mechanism to relativistic energies driven by gyroresonant interactions with whistler mode chorus. In particular, we examine the temporal evolution of the spectral response of the electrons and the waves during the 9 October 1990 geomagnetic storm. The observed hardening of the electron energy spectra over about 3 days in the recovery phase is coincident with prolonged substorm activity, as monitored by the AE index and enhanced levels of whistler mode chorus waves. The observed spectral hardening is observed to take place over a range of energies appropriate to the resonant energies associated with Doppler-shifted cyclotron resonance, as supported by the construction of realistic resonance curves and resonant diffusion surfaces. Furthermore, we show that the observed spectral hardening is not consistent with energy-independent radial diffusion models. These results provide strong circumstantial evidence for a local stochastic acceleration mechanism, involving the energisation of a seed population of electrons with energies of the order of a few hundred keV to relativistic energies, driven by wave-particle interactions involving whistler mode chorus. The results suggest that this mechanism contributes to the reformation of the relativistic outer zone population during geomagnetic storms, and is most effective when the recovery phase is characterised by prolonged substorm activity. An additional significant result of this paper is that we demonstrate that the lower energy part of the storm-time electron distribution is in steady-state balance, in accordance with the Kennel and Petschek (1966 theory of limited stably-trapped particle fluxes.
Key words. Magnetospheric physics (storms and substorms, energetic particles, trapped – Space plasma physics (wave
Rocca, J.; Bargsten, C.; Hollinger, R.; Shylaptsev, V.; Wang, S.; Rockwood, A.; Wang, Y.; Keiss, D.; Capeluto, M.; Kaymak, V.; Pukhov, A.; Tommasini, R.; London, R.; Park, J.
2016-10-01
Ultra-high-energy-density (UHED) plasmas, characterized by energy densities >1 x 108 J cm-3 and pressures greater than a gigabar are encountered in the center of stars and in inertial confinement fusion capsules driven by the world's largest lasers. Similar conditions can be obtained with compact, ultra-high contrast, femtosecond lasers focused to relativistic intensities onto aligned nanowire array targets. Here we report the measurement of the key physical process in determining the energy density deposited in high aspect ratio nanowire array plasmas: the energy penetration. By monitoring the x-ray emission from buried Co tracer segments in Ni nanowire arrays irradiated at an intensity of 4 x 1019 W cm-2, we demonstrate energy penetration depths of several μm, leading to UHED plasmas of that size. Relativistic 3D particle-in-cell-simulations validated by these measurements predict that irradiation of nanostructures at increased intensity will lead to a virtually unexplored extreme UHED plasma regime characterized by energy densities in excess of 8 x 1010 J cm-3, equivalent to a pressure of 0.35 Tbar. This work was supported by the Fusion Energy Program, Office of Science of the U.S Department of Energy, and by the Defense Threat Reduction Agency.
Microgrids: Energy management by loss minimization technique
A. K. Basu, S. Chowdhury, S.P. Chowdhury
2011-03-01
Full Text Available Energy management is a techno-economic issue, which dictates, in the context of microgrids, how optimal investment in technology front could bring optimal power quality and reliability (PQR of supply to the consumers. Investment in distributed energy resources (DERs, with their connection to the utility grid at optimal locations and with optimal sizes, saves energy in the form of line loss reduction. Line loss reduction is the indirect benefit to the microgrid owner who may recover it as an incentive from utility. The present paper focuses on planning of optimal siting and sizing of DERs based on minimization of line loss. Optimal siting is done, here, on the loss sensitivity index (LSI method and optimal sizing by differential evolution (DE algorithms, which is, again, compared with particle swarm optimization (PSO technique. Studies are conducted on 6-bus and 14-bus radial networks under islanded mode of operation with electric demand profile. Islanding helps planning of DER capacity of microgrid, which is self-sufficient to cater its own consumers without utility’s support.
Zhou Dai Mei; Sá Ben-Hao; Li Zhong Dao
2002-01-01
Using a hadron and string cascade model, JPCIAE, and the corresponding Monte Carlo events generator, the energy and centrality dependences of charged particle pseudorapidity density in relativistic nuclear collisions were studied. Within the framework of this model, both the relativistic p anti p experimental data and the PHOBOS and PHENIX Au + Au data could be reproduced fairly well without retuning the model parameters. The author shows that since is not a well defined physical variable both experimentally and theoretically, the charged particle pseudorapidity density per participant pair can increase and also can decrease with increasing of , so it may be hard to use charged particle pseudorapidity density per participant pair as a function of to distinguish various theoretical models for particle production
Fiks, E.I., E-mail: elenafiks@gmail.com [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); Pivovarov, Yu.L. [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); Bogdanov, O.V. [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); INFN Laboratori Nazionali di Frascati, Frascati (RM) (Italy); Geissel, H.; Scheidenberger, C. [Helmholtzzentrum für Schwerionenforschung GSI, Darmstadt (Germany)
2013-08-15
The calculations of Cherenkov radiation (ChR) angular distributions from relativistic heavy ions (RHI) at very high energies (from 30 GeV/u up to 3000 GeV/u) taking into account their slowing-down (ionization energy loss) in a radiator are performed for the first time. The slowing-down of RHI in an optically transparent solid radiator can drastically change the ChR angular distributions at RHI energies of order of 1 GeV/u. The results of calculation show that at higher RHI energies (>30 GeV/u) (FAIR, SPS and LHC), the ChR angular distribution (at the reasonable radiator thickness) is very close to the Tamm–Frank distribution and practically does not depend on the RHI slowing-down in a radiator, if only ionization energy loss is taken into account.
Bargsten, Clayton [Colorado State Univ., Fort Collins, CO (United States); Hollinger, Reed [Colorado State Univ., Fort Collins, CO (United States); Capeluto, Maria Gabriela [Univ. of Buenos Aires (Argentina); Kaymak, Vural [Heinrich Heine Univ., Dusseldorf (Germany); Pukhov, Alexander [Heinrich Heine Univ., Dusseldorf (Germany); Wang, Shoujun [Colorado State Univ., Fort Collins, CO (United States); Rockwood, Alex [Colorado State Univ., Fort Collins, CO (United States); Wang, Yong [Colorado State Univ., Fort Collins, CO (United States); Keiss, David [Colorado State Univ., Fort Collins, CO (United States); Tommasini, Riccardo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); London, Richard [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Park, Jaebum [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Busquet, Michel [ARTEP Inc., Ellicott City, MD (United States); Klapisch, M [ARTEP Inc., Ellicott City, MD (United States); Shlyaptsev, Vyacheslav N. [Colorado State Univ., Fort Collins, CO (United States); Rocca, Jorge J. [Colorado State Univ., Fort Collins, CO (United States)
2016-11-11
Ultra-high-energy-density (UHED) matter, characterized by energy densities > 1 x 10^{8} J cm^{-3} and pressures greater than a gigabar, is encountered in the center of stars and in inertial confinement fusion capsules driven by the world’s largest lasers. Similar conditions can be obtained with compact, ultra-high contrast, femtosecond lasers focused to relativistic intensities onto targets composed of aligned nanowire arrays. Here we report the measurement of the key physical process in determining the energy density deposited in high aspect ratio nanowire array plasmas: the energy penetration. By monitoring the x-ray emission from buried Co tracer segments in Ni nanowire arrays irradiated at an intensity of 4 x 10^{19} W cm^{-2}, we demonstrate energy penetration depths of several μm, leading to UHED plasmas of that size. Relativistic 3D particle-in-cell-simulations, validated by these measurements, predict that irradiation of nanostructures at intensities of > 1 x 10^{22} W cm^{-2} will lead to a virtually unexplored extreme UHED plasma regime characterized by energy densities in excess of 8 x 10^{10} J cm^{-3}, equivalent to a pressure of 0.35 Tbar.
Bargsten, Clayton; Hollinger, Reed; Capeluto, Maria Gabriela; Kaymak, Vural; Pukhov, Alexander; Wang, Shoujun; Rockwood, Alex; Wang, Yong; Keiss, David; Tommasini, Riccardo; London, Richard; Park, Jaebum; Busquet, Michel; Klapisch, Marcel; Shlyaptsev, Vyacheslav N.; Rocca, Jorge J.
2017-01-01
Ultrahigh-energy density (UHED) matter, characterized by energy densities >1 × 108 J cm−3 and pressures greater than a gigabar, is encountered in the center of stars and inertial confinement fusion capsules driven by the world’s largest lasers. Similar conditions can be obtained with compact, ultrahigh contrast, femtosecond lasers focused to relativistic intensities onto targets composed of aligned nanowire arrays. We report the measurement of the key physical process in determining the energy density deposited in high-aspect-ratio nanowire array plasmas: the energy penetration. By monitoring the x-ray emission from buried Co tracer segments in Ni nanowire arrays irradiated at an intensity of 4 × 1019 W cm−2, we demonstrate energy penetration depths of several micrometers, leading to UHED plasmas of that size. Relativistic three-dimensional particle-in-cell simulations, validated by these measurements, predict that irradiation of nanostructures at intensities of >1 × 1022 W cm−2 will lead to a virtually unexplored extreme UHED plasma regime characterized by energy densities in excess of 8 × 1010 J cm−3, equivalent to a pressure of 0.35 Tbar. PMID:28097218
Bargsten, Clayton; Hollinger, Reed; Capeluto, Maria Gabriela; Kaymak, Vural; Pukhov, Alexander; Wang, Shoujun; Rockwood, Alex; Wang, Yong; Keiss, David; Tommasini, Riccardo; London, Richard; Park, Jaebum; Busquet, Michel; Klapisch, Marcel; Shlyaptsev, Vyacheslav N; Rocca, Jorge J
2017-01-01
Ultrahigh-energy density (UHED) matter, characterized by energy densities >1 × 10(8) J cm(-3) and pressures greater than a gigabar, is encountered in the center of stars and inertial confinement fusion capsules driven by the world's largest lasers. Similar conditions can be obtained with compact, ultrahigh contrast, femtosecond lasers focused to relativistic intensities onto targets composed of aligned nanowire arrays. We report the measurement of the key physical process in determining the energy density deposited in high-aspect-ratio nanowire array plasmas: the energy penetration. By monitoring the x-ray emission from buried Co tracer segments in Ni nanowire arrays irradiated at an intensity of 4 × 10(19) W cm(-2), we demonstrate energy penetration depths of several micrometers, leading to UHED plasmas of that size. Relativistic three-dimensional particle-in-cell simulations, validated by these measurements, predict that irradiation of nanostructures at intensities of >1 × 10(22) W cm(-2) will lead to a virtually unexplored extreme UHED plasma regime characterized by energy densities in excess of 8 × 10(10) J cm(-3), equivalent to a pressure of 0.35 Tbar.
Energy loss rate in disordered quantum well
Tripathi, P.; Ashraf, S. S. Z. [Centre of Excellence in Nanomaterials, Faculty of Engineering and Technology, Aligarh Muslim University, Aligarh-202002 (India); Hasan, S. T. [Physics Department, Faculty of Science, The M.S. University of Baroda, Vadodara-390002 (India); Sharma, A. C. [Physics Department, Sibli National College, Azamgarh-276128 (India)
2014-04-24
We report the effect of dynamically screened deformation potential on the electron energy loss rate in disordered semiconductor quantum well. Interaction of confined electrons with bulk acoustic phonons has been considered in the deformation coupling. The study concludes that the dynamically screened deformation potential coupling plays a significant role as it substantially affects the power dependency of electron relaxation on temperature and mean free path.
Werner, G R; Cerutti, B; Nalewajko, K; Begelman, M C
2014-01-01
Using two-dimensional particle-in-cell simulations, we characterize the energy spectra of particles accelerated by relativistic magnetic reconnection (without guide field) in collisionless electron-positron plasmas, for a wide range of upstream magnetizations $\\sigma$ and system sizes $L$. The particle spectra are well-represented by a power law $\\gamma^{-\\alpha}$, with a combination of exponential and super-exponential high-energy cutoffs, proportional to $\\sigma$ and $L$, respectively. For large $L$ and $\\sigma$, the power-law index $\\alpha$ approaches about 1.2.
Jet suppression and the flavor dependence of partonic energy loss with ATLAS
AUTHOR|(INSPIRE)INSPIRE-00364770; The ATLAS collaboration
2016-01-01
In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced. One manifestation of the energy loss of jets propagating through the medium is a lower yield of jets and hadrons emerging from this medium than expected in the absence of medium effects. Therefore modifications of the jet yield are directly sensitive to the energy loss mechanism. Furthermore, jets with different flavor content are expected to be affected by the medium in different ways. In this publication, the latest ATLAS results on single hadron suppression along with the complementary measurements of single jet suppression are presented. Rapidity dependence, which is sensitive to the relative energy loss between quark and gluon jets, is discussed. Finally, a new measurement of jet fragmentation functions is presented.
Jet suppression and the flavor dependence of partonic energy loss with ATLAS
Kosek, Tomas
2016-12-01
In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced. One manifestation of the energy loss of jets propagating through the medium is a lower yield of jets and hadrons emerging from this medium than expected in the absence of medium effects. Therefore modifications of the jet yield are directly sensitive to the energy loss mechanism. Furthermore, jets with different flavor content are expected to be affected by the medium in different ways. In this publication, the latest ATLAS results on single hadron suppression along with the complementary measurements of single jet suppression are presented. Rapidity dependence, which is sensitive to the relative energy loss between quark and gluon jets, is discussed. Finally, a new measurement of jet fragmentation functions is presented.
ENERGY-LOSS FUNCTIONS DERIVED FROM REELS SPECTRA FOR ALUMINUM
Z.M. Zhang; Z.J. Ding; H.M. Li; K. Salma; X. Sun; R. Shimizu; T. Koshikawa; K. Goto
2005-01-01
The effective energy loss functions for Al have been derived from differential inverse inelastic mean free path based on the extended Landau approach. It has been revealed that the effective energy loss function is very close in value to the theoretical surface energy loss function in the lower energy loss region but gradually approaches the theoretical bulk energy loss function in the higher energy loss region. Moreover, the intensity corresponding to surface excitation in effective energy loss functions decreases with the increase of primary electron energy. These facts show that the present effective energy loss function describes not only surface excitation but also bulk excitation. At last, REELS spectra simulated by Monte Carlo method based on use of the effective energy loss functions has reproduced the experimental REELS spectra with considerable success.
Li, Ming; Kapusta, Joseph I.
2017-01-01
In very high-energy collisions nuclei are practically transparent to each other but produce very hot nearly baryon-free matter in the so-called central rapidity region. The energy in the central rapidity region comes from the kinetic energy of the colliding nuclei. We calculate the energy and rapidity loss of the nuclei using the color glass condensate model. This model also predicts the excitation energy of the nuclear fragments. Using a space-time picture of the collision we calculate the baryon and energy densities of the receding baryonic fireballs. For central collisions of gold nuclei at the highest energy attainable at the Relativistic Heavy-Ion Collider, for example, we find baryon densities more than ten times that of atomic nuclei over a large volume.
Li, Ming
2016-01-01
In very high energy collisions nuclei are practically tranparent to each other but produce very hot, nearly baryon-free, matter in the so-called central rapidity region. The energy in the central rapidity region comes from the kinetic energy of the colliding nuclei. We calculate the energy and rapidity loss of the nuclei using the color glass condensate model. This model also predicts the excitation energy of the nuclear fragments. Using a space-time picture of the collision we calculate the baryon and energy densities of the receding baryonic fireballs. For central collisions of gold nuclei at the highest energy attainable at the Relativistic Heavy Ion Collider, for example, we find baryon densities more than ten times that of atomic nuclei over a large volume.
Use of relativistic rise in ionization chambers for measurement of high energy heavy nuclei
Barthelmy, S. D.; Israel, M. H.; Klarmann, J.; Vogel, J. S.
1983-01-01
A balloon-borne instrument has been constructed to measure the energy spectra of cosmic-ray heavy nuclei in the range of about 0.3 to about 100 GeV/amu. It makes use of the relativistic rise portion of the Bethe-Bloch curve in ionization chambers for energy determination in the 10- to 100-GeV/amu interval. The instrument consists of six layers of dual-gap ionization chambers for energy determination above 10 GeV/amu. Charge is determined with a NE114 scintillator and a Pilot 425 plastic Cerenkov counter. A CO2 gas Cerenkov detector (1 atm; threshold of 30 GeV/amu) calibrates the ion chambers in the relativistic rise region. The main emphasis of the instrument is the determination of the change of the ratio of Iron (26) to the Iron secondaries (21-25) in the energy range of 10 to 100 GeV/amu. Preliminary data from a balloon flight in the fall of 1982 from Palestine, TX is presented.
Hidalgo-Gato, Rafael A Valls
2012-01-01
From a rigorous historic analysis of 1686 I. Newton and 1905 A. Einstein works where the last derived the universal mass-energy relationship, it is concluded that rest mass measures potential energy. From the same formula used to obtain that relation, it is derived the ratio Total Energy/Potential Energy is equal to the gamma relativistic factor. It is derived a formula for the variation of a body rest mass with its position in a gravity field, explaining with it the behavior of an atomic clock. It is revised the bodies free fall in a gravitational field, finding that a constant total mass is equal to the gravitational mass, while the variable rest mass is equal to the inertial mass, maintaining all an identical behavior independent of their masses. A revision of the E\\"otv\\"os experiment concludes that it is unable to detect the found difference between inertial and gravitational mass. Applying the extended 1905 relativistic dynamics to Mercury, its perihelion shift is determined; it is concluded with the co...
On the maximum energy of shock-accelerated cosmic rays at ultra-relativistic shocks
Reville, B
2014-01-01
The maximum energy to which cosmic rays can be accelerated at weakly-magnetised ultra-relativistic shocks is investigated. We demonstrate that for such shocks, in which the scattering of energetic particles is mediated exclusively by ion skin-depth scale structures, as might be expected for a Weibel-mediated shock, there is an intrinsic limit on the maximum energy to which particles can be accelerated. This maximum energy is determined from the requirement that particles must be isotropised in the downstream plasma frame before the mean field transports them far downstream, and falls considerably short of what is required to produce ultra-high energy cosmic rays. To circumvent this limit, a highly disorganised field is required on larger scales. The growth of cosmic-ray induced instabilities on wavelengths much longer than the ion-plasma skin depth, both upstream and downstream of the shock, is considered. While these instabilities may play an important role in magnetic field amplification at relativistic sho...
Energy loss distributions of 7 TeV protons channeled in a bent silicon crystals
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
Boundedness of the total energy of relativistic membranes evolving in a curved spacetime
LeFloch, Philippe G
2016-01-01
We establish a global existence theory for the equation governing the evolution of a relativistic membrane in a (possibly curved) Lorentzian manifold, when the spacetime metric is a perturbation of the Minkowski metric. Relying on the Hyperboloidal Foliation Method introduced by LeFloch and Ma in 2014, we revisit a theorem established earlier by Lindblad (who treated membranes in the flat Minkowski spacetime) and we provide a simpler proof of existence, which is also valid in a curved spacetime and, most importantly, leads to the important property that the total energy of the membrane is globally bounded in time.
High efficiency energy extraction from a relativistic electron beam in a strongly tapered undulator
Sudar, Nicholas; Duris, Joe; Gadjev, Ivan; Polyaniy, Mikhail; Pogorelsky, Igor; Fedurin, Mikhail; Swinson, Christina; Babzien, Marcus; Kusche, Karl; Gover, Avi
2016-01-01
We present results of an experiment where, using a 200 GW CO2 laser seed, a 65 MeV electron beam was decelerated down to 35 MeV in a 54 cm long strongly tapered helical magnetic undulator, extracting over 30$\\%$ of the initial electron beam energy to coherent radiation. These results demonstrate unparalleled electro-optical conversion efficiencies for a relativistic beam in an undulator field and represent an important step in the development of high peak and average power coherent radiation sources.
High Efficiency Energy Extraction from a Relativistic Electron Beam in a Strongly Tapered Undulator
Sudar, N.; Musumeci, P.; Duris, J.; Gadjev, I.; Polyanskiy, M.; Pogorelsky, I.; Fedurin, M.; Swinson, C.; Kusche, K.; Babzien, M.; Gover, A.
2016-10-01
We present results of an experiment where, using a 200 GW CO2 laser seed, a 65 MeV electron beam was decelerated down to 35 MeV in a 54-cm-long strongly tapered helical magnetic undulator, extracting over 30% of the initial electron beam energy to coherent radiation. These results, supported by simulations of the radiation field evolution, demonstrate unparalleled electro-optical conversion efficiencies for a relativistic beam in an undulator field and represent an important step in the development of high peak and average power coherent radiation sources.
Khandelwal, Govind S.; Khan, Ferdous
1989-01-01
An optical model description of energy and momentum transfer in relativistic heavy-ion collisions, based upon composite particle multiple scattering theory, is presented. Transverse and longitudinal momentum transfers to the projectile are shown to arise from the real and absorptive part of the optical potential, respectively. Comparisons of fragment momentum distribution observables with experiments are made and trends outlined based on our knowledge of the underlying nucleon-nucleon interaction. Corrections to the above calculations are discussed. Finally, use of the model as a tool for estimating collision impact parameters is indicated.
Schiller, Q.; Tu, W.; Ali, A. F.; Li, X.; Godinez, H. C.; Turner, D. L.; Morley, S. K.; Henderson, M. G.
2017-03-01
The most significant unknown regarding relativistic electrons in Earth's outer Van Allen radiation belt is the relative contribution of loss, transport, and acceleration processes within the inner magnetosphere. Detangling each individual process is critical to improve the understanding of radiation belt dynamics, but determining a single component is challenging due to sparse measurements in diverse spatial and temporal regimes. However, there are currently an unprecedented number of spacecraft taking measurements that sample different regions of the inner magnetosphere. With the increasing number of varied observational platforms, system dynamics can begin to be unraveled. In this work, we employ in situ measurements during the 13-14 January 2013 enhancement event to isolate transport, loss, and source dynamics in a one-dimensional radial diffusion model. We then validate the results by comparing them to Van Allen Probes and Time History of Events and Macroscale Interactions during Substorms observations, indicating that the three terms have been accurately and individually quantified for the event. Finally, a direct comparison is performed between the model containing event-specific terms and various models containing terms parameterized by geomagnetic index. Models using a simple 3/Kp loss time scale show deviation from the event-specific model of nearly 2 orders of magnitude within 72 h of the enhancement event. However, models using alternative loss time scales closely resemble the event-specific model.
Liu, Ruoyu
2015-06-10
Ultrahigh energy cosmic rays are extreme energetic particles from outer space. They have aroused great interest among scientists for more than fifty years. However, due to the rarity of the events and complexity of the process of their propagation to Earth, they are still one of the biggest puzzles in modern high energy astrophysics. This dissertation is dedicated to study the origin of ultrahigh energy cosmic rays from various aspects. Firstly, we discuss a possible link between recently discovered sub-PeV/PeV neutrinos and ultrahigh energy cosmic rays. If these two kinds of particles share the same origin, the observation of neutrinos may provide additional and non-trivial constraints on the sources of ultrahigh energy cosmic rays. Secondly, we jointly employ the chemical composition measurement and the arrival directions of ultrahigh energy cosmic rays, and find a robust upper limit for distances of sources of ultrahigh energy cosmic rays above ∝55 EeV, as well as a lower limit for their metallicities. Finally, we study the shear acceleration mechanism in relativistic jets, which is a more efficient mechanism for the acceleration of higher energy particle. We compute the acceleration efficiency and the time-dependent particle energy spectrum, and explore the feature of synchrotron radiation of the accelerated particles. The possible realizations of this mechanism for acceleration of ultrahigh energy cosmic rays in different astrophysical environments is also discussed.
Energy losses in mechanically modified bacterial magnetosomes
Molcan, Matus; Gojzewski, Hubert; Skumiel, Andrzej; Dutz, Silvio; Kovac, Jozef; Kubovcikova, Martina; Kopcansky, Peter; Vekas, Ladislau; Timko, Milan
2016-09-01
Magnetosomes are isolated from the Magnetospirillum magneticum strain AMB-1 bacteria. Two samples are compared: magnetosomes normally prepared of a ‘standard’ length and magnetosomes of a short length. Chains of magnetosomes are shortened by mechanical modification (cleavage) by means of sonication treatment. They represent a new geometry of magnetosomes that have not been investigated before. The effect of the sonication is analysed using transmission and electron microscopy, atomic force microscopy, and dynamic light scattering. Scanning imaging reveals three types of shortening effect in a sample of shortened magnetosomes, namely, membrane collapse, membrane destruction, and magnetosome cleavage. Dynamic light scattering shows a reduction of hydrodynamic diameter in a sample of shortened magnetosomes. The magnetic properties of magnetosomes are analysed and compared in DC and AC magnetic fields based on the evaluation of quasi-static hysteresis loops (energy losses) and calorimetric hyperthermia measurements (specific absorption rate), respectively. A sample of shortened magnetosomes behaves magnetically in a different manner, showing that both the energy loss and the specific absorption rate are reduced, and thereby indicates a variation in the heating process. The magnetic properties of magnetosomes, together with the new and stable geometry, are balanced, which opens the way for a better adaptation of the magnetic field parameters for particular applications.
New approach to energy loss measurements
Trzaska, W H; Alanko, T; Mutterer, M; Raeisaenen, J; Tjurin, G; Wojdyr, M
2002-01-01
A new approach to energy loss measurements is proposed. In the same experiment electronic stopping force (power) in gold, nickel, carbon, polycarbonate and Havar for sup 4 sup 0 Ar, sup 2 sup 8 Si, sup 1 sup 6 O, sup 4 He and sup 1 H ions in the energy range 0.12-11 MeV/u has been measured. In this paper we give the full results for gold, nickel, and carbon and for sup 4 sup 0 Ar, sup 1 sup 6 O, sup 4 He and sup 1 H ions. Good agreement of the measured stopping force values for light ions with literature data is interpreted as the positive test of the experimental technique. The same technique used with heavy ions yields agreement with the published data only for energies above 1 MeV/u. At lower energies we observe progressively increasing discrepancy. This discrepancy is removed completely as soon as we neglect pulse height defect compensation. This observation makes us believe that the majority of the published results as well as semi-empirical calculations based on them (like the popular SRIM) may be in er...
John R. Fanchi
2017-07-01
Full Text Available Jüttner used the conventional theory of relativistic statistical mechanics to calculate the energy of a relativistic ideal gas in 1911. An alternative derivation of the energy of a relativistic ideal gas was published by Horwitz, Schieve and Piron in 1981 within the context of parametrized relativistic statistical mechanics. The resulting energy in the ultrarelativistic regime differs from Jüttner’s result. We review the derivations of energy and identify physical regimes for testing the validity of the two theories in accelerator physics and cosmology.
A. Chandrasekhar Reddy; Jatin Rathod; Girija Rajaram; Radharani Alyana; D. S. Misra; C. G. Patil; M. Y. S. Prasad; A. G. Ananth
2008-03-01
In view of the renewed interest in the study of energetic particles in the outer radiation belt of the earth, we feel it will be helpful in looking for the energy dependence of the electron energy spectrum at geostationary orbit. This may give us some insight into how we can safeguard geostationary satellites from functional anomalies of the deep dielectric charging type, which are caused by charge accumulation and subsequent discharge of relativistic electrons. In this study we examine whether there is any energy dependence in relativistic electron enhancements at geosynchronous altitudes during solar energetic proton events of 2005.
On the Casimir energy for a 2N-piece relativistic string
Brevik, I
1997-01-01
The Casimir energy for the transverse oscillations of a piecewise uniform closed string is calculated. The string consists of 2N pieces of equal length, of alternating type I and type II material, and is taken to be relativistic in the sense that the velocity of sound always equals the velocity of light. By means of a new recursion formula we manage to calculate the Casimir energy for arbitrary integers N. Agreement with results obtained in earlier works on the string is found in all special cases. As basic regularization method we use the contour integration method. As a check, agreement is found with results obtained from the \\zeta function method (the Hurwitz function) in the case of low N (N = 1-4). The Casimir energy is generally negative, and the more so the larger is the value of N. We illustrate the results graphically in some cases. The generalization to finite temperature theory is also given.
Laser-driven micro-Coulomb charge movement and energy conversion to relativistic electrons
Cobble, J. A.; Palaniyappan, S.; Johnson, R. P.; Shimada, T.; Huang, C.; Gautier, D. C.; Clark, D. D.; Falk, K.; Jung, D.
2016-09-01
Development of robust instrumentation has shown evidence for a multi-μC expulsion of relativistic electrons from a sub-μm-thick foil, laser illuminated with 60-70 J on target at 2 × 1020 W/cm2. From previous work and with electron spectroscopy, it is seen that an exponential electron energy distribution is accurate enough to calculate the emitted electron charge and energy content. The 5-10-μC charge for the >100-TW Trident Laser represents the first active measurement of the >50% laser-light-to-electron conversion efficiency. By shorting out the TV/m electric field usually associated with accelerating multi-MeV ions from such targets, one finds that this charge is representative of a multi-MA current of relativistic electrons for diverse applications from electron fast ignition to advanced radiography concepts. Included with the details of the discoveries of this research, shortcomings of the diagnostics and means of improving their fidelity are discussed.
High-energy emission from non-relativistic radiative shocks: application to gamma-ray novae
Vurm, Indrek
2016-01-01
Multiwavelength radiation from relativistic particles accelerated at shocks in novae and other astrophysical sources carries a wealth of information about the outflow properties and the microphysical processes at work near the shocks. The observation of GeV gamma-rays from novae by Fermi/LAT demonstrates that the shocks in these systems can accelerate particles to energies of at least $\\sim 10$ GeV. The low-energy extension of the same non-thermal particle distribution inevitably gives rise to emission extending into the X-ray band. Above $\\gtrsim 10$ keV this radiation can escape the system without significant absorption/attenuation, and can potentially be detected by NuSTAR. We present theoretical models for hard X-ray and gamma-ray emission from radiative shocks in both leptonic and hadronic scenarios, accounting for the rapid evolution of the downstream properties due to the fast cooling of thermal plasma. Due to strong Coulomb cooling of the mildly relativistic electrons nominally responsible for produci...
De Soto, F
2006-01-01
The numerical solutions of the non-relativistic Yukawa model on a 3-dimensional size lattice with periodic boundary conditions are obtained. The possibility to extract the corresponding -- infinite space -- low energy parameters and bound state binding energies from eigensates computed at finite lattice size is discussed.
Parton energy loss in hot and dense QCD medium
LIU Jie; MAO Yaxian; XIANG Wenchang; ZHOU Daicui
2006-01-01
Induced gluon radiation and energy loss of heavy quark in hot and dense QCD media are discussed. Using the light-cone path integral approach, an analytical formula of the energy loss of heavy quark is derived. The results show that the quark energy loss obviously depends on the mass of quark, i. e. a remarkable suppression occurs in the case of heavy quark comparing to a light one. The radiative energy loss of energetic quark is proportional to L2, where L is the length of the medium. The dependence of energy loss on L2 turns to L with decreasing quark energy.
Calculation of Energy Spectrum of 12C Isotope by Relativistic Cluster model
Roshanbakht, Nafiseh
2016-01-01
In this paper, we have calculated the energy spectrum of 12C isotope by cluster model. The experimental results show that the "Hoyle" state at 7.65 MeV in 12C isotope has a well-developed three-alpha structure. Hence, we select a three-body system and for interaction between the clusters we use modified Yukawa potential plus coulomb potential. Then, we solve the relativistic Klein-Gordon equation using Nikiforov-Uvarov method to calculate the energy spectrum. Finally, the calculated results are compared with the experimental data. The results show that the isotope 12C should be considered as consisting of three-alpha cluster and the modified Yukawa potential is adaptable for cluster interactions.
Ultra high energy cosmic rays from non-relativistic quasar outflows
Wang, Xiawei
2016-01-01
It has been suggested that non-relativistic outflows from quasars can naturally account for the missing component of the extragalactic $\\gamma$-ray background and explain the cumulative neutrino background through pion decay in collisions between protons accelerated by the outflow shock and interstellar protons. Here we show that the same quasar outflows are capable of accelerating protons to energies of $\\sim 10^{20}$ eV during the early phase of their propagation. The overall quasar population is expected to produce a cumulative ultra high energy cosmic ray flux of $\\sim10^{-7}\\,\\rm GeV\\,cm^{-2}s^{-1}sr^{-1}$ at $E_{\\rm CR}\\gtrsim10^{18}$ eV. The spectral shape and amplitude is consistent with recent observations for outflow parameters constrained to fit secondary $\\gamma$-rays and neutrinos without any additional parameter tuning. This indicates that quasar outflows simultaneously account for all three messengers at their observed levels.
S. W. H. Cowley
2006-03-01
Full Text Available Recent spectroscopic observations of Jupiter's "main oval" auroras indicate that the primary auroral electron beam is routinely accelerated to energies of ~100 keV, and sometimes to several hundred keV, thus approaching the relativistic regime. This suggests the need to re-examine the classic non-relativistic theory of auroral electron acceleration by field-aligned electric fields first derived by Knight (1973, and to extend it to cover relativistic situations. In this paper we examine this problem for the case in which the source population is an isotropic Maxwellian, as also assumed by Knight, and derive exact analytic expressions for the field-aligned current density (number flux and kinetic energy flux of the accelerated population, for arbitrary initial electron temperature, acceleration potential, and field strength beneath the acceleration region. We examine the limiting behaviours of these expressions, their regimes of validity, and their implications for auroral acceleration in planetary magnetospheres (and like astrophysical systems. In particular, we show that for relativistic accelerating potentials, the current density increases as the square of the minimum potential, rather than linearly as in the non-relativistic regime, while the kinetic energy flux then increases as the cube of the potential, rather than as the square.
Low-energy effective field theory for finite-temperature relativistic superfluids
Nicolis, Alberto
2011-01-01
We derive the low-energy effective action governing the infrared dynamics of relativistic superfluids at finite temperature. We organize our derivation in an effective field theory fashion-purely in terms of infrared degrees of freedom and symmetries. Our degrees of freedom are the superfluid phase \\psi, and the comoving coordinates for the volume elements of the normal fluid component. The presence of two sound modes follows straightforwardly from Taylor-expanding the action at second order in small perturbations. We match our description to more conventional hydrodynamical ones, thus linking the functional form of our Lagrangian to the equation of state, which we assume as an input. We re-derive in our language some standard properties of relativistic superfluids in the high-temperature and low-temperature limits. As an illustration of the efficiency of our methods, we compute the cross-section for a sound wave (of either type) scattering off a superfluid vortex at temperatures right beneath the critical on...
Cheung, C.C.Teddy; Stawarz, L.; Harris, D.E.; Ostrowski, M.
2007-10-15
We report new detections of the hotspots in Cygnus A at 4.5 and 8.0 microns with the Spitzer Space Telescope. Together with detailed published radio observations and synchrotron self-Compton modeling of previous X-ray detections, we reconstruct the underlying electron energy spectra of the two brightest hotspots (A and D). The low-energy portion of the electron distributions have flat power-law slopes (s {approx} 1.5) up to the break energy which corresponds almost exactly to the mass ratio between protons and electrons; we argue that these features are most likely intrinsic rather than due to absorption effects. Beyond the break, the electron spectra continue to higher energies with very steep slopes s>3. Thus, there is no evidence for the 'canonical' s=2 slope expected in 1st order Fermi-type shocks within the whole observable electron energy range. We discuss the significance of these observations and the insight offered into high-energy particle acceleration processes in mildly relativistic shocks.
Ndome, Hameth; Eisfeld, Wolfgang
2012-08-01
A new method has been reported recently [H. Ndome, R. Welsch, and W. Eisfeld, J. Chem. Phys. 136, 034103 (2012)], 10.1063/1.3675846 that allows the efficient generation of fully coupled potential energy surfaces (PESs) including derivative and spin-orbit (SO) coupling. The method is based on the diabatic asymptotic representation of the molecular fine structure states and an effective relativistic coupling operator and therefore is called effective relativistic coupling by asymptotic representation (ERCAR). The resulting diabatic spin-orbit coupling matrix is constant and the geometry dependence of the coupling between the eigenstates is accounted for by the diabatization. This approach allows to generate an analytical model for the fully coupled PESs without performing any ab initio SO calculations (except perhaps for the atoms) and thus is very efficient. In the present work, we study the performance of this new method for the example of hydrogen iodide as a well-established test case. Details of the diabatization and the accuracy of the results are investigated in comparison to reference ab initio calculations. The energies of the adiabatic fine structure states are reproduced in excellent agreement with reference ab initio data. It is shown that the accuracy of the ERCAR approach mainly depends on the quality of the underlying ab initio data. This is also the case for dissociation and vibrational level energies, which are influenced by the SO coupling. A method is presented how one-electron operators and the corresponding properties can be evaluated in the framework of the ERCAR approach. This allows the computation of dipole and transition moments of the fine structure states in good agreement with ab initio data. The new method is shown to be very promising for the construction of fully coupled PESs for more complex polyatomic systems to be used in quantum dynamics studies.
Loveland, W.D.
1991-08-01
The work described herein is part of a project involving the study of low energy (< 10 MeV/A), intermediate energy (10--100 MeV/A) and relativistic (> 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of ``best`` semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon {sup 129}Xe with {sup 197}Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon {sup 12}C with {sup 197}Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated.
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.
Partonic Energy Loss and the Drell-Yan Process
2002-01-01
We examine the current status of the extraction of the rate of partonic energy loss in nuclei from A dependent data. The advantages and difficulties of using the Drell-Yan process to measure the energy loss of a parton traversing a cold nuclear medium are discussed. The prospects of using relatively low energy proton beams for a definitive measurement of partonic energy loss are presented.
Zhong, Yang; Yang, Chun-Bin; Cai, Xu; Feng, Sheng-Qin
2016-08-01
It has been proposed that electric fields may lead to chiral separation in quark-gluon plasma (QGP). This is called the chiral electric separation effect. The strong electromagnetic field and the QCD vacuum can both be completely produced in off-central nuclear-nuclear collision. We use the Woods-Saxon nucleon distribution to calculate the electric field distributions of off-central collisions. The chiral electric field spatial distribution at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) energy regions are systematically studied in this paper. The dependence of the electric field produced by the thermal quark in the central position with different impact parameters on the proper time with different collision energies in the RHIC and LHC energy regions are studied in this paper. Supported by National Natural Science Foundation of China (11375069, 11435054, 11075061, 11221504) and Key Laboratory Foundation of Quark and Lepton Physics (Hua-Zhong Normal University)(QLPL2014P01)
Zabalza, Víctor
2015-01-01
The ultimate goal of the observation of nonthermal emission from astrophysical sources is to understand the underlying particle acceleration and evolution processes, and few tools are publicly available to infer the particle distribution properties from the observed photon spectra from X-ray to VHE gamma rays. Here I present naima, an open source Python package that provides models for nonthermal radiative emission from homogeneous distribution of relativistic electrons and protons. Contributions from synchrotron, inverse Compton, nonthermal bremsstrahlung, and neutral-pion decay can be computed for a series of functional shapes of the particle energy distributions, with the possibility of using user-defined particle distribution functions. In addition, naima provides a set of functions that allow to use these models to fit observed nonthermal spectra through an MCMC procedure, obtaining probability distribution functions for the particle distribution parameters. Here I present the models and methods availabl...
Nemchik, J.; Petráček, V.; Potashnikova, I. K.; Šumbera, M.
2008-08-01
We study a strong suppression of the relative production rate (d-Au)/(p-p) for inclusive high-pT hadrons of different species at large forward rapidities (large Feynman xF). The model predictions calculated in the light-cone dipole approach are in a good agreement with the recent measurements by the BRAHMS and STAR Collaborations at the BNL Relativistic Heavy Ion Collider. We predict a similar suppression at large pT and large xF also at lower energies, where no effect of coherence is possible. This allows us to exclude the saturation models or the models based on Color Glass Condensate from interpretation of nuclear effects.
Pareja, M J
2004-01-01
For general relativistic equilibrium stellar models (stationary axisymmetric asymptotically flat and convection-free) with differential rotation, it is shown that for a wide class of rotation laws the distribution of angular velocity of the fluid has a sign, say "positive", and then both the dragging rate and the angular momentum density are positive. In addition, the "mean value" (with respect to an intrinsic density) of the dragging rate is shown to be less than the mean value of the fluid angular velocity (in full general, without having to restrict the rotation law, nor the uniformity in sign of the fluid angular velocity); this inequality yields the positivity and an upper bound of the total rotational energy.
Pareja, M J
2003-01-01
For relativistic stars rotating slowly and differentially with a positive angular velocity, some properties in relation to the positiveness of the rate of rotational dragging and of the angular momentum density are derived. Also, a new proof for the bounds on the rotational mass-energy is given.
Toyota, Koudai; Son, Sang-Kil; Santra, Robin
2017-04-01
In this paper, we theoretically study x-ray multiphoton ionization dynamics of heavy atoms taking into account relativistic and resonance effects. When an atom is exposed to an intense x-ray pulse generated by an x-ray free-electron laser (XFEL), it is ionized to a highly charged ion via a sequence of single-photon ionization and accompanying relaxation processes, and its final charge state is limited by the last ionic state that can be ionized by a single-photon ionization. If x-ray multiphoton ionization involves deep inner-shell electrons in heavy atoms, energy shifts by relativistic effects play an important role in ionization dynamics, as pointed out in Phys. Rev. Lett. 110, 173005 (2013), 10.1103/PhysRevLett.110.173005. On the other hand, if the x-ray beam has a broad energy bandwidth, the high-intensity x-ray pulse can drive resonant photoexcitations for a broad range of ionic states and ionize even beyond the direct one-photon ionization limit, as first proposed in Nat. Photon. 6, 858 (2012), 10.1038/nphoton.2012.261. To investigate both relativistic and resonance effects, we extend the xatom toolkit to incorporate relativistic energy corrections and resonant excitations in x-ray multiphoton ionization dynamics calculations. Charge-state distributions are calculated for Xe atoms interacting with intense XFEL pulses at a photon energy of 1.5 keV and 5.5 keV, respectively. For both photon energies, we demonstrate that the role of resonant excitations in ionization dynamics is altered due to significant shifts of orbital energy levels by relativistic effects. Therefore, it is necessary to take into account both effects to accurately simulate multiphoton multiple ionization dynamics at high x-ray intensity.
Energy deposition of quasi-two temperature relativistic electrons in fast-shock ignition scenario
Ghasemi, Seyed Abolfazl; Farahbod, Amir Hossein
2016-10-01
Previous calculations from Solodov et al. (2008) indicate that classical stopping and scattering dominate electrons energy deposition and transport when the electrons reach the dense plasma in FSI inertial confinement fusion concept [1]. Our calculations show that, by using quasi- two temperature electrons energy distribution function [2] in comparison with exponential [3] or monoenergetic distribution function and also increasing fast electrons energy to about 7 MeV, the ratio of beam blooming to straggling definitely decreases. Our analytical analysis shows that for fuel mass more than 1 mg and for fast ignitor wavelength λif > 0.53 μ m, straggling and beam blooming increases. Meanwhile, by reducing fast ignitor wavelength from 0.53 to 0.35 micron, and for fuel mass about 2 mg, electron penetration into the dense fuel slightly increases. Therefore, reduction of scattering (blooming and straggling) of electrons and enhancement of electron penetration into the dense fuel, can be obtained in relativistic regime with high energy fast electrons of the order of 5 Mev and more. Such derivations can be used in theoretical studies of the ignition conditions and PIC simulations of the electron transport in fast ignition scenario.
The Work and the Energy in Special Theory of Relativistic Dynamics%相对论中的功和能
籍延坤; 郭红
2001-01-01
以经典力学某些量为线索,根据经典动力学的基本方程,采用物理上常用的类比的方法建立了狭义相对论动力学的基本方程,由该基本方程对空间的累积效应,可以引入相对论动力学中质点和质点系的质量、运动质量、动量、动能、静能、机械能、相对论能量和力以及力的功的基本概念。得到了相对论动力学中的功和能关系式即质点和质点系的动能定理、质点系的功能原理、机械能守恒定律与能量守恒定律以及能量准守恒定律。%Some quantities in classical mechanics being taken as clue, a fundamental equation of special theory of relativistic dynamics has been established based on the fundamental equation of classical mechanics and by using analogy method . From the accumulative effect of this equation to space, the basic concepts of rest mass, moving mass, momentum, kinetic energy, rest energy, mechanical energy, relativistic energy , force, and the work of force of particle or particle system in special theory of relativistic dynamics can be introduced. The relation formula between work and energy in special theory of relativistic dynamics, i.e. kinetic energy theorem of particle or particle system, the principle of work and energy, the conservation law of mechanical energy and quasi-conservation law of energy in particle system have been obtained as well.
Energy losses of superconducting power transmission cables in the grid
Østergaard, Jacob; Okholm, Jan; Lomholt, Karin
2001-01-01
One of the obvious motives for development of superconducting power transmission cables is reduction of transmission losses. Loss components in superconducting cables as well as in conventional cables have been examined. These losses are used for calculating the total energy losses of conventional...... as well as superconducting cables when they are placed in the electric power transmission network. It is concluded that high load connections are necessary to obtain energy saving by the use of HTSC cables. For selected high load connections, an energy saving of 40% is expected. It is shown...... that the thermal insulation and cooling machine efficiency are the most important loss element in a superconducting cable system...
High energy neutrino and gamma ray transients from relativistic supernova shock breakouts
Kashiyama, Kazumi; Horiuchi, Shunsaku; Gao, Shan; Mészáros, Peter
2013-01-01
Relativistic shocks that accompany supernovae (SNe) produce X-ray burst emissions as they break out in the dense circumstellar medium around the progenitors. This phenomenon is sometimes associated with peculiar low-luminosity gamma-ray bursts (LL GRBs). Here, we investigate the high energy neutrino and gamma-ray counterparts of such a class of SNe. Just beyond the shock breakout radius, particle acceleration in the collisionless shock starts to operate in the presence of breakout photons. We show that protons may be accelerated to sufficiently high energies and produce high energy neutrinos and gamma rays via the photomeson interaction. These neutrinos and gamma rays may be detectable from 10 Mpc away by IceCube/KM3Net as multi-TeV transients almost simultaneously with the X-ray burst emission, and even from 100 Mpc away with follow-up observations by CTA using a wide-field sky monitor like Swift as a trigger. A statistical technique using a stacking approach could also be possible for the detection, with th...
Dubus, Guillaume; Fromang, Sébastien
2015-01-01
Detailed modeling of the high-energy emission from gamma-ray binaries has been propounded as a path to pulsar wind physics. Fulfilling this ambition requires a coherent model of the flow and its emission in the region where the pulsar wind interacts with the stellar wind of its companion. We developed a code that follows the evolution and emission of electrons in the shocked pulsar wind based on inputs from a relativistic hydrodynamical simulation. The code is used to model the well-documented spectral energy distribution and orbital modulations from LS 5039. The pulsar wind is fully confined by a bow shock and a back shock. The particles are distributed into a narrow Maxwellian, emitting mostly GeV photons, and a power law radiating very efficiently over a broad energy range from X-rays to TeV gamma rays. Most of the emission arises from the apex of the bow shock. Doppler boosting shapes the X-ray and VHE lightcurves, constraining the system inclination to $i\\approx 35^{\\rm o}$. There is a tension between th...
Savukov, I.; Safronova, U. I.; Safronova, M. S.
2015-11-01
Excitation energies, term designations, g factors, transition rates, and lifetimes of U2 + are determined using a relativistic configuration interaction (CI) + linearized-coupled-cluster (LCC) approach. The CI-LCC energies are compared with CI + many-body-perturbation-theory (MBPT) and available experimental energies. Close agreement has been found with experiment, within hundreds of cm-1. In addition, lifetimes of higher levels have been calculated for comparison with three experimentally measured lifetimes, and close agreement has been found within the experimental error. CI-LCC calculations constitute a benchmark test of the CI + all-order method in complex relativistic systems such as actinides and their ions with many valence electrons. The theory yields many energy levels, g factors, transition rates, and lifetimes of U2 + that are not available from experiment. The theory can be applied to other multivalence atoms and ions, which would be of interest to many applications.
Initial energy density of quark-gluon plasma in relativistic heavy-ion collisions
Wong, C.Y.
1984-01-01
Recently, there has been considerable interest in the central rapidity region of highly relativistic heavy-ion collisions. Such an interest stems from the possibility of creating hadron matter of high energy density which may exceed the critical energy density for a phase transition between ordinary confined matter and the unconfined quark-gluon plasma. The experimental searches and identification of the quark-gluon plasma may provide a new insight into the question of quark confinement. The estimate of the initial energy density is quite uncertain. The initial energy density is nonetheless an important physical quantity. It is one of the factors which determines whether the produced matter can undergo phase transition or not. The energy density has been estimated previously by using the color neutralization model of Brodsky et al. However, the color neutralization model gives a central rapidity multiplicity in heavy-ion collision too low by a factor of two. For this reason, we wish to obtain a better estimate of the energy density (in the central rapidity region). As is well known, a simple Glauber-type multiple collision model can reproduce the total multiplicity and multiplicity plateau near the central rapidity region to within 30%. The simple multiple collision model has an approximate validity as a gross description of the reaction process. We shall adopt a semiempirical approach. Using the multiple collision model and the thickness function of Glauber, we obtain analytical functional form for all the quantities in question. A single parameter, r/sub rms/, is adjusted to fit the experimental central rapidity multiplicity data. The semi-empirical results provide a useful tool to extrapolate to the unknown central rapidity region of heavy-ion collisions.
Electron loss to continuum in near-relativistic ion-atom collisions
Hagmann, Siegbert [GSI, Darmstadt (Germany)]|[Inst. f. Kernphysik, Univ. Frankfurt (Germany); Nofal, Muaffaq [Max Planck Inst. f. Kernphysik, Heidelberg (Germany)]|[GSI, Darmstadt (Germany)]|[Inst. f. Kernphysik, Univ. Frankfurt (Germany); Stoehlker, Thomas; Fritzsche, Stefan [GSI, Darmstadt (Germany)]|[Physikal. Institut, Univ. Heidelberg (Germany); Surzhykov, Andrey; Moshammer, Robert; Ullrich, Joachim [Max Planck Inst. f. Kernphysik, Heidelberg (Germany); Kozhuharov, Christophor; Gumberidze, Alexander; Spillmann, Uwe; Reuschl, Regina; Hess, Sebastian; Trotsenko, Sergej; Bosch, Fritz; Liesen, Dieter [GSI, Darmstadt (Germany); Doerner, Reinhard [Inst. f. Kernphysik, Univ. Frankfurt (Germany); Rothard, Hermann [CIRIL, GANIL, Caen (France)
2008-07-01
In fast ion-atom collisions the projectile electron loss to continuum (ELC) permits to study the dynamics of ionization very close to threshold; it is a test of unparalleled sensitivity for first order theories. We have studied forward electron emission in two collision systems of different projectile Compton profile, U88+ +N2 and Sn47+ +N2 using the forward electron spectrometer at the supersonic jet-target of the ESR storage ring. We report first results for 90 AMeV U88+ and 300 AMeV Sn47+ measuring coincidences between electrons around ve=vProj and charge-exchanged projectiles having lost one electron; results are compared with theory.
Photon emission by ultra-relativistic positrons in crystalline undulators: the high-energy regime
Krause, W; Solov'yov, A V; Greiner, W
2015-01-01
This paper discusses the undulator radiation emitted by high-energy positrons during planar channeling in periodically bent crystals. We demonstrate that the construction of the undulator for positrons with energies of 10 GeV and above is only possible if one takes into account the radiative energy losses. The frequency of the undulator radiation depends on the energy of the particle. Thus the decrease of the particle's energy during the passage of the crystal should result in the destruction of the undulator radiation regime. However, we demonstrate that it is possible to avoid the destructive influence of the radiative losses on the frequency of the undulator radiation by the appropriate variation of the shape of the crystal channels. We also discuss a method by which, to our mind, it would be possible to prepare the crystal with the desired properties of its channels.
Liu, Jing-Jing
2016-01-01
Based on the relativistic mean-field effective interactions theory, and Lai dong model \\citep{b37, b38, b39}, we discuss the influences of superstrong magnetic fields (SMFs) on electron Fermi energy, nuclear blinding energy, and single-particle level structure in magnetars surface. By using the method of Shell-Model Monte Carlo (SMMC), and the Random Phase Approximation (RPA) theory, we detailed analyze the neutrino energy loss rates(NELRs) by electron capture (EC) for iron group nuclei in SMFs.
iVPIC: A low-dispersion, energy-conserving relativistic PIC solver for LPI simulations
Chacon, Luis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-06-07
We have developed a novel low-dispersion, exactly energy-conserving PIC algorithm for the relativistic Vlasov-Maxwell system. The approach features an exact energy conservation theorem while preserving the favorable performance and numerical dispersion properties of explicit PIC. The new algorithm has the potential to enable much longer laser-plasma-interaction (LPI) simulations than are currently possible.
Jet suppression and the flavor dependence of partonic energy loss with ATLAS
Kosek, Tomas; The ATLAS collaboration
2015-01-01
In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced. One manifestation of the energy loss of jets propagating through the medium is a lower yield of jets emerging from the medium than expected in the absence of medium effects. Therefore modifications of the jet yield are directly sensitive to the energy loss mechanism. Furthermore, jets with different flavor content are expected to be affected by the medium in different ways. Parton showers initiated by quarks tend to have fewer fragments carrying a larger fraction of the total jet energy than those resulting from gluons. Jets containing heavy quarks may lose less energy as the large quark mass suppresses the amount of medium-induced radiation. This would lead to different relative contributions of inelastic and elastic energy loss. In this talk, the latest ATLAS results on single jet suppression will be presented. Measurements of the nuclear modification factor, RAA, for fully reconstr...
The central engine of GRB 130831A and the energy breakdown of a relativistic explosion
De Pasquale, M.; Oates, S. R.; Racusin, J. L.; Kann, D. A.; Zhang, B.; Pozanenko, A.; Volnova, A. A.; Trotter, A.; Frank, N.; Cucchiara, A.; Troja, E.; Sbarufatti, B.; Butler, N. R.; Schulze, S.; Cano, Z.; Page, M. J.; Castro-Tirado, A. J.; Gorosabel, J.; Lien, A.; Fox, O.; Littlejohns, O.; Bloom, J. S.; Prochaska, J. X.; de Diego, J. A.; Gonzalez, J.; Richer, M. G.; Román-Zúñiga, C.; Watson, A. M.; Gehrels, N.; Moseley, H.; Kutyrev, A.; Zane, S.; Hoette, V.; Russell, R. R.; Rumyantsev, V.; Klunko, E.; Burkhonov, O.; Breeveld, A. A.; Reichart, D. E.; Haislip, J. B.
2016-01-01
Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, yet the nature and physical properties of their energy sources are far from understood. Very important clues, however, can be inferred by studying the afterglows of these events. We present optical and X-ray observations of GRB 130831A obtained by Swift, Chandra, Skynet, Reionization And Transients Infra-Red camera, Maidanak, International Scientific Optical-Observation Network, Nordic Optical Telescope, Liverpool Telescope and Gran Telescopio Canarias. This burst shows a steep drop in the X-ray light curve at ≃105 s after the trigger, with a power-law decay index of α ˜ 6. Such a rare behaviour cannot be explained by the standard forward shock (FS) model and indicates that the emission, up to the fast decay at 105 s, must be of `internal origin', produced by a dissipation process within an ultrarelativistic outflow. We propose that the source of such an outflow, which must produce the X-ray flux for ≃1 d in the cosmological rest frame, is a newly born magnetar or black hole. After the drop, the faint X-ray afterglow continues with a much shallower decay. The optical emission, on the other hand, shows no break across the X-ray steep decrease, and the late-time decays of both the X-ray and optical are consistent. Using both the X-ray and optical data, we show that the emission after ≃105 s can be explained well by the FS model. We model our data to derive the kinetic energy of the ejecta and thus measure the efficiency of the central engine of a GRB with emission of internal origin visible for a long time. Furthermore, we break down the energy budget of this GRB into the prompt emission, the late internal dissipation, the kinetic energy of the relativistic ejecta, and compare it with the energy of the associated supernova, SN 2013 fu.
Low-loss energy storage flywheel
Evans, H. E.; Studer, P. A.
1977-01-01
Magnetically-levitated, ironless-armature spokeless rotor is used. Ironless armature construction eliminates core losses due to hysteresis and eddy currents. Device combines features of homopolar salient poles and stationary ironless electronically commutated armature.
Haba, Z
2009-02-01
We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.
Energy loss distributions of 7 TeV protons axially channeled in the bent Si crystal
Stojanov, Nace; Petrović, Srdjan
2016-04-01
In this article, the energy loss distributions of relativistic protons axially channeled in the bent Si crystal are studied. The crystal thickness is equal to 1 mm, which corresponds to the reduced crystal thickness, Λ, equal to 1.22, whereas the bending angle, α, was varied from 0 to 30 μrad. The proton energy of 7 TeV was chosen in accordance with the concept of using the bent crystals as a tool for selective deflection of the beam halo particles from the LUA9 experiment at LHC. For the continuum interaction potential of the proton and the crystal the Molière's expression was used and the energy loss of a proton was calculated by applying the trajectory dependent stopping power model. Further, the uncertainness of the scattering angle of the proton caused by its collisions with the electrons of the crystal and the divergence of the proton beam were taken into account. The energy loss distribution of the channeled protons was obtained via the numerical solution of the proton equations of motion in the transverse plane and the computer simulation method. The analysis of the obtained theoretical data shows that the shape of the energy loss distribution strongly depends on the horizontal or vertical direction of the curvature of the crystal. The number of dechanneled protons as a function of the bending angle also strongly depends on the direction of the crystal's curvature. As a result, the dechanneling rates and ranges, obtained from the Gompertz type sigmoidal fitting functions, have different sets of values for different bending orientations. We have also studied the influence of the proton beam divergence on the energy loss distribution of channeled protons.
Energy loss correction for a crystal calorimeter
HE Miao; LI Hai-Bo; LI Wei-Dong; LIU Chun-Xiu; LIU Huai-Min; MA Qiu-Mei; MA Xiang; MAO Ya-Jun; MAO Ze-Pu; MO Xiao-Hu; QIU Jin-Fa; WANG Yi-Fang; SUN Sheng-Sen; SUN Yong-Zhao; WANG Ji-Ke; WANG Liang-Liang; WEN Shuo-Pin; WU Ling-Hui; XIE Yu-Guang; YANG Ming; YOU Zheng-Yun; YU Guo-Wei; BIAN Jian-Ming; YUAN Chang-Zheng; YUAN Ye; ZANG Shi-Lei; ZHANG Chang-Chun; ZHANG Jian-Yong; ZHANG Ling; ZHANG Xue-Yao; ZHANG Yao; ZHENG Zhi-Peng; ZHU Yong-Sheng; CAO Guo-Fu; ZOU Jia-Heng; DENG Zi-Yan; HE Kang-Lin; HUANG Bin; JI Xiao-Bin; LI Gang
2008-01-01
Material effect of inner-detectors on the performances of the BESⅢ Electromagnetic Calorimeter (EMC)is investigated.The BESⅢ Time-Of-Flight counters(TOF)have been utilized to improve the energy resolution and detection efficiency for photons after a careful energy calibration.A matching algorithm between TOF and EMC energy deposits is developed,and the effects of beam-related background are discussed.The energy resolution is improved and the photon detection efficiency can be increased by the combined measurement of EMC and TOF detectors.
Collisional Energy Loss of Non Asymptotic Jets in a QGP
Adil, A; Horowitz, W A; Wicks, S
2006-01-01
We calculate the collisional energy loss suffered by a heavy (charm) quark created at a finite time within a Quark Gluon Plasma (QGP) in the classical linear response formalism. We pay close attention to the problem of formulating a conserved current and accounting for binding and radiative energy loss effects. We find that the finite time correction is on the order of a Debye length as expected and the overall energy loss is similar in magnitude to the energy loss suffered by a charge created in the asymptotic past. This result has significant implications for the relative contribution to energy loss from collisional and radiative sources and will have ramifications for the ``single electron puzzle'' at RHIC as well as other experimental observables.
The electron energy loss rate due to radiative recombination
Mao, Junjie; Kaastra, Jelle; Badnell, N. R.
2017-02-01
Context. For photoionized plasmas, electron energy loss rates due to radiative recombination (RR) are required for thermal equilibrium calculations, which assume a local balance between the energy gain and loss. While many calculations of total and/or partial RR rates are available from the literature, specific calculations of associated RR electron energy loss rates are lacking. Aims: Here we focus on electron energy loss rates due to radiative recombination of H-like to Ne-like ions for all the elements up to and including zinc (Z = 30), over a wide temperature range. Methods: We used the AUTOSTRUCTURE code to calculate the level-resolved photoionization cross section and modify the ADASRR code so that we can simultaneously obtain level-resolved RR rate coefficients and associated RR electron energy loss rate coefficients. We compared the total RR rates and electron energy loss rates of H i and He i with those found in the literature. Furthermore, we utilized and parameterized the weighted electron energy loss factors (dimensionless) to characterize total electron energy loss rates due to RR. Results: The RR electron energy loss data are archived according to the Atomic Data and Analysis Structure (ADAS) data class adf48. The RR electron energy loss data are also incorporated into the SPEX code for detailed modeling of photoionized plamsas. Full Tables 1 and 2 are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/599/A10
Asymptotic domination of cold relativistic MHD winds by kinetic energy flux
Begelman, Mitchell C.; Li, Zhi-Yun
1994-01-01
We study the conditions which lead to the conversion of most Poynting flux into kinetic energy flux in cold, relativistic hydromagnetic winds. It is shown that plasma acceleration along a precisely radial flow is extremely inefficient due to the near cancellation of the toroidal magnetic pressure and tension forces. However, if the flux tubes in a flow diverge even slightly faster than radially, the fast magnetosonic point moves inward from infinity to a few times the light cylinder radius. Once the flow becomes supermagnetosonic, further divergence of the flux tubes beyond the fast point can accelerate the flow via the 'magnetic nozzle' effect, thereby further converting Poynting flux to kinetic energy flux. We show that the Grad-Shafranov equation admits a generic family of kinetic energy-dominated asymptotic wind solutions with finite total magnetic flux. The Poynting flux in these solutions vanishes logarithmically with distance. The way in which the flux surfaces are nested within the flow depends only on the ratio of angular velocity to poliodal 4-velocity as a function of magnetic flux. Radial variations in flow structure can be expressed in terms of a pressure boundary condition on the outermost flux surface, provided that no external toriodal field surrounds the flow. For a special case, we show explicitly how the flux surfaces merge gradually to their asymptotes. For flows confined by an external medium of pressure decreasing to zero at infinity we show that, depending on how fast the ambient pressure declines, the final flow state could be either a collimated jet or a wind that fills the entire space. We discuss the astrophysical implications of our results for jets from active galactic nuclei and for free pulsar winds such as that believed to power the Crab Nebula.
Magnetizabilities of relativistic hydrogenlike atoms in some arbitrary discrete energy eigenstates
Stefańska, Patrycja
2016-01-01
We present the results of numerical calculations of magnetizability ($\\chi$) of the relativistic one-electron atoms with a pointlike, spinless and motionless nuclei of charge $Ze$. Exploiting the analytical formula for $\\chi$ recently derived by us [P. Stefa{\\'n}ska, 2015], valid for an arbitrary discrete energy eigenstate, we have found the values of the magnetizability for the ground state and for the first and the second set of excited states (i.e.: $2s_{1/2}$, $2p_{1/2}$, $2p_{3/2}$, $3s_{1/2}$, $3p_{1/2}$, $3p_{3/2}$, $3d_{3/2}$, and $3d_{5/2}$) of the Dirac one-electron atom. The results for ions with the atomic number $1 \\leqslant Z \\leqslant 137$ are given in 14 tables. The comparison of the numerical values of magnetizabilities for the ground state and for each states belonging to the first set of excited states of selected hydrogenlike ions, obtained with the use of two different values of the fine-structure constant, i.e.: $\\alpha^{-1}=137.035 999 139$ (CODATA 2014) and $\\alpha^{-1}=137.035 999 074...
Very high energy emission as a probe of relativistic magnetic reconnection in pulsar winds
Mochol, Iwona
2015-01-01
The population of gamma-ray pulsars, including Crab observed in the TeV range, and Vela detected above 50 GeV, challenges existing models of pulsed high-energy emission. Such models should be universally applicable, yet they should account for spectral differences among the pulsars. We show that the gamma-ray emission of Crab and Vela can be explained by synchrotron radiation from the current sheet of a striped wind, expanding with a modest Lorentz factor $\\Gamma\\lesssim100$ in the Crab case, and $\\Gamma\\lesssim50$ in the Vela case. In the Crab spectrum a new synchrotron self-Compton component is expected to be detected by the upcoming experiment CTA. We suggest that the gamma-ray spectrum directly probes the physics of relativistic magnetic reconnection in the striped wind. In the most energetic pulsars, like Crab, with $\\dot{E}_{38}^{3/2}/P_{-2}\\gtrsim0.002$ (where $\\dot{E}$ is the spin down power, $P$ is the pulsar period, and $X=X_i\\times10^i$ in CGS units), reconnection proceeds in the radiative cooling ...
Nuclear matter fourth-order symmetry energy in relativistic mean field models
Cai, Bao-Jun
2011-01-01
Within the nonlinear relativistic mean field model, we derive the analytical expression of the nuclear matter fourth-order symmetry energy $E_{4}(\\rho)$. Our results show that the value of $E_{4}(\\rho)$ at normal nuclear matter density $\\rho_{0}$ is generally less than 1 MeV, confirming the empirical parabolic approximation to the equation of state for asymmetric nuclear matter at $\\rho_{0}$. On the other hand, we find that the $E_{4}(\\rho)$ may become nonnegligible at high densities. Furthermore, the analytical form of the $E_{4}(\\rho)$ provides the possibility to study the higher-order effects on the isobaric incompressibility of asymmetric nuclear matter, i.e., $K_{\\mathrm{sat}}(\\delta)=K_{0}+K_{\\mathrm{{sat},2}}\\delta ^{2}+K_{\\mathrm{{sat},4}}\\delta ^{4}+\\mathcal{O}(\\delta ^{6})$ where $\\delta =(\\rho_{n}-\\rho_{p})/\\rho $ is the isospin asymmetry, and we find that the value of $K_{\\mathrm{{sat},4}}$ is generally comparable with that of the $K_{\\mathrm{{sat},2}}$. In addition, we study the effects of the $E...
Measurement of TeV muon energy loss in iron
Sakumoto, W.K.; de Barbaro, P.; Bodek, A.; Budd, H.S.; Kim, B.J. (Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)); Merritt, F.S.; Oreglia, M.J.; Schellman, H.; Schumm, B.A. (Enrico Fermi Institute and Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States)); Bachmann, K.T.; Blair, R.E.; Foudas, C.; King, B.J.; Lefmann, W.C.; Leung, W.C.; Mishra, S.R.; Oltman, E.; Quintas, P.Z.; Rabinowitz, S.A.; Sciulli, F.; Seligman, W.G.; Shaevitz, M.H. (Department of Physics, Columbia University, New York, New York 10027 (United States)); Bernstein, R.H.; Borcherding, F.O.; Fisk, H.E.; Lamm, M.J.; Marsh, W.; Merritt, K.W.; Rapidis, P.A.; Yovanovitch, D. (Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)); Sandler, P.H.; Smith, W.H. (University of Wisconsin, Madison, Wisconsin 53706 (United States))
1992-05-01
We measure the energy loss of high-energy muons (up to 1 TeV) from cosmic-ray muons incident on the iron-scintillator calorimeter of the Chicago-Columbia-Fermilab-Rochester Collaboration (Lab E) neutrino detector at Fermilab. Measurements of the differential energy loss spectra in Fe and the average {ital dE}/{ital dx} energy loss in Fe are presented as functions of muon energy and are compared against calculations. There is reasonable agreement between the measurements and calculations except in the region of small energy losses (under a few GeV) for 1-TeV muons, where the measurement is about 30% lower than the calculation. This level of agreement with theory implies that reliable simulations of the performance of muon detectors for future TeV colliders can be done.
Muon Energy Loss Upsteam of the Muon Spectrometer
Nikolopoulos, K; Kourkoumelis, C; Poppleton, A
2006-01-01
A method for the estimation of the muon energy loss downstream of the Muons Spectrometer is presented. The method provides an improved and updated parametrization of the muon energy loss in ATLAS, along with an estimation based on the actual energy deposition in the calorimeters. The latter aims to account, on an event-by-event basis, for the statistical fluctuations of the energy loss. The final implementation of the presented method combines both the energy loss parametrization and the calorimeter information. This hybrid method provides on average a 5% improvement on the muon stand-alone momentum resolution, reaching 10% for , and reduces the non-gaussian tails. The method is implemented inside the ATHENA framework, in the MuidCaloEnergyTools package.
Decowski, M P
2002-01-01
The properties of quantum chromodynamics (QCD), the modern theory of the strong interaction, can be investigated through the study of relativistic nucleus- nucleus collisions. Recently, the Relativistic Heavy-Ion Collider (RHIC) was completed and started taking data at ten times higher center-of-mass energies than the previous most energetic heavy-ion collisions. This thesis presents some of the first measurements at RHIC from any experiment. The PHOBOS detector is used to measure the charged particle pseudo- rapidity density at mid-rapidity (i.e., in |η| < 1) as a function of collision energy and centrality. The multiplicity is measured by counting short tracks in the silicon spectrometer; the centrality measurement uses two scintillator detectors covering 3 < |η| < 4.5. The charged particle multiplicity at mid-rapidity for the 6% most central collisions is 379 ± 9(stat.) ± 42(syst.), 555 ± 3(stat.) ± 35(syst.) and 661 &plus...
Energy loss in grazing proton-surface collisions
Juaristi, J.I. (Dept. Fisica de Materiales, Facultad de Quimicas, UPV/EHU, San Sebastian (Spain)); Garcia de Abajo, F.J. (Dept. Ciencias de la Computacion e Inteligencia Artificial, Facultad de Informatica, UPV/EHU, San Sebastian (Spain))
1994-05-01
The energy loss of fast protons, with energy E > 100 keV, specularly reflected on a solid surface with glancing angle of incidence of the order of a mrad is analysed on theoretical grounds. Two different contributions can be distinguished: (i) energy losses originating from the interaction with the valence band, accounted for through an induced force, and (ii) the excitation of electron bound states of the target atoms. The results are compared with available experimental data. (orig.)
Vayenas, C. G.; Fokas, A. S.; Grigoriou, D.
2016-08-01
We compute analytically the masses, binding energies and hamiltonians of gravitationally bound Bohr-type states via the rotating relativistic lepton model which utilizes the de Broglie wavelength equation in conjunction with special relativity and Newton's relativistic gravitational law. The latter uses the inertial-gravitational masses, rather than the rest masses, of the rotating particles. The model also accounts for the electrostatic charge- induced dipole interactions between a central charged lepton, which is usually a positron, with the rotating relativistic lepton ring. We use three rotating relativistic neutrinos to model baryons, two rotating relativistic neutrinos to model mesons, and a rotating relativistic electron neutrino - positron (or electron) pair to model the W± bosons. It is found that gravitationally bound ground states comprising three relativistic neutrinos have masses in the baryon mass range (∼⃒ 0.9 to 1 GeV/c2), while ground states comprising two neutrinos have masses in the meson mass range (∼⃒ 0.4 to 0.8 GeV/c2). It is also found that the rest mass values of quarks are in good agreement with the heaviest neutrino mass value of 0.05 eV/c2 and that the mass of W± bosons (∼⃒ 81 GeV/c2) corresponds to the mass of a rotating gravitationally confined e± — ve pair. A generalized expression is also derived for the gravitational potential energy of such relativistic Bohr-type structures.
Borovskiy, A. V. [Department of Computer Science and Cybernetics, Baikal State University of Economics and Law, 11 Lenin Street, Irkutsk 664003 (Russian Federation); Galkin, A. L. [Coherent and Nonlinear Optics Department, A.M. Prokhorov General Physics Institute of the RAS, 38 Vavilov Street, Moscow 119991 (Russian Federation); Department of Physics of MBF, Pirogov Russian National Research Medical University, 1 Ostrovitianov Street, Moscow 117997 (Russian Federation); Kalashnikov, M. P., E-mail: galkin@kapella.gpi.ru [Max-Born-Institute for Nonlinear Optics and Short-Time Spectroscopy, 2a Max-Born-Strasse, Berlin 12489 (Germany)
2015-04-15
The new method of calculating energy spectra of accelerated electrons, based on the parameterization by their initial coordinates, is proposed. The energy spectra of electrons accelerated by Gaussian ultra-short relativistic laser pulse at a selected angle to the axis of the optical system focusing the laser pulse in a low density gas are theoretically calculated. The two-peak structure of the electron energy spectrum is obtained. Discussed are the reasons for its appearance as well as an applicability of other models of the laser field.
J. B. Rosenzweig
2004-06-01
Full Text Available The energy loss and gain of a beam in the nonlinear, “blowout” regime of the plasma wakefield accelerator, which features ultrahigh accelerating fields, linear transverse focusing forces, and nonlinear plasma motion, has been asserted, through previous observations in simulations, to scale linearly with beam charge. Additionally, from a recent analysis by Barov et al., it has been concluded that for an infinitesimally short beam, the energy loss is indeed predicted to scale linearly with beam charge for arbitrarily large beam charge. This scaling is predicted to hold despite the onset of a relativistic, nonlinear response by the plasma, when the number of beam particles occupying a cubic plasma skin depth exceeds that of plasma electrons within the same volume. This paper is intended to explore the deviations from linear energy loss using 2D particle-in-cell simulations that arise in the case of experimentally relevant finite length beams. The peak accelerating field in the plasma wave excited behind the finite-length beam is also examined, with the artifact of wave spiking adding to the apparent persistence of linear scaling of the peak field amplitude into the nonlinear regime. At large enough normalized charge, the linear scaling of both decelerating and accelerating fields collapses, with serious consequences for plasma wave excitation efficiency. Using the results of parametric particle-in-cell studies, the implications of these results for observing severe deviations from linear scaling in present and planned experiments are discussed.
Torque model of hydro turbine with inner energy loss characteristics
无
2010-01-01
This paper presents the result and analysis of the composition of energy loss occurring in the hydro turbine. Two new types of energy losses,namely the hydraulic loss in the flow channel and the impact loss,are defined. All losses within the hydro turbine are divided into four types and the loss coefficients are defined accordingly. Expressions or characteristic descriptions of these losses as well as the calibration method of the loss coefficients are presented. Furthermore,the torque model of the hydro turbine where the inner energy loss takes place is established. The developed model has been used to calculate the power loss due to the mechanical friction generated by the units’ rotation to solve the difficulty of measurements of the mechanical friction loss in the hydro turbine. The definition of the impact loss explains the phenomenon that the loss of no-load is greater than that of the rated operation. A set of conversion coefficients are defined using the characteristic parameters at the rated operation,which are used to transform the parameters in the torque model into those that are easily measured. Therefore,the expression of the hydro turbine power is converted into a function that has the main servomotor displacement as its single variable. This makes the proposed model be convenient to use. Finally,the proposed model and methods are calibrated and verified using the measured data of a hydropower plant. Good agreement between the modeled results and the measurements indicates that the proposed model can represent the inner energy loss characteristics of the hydro turbine.
Characteristic energy losses of electrons in organic NTCDA-films
Komolov, S A; Sidorenko, A G; Alyaev, Y G; Novolodskij, V A
2001-01-01
The studies on the characteristic energy losses of slow electrons in the NTCDA thin film on the ZnO (0001) surface are presented. It is shown, that the spectrum of the energy losses (E sub p =4.0; 5.6; 12.5 and 14.5 eV) in the area of low energies (< 60 eV) reflects the structure of transitions between the valency zone and the conductivity zone. The energy losses on the plasma oscillations excitation the excitation of pi-plasmon with the energy of 6.5 eV and excitation of the pi-sigma plasmon with the energy of 25 eV become prevailing with the growth of the initial electrons energy
Relativistic Guiding Center Equations
White, R. B. [PPPL; Gobbin, M. [Euratom-ENEA Association
2014-10-01
In toroidal fusion devices it is relatively easy that electrons achieve relativistic velocities, so to simulate runaway electrons and other high energy phenomena a nonrelativistic guiding center formalism is not sufficient. Relativistic guiding center equations including flute mode time dependent field perturbations are derived. The same variables as used in a previous nonrelativistic guiding center code are adopted, so that a straightforward modifications of those equations can produce a relativistic version.
Energy Loss in Pulse Detonation Engine due to Fuel Viscosity
Weipeng Hu
2014-01-01
Full Text Available Fluid viscosity is a significant factor resulting in the energy loss in most fluid dynamical systems. To analyze the energy loss in the pulse detonation engine (PDE due to the viscosity of the fuel, the energy loss in the Burgers model excited by periodic impulses is investigated based on the generalized multisymplectic method in this paper. Firstly, the single detonation energy is simplified as an impulse; thus the complex detonation process is simplified. And then, the symmetry of the Burgers model excited by periodic impulses is studied in the generalized multisymplectic framework and the energy loss expression is obtained. Finally, the energy loss in the Burgers model is investigated numerically. The results in this paper can be used to explain the difference between the theoretical performance and the experimental performance of the PDE partly. In addition, the analytical approach of this paper can be extended to the analysis of the energy loss in other fluid dynamic systems due to the fluid viscosity.
Single-atom electron energy loss spectroscopy of light elements
Senga, Ryosuke; Suenaga, Kazu
2015-01-01
... scattering power and higher knock-on probability. Here we propose a concept for detecting light atoms encaged in a nanospace by means of electron energy loss spectroscopy using inelastically scattered electrons...
Complex suppression patterns distinguish between major energy loss effects in Quark-Gluon Plasma
Djordjevic, Magdalena
2015-01-01
Interactions of high momentum partons with Quark-Gluon Plasma created in relativistic heavy-ion collisions provide an excellent tomography tool for this new form of matter. Recent measurements for charged hadrons and unidentified jets at the LHC show an unexpected flattening of the suppression curves at high momentum, exhibited when either momentum or the collision centrality is changed. Furthermore, a limited data available for B probes indicate a qualitatively different pattern, as nearly the same flattening is exhibited for the curves corresponding to two opposite momentum ranges. We here show that the experimentally measured suppression curves are well reproduced by our theoretical predictions, and that the complex suppression patterns are due to an interplay of collisional, radiative energy loss and the dead-cone effect. Furthermore, for B mesons, we predict that the uniform flattening of the suppression indicated by the limited dataset is in fact valid across the entire span of the momentum ranges, whic...
Norbury, John W.
1992-01-01
Single nucleon removal in relativistic and intermediate energy nucleus-nucleus collisions is studied using a generalization of Weizsacker-Williams theory that treats each electromagnetic multipole separately. Calculations are presented for electric dipole and quadrupole excitations and incorporate a realistic minimum impact parameter, Coulomb recoil corrections, and the uncertainties in the input photonuclear data. Discrepancies are discussed. The maximum quadrupole effect to be observed in future experiments is estimated and also an analysis of the charge dependence of the electromagnetic cross sections down to energies as low as 100 MeV/nucleon is made.
Norbury, John W.
1992-01-01
Single nucleon removal in relativistic and intermediate energy nucleus-nucleus collisions is studied using a generalization of Weizsacker-Williams theory that treats each electromagnetic multipole separately. Calculations are presented for electric dipole and quadrupole excitations and incorporate a realistic minimum impact parameter, Coulomb recoil corrections, and the uncertainties in the input photonuclear data. Discrepancies are discussed. The maximum quadrupole effect to be observed in future experiments is estimated and also an analysis of the charge dependence of the electromagnetic cross sections down to energies as low as 100 MeV/nucleon is made.
Radiative energy loss of neighboring subjets arXiv
Mehtar-Tani, Yacine
We compute the in-medium energy loss probability distribution of two neighboring subjets at leading order, in the large-$N_c$ approximation. Our result exhibits a gradual onset of color decoherence of the system and accounts for two expected limiting cases. When the angular separation is smaller than the characteristic angle for medium-induced radiation, the two-pronged substructure lose energy coherently as a single color charge, namely that of the parent parton. At large angular separation the two subjets lose energy independently. Our result is a first step towards quantifying effects of energy loss as a result of the fluctuation of the multi-parton jet substructure and therefore goes beyond the standard approach to jet quenching based on single parton energy loss. We briefly discuss applications to jet observables in heavy-ion collisions.
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.
Radiation reaction in a system of relativistic gravitating particles
Galtsov, D. V.
A Lorentz-covariant approach is developed to the description of electromagnetic and gravitational radiation in general relativity. A model of a relativistic system of gravitating point particles is constructed in which energy losses can be interpreted in terms of radiation-reaction forces. These forces are applied not only to the point particles but also to fields generated by these particles in the near zone. It is concluded that radiation friction in a system of relativistic gravitating particles is collective in character.
Tailoring the energy distribution and loss of 2D plasmons
Lin, Xiao; López, Josué J; Kaminer, Ido; Chen, Hongsheng; Soljačić, Marin
2016-01-01
The ability to tailor the energy distribution of plasmons at the nanoscale has many applications in nanophotonics, such as designing plasmon lasers, spasers, and quantum emitters. To this end, we analytically study the energy distribution and the proper field quantization of 2D plasmons with specific examples for graphene plasmons. We find that the portion of the plasmon energy contained inside graphene (energy confinement factor) can exceed 50%, despite graphene being infinitely thin. In fact, this very high energy confinement can make it challenging to tailor the energy distribution of graphene plasmons just by modifying the surrounding dielectric environment or the geometry, such as changing the separation distance between two coupled graphene layers. However, by adopting concepts of parity-time symmetry breaking, we show that tuning the loss in one of the two coupled graphene layers can simultaneously tailor the energy confinement factor and propagation characteristics, causing the phenomenon of loss-indu...
Tailoring the energy distribution and loss of 2D plasmons
Lin, Xiao; Rivera, Nicholas; López, Josué J.; Kaminer, Ido; Chen, Hongsheng; Soljačić, Marin
2016-10-01
The ability to tailor the energy distribution of plasmons at the nanoscale has many applications in nanophotonics, such as designing plasmon lasers, spasers, and quantum emitters. To this end, we analytically study the energy distribution and the proper field quantization of 2D plasmons with specific examples for graphene plasmons. We find that the portion of the plasmon energy contained inside graphene (energy confinement factor) can exceed 50%, despite graphene being infinitely thin. In fact, this very high energy confinement can make it challenging to tailor the energy distribution of graphene plasmons just by modifying the surrounding dielectric environment or the geometry, such as changing the separation distance between two coupled graphene layers. However, by adopting concepts of parity-time symmetry breaking, we show that tuning the loss in one of the two coupled graphene layers can simultaneously tailor the energy confinement factor and propagation characteristics, causing the phenomenon of loss-induced plasmonic transparency.
Soto, F. de [Laboratoire Physique Subatomique et Cosmologie, 53 av. des Martyrs, 38026 Grenoble (France)]|[Dpto. Sistemas Fisicos, Quimicos y Naturales, U. Pablo de Olavide, 41013 Sevilla (Spain); Carbonell, J. [Laboratoire Physique Subatomique et Cosmologie, 53 av. des Martyrs, 38026 Grenoble (France)
2007-04-15
The numerical solutions of the non-relativistic Yukawa model on a 3-dimensional size lattice with periodic boundary conditions are obtained. The possibility to extract the corresponding - infinite space - low energy parameters and bound state binding energies from eigenstates computed at finite lattice size is discussed. The results have been obtained with a non relativistic model, which is justified by the small energies involved in the calculations. Despite its simplicity, the model considered contains an essential ingredient of the hadron-hadron interaction - its finite range - which plays a relevant role in view of extracting the low energy parameters from the finite volume spectra. It offers a wieldy and physically sound tool to test the validity of the different approaches discussed in the literature to study the low energy scattering of baryon-baryon or meson-baryon systems from a lattice simulations in QCD. The results presented in this work have been essentially limited to the ground state of central attractive interactions, depending only on one parameter. The method can be easily applied to more involved interactions, like hard core repulsive terms or non central potentials leading to coupled channel equations. (authors)
Hale, Alison C
2009-01-01
The spectrum of electromagnetic fields satisfying perfectly conducting boundary conditions in a segment of a straight beam pipe with a circular cross-section is discussed as a function of various source models. These include charged bunches that move along the axis of the pipe with constant speed for which an exact solution to the initial-boundary value problem for Maxwell's equations in the beam pipe is derived. In the ultra-relativistic limit all longitudinal components of the fields tend to zero and the spectral content of the transverse fields and average total electromagnetic energy crossing any section of the beam pipe are directly related to the properties of the ultra-relativistic source. It is shown that for axially symmetric ultra-relativistic bunches interference effects occur that show a striking resemblance to those that occur due to CSR in cyclic machines despite the fact that in this limit the source is no longer accelerating. The results offer an analytic description showing how such enhanced ...
Baker, D N; Jaynes, A N; Kanekal, S G; Foster, J C; Erickson, P J; Fennell, J F; Blake, J B; Zhao, H; Li, X; Elkington, S R; Henderson, M G; Reeves, G D; Spence, H E; Kletzing, C A; Wygant, J R
2016-07-01
Two of the largest geomagnetic storms of the last decade were witnessed in 2015. On 17 March 2015, a coronal mass ejection-driven event occurred with a Dst (storm time ring current index) value reaching -223 nT. On 22 June 2015 another strong storm (Dst reaching -204 nT) was recorded. These two storms each produced almost total loss of radiation belt high-energy (E ≳ 1 MeV) electron fluxes. Following the dropouts of radiation belt fluxes there were complex and rather remarkable recoveries of the electrons extending up to nearly 10 MeV in kinetic energy. The energized outer zone electrons showed a rich variety of pitch angle features including strong "butterfly" distributions with deep minima in flux at α = 90°. However, despite strong driving of outer zone earthward radial diffusion in these storms, the previously reported "impenetrable barrier" at L ≈ 2.8 was pushed inward, but not significantly breached, and no E ≳ 2.0 MeV electrons were seen to pass through the radiation belt slot region to reach the inner Van Allen zone. Overall, these intense storms show a wealth of novel features of acceleration, transport, and loss that are demonstrated in the present detailed analysis.
Heat Loss Experiments: Teach Energy Savings with Cardboard "House"
Roman, Harry T.
2011-01-01
Using two cardboard boxes, a light bulb socket, light bulbs of varying wattage, a thermometer, and some insulation, students can learn some interesting lessons about how heat loss occurs in homes. This article describes practical experiments that work well on units related to energy, sustainable energy, renewables, engineering, and construction.…
The energy loss of medium-energy He+ ions backscattered from a Cu(100) surface
Alkemade, P.F.A.; Turkenburg, W.C.; Weg, W.F. van der
1987-01-01
A model is presented for the shape of the surface peak in the energy spectrum of backscattered ions in a channeling and blocking experiment. The elastic energy loss distribution of the ions is calculated by use of Monte Carlo simulation. The inelastic energy loss distribution is calculated by use of
Exercise Training and Energy Expenditure following Weight Loss.
Hunter, Gary R; Fisher, Gordon; Neumeier, William H; Carter, Stephen J; Plaisance, Eric P
2015-09-01
This study aims to determine the effects of aerobic or resistance training on activity-related energy expenditure (AEE; kcal·d(-1)) and physical activity index (activity-related time equivalent (ARTE)) following weight loss. It was hypothesized that weight loss without exercise training would be accompanied by decreases in AEE, ARTE, and nontraining physical activity energy expenditure (nonexercise activity thermogenesis (NEAT)) and that exercise training would prevent decreases in free-living energy expenditure. One hundred forty premenopausal women had an average weight loss of 25 lb during a diet (800 kcal·d(-1)) of furnished food. One group aerobically trained 3 times per week (40 min·d(-1)), another group resistance-trained 3 times per week (10 exercises/2 sets × 10 repetitions), and the third group did not exercise. Dual-energy x-ray absorptiometry was used to measure body composition, indirect calorimetry was used to measure resting energy expenditure (REE) and walking energy expenditure, and doubly labeled water was used to measure total energy expenditure (TEE). AEE, ARTE, and nontraining physical activity energy expenditure (NEAT) were calculated. TEE, REE, and NEAT all decreased following weight loss for the no-exercise group, but not for aerobic and resistance trainers. Only REE decreased in the two exercise groups. Resistance trainers increased ARTE. HR and oxygen uptake while walking on the flat and up a grade were consistently related to TEE, AEE, NEAT, and ARTE. Exercise training prevents a decrease in energy expenditure, including free-living energy expenditure separate from exercise training, following weight loss. Resistance training increases physical activity, whereas economy/ease of walking is associated with increased TEE, AEE, NEAT, and ARTE.
Energy-Efficiency Options for Insurance Loss Prevention
Mills, E. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.; Knoepfel, I. [Swiss Reinsurance Co., Zurich (Switzerland)
1997-06-09
Energy-efficiency improvements offer the insurance industry two areas of opportunity: reducing ordinary claims and avoiding greenhouse gas emissions that could precipitate natural disaster losses resulting from global climate change. We present three vehicles for taking advantage of this opportunity, including research and development, in- house energy management, and provision of key information to insurance customers and risk managers. The complementary role for renewable energy systems is also introduced.
Energy loss of low energy ion N+q grazing on the Al(111) surface
Hu Bi-Tao; Chen Chun-Hua; Song Yu-Shou; Gu Jian-Gang
2007-01-01
The total energy loss of N+q ions (for v ＜ Bohr velocity) grazing on the Al(111) has been simulated without any 'fit' parameter and compared with the experimental data. The energy loss due to the charge exchange, happening before the N+q hits the Al(111) surface, is studied. The present simulation shows that the energy loss strongly depends on the charge state of the projectile and the lattice orientation of Al(111) surface. The calculated total energy loss agrees with experimental data very well.
Relativistic Runaway Electrons
Breizman, Boris
2014-10-01
This talk covers recent developments in the theory of runaway electrons in a tokamak with an emphasis on highly relativistic electrons produced via the avalanche mechanism. The rapidly growing population of runaway electrons can quickly replace a large part of the initial current carried by the bulk plasma electrons. The magnetic energy associated with this current is typically much greater than the particle kinetic energy. The current of a highly relativistic runaway beam is insensitive to the particle energy, which separates the description of the runaway current evolution from the description of the runaway energy spectrum. A strongly anisotropic distribution of fast electrons is generally prone to high-frequency kinetic instabilities that may cause beneficial enhancement of runaway energy losses. The relevant instabilities are in the frequency range of whistler waves and electron plasma waves. The instability thresholds reported in earlier work have been revised considerably to reflect strong dependence of collisional damping on the wave frequency and the role of plasma non-uniformity, including radial trapping of the excited waves in the plasma. The talk also includes a discussion of enhanced scattering of the runaways as well as the combined effect of enhanced scattering and synchrotron radiation. A noteworthy feature of the avalanche-produced runaway current is a self-sustained regime of marginal criticality: the inductive electric field has to be close to its critical value (representing avalanche threshold) at every location where the runaway current density is finite, and the current density should vanish at any point where the electric field drops below its critical value. This nonlinear Ohm's law enables complete description of the evolving current profile. Work supported by the U.S. Department of Energy Contract No. DEFG02-04ER54742 and by ITER contract ITER-CT-12-4300000273. The views and opinions expressed herein do not necessarily reflect those of
Au + Au central collisions at 150, 250 and 400 A MeV energies in QMD with relativistic forces
Németh, J; Feldmeier, H
1999-01-01
Using the small acceleration approximation we derive a relativistic scalar-vector force from a modified Zimanyi-Moszkowski Lagrangian based on sigma, omega and rho meson exchanges. The momentum dependence of the force is fixed automatically by the theory. We present an application of such a force in a QMD calculation at intermediate energies comparing the results with the experimental ones published recently by the FOPI collaboration. For most of the quantities (number of intermediate mass fragments, ERAT, integrated side flow, central flow, charge distributions, etc.) we find agreement with the experimental results.
Zhang Meng; Gou Bing-Cong
2005-01-01
Variational calculations are carried out with a multiconfiguration-interaction wavefunction on the 1s22p2p 1De and 1s22p3p 3pe states to obtain the energies including the mass polarization and relativistic corrections for the beryllium isoelectronic sequence (Z=4-10). The oscillator strengths, transition rates and wavelengths are also calculated. Our results are compared with other theoretical and experimental data in the literatures. The fine structure and hyperfine structure of 1s22p3p 3pe state are also explored.
Impact of temperature dependence of the energy loss on jet quenching observables
Scardina, F; Greco, V
2011-01-01
The quenching of jets (particles with $p_T>>T, \\Lambda_{QCD}$) in ultra-relativistic heavy-ion collisions has been one of the main prediction and discovery at RHIC. We have studied, by a simple jet quenching modeling, the correlation between different observables like the nuclear modification factor $\\Rapt$, the elliptic flow $v_2$ and the ratio of quark to gluon suppression $R_{AA}(quark)/R_{AA}(gluon)$. We show that the relation among these observables is strongly affected by the temperature dependence of the energy loss. In particular the large $v_2$ and and the nearly equal $\\Rapt$ of quarks and gluons can be accounted for only if the energy loss occurs mainly around the temperature $T_c$ and the flavour conversion is significant.Finally we point out that the efficency in the conversion of the space eccentricity into the momentum one ($v_2$) results to be quite smaller respect to the one coming from elastic scatterings in a fluid with a viscosity to entropy density ratio $4\\pi\\eta/s=1$.
Complex suppression patterns distinguish between major energy loss effects in Quark–Gluon Plasma
Magdalena Djordjevic
2016-12-01
Full Text Available Interactions of high momentum partons with Quark–Gluon Plasma created in relativistic heavy-ion collisions provide an excellent tomography tool for this new form of matter. Recent measurements for charged hadrons and unidentified jets at the LHC show an unexpected flattening of the suppression curves at high momentum, exhibited when either momentum or the collision centrality is changed. Furthermore, a limited data available for B probes indicate a qualitatively different pattern, as nearly the same flattening is exhibited for the curves corresponding to two opposite momentum ranges. We here show that the experimentally measured suppression curves are well reproduced by our theoretical predictions, and that the complex suppression patterns are due to an interplay of collisional, radiative energy loss and the dead-cone effect. Furthermore, for B mesons, we predict that the uniform flattening of the suppression indicated by the limited dataset is in fact valid across the entire span of the momentum ranges, which will be tested by the upcoming experiments. Overall, the study presented here, provides a rare opportunity for pQCD theory to qualitatively distinguish between the major energy loss mechanisms at the same (nonintuitive dataset.
Complex suppression patterns distinguish between major energy loss effects in Quark-Gluon Plasma
Djordjevic, Magdalena
2016-12-01
Interactions of high momentum partons with Quark-Gluon Plasma created in relativistic heavy-ion collisions provide an excellent tomography tool for this new form of matter. Recent measurements for charged hadrons and unidentified jets at the LHC show an unexpected flattening of the suppression curves at high momentum, exhibited when either momentum or the collision centrality is changed. Furthermore, a limited data available for B probes indicate a qualitatively different pattern, as nearly the same flattening is exhibited for the curves corresponding to two opposite momentum ranges. We here show that the experimentally measured suppression curves are well reproduced by our theoretical predictions, and that the complex suppression patterns are due to an interplay of collisional, radiative energy loss and the dead-cone effect. Furthermore, for B mesons, we predict that the uniform flattening of the suppression indicated by the limited dataset is in fact valid across the entire span of the momentum ranges, which will be tested by the upcoming experiments. Overall, the study presented here, provides a rare opportunity for pQCD theory to qualitatively distinguish between the major energy loss mechanisms at the same (nonintuitive) dataset.
Detailed Monte Carlo Simulation of electron transport and electron energy loss spectra.
Attarian Shandiz, M; Salvat, F; Gauvin, R
2016-11-01
A computer program for detailed Monte Carlo simulation of the transport of electrons with kinetic energies in the range between about 0.1 and about 500 keV in bulk materials and in thin solid films is presented. Elastic scattering is described from differential cross sections calculated by the relativistic (Dirac) partial-wave expansion method with different models of the scattering potential. Inelastic interactions are simulated from an optical-data model based on an empirical optical oscillator strength that combines optical functions of the solid with atomic photoelectric data. The generalized oscillator strength is built from the adopted optical oscillator strength by using an extension algorithm derived from Lindhard's dielectric function for a free-electron gas. It is shown that simulated backscattering fractions of electron beams from bulk (semi-infinite) specimens are in good agreement with experimental data for beam energies from 0.1 keV up to about 100 keV. Simulations also yield transmitted and backscattered fractions of electron beams on thin solid films that agree closely with measurements for different film thicknesses and incidence angles. Simulated most probable deflection angles and depth-dose distributions also agree satisfactorily with measurements. Finally, electron energy loss spectra of several elemental solids are simulated and the effects of the beam energy and the foil thickness on the signal to background and signal to noise ratios are investigated. SCANNING 38:475-491, 2016. © 2015 Wiley Periodicals, Inc.
Data Acquisition System for Electron Energy Loss Coincident Spectrometers
Zhang Chi; Yu Xiaoqi; Yang Tao
2005-01-01
A Data Acquisition System (DAQ) for electron energy loss coincident spectrometers (EELCS) has been developed. The system is composed of a Multiplex Time-Digital Converter (TDC) that measures the flying time of positive and negative ions and a one-dimension positionsensitive detector that records the energy loss of scattering electrons. The experimental data are buffered in a first-in-first-out(FIFO) memory module, then transferred from the FIFO memory to PC by the USB interface. The DAQ system can record the flying time of several ions in one collision, and allows of different data collection modes. The system has been demonstrated at the Electron Energy Loss Coincident Spectrometers at the Laboratory of Atomic and Molecular Physics, USTC. A detail description of the whole system is given and experimental results shown.
Drescher, H.J
1999-06-11
In this work we have developed hard processes and string fragmentation in the framework of interactions at relativistic energies. The hypothesis of the universality of high energy interactions means that many elements of heavy ion collisions can be studied and simulated in simpler nuclear reactions. In particular this hypothesis implies that the fragmentation observed in the reaction e{sup +}e{sup -} follows the same rules as in the collision of 2 lead ions. This work deals with 2 nuclear processes: the e{sup +}e{sup -} annihilation reaction and the deep inelastic diffusion. For the first process the string model has been developed to simulate fragmentation by adding an artificial breaking of string due to relativistic effects. A monte-Carlo method has been used to determine the points in a Minkowski space where this breaking occurs. For the second reaction, the theory of semi-hard pomerons is introduced in order to define elementary hadron-hadron interactions. The model of fragmentation proposed in this work can be applied to more complicated reactions such as proton-proton or ion-ion collisions.
Computation of electron energy loss spectra by an iterative method
Koval, Peter [Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, E-20018 San Sebastián (Spain); Centro de Física de Materiales CFM-MPC, Centro Mixto CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, E-20018 San Sebastián (Spain); Ljungberg, Mathias Per [Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, E-20018 San Sebastián (Spain); Foerster, Dietrich [LOMA, Université de Bordeaux 1, 351 Cours de la Liberation, 33405 Talence (France); Sánchez-Portal, Daniel [Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, E-20018 San Sebastián (Spain); Centro de Física de Materiales CFM-MPC, Centro Mixto CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, E-20018 San Sebastián (Spain)
2015-07-01
A method is presented to compute the dielectric function for extended systems using linear response time-dependent density functional theory. Localized basis functions with finite support are used to expand both eigenstates and response functions. The electron-energy loss function is directly obtained by an iterative Krylov-subspace method. We apply our method to graphene and silicon and compare it to plane-wave based approaches. Finally, we compute electron-energy loss spectrum of C{sub 60} crystal to demonstrate the merits of the method for molecular crystals, where it will be most competitive.
M MOUSAVI; M R SHOJAEI
2017-02-01
In this work, we have obtained energy levels and charge radius for the $\\beta$-stability line nucleus, in relativistic shell model. In this model, we considered a close shell for each nucleus containing double magicnumber and a single nucleon energy level. Here we have taken $^{41}$Ca with a single neutron in the $^{40}$Ca core as an illustrative example. Then we have selected the Eckart plus Hulthen potentials for interaction between the coreand the single nucleon. By using parametric Nikiforov–Uvarov (PNU) method, we have calculated the energy values and wave function. Finally, we have calculated the charge radius for 17O, $^{41}$Ca, $^{49}$Ca and $^{57}$Ni. Our results are in agreement with experimental values and hence this model can be applied for similar nuclei.
Doornenbal, P., E-mail: pieter@ribf.riken.j [Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Reiter, P. [Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany); Grawe, H.; Saito, T. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Al-Khatib, A. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, 53115 Bonn (Germany); Banu, A.; Beck, T.; Becker, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Bednarczyk, P. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); The Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakow (Poland); Benzoni, G. [INFN Sezione di Milano, 20133 Milano (Italy); Bracco, A. [INFN Sezione di Milano, 20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, 20133 Milano (Italy); Buerger, A. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, 53115 Bonn (Germany); Caceres, L. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Departamento de Fisica Teorica, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Camera, F. [INFN Sezione di Milano, 20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, 20133 Milano (Italy); Chmel, S. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, 53115 Bonn (Germany); Crespi, F.C.L. [INFN Sezione di Milano, 20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, 20133 Milano (Italy); Geissel, H.; Gerl, J.; Gorska, M. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Grebosz, J. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakow (Poland)
2010-02-01
The lineshapes and peak position of Doppler corrected gamma-ray spectra from in-beam experiments at relativistic energies are investigated with respect to the intrinsic energy resolution of the employed detectors, the particles' velocities, and the photons' emission angle uncertainties at the moment of gamma-ray emission. The uncertainties in velocity and photon emission angle are dependent on the lifetime of the excited state. The impact of these two observables on the lineshape and energy resolution are studied for the RISING gamma-spectrometer by means of simulations and experimental results from a two-step fragmentation experiment at approx200MeV/u. Potential use of the distinct lineshape for lifetime determination is demonstrated for measured gamma-ray transitions.
Potter, William J.
2017-02-01
We calculate the severe radiative energy losses which occur at the base of black hole jets using a relativistic fluid jet model, including in situ acceleration of non-thermal leptons by magnetic reconnection. Our results demonstrate that including a self-consistent treatment of radiative energy losses is necessary to perform accurate magnetohydrodynamic simulations of powerful jets and that jet spectra calculated via post-processing are liable to vastly overestimate the amount of non-thermal emission. If no more than 95 per cent of the initial total jet power is radiated away by the plasma travels as it travels along the length of the jet, we can place a lower bound on the magnetization of the jet plasma at the base of the jet. For typical powerful jets, we find that the plasma at the jet base is required to be highly magnetized, with at least 10 000 times more energy contained in magnetic fields than in non-thermal leptons. Using a simple power-law model of magnetic reconnection, motivated by simulations of collisionless reconnection, we determine the allowed range of the large-scale average reconnection rate along the jet, by restricting the total radiative energy losses incurred and the distance at which the jet first comes into equipartition. We calculate analytic expressions for the cumulative radiative energy losses due to synchrotron and inverse-Compton emission along jets, and derive analytic formulae for the constraint on the initial magnetization.
Cheng, Roseanne M
2013-01-01
We consider tidal encounters between a white dwarf and an intermediate mass black hole. Both weak encounters and those at the threshold of disruption are modeled. The numerical code combines mesh-based (PPM) hydrodynamics, a spectral method (FFT) solution of the self-gravity, and a general relativistic Fermi normal coordinate (FNC) system that follows the star and debris. FNCs provide an expansion of the black hole tidal field that includes quadrupole and higher multipole moments and relativistic corrections. We compute the mass loss from the white dwarf that occurs in weak tidal encounters. Secondly, we compute carefully the energy deposition onto the star, examining the effects of non-radial and radial mode excitation, surface layer heating, mass loss, and relativistic orbital motion. We find evidence of a slight relativistic suppression in tidal energy transfer. Tidal energy deposition is compared to orbital energy loss due to gravitational bremsstrahlung and the combined losses are used to estimate tidal ...
Varying and inverting the mass hierarchy in collisional energy loss
Kolevatov, Rodion
2008-01-01
Heavy ion collisions at RHIC and at the LHC give access to the medium-induced suppression patterns of heavy-flavored single inclusive hadron spectra at high transverse momentum. This opens novel opportunities for a detailed characterization of the medium produced in the collision. In this note, we point out that the capacity of a QCD medium to absorb the recoil of a partonic projectile is an independent signature, which may differ for different media at the same density. In particular, while the mass hierarchy (i.e., the projectile mass dependence) of radiative energy loss depends solely on a property of the projectile, the mass hierarchy of collisional energy loss depends significantly on properties of the medium. By varying these properties in a class of models, we find that the mass hierarchy of collisional parton energy loss can be modified considerably and can even be inverted, compared to that of radiative parton energy loss. This may help to disentangle the relative strengths of radiative and collision...
Probing Plasmonic Nanostructures with Electron Energy - Loss Spectroscopy
Raza, Søren
for nonlocal response. The experimental work comprises the use of electron energy-loss spectroscopy (EELS) to excite and study both localized and propagating surface plasmons in metal structures. Following a short introduction, we present the theoretical foundation to describe nonlocal response in Maxwell...
Energy Drinks, Weight Loss, and Disordered Eating Behaviors
Jeffers, Amy J.; Vatalaro Hill, Katherine E.; Benotsch, Eric G.
2014-01-01
Objective: The present study examined energy drink consumption and relations with weight loss attempts and behaviors, body image, and eating disorders. Participants/Methods: This is a secondary analysis using data from 856 undergraduate students who completed the American College Health Association-National College Health Assessment II…
Energy Drinks, Weight Loss, and Disordered Eating Behaviors
Jeffers, Amy J.; Vatalaro Hill, Katherine E.; Benotsch, Eric G.
2014-01-01
Objective: The present study examined energy drink consumption and relations with weight loss attempts and behaviors, body image, and eating disorders. Participants/Methods: This is a secondary analysis using data from 856 undergraduate students who completed the American College Health Association-National College Health Assessment II…
Electron energy-loss spectroscopy of branched gap plasmon resonators
Raza, Søren; Esfandyarpour, Majid; Koh, Ai Leen
2016-01-01
The miniaturization of integrated optical circuits below the diffraction limit for high-speed manipulation of information is one of the cornerstones in plasmonics research. By coupling to surface plasmons supported on nanostructured metallic surfaces, light can be confined to the nanoscale...... microscope combined with electron energy-loss spectroscopy, we experimentally show the propagation, bending and splitting of slot gap plasmons....
Elucidating Jet Energy Loss Using Jets: Prospects from ATLAS
Grau, N
2009-01-01
The details of jet energy loss, as measured at RHIC with single particles and mu lti-particle correlations, are unresolved, and new experimental measurements are necessary in order to shed light on the mechanism and behavior of energy loss. Utilizing the ATLAS electromagnetic and hadronic calorimetry, full jet reconstru ction in a heavy ion environment will be performed over a wide range of $p_T$ an d rapidity. With fully reconstructed jets, new and more sensitive probes are ava ilable to test models of energy loss. In this talk, we present a series of obser vables such as the jet $R_{AA}$, the transverse momentum, $j_T$, spectrum of fra gments, the fragmentation function $D(z)$, jet shapes, and di-jet correlations, that aresensitive to perturbative and non-perturbative energy loss. We also disc uss the current level of sensitivity to expected modifications using several dif ferent jet algorithms, the cone, $k_T$, and anti-$k_T$ algorithms.
Trans-Relativistic Particle Acceleration in Astrophysical Plasmas
Becker, Peter A.; Subramanian, P.
2014-01-01
Trans-relativistic particle acceleration due to Fermi interactions between charged particles and MHD waves helps to power the observed high-energy emission in AGN transients and solar flares. The trans-relativistic acceleration process is challenging to treat analytically due to the complicated momentum dependence of the momentum diffusion coefficient. For this reason, most existing analytical treatments of particle acceleration assume that the injected seed particles are already relativistic, and therefore they are not suited to study trans-relativistic acceleration. The lack of an analytical model has forced workers to rely on numerical simulations to obtain particle spectra describing the trans-relativistic case. In this work we present the first analytical solution to the global, trans-relativistic problem describing the acceleration of seed particles due to hard-sphere collisions with MHD waves. The new results include the exact solution for the steady-state Green's function resulting from the continual injection of monoenergetic seed particles with an arbitrary energy. We also introduce an approximate treatment of the trans-relativistic acceleration process based on a hybrid form for the momentum diffusion coefficient, given by the sum of the two asymptotic forms. We refer to this process as "quasi hard-sphere scattering." The main advantage of the hybrid approximation is that it allows the extension of the physical model to include (i) the effects of synchrotron and inverse-Compton losses and (ii) time dependence. The new analytical results can be used to model the trans-relativistic acceleration of particles in AGN and solar environments, and can also be used to compute the spectra of the associated synchrotron and inverse-Compton emission. Applications of both types are discussed. We highlight (i) relativistic ion acceleration in black hole accretion coronae, and (ii) the production of gyrosynchrotron microwave emission due to relativistic electron
Flow effects on jet energy loss with detailed balance
CHENG Luan; LIU Jia; WANG EnKe
2014-01-01
In the presence of collective flow a new model potential describing the interaction of the hard jet with scattering centers is derived based on the static color-screened Yukawa potential.The flow effect on jet quenching with detailed balance is investigated in pQCD.It turns out,considering the collective flow with velocity vz along the jet direction,the collective flow decreases the LPM destructive interference comparing to that in the static medium.The gluon absorption plays a more important role in the moving medium.The collective flow increases the energy gain from gluon absorption,however,decreases the energy loss from gluon radiation,which is (1-vz) times as that in the static medium to the first order of opacity.In the presence of collective flow,the second order in opacity correction is relatively small compared to the first order.So that the total effective energy loss is decreased.The flow dependence of the energy loss will affect the suppression of high PT hadron spectrum and anisotropy parameter v2 in high-energy heavy-ion collisions.
Energy current loss instability model on a computer
Edighoffer, John A.
1995-04-01
The computer program called Energy Stability in a Recirculating Accelerator (ESRA) Free Electron Laser (FEL) has been written to model bunches of particles in longitudinal phase space transversing a recirculating accelerator and the associated rf changes and aperture current losses. This energy-current loss instability was first seen by Los Alamos's FEL group in their energy recovery experiments. This code addresses these stability issues and determines the transport, noise, feedback and other parameters for which these FEL systems are stable or unstable. Two representative systems are modeled, one for the Novosibirisk high power FEL racetrack microtron for photochemical research, the other is the CEBAF proposed UV FEL system. Both of these systems are stable with prudent choices of parameters.
Theoretical study of core-loss electron energy-loss spectroscopy at graphene nanoribbon edges
Fujita, N.; Hasnip, P. J.; Probert, M. I. J.; Yuan, J.
2015-08-01
A systematic study of simulated atomic-resolution electronic energy-loss spectroscopy (EELS) for different graphene nanoribbons (GNRs) is presented. The results of ab initio studies of carbon 1s core-loss EELS on GNRs with different ribbon edge structures and different hydrogen terminations show that theoretical core-loss EELS can distinguish key structural features at the atomic scale. In addition, the combination of polarized core-loss EELS with symmetry resolved electronic partial density of states calculations can be used to identify the origins of all the primary features in the spectra. For example, the nature of the GNR edge structure (armchair, zigzag, etc) can be identified, along with the degree of hydrogenation. Hence it is possible to use the combination of ab initio calculations with high resolution, high energy transmission core-loss EELS experiments to determine the local atomic arrangement and chemical bonding states (i.e. a structural fingerprint) in GNRs, which is essential for future practical applications of graphene.
Theoretical study of core-loss electron energy-loss spectroscopy at graphene nanoribbon edges.
Fujita, N; Hasnip, P J; Probert, M I J; Yuan, J
2015-08-01
A systematic study of simulated atomic-resolution electronic energy-loss spectroscopy (EELS) for different graphene nanoribbons (GNRs) is presented. The results of ab initio studies of carbon [Formula: see text] core-loss EELS on GNRs with different ribbon edge structures and different hydrogen terminations show that theoretical core-loss EELS can distinguish key structural features at the atomic scale. In addition, the combination of polarized core-loss EELS with symmetry resolved electronic partial density of states calculations can be used to identify the origins of all the primary features in the spectra. For example, the nature of the GNR edge structure (armchair, zigzag, etc) can be identified, along with the degree of hydrogenation. Hence it is possible to use the combination of ab initio calculations with high resolution, high energy transmission core-loss EELS experiments to determine the local atomic arrangement and chemical bonding states (i.e. a structural fingerprint) in GNRs, which is essential for future practical applications of graphene.
Zhang, C J; Hua, J F; Xu, X L; Li, F; Pai, C-H; Wan, Y; Wu, Y P; Gu, Y Q; Mori, W B; Joshi, C; Lu, W
2016-07-11
A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime, and it can also qualitatively map the major features of nonlinear wakes. The capturing of the injection in a nonlinear wake is demonstrated through 3D PIC simulations as an example of the application of this new method.
Zhang, C J; Xu, X L; Li, F; Pai, C -H; Wan, Y; Wu, Y P; Gu, Y Q; Mori, W B; Joshi, C; Lu, W
2016-01-01
A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime...
Zhang, C. J.; Hua, J. F.; Xu, X. L.; Li, F.; Pai, C.-H.; Wan, Y.; Wu, Y. P.; Gu, Y. Q.; Mori, W. B.; Joshi, C.; Lu, W.
2016-07-01
A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime, and it can also qualitatively map the major features of nonlinear wakes. The capturing of the injection in a nonlinear wake is demonstrated through 3D PIC simulations as an example of the application of this new method.
Deconvolution of the energy loss function of the KATRIN experiment
Hannen, V.; Heese, I.; Weinheimer, C.; Sejersen Riis, A.; Valerius, K.
2017-03-01
The KATRIN experiment aims at a direct and model independent determination of the neutrino mass with 0.2 eV/c2 sensitivity (at 90% C.L.) via a measurement of the endpoint region of the tritium beta-decay spectrum. The main components of the experiment are a windowless gaseous tritium source (WGTS), differential and cryogenic pumping sections and a tandem of a pre- and a main-spectrometer, applying the concept of magnetic adiabatic collimation with an electrostatic retardation potential to analyze the energy of beta decay electrons and to guide electrons passing the filter onto a segmented silicon PIN detector. One of the important systematic uncertainties of such an experiment are due to energy losses of β-decay electrons by elastic and inelastic scattering off tritium molecules within the source volume which alter the shape of the measured spectrum. To correct for these effects an independent measurement of the corresponding energy loss function is required. In this work we describe a deconvolution method to extract the energy loss function from measurements of the response function of the experiment at different column densities of the WGTS using a monoenergetic electron source.
The population of metastable states as a probe of relativistic-energy fragmentation reactions
Denis Bacelar, A.M. [School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ (United Kingdom); Bruce, A.M., E-mail: alison.bruce@brighton.ac.uk [School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ (United Kingdom); Podolyák, Zs.; Al-Dahan, N. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Górska, M. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstr 1, D-64291 Darmstadt (Germany); Lalkovski, S. [School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ (United Kingdom); Department of Physics, University of Sofia, 1164 Sofia (Bulgaria); Pietri, S.; Ricciardi, M.V. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstr 1, D-64291 Darmstadt (Germany); Algora, A. [Instituto de Física Corpuscular, CSIC, Universitat de Valencia, E-40671 Valencia (Spain); Institute of Nuclear Research of the Hungarian Academy of Sciences, P.O. Box 51, Debrecen, 4001 (Hungary); Alkhomashi, N. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Benlliure, J. [Universidad de Santiago de Compostela, 15706 (Spain); Boutachkov, P. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstr 1, D-64291 Darmstadt (Germany); Bracco, A. [Department of Physics, Università degli Studi di Milano and INFN, 20133 Milano (Italy); Calore, E. [INFN, Laboratori Nazionali di Legnaro (Italy); Casarejos, E. [University of Vigo, E-36310, Vigo (Spain); Cullen, I.J.; Deo, A.Y. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Detistov, P. [Department of Physics, University of Sofia, 1164 Sofia (Bulgaria); Laboratorio de Radiaciones Ionizantes, Universidad de Salamanca, 37008 (Spain); and others
2013-06-25
Isomeric ratios have been measured for high-spin states in {sup 198,200,206,208}{sub 84}Po, {sup 208,209,210,211}{sub 85}At, {sup 210,211,212,213,214}{sub 86}Rn, {sup 208,211,212,213,214}{sub 87}Fr, {sup 210,211,212,214,215}{sub 88}Ra, and {sup 215}{sub 89}Ac following the projectile fragmentation of a 1 A GeV {sup 238}U beam by a {sup 9}Be target at GSI Helmholtzzentrum für Schwerionenforschung. The fragments were separated in the fragment separator (FRS) and identified by means of energy loss and time-of-flight techniques. They were brought to rest at the centre of the RISING gamma-ray detector array and intensities of gamma rays emitted in the decay of isomeric states with half-lives between 100 ns and 40 μs and spin values up to 55/2 ℏ were used to obtain the corresponding isomeric ratios. The data are compared to theoretical isomeric ratios calculated in the framework of the abrasion–ablation model. Large experimental enhancements are obtained for high-spin isomers in comparison to expected values.
Did high energy astrophysical sources contribute to Martian atmospheric loss?
Atri, Dimitra
2016-01-01
Mars is believed to have had a substantial atmosphere in the past. Atmospheric loss led to depressurization and cooling, and is thought to be the primary driving force responsible for the loss of liquid water from its surface. Recently, MAVEN observations have provided new insight into the physics of atmospheric loss induced by ICMEs and solar wind interacting with the Martian atmosphere. In addition to solar radiation, it is likely that its atmosphere has been exposed to radiation bursts from high-energy astrophysical sources which become highly probable on timescales of ~Gy and beyond. These sources are capable of significantly enhancing the rates of photoionization and charged particle-induced ionization in the upper atmosphere. Here, we explore the possibility of damage from Galactic Gamma Ray Bursts, nearby supernovae, encounter with dense interstellar clouds and extreme solar events. We use Monte Carlo simulations to model the interaction of charged particles and photons from astrophysical sources in th...
Aromatic Polyurea Possessing High Electrical Energy Density and Low Loss
Thakur, Yash; Lin, Minren; Wu, Shan; Zhang, Q. M.
2016-10-01
We report the development of a dielectric polymer, poly (ether methyl ether urea) (PEMEU), which possesses a dielectric constant of 4 and is thermally stable up to 150°C. The experimental results show that the ether units are effective in softening the rigid polymer and making it thermally processable, while the high dipole moment of urea units and glass structure of the polymer leads to a low dielectric loss and low conduction loss. As a result, PEMEU high quality thin films can be fabricated which exhibit exceptionally high breakdown field of >1.5 GV/m, and a low conduction loss at fields up to the breakdown. Consequently, the PEMEU films exhibit a high charge-discharge efficiency of 90% and a high discharged energy density of 36 J/cm3.
Anisotropic plasmons, excitons, and electron energy loss spectroscopy of phosphorene
Ghosh, Barun; Kumar, Piyush; Thakur, Anmol; Chauhan, Yogesh Singh; Bhowmick, Somnath; Agarwal, Amit
2017-07-01
In this article, we explore the anisotropic electron energy loss spectrum (EELS) in monolayer phosphorene based on ab initio time-dependent density-functional-theory calculations. Similarly to black phosphorus, the EELS of undoped monolayer phosphorene is characterized by anisotropic excitonic peaks for energies in the vicinity of the band gap and by interband plasmon peaks for higher energies. On doping, an additional intraband plasmon peak also appears for energies within the band gap. Similarly to other two-dimensional systems, the intraband plasmon peak disperses as ωpl∝√{q } in both the zigzag and armchair directions in the long-wavelength limit and deviates for larger wave vectors. The anisotropy of the long-wavelength plasmon intraband dispersion is found to be inversely proportional to the square root of the ratio of the effective masses: ωpl(q y ̂) /ωpl(q x ̂) =√{mx/my } .
In Situ Electron Energy Loss Spectroscopy in Liquids
Holtz, Megan E; Gao, Jie; Abruña, Héctor D; Muller, David A
2012-01-01
In situ scanning transmission electron microscopy (STEM) through liquids is a promising approach for exploring biological and materials processes. However, options for in situ chemical identification are limited: X-ray analysis is precluded because the holder shadows the detector, and electron energy loss spectroscopy (EELS) is degraded by multiple scattering events in thick layers. Here, we explore the limits of EELS for studying chemical reactions in their native environments in real time and on the nanometer scale. The determination of the local electron density, optical gap and thickness of the liquid layer by valence EELS is demonstrated for liquids. By comparing theoretical and experimental plasmon energies, we find that liquids appear to follow the free-electron model that has been previously established for solids. Signals at energies below the optical gap and plasmon energy of the liquid provide a high signal-to-background ratio as demonstrated for LiFePO4 in aqueous solution. The potential for using...
Relativistic Corrections to the Bohr Model of the Atom
Kraft, David W.
1974-01-01
Presents a simple means for extending the Bohr model to include relativistic corrections using a derivation similar to that for the non-relativistic case, except that the relativistic expressions for mass and kinetic energy are employed. (Author/GS)
Vilkas, M J; Ishikawa, Y; Trabert, E
2007-03-27
Relativistic multireference many-body perturbation theory calculations have been performed on Xe{sup 43+}-Xe{sup 39+} ions, resulting in energy levels, electric dipole transition probabilities, and level lifetimes. The second-order many-body perturbation theory calculation of energy levels included mass shifts, frequency-dependent Breit correction and Lamb shifts. The calculated transition energies and E1 transition rates are used to present synthetic spectra in the extreme ultraviolet range for some of the Xe ions.
Tang, Sai Chun; McDannold, Nathan J
2015-03-01
This paper investigated the power losses of unsegmented and segmented energy coupling coils for wireless energy transfer. Four 30-cm energy coupling coils with different winding separations, conductor cross-sectional areas, and number of turns were developed. The four coils were tested in both unsegmented and segmented configurations. The winding conduction and intrawinding dielectric losses of the coils were evaluated individually based on a well-established lumped circuit model. We found that the intrawinding dielectric loss can be as much as seven times higher than the winding conduction loss at 6.78 MHz when the unsegmented coil is tightly wound. The dielectric loss of an unsegmented coil can be reduced by increasing the winding separation or reducing the number of turns, but the power transfer capability is reduced because of the reduced magnetomotive force. Coil segmentation using resonant capacitors has recently been proposed to significantly reduce the operating voltage of a coil to a safe level in wireless energy transfer for medical implants. Here, we found that it can naturally eliminate the dielectric loss. The coil segmentation method and the power loss analysis used in this paper could be applied to the transmitting, receiving, and resonant coils in two- and four-coil energy transfer systems.
Yu, Xun; Wang, Hui; Wu, Ji'an; Wang, Fang; Li, Qian
2009-11-01
The energy measurement of high energy laser is converts incident laser energy into heat energy, calculates energy utilizing absorber temperature rise, thus the energy value can be gained. Temperature measurement of high-energy laser energy meter and energy loss compensation during the course of the measurement were studied here. Firstly, temperature-resistance characteristics of resistance wire was analyzed, which was winded on exterior surface of the absorbing cavity of high-energy laser energy meter and used in temperature measurement. Least square method was used to process experiment data and a compensation model was established to calibrate the relationship of temperature vs. resistance. Experiment proved that, error between resistance wire and Pt100 is less than 0.01Ω and temperature error is less than 0.02°C. This greatly improves accuracy of the high energy meter measurement result. Secondly, aimed to the compensation of laser energy loss caused by absorbing cavity's heat exchange, the heat energy loss of absorbing cavity, resulted from thermal radiation, heat convection and heat conduction was analyzed based on heat transfer theory. Its mathematics model was established. Least square method was used to fit a curve of experiment data in order to compensate energy loss. Repetitiveness of measurement is 0.7%, which is highly improved.
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
Abdurakhmanov, U U
2013-01-01
By the methods of mathematical statistics we test a qualitative prediction of the old theory of relativistic hydrodynamics non-viscous liquid which can be used as a part of the process of hadronization within the modern hydrodynamical approach for the description of the quark-gluon plasma. Experimental data on the interaction of protons with the energies of 0.8 TeV with emulsion nuclei are used. Results do not contradict the formation of relativistic ideal non-viscous liquid in rare central collisions.
Beam Loss Calibration Studies for High Energy Proton Accelerators
Stockner, M
2007-01-01
CERN's Large Hadron Collider (LHC) is a proton collider with injection energy of 450 GeV and collision energy of 7 TeV. Superconducting magnets keep the particles circulating in two counter rotating beams, which cross each other at the Interaction Points (IP). Those complex magnets have been designed to contain both beams in one yoke within a cryostat. An unprecedented amount of energy will be stored in the circulating beams and in the magnet system. The LHC outperforms other existing accelerators in its maximum beam energy by a factor of 7 and in its beam intensity by a factor of 23. Even a loss of a small fraction of the beam particles may cause the transition from the superconducting to the normal conducting state of the coil or cause physical damage to machine components. The unique combination of these extreme beam parameters and the highly advanced superconducting technology has the consequence that the LHC needs a more efficient beam cleaning and beam loss measurement system than previous accelerators....
Beam Loss Calibration Studies for High Energy Proton Accelerators
Stockner, M
2007-01-01
CERN's Large Hadron Collider (LHC) is a proton collider with injection energy of 450 GeV and collision energy of 7 TeV. Superconducting magnets keep the particles circulating in two counter rotating beams, which cross each other at the Interaction Points (IP). Those complex magnets have been designed to contain both beams in one yoke within a cryostat. An unprecedented amount of energy will be stored in the circulating beams and in the magnet system. The LHC outperforms other existing accelerators in its maximum beam energy by a factor of 7 and in its beam intensity by a factor of 23. Even a loss of a small fraction of the beam particles may cause the transition from the superconducting to the normal conducting state of the coil or cause physical damage to machine components. The unique combination of these extreme beam parameters and the highly advanced superconducting technology has the consequence that the LHC needs a more efficient beam cleaning and beam loss measurement system than previous accelerators....
Technology Roadmap. Energy Loss Reduction and Recovery in Industrial Energy Systems
none,
2004-11-01
To help guide R&D decision-making and gain industry insights on the top opportunities for improved energy systems, ITP sponsored the Energy Loss Reduction and Recoveryin Energy Systems Roadmapping Workshopin April 2004 in Baltimore, Maryland. This Technology Roadmapis based largely on the results of the workshop and additional industrial energy studies supported by ITP and EERE. It summarizes industry feedback on the top opportunities for R&D investments in energy systems, and the potential for national impacts on energy use and the environment.
Nonconservation of Energy and Loss of Determinism I. Infinitely Many Colliding Balls
Atkinson, David; Johnson, Porter
2009-01-01
An infinite number of elastically colliding balls is considered in a classical, and then in a relativistic setting. Energy and momentum are not necessarily conserved globally, even though each collision does separately conserve them. This result holds in particular when the total mass of all the bal
Bliokh, Konstantin Y
2011-01-01
We consider the relativistic deformation of quantum waves and mechanical bodies carrying intrinsic angular momentum (AM). When observed in a moving reference frame, the centroid of the object undergoes an AM-dependent transverse shift. This is the relativistic analogue of the spin Hall effect, which occurs in free space without any external fields. Remarkably, the shifts of the geometric and energy centroids differ by a factor of 2, and both centroids are crucial for the correct Lorentz transformations of the AM tensor. We examine manifestations of the relativistic Hall effect in quantum vortices, mechanical flywheel, and discuss various fundamental aspects of the phenomenon. The perfect agreement of quantum and relativistic approaches allows applications at strikingly different scales: from elementary spinning particles, through classical light, to rotating black-holes.
Very Low Energy Supernovae from Neutrino Mass Loss
Lovegrove, Elizabeth
2013-01-01
The continuing difficulty of achieving a reliable explosion in simulations of core-collapse supernovae, especially for more massive stars, has led to speculation concerning the observable transients that might be produced if such a supernova fails. Even if a prompt outgoing shock fails to form in a collapsing presupernova star, one must still consider the hydrodynamic response of the star to the abrupt loss of mass via neutrinos as the core forms a protoneutron star. Following a suggestion by Nadezhin (1980), we calculate the hydrodynamical responses of typical supernova progenitor stars to the rapid loss of approximately 0.2 to 0.5 M_sun of gravitational mass from their centers. In a red supergiant star, a very weak supernova with total kinetic energy ~ 10^47 erg results. The binding energy of a large fraction of the hydrogen envelope before the explosion is of the same order and, depending upon assumptions regarding the neutrino loss rates, most of it is ejected. Ejection speeds are ~ 100 km/s and luminosit...
On a Singular Solution in Higgs Field (3) - Relativistical Energy Flow towards Higgs boson
Kitazawa, Kazuyoshi
2012-03-01
The mass of SM Higgs boson (H^0) is re-examined under fluid mechanical consideration of micro (femt-scale) Reynolds number in Higgs boson sea for the process of Higgs mechanism. In this analysis, two gauge particles (W and Z bosons) are adopted as representatives to describe the process through their each mass acquisition. The mass value of fluid mechanical H^0 (f.m.-H^0) is calculated relativistically at 128.6 GeV/c^2, which is a little (6.6 per-cent) larger than our mass value of the asymptotic solution (theoretical mass: 120.611 GeV/c^2) of Higgs field.footnotetextK. Kitazawa, DPF MEETING 2011: 166. This difference of mass value shows that there would be some extent of excess in sectional area's evaluation for f.m.-H^0. Because, in this numerical calculation we assumed that f.m.-H^0 in Higgs boson sea is sphere. While theoretical mass of H^0 had a shape of truncated-Octahedron which inscribes to the sectional circle of f.m.-H^0. So we may reduce this excess of mass since the drag force against the flow, which is proportional to sectional area of f.m.-H^0, corresponds to acquired mass by Higgs mechanism. It is noteworthy that theoretical mass above is almost at center of the most like range of latest LHC's result for SM Higgs boson mass.
Chainakun, P; Kara, E
2016-01-01
General relativistic ray tracing simulations of the time-averaged spectrum and energy-dependent time delays in AGN are presented. We model the lamp-post geometry in which the accreting gas is illuminated by an X-ray source located on the rotation axis of the black hole. The spectroscopic features imprinted in the reflection component are modelled using REFLIONX. The associated time delays after the direct continuum, known as reverberation lags, are computed including the full effects of dilution and ionization gradients on the disc. We perform, for the first time, simultaneous fitting of the time-averaged and lag-energy spectra in three AGN: Mrk 335, IRAS 13224-3809 and Ark 564 observed with XMM-Newton. The best fitting source height and central mass of each AGN partly agree with those previously reported. We find that including the ionization gradient in the model naturally explains lag-energy observations in which the 3 keV and 7-10 keV bands precede other bands. To obtain the clear 3 keV and 7-10 keV dips ...
Gestrina, G N
2005-01-01
The relativistic effect of energy increase in a particle freely moving in vacuum is discussed on the basis of quantum field theory and probability theory using some ideas of super-symmetrical theories. The particle is assumed to consist of a "seed" whose energy is equal to the particle rest energy and whose pulse is equal to the product of the particle mass by its velocity and of a "fur coat" - the system of virtual quanta of the material field - vacuum. Each of these quanta possesses the same energy and pulse as the "seed" but have no mass. The system of the quanta is in a state being the superposition of quantum states with energies and pulses multiple of the "seed" energy and pulse. The virtual quanta is created (or destroyed) in of such states. The probability of creating a quanta in any state is the inverse of the relativistic factor, and the average number of the quanta making up the "fur coat" with a "seed" is equal to this particular factor. The kinetic energy and the relativistic addition to the part...
Systematic Comparison of Jet Energy-Loss Schemes in a realistic hydrodynamic medium
Bass, Steffen A; Majumder, Abhijit; Nonaka, Chiho; Qin, Guang-You; Renk, Thorsten; Ruppert, Jörg
2008-01-01
We perform a systematic comparison of three different jet energy-loss approaches. These include the Armesto-Salgado-Wiedemann scheme based on the approach of Baier-Dokshitzer-Mueller-Peigne-Schiff (BDMPS/ASW), the Higher Twist approach (HT) and a scheme based on the approach of Arnold-Moore-Yaffe (AMY). In this comparison, an identical medium evolution will be utilized for all three approaches: not only does this entail the use of the same realistic three-dimensional relativistic fluid dynamics (RFD) simulation, but also includes the use of identical initial parton-distribution functions and final fragmentation functions. We are, thus, in a unique position, not only to isolate fundamental differences between the various approaches, but also to make rigorous calculations for different experimental measurements using "state of the art" components. All three approaches are reduced to a version which contains only one free tunable parameter, this is then related to the well known transport parameter $\\hat{q}$. We...
Multiple scattering of low energy ions in matter: Influence of energy loss and interaction potential
Mekhtiche, A. [Laboratoire SNIRM, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia, Bab Ezzouar, Algiers (Algeria); Faculté des Sciences et de la Technologie, Université Yahia Farès de Médéa (Algeria); Khalal-Kouache, K., E-mail: kkouache@yahoo.fr [Laboratoire SNIRM, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia, Bab Ezzouar, Algiers (Algeria)
2015-07-01
In this paper, the effect of inelastic energy loss and interaction potential on transmitted ions at low energy is studied. For this purpose, angular distributions of slow He{sup +} ions transmitted through thin Ag films are calculated using the theory of multiple scattering. Thin films (20–50 Å at 2 keV and 50–200 Å at 10 keV) are considered so that the total path length of transmitted ions can be approximated by the value of the target thickness in this calculation. The corresponding values of the relative energy loss ΔE/E are comprised between 0.04 and 0.17. We show that even if low values of the thickness are considered, the total energy loss of ions in the target should be included in the calculation. These calculated angular distributions are also influenced by the potential used to describe the interaction between the incident ion and the target atom.
Jet energy loss in heavy ion collisions from RHIC to LHC energies
Levai, Peter
2011-01-01
The suppression of hadron production originated from the induced jet energy loss is one of the most accepted and well understood phenomena in heavy ion collisions, which indicates the formation of color deconfined matter consists of quarks, antiquarks and gluons. This phenomena has been seen at RHIC energies and now the first LHC results display a very similar effect. In fact, the suppression is so close to each other at 200 AGeV and 2.76 ATeV, that it is interesting to investigate if such a suppression pattern can exist at all. We use the Gyulassy-Levai-Vitev description of induced jet energy loss combined with different nuclear shadowing functions and describe the experimental data. We claim that a consistent picture can be obtained for the produced hot matter with a weak nuclear shadowing. The interplay between nuclear shadowing and jet energy loss playes a crucial role in the understanding of the experimental data.
The role of energy losses in photosynthetic light harvesting
Krüger, T. P. J.; van Grondelle, R.
2017-07-01
Photosynthesis operates at the bottom of the food chain to convert the energy of light into carbohydrates at a remarkable global rate of about 130 TW. Nonetheless, the overall photosynthetic process has a conversion efficiency of a few percent at best, significantly less than bottom-up photovoltaic cells. The primary photosynthetic steps, consisting of light harvesting and charge separation, are often presented as having near-unity quantum efficiency but this holds only true under ideal conditions. In this review, we discuss the importance of energy loss mechanisms to establish robustness in photosynthetic light harvesting. Thermal energy dissipation of light-harvesting complexes (LHCs) in different environments is investigated and the relationships and contrasts between concentration quenching of high pigment concentrations, photoprotection (non-photochemical quenching), quenching due to protein aggregation, and fluorescence blinking are discussed. The role of charge-transfer states in light harvesting and energy dissipation is highlighted and the importance of controlled protein structural disorder to switch the light-harvesting antennae between effective light harvesters and efficient energy quenchers is underscored. The main LHC of plants, LHCII, is used as a prime example.
Simulating electron energy loss spectroscopy with the MNPBEM toolbox
Hohenester, Ulrich
2014-03-01
Within the MNPBEM toolbox, we show how to simulate electron energy loss spectroscopy (EELS) of plasmonic nanoparticles using a boundary element method approach. The methodology underlying our approach closely follows the concepts developed by García de Abajo and coworkers (Garcia de Abajo, 2010). We introduce two classes eelsret and eelsstat that allow in combination with our recently developed MNPBEM toolbox for a simple, robust, and efficient computation of EEL spectra and maps. The classes are accompanied by a number of demo programs for EELS simulation of metallic nanospheres, nanodisks, and nanotriangles, and for electron trajectories passing by or penetrating through the metallic nanoparticles. We also discuss how to compute electric fields induced by the electron beam and cathodoluminescence. Catalogue identifier: AEKJ_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKJ_v2_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 38886 No. of bytes in distributed program, including test data, etc.: 1222650 Distribution format: tar.gz Programming language: Matlab 7.11.0 (R2010b). Computer: Any which supports Matlab 7.11.0 (R2010b). Operating system: Any which supports Matlab 7.11.0 (R2010b). RAM:≥1 GB Classification: 18. Catalogue identifier of previous version: AEKJ_v1_0 Journal reference of previous version: Comput. Phys. Comm. 183 (2012) 370 External routines: MESH2D available at www.mathworks.com Does the new version supersede the previous version?: Yes Nature of problem: Simulation of electron energy loss spectroscopy (EELS) for plasmonic nanoparticles. Solution method: Boundary element method using electromagnetic potentials. Reasons for new version: The new version of the toolbox includes two additional classes for the simulation of electron energy
Electron energy-loss spectroscopy study of hydrogenated amorphous silicon
Burnham, N.A.; Fisher, R.F.; Asher, S.E.; Kazmerski, L.L.
1987-07-01
Electron energy-loss spectroscopy is used to study hydrogenated amorphous silicon (a-Si:H). Core-level and plasma excitations were examined as a function of hydrogen content. This technique and its interpretation reveals a consistent picture of the electron excitations within this important material. The a-Si:H thin films were fabricated by rf sputtering. Their hydrogen concentrations ranged from 0% to 15%. Hydrogen content was determined by infrared spectroscopy and secondary ion mass spectroscopy. X-ray photoelectron spectroscopy and inspection of the silicon Auger-KLL peak confirmed the silicon core levels.
Probing Battery Chemistry with Liquid Cell Electron Energy Loss Spectroscopy
Unocic, Raymond R.; Baggetto, Loic; Veith, Gabriel M.; Aguiar, Jeffery A.; Unocic, Kinga A.; Sacci, Robert L.; Dudney, Nancy J.; More, Karren L.
2015-11-25
We demonstrate the ability to apply electron energy loss spectroscopy (EELS) to follow the chemistry and oxidation states of LiMn_{2}O_{4} and Li_{4}Ti_{5}O1_{2} battery electrodes within a battery solvent. The use and importance of in situ electrochemical cells coupled with a scanning/transmission electron microscope (S/TEM) has expanded and been applied to follow changes in battery chemistry during electrochemical cycling. Furthermore, we discuss experimental parameters that influence measurement sensitivity and provide a framework to apply this important analytical method to future in situ electrochemical studies.
Nonequilibrium electron energy-loss kinetics in metal clusters
Guillon, C; Fatti, N D; Vallee, F
2003-01-01
Ultrafast energy exchanges of a non-Fermi electron gas with the lattice are investigated in silver clusters with sizes ranging from 4 to 26 nm using a femtosecond pump-probe technique. The results yield evidence for a cluster-size-dependent slowing down of the short-time energy losses of the electron gas when it is strongly athermal. A constant rate is eventually reached after a few hundred femtoseconds, consistent with the electron gas internal thermalization kinetics, this behaviour reflecting evolution from an individual to a collective electron-lattice type of coupling. The timescale of this transient regime is reduced in small nanoparticles, in agreement with speeding up of the electron-electron interactions with size reduction. The experimental results are in quantitative agreement with numerical simulations of the electron kinetics.
Medical radiation dosimetry theory of charged particle collision energy loss
McParland, Brian J
2014-01-01
Accurate radiation dosimetry is a requirement of radiation oncology, diagnostic radiology and nuclear medicine. It is necessary so as to satisfy the needs of patient safety, therapeutic and diagnostic optimisation, and retrospective epidemiological studies of the biological effects resulting from low absorbed doses of ionising radiation. The radiation absorbed dose received by the patient is the ultimate consequence of the transfer of kinetic energy through collisions between energetic charged particles and atoms of the tissue being traversed. Thus, the ability of the medical physicist to both measure and calculate accurately patient dosimetry demands a deep understanding of the physics of charged particle interactions with matter. Interestingly, the physics of charged particle energy loss has an almost exclusively theoretical basis, thus necessitating an advanced theoretical understanding of the subject in order to apply it appropriately to the clinical regime. Each year, about one-third of the worl...
Precipitation of relativistic electrons of the Van Allen belts into the proton aurora
Jordanova, Vania K [Los Alamos National Laboratory; Miyoshi, Y [NAGOYA UNIV; Sakaguchi, K [NAGOYA UNIV; Shiokawa, K [NAGOYA UNIV; Evans, D S [SEC/NOAA; Albert, Jay [AFRL; Connors, M [UNIV OF ATHABASCA
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.
Constraints on dark energy with the LOSS SN Ia sample
Ganeshalingam, Mohan; Filippenko, Alexei V
2013-01-01
We present a cosmological analysis of the Lick Observatory Supernova Search (LOSS) Type Ia supernova (SN Ia) photometry sample introduced by Ganeshalingam et al. (2010). These SNe provide an effective anchor point to estimate cosmological parameters when combined with datasets at higher redshift. The data presented by Ganeshalingam et al. (2010) have been rereduced in the natural system of the KAIT and Nickel telescopes to minimise systematic uncertainties. We have run the light-curve-fitting software SALT2 on our natural-system light curves to measure light-curve parameters for LOSS light curves and available SN Ia datasets in the literature. We present a Hubble diagram of 586 SNe in the redshift range z=0.01-1.4 with a residual scatter of 0.176 mag. Of the 226 low-z objects in our sample, 91 objects are from LOSS, including 45 SNe without previously published distances. Assuming a flat Universe, we find that the best fit for the dark energy equation-of-state parameter w = -0.86^+0.13_-0.16 (stat) +- 0.11 (s...
Nonequilibrium thermodynamics and energy efficiency in weight loss diets.
Feinman, Richard D; Fine, Eugene J
2007-07-30
Carbohydrate restriction as a strategy for control of obesity is based on two effects: a behavioral effect, spontaneous reduction in caloric intake and a metabolic effect, an apparent reduction in energy efficiency, greater weight loss per calorie consumed. Variable energy efficiency is established in many contexts (hormonal imbalance, weight regain and knock-out experiments in animal models), but in the area of the effect of macronutrient composition on weight loss, controversy remains. Resistance to the idea comes from a perception that variable weight loss on isocaloric diets would somehow violate the laws of thermodynamics, that is, only caloric intake is important ("a calorie is a calorie"). Previous explanations of how the phenomenon occurs, based on equilibrium thermodynamics, emphasized the inefficiencies introduced by substrate cycling and requirements for increased gluconeogenesis. Living systems, however, are maintained far from equilibrium, and metabolism is controlled by the regulation of the rates of enzymatic reactions. The principles of nonequilibrium thermodynamics which emphasize kinetic fluxes as well as thermodynamic forces should therefore also be considered. Here we review the principles of nonequilibrium thermodynamics and provide an approach to the problem of maintenance and change in body mass by recasting the problem of TAG accumulation and breakdown in the adipocyte in the language of nonequilibrium thermodynamics. We describe adipocyte physiology in terms of cycling between an efficient storage mode and a dissipative mode. Experimentally, this is measured in the rate of fatty acid flux and fatty acid oxidation. Hormonal levels controlled by changes in dietary carbohydrate regulate the relative contributions of the efficient and dissipative parts of the cycle. While no experiment exists that measures all relevant variables, the model is supported by evidence in the literature that 1) dietary carbohydrate, via its effect on hormone levels
Nonequilibrium thermodynamics and energy efficiency in weight loss diets
Fine Eugene J
2007-07-01
Full Text Available Abstract Carbohydrate restriction as a strategy for control of obesity is based on two effects: a behavioral effect, spontaneous reduction in caloric intake and a metabolic effect, an apparent reduction in energy efficiency, greater weight loss per calorie consumed. Variable energy efficiency is established in many contexts (hormonal imbalance, weight regain and knock-out experiments in animal models, but in the area of the effect of macronutrient composition on weight loss, controversy remains. Resistance to the idea comes from a perception that variable weight loss on isocaloric diets would somehow violate the laws of thermodynamics, that is, only caloric intake is important ("a calorie is a calorie". Previous explanations of how the phenomenon occurs, based on equilibrium thermodynamics, emphasized the inefficiencies introduced by substrate cycling and requirements for increased gluconeogenesis. Living systems, however, are maintained far from equilibrium, and metabolism is controlled by the regulation of the rates of enzymatic reactions. The principles of nonequilibrium thermodynamics which emphasize kinetic fluxes as well as thermodynamic forces should therefore also be considered. Here we review the principles of nonequilibrium thermodynamics and provide an approach to the problem of maintenance and change in body mass by recasting the problem of TAG accumulation and breakdown in the adipocyte in the language of nonequilibrium thermodynamics. We describe adipocyte physiology in terms of cycling between an efficient storage mode and a dissipative mode. Experimentally, this is measured in the rate of fatty acid flux and fatty acid oxidation. Hormonal levels controlled by changes in dietary carbohydrate regulate the relative contributions of the efficient and dissipative parts of the cycle. While no experiment exists that measures all relevant variables, the model is supported by evidence in the literature that 1 dietary carbohydrate, via its
Fauad Rami
2003-05-01
Charged particle pseudorapidity distributions have been measured in Au + Au collisions using the BRAHMS detector at RHIC. The results are presented as a function of the collision centrality and the center of mass energy. They are compared to the predictions of different parton scattering models and the important role of hard scattering processes at RHIC energies is discussed.
LI XIANG-DONG; TAN MING-LIANG; YI YOU-GEN; SHENG YONG; JIANG GANG; ZHANG ZHI-HONG; ZHU ZHENG-HE; ZHAO YONG-KUAN
2000-01-01
This paper reports the theoretical calculation of Breit, self-energy, and vacuum polarization corrections in the Ne like system using multi-configuration Dirac-Fock method with the orbital polarization. The relations of these corrections with the atomic number and the orbital symmetries are shown and the calculated correction energies are compared with other calculated results. Our Breit correction energies are all smaller by leV as maximum than the other theoretical Breit correction energies and the differences reveal systematical relation with atomic number. It is found that the configuration interactions have great effect on Breit corrections while the orbital polarization has much smaller effect on Breit corrections. The self-energy and vacuum polarization obtained by our calculation are much different from that in previous literatures for some transitions.
Elastic deformation and energy loss of flapping fly wings.
Lehmann, Fritz-Olaf; Gorb, Stanislav; Nasir, Nazri; Schützner, Peter
2011-09-01
During flight, the wings of many insects undergo considerable shape changes in spanwise and chordwise directions. We determined the origin of spanwise wing deformation by combining measurements on segmental wing stiffness of the blowfly Calliphora vicina in the ventral and dorsal directions with numerical modelling of instantaneous aerodynamic and inertial forces within the stroke cycle using a two-dimensional unsteady blade elementary approach. We completed this approach by an experimental study on the wing's rotational axis during stroke reversal. The wing's local flexural stiffness ranges from 30 to 40 nN m(2) near the root, whereas the distal wing parts are highly compliant (0.6 to 2.2 nN m(2)). Local bending moments during wing flapping peak near the wing root at the beginning of each half stroke due to both aerodynamic and inertial forces, producing a maximum wing tip deflection of up to 46 deg. Blowfly wings store up to 2.30 μJ elastic potential energy that converts into a mean wing deformation power of 27.3 μW. This value equates to approximately 5.9 and 2.3% of the inertial and aerodynamic power requirements for flight in this animal, respectively. Wing elasticity measurements suggest that approximately 20% or 0.46 μJ of elastic potential energy cannot be recovered within each half stroke. Local strain energy increases from tip to root, matching the distribution of the wing's elastic protein resilin, whereas local strain energy density varies little in the spanwise direction. This study demonstrates a source of mechanical energy loss in fly flight owing to spanwise wing bending at the stroke reversals, even in cases in which aerodynamic power exceeds inertial power. Despite lower stiffness estimates, our findings are widely consistent with previous stiffness measurements on insect wings but highlight the relationship between local flexural stiffness, wing deformation power and energy expenditure in flapping insect wings.
Lacey, Roy A; Wei, R; Ajitanand, N N; Alexander, J M; Gong, X; Jia, J; Mawi, A; Mohapatra, S; Reynolds, D; Salnikov, S; Taranenko, A
2009-10-01
The scaling properties of jet-suppression measurements are compared for nonphotonic electrons (e+/-) and neutral pions (pi(0)) in Au+Au collisions at sqrt[S(NN)]=200 GeV. For a broad range of transverse momenta and collision centralities, the comparison is consistent with jet quenching dominated by radiative energy loss for both heavy and light partons. Less quenching is indicated for heavy quarks via e+/-; this gives an independent estimate of the transport coefficient q that agrees with its magnitude obtained from quenching of light partons via pi(0)'s.
Collective Flow in Heavy Ion Collisions at Low to Relativistic Energies
Lisa, M. A.
1997-04-01
Recently, the phenomenon of collective flow in heavy ion collisions has been the subject of intense study. First observed at the Bevalac more than a decade ago, flow is now recognized as a universal feature of heavy ion collisions at all bombarding energies. Recent developments in three identified forms of flow-- sidewards flow, radial flow, and squeeze-out-- will be reviewed. At low energies (EOS and FOPI collaborations have considerably extended the work begun by the Plastic Ball group; here, studies of the flow of nucleons, fragments, and pions lead to a better understanding of the Equation of State of nuclear matter, momentum dependent interactions, and pion shadowing. The squeeze-out effect at Bevalac energies may be the most sensitive form of flow to the equation of state. Recent studies suggest that squeeze-out may be considered as an azimuthal modulation of the radial flow. The E895 collaboration is continuing the flow excitation function of the EOS/FOPI groups for 2-10 A GeV bombarding energies, with the aim of increasing the sensitivity to Equation of State parameters, as well as searching for flow signatures of Quark Gluon Plasma creation. Sidewards flow at the highest AGS energy for Au beams(11 A GeV) has been reported by the E877 collaboration, which has correlated the effect with pion interferometry measurements to identify possible dynamical correlations in the collision. Finally, at the highest energies currently available, the NA49 collaboration has found sidewards flow at SPS energies (160 A GeV); preliminary comparisons to RQMD calculations indicate that the model reproduces the flow well. At all of these bombarding energies (over 3 orders of magnitude!), the particle spectra show a strong non-thermal component which has been identified as largely isotropic or "radial" flow. While the sidewards flow accounts for only ~5% of emitted particles' energy, roughly 30-50% of the energy of emitted particles is found in radial flow. Several groups are
Gonthier, P L; Baring, M G; Costello, R M; Mercer, C L; Gonthier, Peter L.; Harding, Alice K.; Baring, Matthew G.; Costello, Rachel M.; Mercer, Cassandra L.
2000-01-01
This paper explores the effects of strong magnetic fields on the Compton scattering of relativistic electrons. Recent studies of upscattering and energy loss by relativistic electrons that have used the non-relativistic, magnetic Thomson cross section for resonant scattering or the Klein-Nishina cross section for non-resonant scattering do not account for the relativistic quantum effects of strong fields ($ > 4 \\times 10^{12}$ G). We have derived a simplified expression for the exact QED scattering cross section for the broadly-applicable case where relativistic electrons move along the magnetic field. To facilitate applications to astrophysical models, we have also developed compact approximate expressions for both the differential and total polarization-dependent cross sections, with the latter representing well the exact total QED cross section even at the high fields believed to be present in environments near the stellar surfaces of Soft Gamma-Ray Repeaters and Anomalous X-Ray Pulsars. We find that stron...
General Relativistic Energy Conditions The Hubble expansion in the epoch of galaxy formation
Visser, M
1997-01-01
The energy conditions of Einstein gravity (classical general relativity) are designed to extract as much information as possible from classical general relativity without enforcing a particular equation of state for the stress-energy. This systematic avoidance of the need to specify a particular equation of state is particularly useful in a cosmological setting --- since the equation of state for the cosmological fluid in a Friedmann-Robertson-Walker type universe is extremely uncertain. I shall show that the energy conditions provide simple and robust bounds on the behaviour of both the density and look-back time as a function of red-shift. I shall show that current observations suggest that the so-called strong energy condition (SEC) is violated sometime between the epoch of galaxy formation and the present. This implies that no possible combination of ``normal'' matter is capable of fitting the observational data.
Fu, Feichao; Zhu, Pengfei; Zhao, Lingrong; Jiang, Tao; Lu, Chao; Liu, Shengguang; Shi, Libin; Yan, Lixin; Deng, Haixiao; Feng, Chao; Gu, Qiang; Huang, Dazhang; Liu, Bo; Wang, Dong; Wang, Xingtao; Zhang, Meng; Zhao, Zhentang; Stupakov, Gennady; Xiang, Dao; Zhang, Jie
2015-01-01
High quality electron beams with flat distributions in both energy and current are critical for many accelerator-based scientific facilities such as free-electron lasers and MeV ultrafast electron diffraction and microscopes. In this Letter we report on using corrugated structures to compensate for the beam nonlinear energy chirp imprinted by the curvature of the radio-frequency field, leading to a significant reduction in beam energy spread. By using a pair of corrugated structures with orthogonal orientations, we show that the quadrupole wake fields which otherwise increase beam emittance can be effectively canceled. This work also extends the applications of corrugated structures to the low beam charge (a few pC) and low beam energy (a few MeV) regime and may have a strong impact in many accelerator-based facilities.
Spinless relativistic particle in energy-dependent potential and normalization of the wave function
Benchikha, Amar; Chetouani, Lyazid
2014-06-01
The problem of normalization related to a Klein-Gordon particle subjected to vector plus scalar energy-dependent potentials is clarified in the context of the path integral approach. In addition the correction relating to the normalizing constant of wave functions is exactly determined. As examples, the energy dependent linear and Coulomb potentials are considered. The wave functions obtained via spectral decomposition, were found exactly normalized.
Hamzavi, Majid
2012-01-01
The exact Dirac equation for the energy-dependent Coulomb (EDC) potential including a Coulomb-like tensor (CLT) potential has been studied in the presence of spin and pseudospin (p-spin) symmetries with arbitrary spin-orbit quantum number The energy eigenvalues and corresponding eigenfunctions are obtained in the framework of asymptotic iteration method (AIM). Some numerical results are obtained in the presence and absence of EDC and CLT potentials.
Energy loss and (de)coherence effects beyond eikonal approximation
Apolinário, Liliana, E-mail: lilianamarisa.cunha@usc.es [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); CENTRA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Armesto, Néstor [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Milhano, Guilherme [CENTRA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Physics Department, Theory Unit, CERN, CH-1211 Genéve 23 (Switzerland); Salgado, Carlos A. [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain)
2014-11-15
The parton branching process is known to be modified in the presence of a medium. Colour decoherence processes are known to determine the process of energy loss when the density of the medium is large enough to break the correlations between partons emitted from the same parent. In order to improve existing calculations that consider eikonal trajectories for both the emitter and the hardest emitted parton, we provide in this work the calculation of all finite energy corrections for the gluon radiation off a quark in a QCD medium that exist in the small angle approximation and for static scattering centres. Using the path integral formalism, all particles are allowed to undergo Brownian motion in the transverse plane and the offspring is allowed to carry an arbitrary fraction of the initial energy. The result is a general expression that contains both coherence and decoherence regimes that are controlled by the density of the medium and by the amount of broadening that each parton acquires independently.
Nicotinamide prevents ultraviolet radiation-induced cellular energy loss.
Park, Joohong; Halliday, Gary M; Surjana, Devita; Damian, Diona L
2010-01-01
UV radiation is carcinogenic by causing mutations in the skin and also by suppressing cutaneous antitumor immunity. We previously found nicotinamide (vitamin B3) to be highly effective at reducing UV-induced immunosuppression in human volunteers, with microarray studies on in vivo irradiated human skin suggesting that nicotinamide normalizes subsets of apoptosis, immune function and energy metabolism-related genes that are downregulated by UV exposure. Using human adult low calcium temperature keratinocytes, we further investigated nicotinamide's effects on cellular energy metabolism. We found that nicotinamide prevented UV-induced cellular ATP loss and protected against UV-induced glycolytic blockade. To determine whether nicotinamide alters the effects of UV-induced oxidative stress posttranslationally, we also measured UV-induced reactive oxygen species (ROS). Nicotinamide had no effect on ROS formation, and at the low UV doses used in these studies, equivalent to ambient daily sun exposure, there was no evidence of apoptosis. Hence, nicotinamide appears to exert its UV protective effects on the skin via its role in cellular energy pathways.
Energy loss and (de)coherence effects beyond eikonal approximation
Apolinário, Liliana; Milhano, Guilherme; Salgado, Carlos A.
2014-01-01
The parton branching process is known to be modified in the presence of a medium. Colour decoherence processes are known to determine the process of energy loss when the density of the medium is large enough to break the correlations between partons emitted from the same parent. In order to improve existing calculations that consider eikonal trajectories for both the emitter and the hardest emitted parton, we provide in this work, the calculation of all finite energy corrections for the gluon radiation off a quark in a QCD medium that exist in the small angle approximation and for static scattering centres. Using the path integral formalism, all particles are allowed to undergo Brownian motion in the transverse plane and the offspring allowed to carry an arbitrary fraction of the initial energy. The result is a general expression that contains both coherence and decoherence regimes that are controlled by the density of the medium and by the amount of broadening that each parton acquires independently.
Energy loss and (de)coherence effects beyond eikonal approximation
Apolinário, Liliana; Armesto, Néstor; Milhano, Guilherme; Salgado, Carlos A.
2014-11-01
The parton branching process is known to be modified in the presence of a medium. Colour decoherence processes are known to determine the process of energy loss when the density of the medium is large enough to break the correlations between partons emitted from the same parent. In order to improve existing calculations that consider eikonal trajectories for both the emitter and the hardest emitted parton, we provide in this work the calculation of all finite energy corrections for the gluon radiation off a quark in a QCD medium that exist in the small angle approximation and for static scattering centres. Using the path integral formalism, all particles are allowed to undergo Brownian motion in the transverse plane and the offspring is allowed to carry an arbitrary fraction of the initial energy. The result is a general expression that contains both coherence and decoherence regimes that are controlled by the density of the medium and by the amount of broadening that each parton acquires independently.
Physics of Nonmagnetic Relativistic Thermal Plasmas. Ph.D. Thesis - Calif. Univ., San Diego
Dermer, C. D.
1984-01-01
A detailed treatment of the kinematics of relativistic systems of particles and photons is presented. In the case of a relativistic Maxwell-Boltzmann distribution of particles, the reaction rate and luminosity are written as single integrals over the invariant cross section, and the production spectrum is written as a double integral over the cross section differential in the energy of the produced particles (or photons) in the center-of-momentum system of two colliding particles. The results are applied to the calculation of the annihilation spectrum of a thermal electron-positron plasma, confirming previous numerical and analytic results. Relativistic thermal electron-ion and electron-electron bremsstrahlung are calculated exactly to lowest order, and relativistic thermal electron-positron bremsstrahlung is calculated in an approximate fashion. An approximate treatment of relativistic Comptonization is developed. The question of thermalization of a relativistic plasma is considered. A formula for the energy loss or exchange rate from the interaction of two relativistic Maxwell-Boltzmann plasmas at different temperatures is derived. Application to a stable, uniform, nonmagnetic relativistic thermal plasma is made. Comparison is made with other studies.
Relativistic Hydrodynamics for Heavy-Ion Collisions
Ollitrault, Jean-Yves
2008-01-01
Relativistic hydrodynamics is essential to our current understanding of nucleus-nucleus collisions at ultrarelativistic energies (current experiments at the Relativistic Heavy Ion Collider, forthcoming experiments at the CERN Large Hadron Collider). This is an introduction to relativistic hydrodynamics for graduate students. It includes a detailed…
Potter, William J
2016-01-01
We calculate the severe radiative energy losses which occur at the base of black hole jets using a relativistic fluid jet model, including in-situ acceleration of non-thermal leptons by magnetic reconnection. Our results demonstrate that including a self-consistent treatment of radiative energy losses is necessary to perform accurate MHD simulations of powerful jets and that jet spectra calculated via post-processing are liable to vastly overestimate the amount of non-thermal emission. If no more than 95% of the initial total jet power is radiated away by the plasma travels as it travels along the length of the jet, we can place a lower bound on the magnetisation of the jet plasma at the base of the jet. For typical powerful jets, we find that the plasma at the jet base is required to be highly magnetised, with at least 10,000 times more energy contained in magnetic fields than in non-thermal leptons. Using a simple power-law model of magnetic reconnection, motivated by simulations of collisionless reconnecti...
High resolution electron energy loss spectroscopy with two-dimensional energy and momentum mapping
Zhu, Xuetao; Cao, Yanwei; Zhang, Shuyuan; Jia, Xun; Guo, Qinlin; Yang, Fang [Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhu, Linfan [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, Jiandi; Plummer, E. W. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70808 (United States); Guo, Jiandong, E-mail: jdguo@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100871 (China)
2015-08-15
High resolution electron energy loss spectroscopy (HREELS) is a powerful technique to probe vibrational and electronic excitations at surfaces. The dispersion relation of surface excitations, i.e., energy as a function of momentum, has in the past, been obtained by measuring the energy loss at a fixed angle (momentum) and then rotating sample, monochromator, or analyzer. Here, we introduce a new strategy for HREELS, utilizing a specially designed lens system with a double-cylindrical Ibach-type monochromator combined with a commercial VG Scienta hemispherical electron energy analyzer, which can simultaneously measure the energy and momentum of the scattered electrons. The new system possesses high angular resolution (<0.1°), detecting efficiency and sampling density. The capabilities of this system are demonstrated using Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ}. The time required to obtain a complete dispersion spectrum is at least one order of magnitude shorter than conventional spectrometers, with improved momentum resolution and no loss in energy resolution.
ANALYSIS OF STORAGE SYSYTEM INFLUENCE ON ENERGY LOSSES IN POWER SYSTEM (Part 1
A. M. Golubev
2014-01-01
Full Text Available The paper proposes methodology for evaluation of storage system influence on energy losses. The methodology makes it possible to investigate influence of some operational modes of devices on energy losses for a wide range of variants pertaining to reset conditions. The paper provides mathematical dependences that determine criteria for maximization of energy loss reduction.
Fast magnetic energy dissipation in relativistic plasma induced by high order laser modes
Y.J.Gu; Q.Yu; O.Klimo; T.Zh.Esirkepov; S.V.Bulanov; S.Weber; G.Korn
2016-01-01
Fast magnetic field annihilation in a collisionless plasma is induced by using TEM(1,0) laser pulse. The magnetic quadrupole structure formation, expansion and annihilation stages are demonstrated with 2.5-dimensional particle-in-cell simulations. The magnetic field energy is converted to the electric field and accelerate the particles inside the annihilation plane. A bunch of high energy electrons moving backwards is detected in the current sheet. The strong displacement current is the dominant contribution which induces the longitudinal inductive electric field.
On the Origins of the Planck Zero Point Energy in Relativistic Quantum Field Theory
Widom, A; Srivastava, Y N
2015-01-01
It is argued that the zero point energy in quantum field theory is a reflection of the particle anti-particle content of the theory. This essential physical content is somewhat disguised in electromagnetic theory wherein the photon is its own anti-particle. To illustrate this point, we consider the case of a charged Boson theory $(\\pi^+,\\pi^-)$ wherein the particle and anti-particle can be distinguished by the charge $\\pm e$. Starting from the zero point energy, we derive the Boson pair production rate per unit time per unit volume from the vacuum in a uniform external electric field. The result is further generalized for arbitrary spin $s$.
The Effect of Tensor Interaction in Splitting the Energy Levels of Relativistic Systems
Mohammad Reza Shojaei
2016-01-01
Full Text Available We solve approximately Dirac equation for Eckart plus Hulthen potentials with Coulomb-like and Yukawa-like tensor interaction in the presence of spin and pseudospin symmetry for k≠0. The formula method is used to obtain the energy eigenvalues and wave functions. We also discuss the energy eigenvalues and the Dirac spinors for Eckart plus Hulthen potentials with formula method. To show the accuracy of the present model, some numerical results are shown in both pseudospin and spin symmetry limits.
Safronova, U I; Johnson, W R
2016-01-01
Energy levels of 30 low-lying states of Lu2+ and allowed electric-dipole matrix elements between these states are evaluated using a relativistic all-order method in which all single, double and partial triple excitations of Dirac-Fock wave functions are included to all orders of perturbation theory. Matrix elements are critically evaluated for their accuracy and recommended values of the matrix elements are given together with uncertainty estimates. Line strengths, transition rates and lifetimes of the metastable 5d(3/2) and 5d(5/2) states are calculated. Recommended values are given for static polarizabilities of the 6s, 5d and 6p states and tensor polarizabilities of the 5d and 6p(3/2) states. Uncertainties of the polarizability values are estimated in all cases. The blackbody radiation shift of the 6s(1/2)-5d(5/2) transition frequency of the Lu2+ ion is calculated with the aid of the recommended scalar polarizabilities of the 6s(1/2) and 5d(5/2) states. Finally, A and B hyperfine constants are determined f...
Safronova, U. I.; Safronova, M. S.; Johnson, W. R.
2016-09-01
Energy levels of 30 low-lying states of Lu2 + and allowed electric-dipole matrix elements between these states are evaluated using a relativistic all-order method in which all single, double, and partial triple excitations of Dirac-Fock wave functions are included to all orders of perturbation theory. Matrix elements are critically evaluated for their accuracy and recommended values of the matrix elements are given together with uncertainty estimates. Line strengths, transition rates, and lifetimes of the metastable 5 d3 /2 and 5 d5 /2 states are calculated. Recommended values are given for static polarizabilities of the 6 s , 5 d , and 6 p states and tensor polarizabilities of the 5 d and 6 p3 /2 states. Uncertainties of the polarizability values are estimated in all cases. The blackbody radiation shift of the 6 s1 /2-5 d5 /2 transition frequency of the Lu2 + ion is calculated with the aid of the recommended scalar polarizabilities of the 6 s1 /2 and 5 d5 /2 states. Finally, A and B hyperfine constants are determined for states of 2+175Lu with n ≤9 . This work provides recommended values of transition matrix elements, polarizabilities, and hyperfine constants of Lu2 +, critically evaluated for accuracy, for benchmark tests of high-precision theoretical methodology and planning of future experiments.
Electron energy-loss spectroscopy of branched gap plasmon resonators
Raza, Søren; Esfandyarpour, Majid; Koh, Ai Leen; Mortensen, N. Asger; Brongersma, Mark L.; Bozhevolnyi, Sergey I.
2016-12-01
The miniaturization of integrated optical circuits below the diffraction limit for high-speed manipulation of information is one of the cornerstones in plasmonics research. By coupling to surface plasmons supported on nanostructured metallic surfaces, light can be confined to the nanoscale, enabling the potential interface to electronic circuits. In particular, gap surface plasmons propagating in an air gap sandwiched between metal layers have shown extraordinary mode confinement with significant propagation length. In this work, we unveil the optical properties of gap surface plasmons in silver nanoslot structures with widths of only 25 nm. We fabricate linear, branched and cross-shaped nanoslot waveguide components, which all support resonances due to interference of counter-propagating gap plasmons. By exploiting the superior spatial resolution of a scanning transmission electron microscope combined with electron energy-loss spectroscopy, we experimentally show the propagation, bending and splitting of slot gap plasmons.
Single-atom electron energy loss spectroscopy of light elements
Senga, Ryosuke; Suenaga, Kazu
2015-01-01
Light elements such as alkali metal (lithium, sodium) or halogen (fluorine, chlorine) are present in various substances and indeed play significant roles in our life. Although atomic behaviours of these elements are often a key to resolve chemical or biological activities, they are hardly visible in transmission electron microscope because of their smaller scattering power and higher knock-on probability. Here we propose a concept for detecting light atoms encaged in a nanospace by means of electron energy loss spectroscopy using inelastically scattered electrons. In this method, we demonstrate the single-atom detection of lithium, fluorine, sodium and chlorine with near-atomic precision, which is limited by the incident probe size, signal delocalization and atomic movement in nanospace. Moreover, chemical shifts of lithium K-edge have been successfully identified with various atomic configurations in one-dimensional lithium compounds. PMID:26228378
Single-atom electron energy loss spectroscopy of light elements.
Senga, Ryosuke; Suenaga, Kazu
2015-07-31
Light elements such as alkali metal (lithium, sodium) or halogen (fluorine, chlorine) are present in various substances and indeed play significant roles in our life. Although atomic behaviours of these elements are often a key to resolve chemical or biological activities, they are hardly visible in transmission electron microscope because of their smaller scattering power and higher knock-on probability. Here we propose a concept for detecting light atoms encaged in a nanospace by means of electron energy loss spectroscopy using inelastically scattered electrons. In this method, we demonstrate the single-atom detection of lithium, fluorine, sodium and chlorine with near-atomic precision, which is limited by the incident probe size, signal delocalization and atomic movement in nanospace. Moreover, chemical shifts of lithium K-edge have been successfully identified with various atomic configurations in one-dimensional lithium compounds.
Calculated and experimental low-loss electron energy loss spectra of dislocations in diamond and GaN
Jones, R; Gutiérrez-Sosa, A; Bangert, U; Heggie, M I; Blumenau, A T; Frauenheim, T; Briddon, P R
2002-01-01
First-principles calculations of electron energy loss (EEL) spectra for bulk GaN and diamond are compared with experimental spectra acquired with a scanning tunnelling electron microscope offering ultra-high-energy resolution in low-loss energy spectroscopy. The theoretical bulk low-loss EEL spectra, in the E sub g to 10 eV range, are in good agreement with experimental data. Spatially resolved spectra from dislocated regions in both materials are distinct from bulk spectra. The main effects are, however, confined to energy losses lying above the band edge. The calculated spectra for low-energy dislocations in diamond are consistent with the experimental observations, but difficulties remain in understanding the spectra of threading dislocations in GaN.
Energy Loss Effect in High-Energy Drell-Yan Dimuon Process
DUAN Chun-Gui; WANG Hong-Min
2002-01-01
By means of the nuclear parton distribution obtained from DGLAP equation,measured Drell Yan production cross sections for 800 GeV proton incident on a variety of nuclear targets are analyzed within Glauber framework which takes into account energy loss of the beam proton.It is shown that the theoretical results are in good agreement with the FNAL E866.
Radiation reaction in a system of relativistic gravitating particles
Galtsov, D.V.
1983-01-01
A Lorentz-covariant approach is developed to the description of electromagnetic and gravitational radiation in general relativity. A model of a relativistic system of gravitating point particles is constructed in which energy losses can be interpreted in terms of radiation-reaction forces. These forces are applied not only to the point particles but also to fields generated by these particles in the near zone. It is concluded that radiation friction in a system of relativistic gravitating particles is collective in character. 16 references.
Thermal right-handed neutrino self-energy in the non-relativistic regime
Laine, M
2012-01-01
Recently the issue of radiative corrections to leptogenesis has been raised. Considering the "strong washout" regime, in which OPE-techniques permit to streamline the setup, we report the thermal self-energy matrix of heavy right-handed neutrinos at NLO (resummed 2-loop level) in Standard Model couplings. The renormalized expression describes flavour transitions and "inclusive" decays of chemically decoupled right-handed neutrinos. Although CP-violation is not addressed, the result may find use in existing leptogenesis frameworks.
The Fracture Influence on the Energy Loss of Compressed Air Energy Storage in Hard Rock
Hehua Zhu
2015-01-01
Full Text Available A coupled nonisothermal gas flow and geomechanical numerical modeling is conducted to study the influence of fractures (joints on the complex thermohydromechanical (THM performance of underground compressed air energy storage (CAES in hard rock caverns. The air-filled chamber is modeled as porous media with high porosity, high permeability, and high thermal conductivity. The present analysis focuses on the CAES in hard rock caverns at relatively shallow depth, that is, ≤100 m, and the pressure in carven is significantly higher than ambient pore pressure. The influence of one discrete crack and multiple crackson energy loss analysis of cavern in hard rock media are carried out. Two conditions are considered during each storage and release cycle, namely, gas injection and production mass being equal and additional gas injection supplemented after each cycle. The influence of the crack location, the crack length, and the crack open width on the energy loss is studied.
Pramono, Subur; Cari, Cari
2016-01-01
In this work, we study the exact solution of Dirac equation in the hyper-spherical coordinate under influence of separable q-Deformed quantum potentials. The q-deformed hyperbolic Rosen-Morse potential is perturbed by q-deformed non-central trigonometric Scarf potentials, where whole of them can be solved by using Asymptotic Iteration Method (AIM). This work is limited to spin symmetry case. The relativistic energy equation and orbital quantum number equation lD-1 have been obtained using Asymptotic Iteration Method. The upper radial wave function equations and angular wave function equations are also obtained by using this method. The relativistic energy levels are numerically calculated using Mat Lab, the increase of radial quantum number n causes the increase of bound state relativistic energy level both in dimension D = 5 and D = 3. The bound state relativistic energy level decreases with increasing of both deformation parameter q and orbital quantum number nl.
Structural Variations to a Donor Polymer with Low Energy Losses
Bazan, Guillermo C
2017-08-01
Two regioregular narrow band gap conjugated polymers with a D’-A-D-A repeat unit architecture, namely PIFCF and PSFCF, were designed and synthesized. Both polymers contain strictly organized fluorobenzo[c][1,2,5]thiadiazole (FBT) orientations and different solubilizing side chains for solution processing. Compared to the previously reported asymmetric pyridyl-[2,1,3]thiadiazole (PT) based regioregular polymer, namely PIPCP, PIFCF and PSFCF exhibit wider band gaps, tighter π-π stacking, and improved hole mobilities. When incorporated into solar cells with fullerene acceptors, the Eloss = Eg - eVoc values of PIFCF and PSFCF devices are increased compared to solar cells based on PIPCP. Determination of Ect in these solar cells reveals that, relative to PIPCP, PIFCF solar cells lose more energy from Eg - Ect, and PSFCF solar cells lose more energy from both Eg - Ect and Ect - eVoc. The close structural relationship between PIPCP and PIFCF provides an excellent framework to establish molecular features that impact the relationship between Eg and Ect. Theoretical calculations predict that Eloss of PIFCF:PC61BM would be higher than in the case of PIPCP:PC61BM, due to greater Eg - Ect. These findings provide insight into the design of high performance, low voltage loss photovoltaic polymeric materials with desirable optoelectronic properties.
Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, H. F.; Cheng, J.; Cherney, M.; Christie, W.; Codrington, M. J. M.; Contin, G.; Crawford, H. J.; Cui, X.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, X.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, Z. M.; Li, X.; Li, W.; Li, Y.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R. M.; Ma, Y. G.; Magdy, N.; Mahapatra, D. P.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solanki, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X. M.; Sun, Z.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Takahashi, J.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, H.; Wang, F.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, N.; Xu, Z.; Xu, H.; Xu, Y.; Xu, Q. H.; Yan, W.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Z. P.; Zhang, J. B.; Zhang, J. L.; Zhang, Y.; Zhang, S.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, Y. H.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration
2016-08-01
Balance functions have been measured in terms of relative pseudorapidity (Δ η ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at √{sNN}=7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at √{sNN}=2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at √{sNN}=7.7 GeV implies that a QGP is still being created at this relatively low energy.
Maczyszyn A.
2016-04-01
Full Text Available This paper shows application of the method of sum of power losses to determining energy losses which occur in hydraulic rotary motor in situation when not all laboratory data are at one’s disposal or when no use is made of data contained in catalogue charts. The method makes it possible to determine the coefficients, ki, of energy losses occurring in the motor. The method of sum of power losses is based on the approach proposed by Z. Paszota, in the papers [3 ÷ 9]. It consists in adding power flow of energy losses occurring in the motor to power flow output and comparing the sum to the power flow input. Application of the method is exemplified by using a A6VM hydraulic motor.
Fang He
2016-07-01
Full Text Available Integrating wave energy converters with breakwaters is a promising concept for wave energy utilization. On the basis of fulfilling the wave protection demands, pile-supported Oscillating Water Column (OWC-type breakwaters can also meet the local needs of electricity far from the lands. In the present study, the wave energy extraction and vortex-induced energy loss of pile-supported OWC-type breakwaters were analyzed based on a two-point measurement method. The importance of energy extraction and vortex-induced energy loss on the wave energy dissipation of pile-supported OWC-type breakwaters were experimentally investigated. It was found that the trends of energy extraction and vortex-induced energy loss were generally correlated. The effects of the pneumatic damping induced by top opening affected the vortex-induced energy loss more than the energy extraction. Results showed that a larger pneumatic damping was preferable for the purpose of increasing energy extraction, whereas for a smaller pneumatic damping the vortex-induced energy loss was more important to the energy dissipation. With increasing draft, the energy extraction decreased, but the vortex-induced energy loss complementally contributed to the total energy dissipation and made the energy dissipation at the same level as that for a shallower draft.
Fabian, A C; Parker, M L
2014-01-01
Broad emission lines, particularly broad iron-K lines, are now commonly seen in the X-ray spectra of luminous AGN and Galactic black hole binaries. Sensitive NuSTAR spectra over the energy range of 3-78 keV and high frequency reverberation spectra now confirm that these are relativistic disc lines produced by coronal irradiation of the innermost accretion flow around rapidly spinning black holes. General relativistic effects are essential in explaining the observations. Recent results are briefly reviewed here.
A ’Relativistic Mirror’ Experiment with Frequency Tuning and Energy Gain.
1977-09-01
enhanced by an even greater factor than the scattered energy : Pr/ ’Pi (1 + ~)4 ~ 4 • In this paper we report an experimental study of electro- magnetic...the artifice of greatly reducing Vph ~ the phase velocity in the wave—plasma interaction region , so that v/v Ph could ap- proach unity. Now , however...nearly a factor of 3. Thus, although the in- tensity profile implies a total reflected power of — 700 kW , the actual value is only known with certainty
Liu, Jing-Jing; Gu, Wei-Min
2016-06-01
Based on the relativistic mean-field effective interactions theory, and the Lai dong model, we discuss the influences of superstrong magnetic fields (SMFs) on electron Fermi energy, nuclear blinding energy, and single-particle level structure in magnetar surfaces. Using the Shell-Model Monte Carlo method and the Random Phase Approximation theory, we analyze the neutrino energy loss rates (NELRs) by electron capture for iron group nuclei in SMFs. First, when B 12 100, the NELRs decrease by more than three orders of magnitude (e.g., at T 9 = 15.53 for 52-61Fe, 55-60Co, and 56-63Ni). Second, for a certain value of magnetic field and temperature, the NELRs increase by more than four orders of magnitude when {ρ }7≤slant {10}3, but as the density increases (i.e., when {ρ }7\\gt {10}3), there is almost no influence on the density of NELRs. For the density around {ρ }7={10}2, there is an abrupt increase in NELRs when B 12 ≥ 103.5. Such jumps are an indication that the underlying shell structure has changed due to single-particle behavior by SMFs. Finally, we compare our NELRs with those of Fuller et al. (FFN) and Nabi & Klapdor-Kleingrothaus (NKK). For the case without SMFs, one finds that our rates for certain nuclei are close to about five orders of magnitude lower than FFN and NKK at relativistic low temperatures (e.g., T 9 = 1). However, at a relativistic high temperature (e.g., T 9 = 3), our results are in good agreement with NKK, but about one order of magnitude lower than FFN. For the case with SMFs, our NELRs for some iron group nuclei can be about five orders of magnitude higher than those of FFN and NKK. (Note that B 12, T 9, and ρ 7 are in units of 1012 G, 109 K, and {10}7 {{g}} {{cm}}-3, respectively.)
New developments in energy transfer and transport studies in relativistic laser-plasma interactions
Norreys, P. A.; Green, J. S.; Lancaster, K. L.; Robinson, A. P. L.; Scott, R. H. H.; Perez, F.; Schlenvoight, H.-P.; Baton, S.; Hulin, S.; Vauzour, B.; Santos, J. J.; Adams, D. J.; Markey, K.; Ramakrishna, B.; Zepf, M.; Quinn, M. N.; Yuan, X. H.; McKenna, P.; Schreiber, J.; Davies, J. R.; Higginson, D. P.; Beg, F. N.; Chen, C.; Ma, T.; Patel, P.
2010-12-01
Two critical issues related to the success of fast ignition inertial fusion have been vigorously investigated in a co-ordinated campaign in the European Union and the United States. These are the divergence of the fast electron beam generated in intense, PW laser-plasma interactions and the fast electron energy transport with the use of high intensity contrast ratio laser pulses. Proof is presented that resistivity gradient-induced magnetic fields can guide fast electrons over significant distances in (initially) cold metallic targets. Comparison of experiments undertaken in both France and the United States suggests that an important factor in obtaining efficient coupling into dense plasma is the irradiation with high intensity contrast ratio laser pulses, rather than the colour of the laser pulse itself.
Electron acceleration to relativistic energies at a strong quasi-parallel shock wave
Masters, A; Fujimoto, M; Schwartz, S J; Sergis, N; Thomsen, M F; Retinò, A; Hasegawa, H; Lewis, G R; Coates, A J; Canu, P; Dougherty, M K
2013-01-01
Electrons can be accelerated to ultrarelativistic energies at strong (high-Mach number) collisionless shock waves that form when stellar debris rapidly expands after a supernova. Collisionless shock waves also form in the flow of particles from the Sun (the solar wind), and extensive spacecraft observations have established that electron acceleration at these shocks is effectively absent whenever the upstream magnetic field is roughly parallel to the shock surface normal (quasi-parallel conditions). However, it is unclear whether this magnetic dependence of electron acceleration also applies to the far stronger shocks around young supernova remnants, where local magnetic conditions are poorly understood. Here we present Cassini spacecraft observations of an unusually strong solar system shock wave (Saturn's bow shock) where significant local electron acceleration has been confirmed under quasi-parallel magnetic conditions for the first time, contradicting the established magnetic dependence of electron accele...
Daily energy expenditure, physical activity, and weight loss in Parkinson's disease patients
Patients with Parkinson's disease (PD) commonly exhibit weight loss (WL) which investigators attribute to various factors, including elevated energy expenditure. We tested the hypothesis that daily energy expenditure (DEE) and its components, resting energy expenditure (REE) and physical activity (P...
Parametric study of minimum converter loss in an energy-storage dc-to-dc converter
Wong, R. C.; Owen, H. A., Jr.; Wilson, T. G.
1982-01-01
Through a combination of analytical and numerical minimization procedures, a converter design that results in the minimum total converter loss (including core loss, winding loss, capacitor and energy-storage-reactor loss, and various losses in the semiconductor switches) is obtained. Because the initial phase involves analytical minimization, the computation time required by the subsequent phase of numerical minimization is considerably reduced in this combination approach. The effects of various loss parameters on the optimum values of the design variables are also examined.
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...
Herrera, L
2011-01-01
We identify the factors responsible for the appearance of energy-density inhomogeneities in a self-gravitating fluid, and describe the evolution of those factors from an initially homogeneous distribution. It is shown that a specific combination of the Weyl tensor and/or local anisotropy of pressure and/or dissipative fluxes entails the formation of energy-density inhomogeneities. Different cases are analyzed in detail and in the particular case of dissipative fluids, the role of relaxational processes as well as non-local effects are brought out.
Parton cascade description of relativistic heavy-ion collisions at CERN SPS energies?
Kinder-Geiger, Klaus; Geiger, Klaus; Srivastava, Dinesh Kumar
1997-01-01
We examine Pb+Pb collisions at CERN SPS energy 158 A GeV, by employing the earlier developed and recently refined parton-cascade/cluster-hadronization model and its Monte Carlo implementation. This space-time model involves the dynamical interplay of perturbative QCD parton production and evolution, with non-perturbative parton-cluster formation and hadron production through cluster decays. Using computer simulations, we are able to follow the entwined time-evolution of parton and hadron degrees of freedom in both position and momentum space, from the instant of nuclear overlap to the final yield of particles. We present and discuss results for the multiplicity distributions, which agree well with the measured data from the CERN SPS, including those for K mesons. The transverse momentum distributions of the produced hadrons are also found to be in good agreement with the preliminary data measured by the NA49 and the WA98 collaboration for the collision of lead nuclei at the CERN SPS. The analysis of the time ...
The central engine of GRB 130831A and the energy breakdown of a relativistic explosion
De Pasquale, M; Racusin, J L; Kann, D A; Zhang, B; Pozanenko, A; Volnova, A A; Trotter, A; Frank, N; Cucchiara, A; Troja, E; Sbarufatti, B; Butler, N R; Schulze, S; Cano, Z; Page, M J; Castro-Tirado, A J; Gorosabel, J; Lien, A; Fox, O; Littlejohns, O; Bloom, J S; Prochaska, J X; de Diego, J A; Gonzalez, J; Richer, M G; Román-Zúñiga, C; Watson, A M; Gehrels, N; Moseley, H; Kutyrev, A; Zane, S; Hoette, V; Russell, R R; Rumyantsev, V; Klunko, E; Burkhonov, O; Breeveld, A A; Reichart, D E; Haislip, J B
2015-01-01
Gamma-ray bursts (GRBs) are the most luminous explosions in the universe, yet the nature and physical properties of their energy sources are far from understood. Very important clues, however, can be inferred by studying the afterglows of these events. We present optical and X-ray observations of GRB 130831A obtained by Swift, Chandra, Skynet, RATIR, Maidanak, ISON, NOT, LT and GTC. This burst shows a steep drop in the X-ray light-curve at $\\simeq 10^5$ s after the trigger, with a power-law decay index of $\\alpha \\sim 6$. Such a rare behaviour cannot be explained by the standard forward shock (FS) model and indicates that the emission, up to the fast decay at $10^5$ s, must be of "internal origin", produced by a dissipation process within an ultrarelativistic outflow. We propose that the source of such an outflow, which must produce the X-ray flux for $\\simeq 1$ day in the cosmological rest frame, is a newly born magnetar or black hole. After the drop, the faint X-ray afterglow continues with a much shallower...
Low energy electron loss peaks of CuInTe/sub 2/
Kleint, C. (Karl-Marx-Universitaet, Leipzig (German Democratic Republic). Sektion Physik); Schulze, S. (Technische Hochschule, Karl-Marx-Stadt (German Democratic Republic). Sektion Physik/Elektronische Bauelemente); Tomlinson, R.D. (Salford Univ. (UK). Dept. of Electrical Engineering)
1982-09-01
Reflection low energy electron loss spectra were observed from CuInTe/sub 2/ monocrystals. The spectra were taken with a LEED system to obtain the first derivative of the scattered electron energy distribution using primary energies of 50, 90, and 190 eV. The second derivative and the loss maxima energies have been determined after a smoothing procedure. The loss peaks are coordinated to plasmon features, surfaces states, and interband transitions.
SAMPEX relativistic micorbursts: PET spectra and comparison to DREP and balloon microbursts
Liang, X.; Comess, M.; Smith, D. M.; Selesnick, R. S.; Sample, J. G.; Millan, R. M.
2011-12-01
Relativistic(> 1 MeV) electron microbursts may account for significant relativistic electron losses from the outer belt. We will present the spectral characteristics of relativistic microbursts observed with the Proton/Electron telescope (PET) on board the Solar Anomalous Magnetospheric Particle Explorer (SAMPEX) satellite from 1992 to 2004. We find that these events, concentrated in the morning sector, are well fitted by an exponential spectrum with e-folding energies of 100-375 keV in the 0.5-4 MeV range. We have compared the time-averaged precipitation rate from relativistic microbursts with the time-avearged rate from duskside Relativistic Electron Precipitation (DREP), and find that microbursts appear more important 100 keV microburst e-folding energies contrast with 16 hours of microburst data from the MeV Auroral X-ray Imaging and Spectroscopy (MAXIS) balloon campaign, which show exponential microburst spectra with folding energies ranging from 50-105 keV. We used the Monte Carlo simulation package GEANT3 calculate the count-rate spectra that would have been expected from MAXIS from the SAMPEX microburst spectra. We use these simulations to address the apparent contradictions between the satellite and balloon pictures of microbursts in anticipation of the upcoming flights of the Balloon Array for RBSP Relativistic Electron Losses (BARREL).
Energy-loss measurement with the ZEUS Central Tracking Detector
Bartsch, D.
2007-05-15
The measurement of the specific energy loss due to ionisation, dE/dx, in a drift chamber is a very important tool for particle identification in final states of reactions between high energetic particles. Such identification requires a well understood dE/dx measurement including a precise knowledge of its uncertainties. Exploiting for the first time the full set of ZEUS data from the HERA operation between 1996 and 2005 twelve detector-related influences affecting the dE/dx measurement of the ZEUS Central Tracking Detector have been identified, separately studied and parameterised. A sophisticated iterative procedure has been developed to correct for these twelve effects, which takes into account the correlations between them. A universal parameterisation of the detector-specific Bethe-Bloch curve valid for all particle species has been extracted. In addition, the various contributions to the measurement uncertainty have been disentangled and determined. This yields the best achievable prediction for the single-track dE/dx resolution. For both the analysis of the measured data and the simulation of detector performance, the detailed understanding of the measurement and resolution of dE/dx gained in this work provides a tool with optimum power for particle identification in a physics studies. (orig.)
Honda, Takashi; Itatani, Keiichi; Takanashi, Manabu; Kitagawa, Atsushi; Ando, Hisashi; Kimura, Sumito; Oka, Norihiko; Miyaji, Kagami; Ishii, Masahiro
2017-10-01
Vector flow mapping is a novel echocardiographic flow visualization method, and it has enabled us to quantitatively evaluate the energy loss in the left ventricle (intraventricular energy loss). Although intraventricular energy loss is assumed to be a part of left ventricular workload itself, it is unclear what this parameter actually represents. The aim of the present study was to elucidate the characteristics of intraventricular energy loss. We enrolled 26 consecutive children with ventricular septal defect (VSD). On echocardiography vector flow mapping, intraventricular energy loss was measured in the apical 3-chamber view. We measured peak energy loss and averaged energy loss in the diastolic and systolic phases, and subsequently compared these parameters with catheterization parameters and serum brain natrium peptide (BNP) level. Diastolic, peak, and systolic energy loss were strongly and positively correlated with right ventricular systolic pressure (r=0.76, 0.68, and 0.56, penergy loss were significantly correlated with BNP (r=0.75, 0.69 and 0.49, penergy loss in the left ventricle. The results of the present study encourage further studies in other study populations to elucidate the characteristics of intraventricular energy loss for its possible clinical application. Copyright © 2017 Elsevier B.V. All rights reserved.
Investigation of Relativistic Electron Resonance with EMIC Waves
Woodger, L. A.; Millan, R. M.; Denton, R. E.
2008-12-01
Wave-particle interaction of relativistic electrons with EMIC waves has been proposed as an important loss mechanism for radiation belt electrons (e.g. Thorne and Andreoli, 1980). Lorentzen et al (2000) and Millan et al (2002) suggested this mechanism to be responsible for dusk side relativistic electron precipitation (REP) detected by balloon borne instrumentation. This study will use the linear electromagnetic dispersion code WHAMP to investigate the effects of density, magnetic field, anisotropy, and heavy ions on the minimum resonance energy for relativistic electrons with EMIC waves. Results will be compared with observations of REP during the MAXIS balloon campaign on Jan. 19, 2000 and the MINIS balloon campaign on Jan. 21, 2005.
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.
Bipolar energy-loss measurements on cryostable, low-loss conductors
Wollan, J. J.
1981-11-01
Losses have been measured on a prototype conductor for the 20 MJ coil for conditions which simulate closely the actual coil field sweep. The data on the prototype II conductor indicates coil losses which exceed the coil specification. The application of certain correction factors reduces the projected losses within the specification for a 2 s reversal but not for a 1 s reversal. Verification of these corrections await measurements on the actual strand and completion of coil construction and testing.
Bipolar energy-loss measurements on cryostable, low-loss conductors
Wollan, J.J.
1981-01-01
Losses have been measured on a prototype conductor for the 20 MJ coil for conditions which simulate closely the actual coil field sweep. The data on the prototype II conductor indicates coil losses which exceed the coil specification. The application of certain correction factors reduces the projected losses within the specification for a 2 s reversal but not for a 1 s reversal. Verification of these corrections await measurements on the actual strand and completion of coil construction and testing.
Kovács, Z.; Harko, T.
2011-11-01
We present a full general relativistic numerical code for estimating the energy-momentum deposition rate (EMDR) from neutrino pair annihilation (?). The source of the neutrinos is assumed to be a neutrino-cooled accretion disc around neutron and quark stars. We calculate the neutrino trajectories by using a ray-tracing algorithm with the general relativistic Hamilton's equations for neutrinos and derive the spatial distribution of the EMDR due to the annihilations of neutrinos and antineutrinos around rotating neutron and quark stars. We obtain the EMDR for several classes of rotating neutron stars, described by different equations of state of the neutron matter, and for quark stars, described by the Massachusetts Institute of Technology (MIT) bag model equation of state and in the colour-flavour-locked (CFL) phase. The distribution of the total annihilation rate of the neutrino-antineutrino pairs around rotating neutron and quark stars is studied for isothermal discs and accretion discs in thermodynamical equilibrium. We demonstrate both the differences in the equations of state for neutron and quark matter and rotation with the general relativistic effects significantly modify the EMDR of the electrons and positrons generated by the neutrino-antineutrino pair annihilation around compact stellar objects, as measured at infinity.
Generalized One-Dimensional Point Interaction in Relativistic and Non-relativistic Quantum Mechanics
Shigehara, T; Mishima, T; Cheon, T; Cheon, Taksu
1999-01-01
We first give the solution for the local approximation of a four parameter family of generalized one-dimensional point interactions within the framework of non-relativistic model with three neighboring $\\delta$ functions. We also discuss the problem within relativistic (Dirac) framework and give the solution for a three parameter family. It gives a physical interpretation for so-called high energy substantially differ between non-relativistic and relativistic cases.
Charge exchange and energy loss of slow highly charged ions in 1 nm thick carbon nanomembranes.
Wilhelm, Richard A; Gruber, Elisabeth; Ritter, Robert; Heller, René; Facsko, Stefan; Aumayr, Friedrich
2014-04-18
Experimental charge exchange and energy loss data for the transmission of slow highly charged Xe ions through ultrathin polymeric carbon membranes are presented. Surprisingly, two distinct exit charge state distributions accompanied by charge exchange dependent energy losses are observed. The energy loss for ions exhibiting large charge loss shows a quadratic dependency on the incident charge state indicating that equilibrium stopping force values do not apply in this case. Additional angle resolved transmission measurements point on a significant contribution of elastic energy loss. The observations show that regimes of different impact parameters can be separated and thus a particle's energy deposition in an ultrathin solid target may not be described in terms of an averaged energy loss per unit length.
Au + Au central collisions at 150, 250 and 400 AMeV energies in QMD with relativistic forces
Németh, J; Feldmeier, H
1999-01-01
An extensive comparison of the recent experimental data published by the FOPI collaboration at GSI with the results of a relativistically covariant formulation of a QMD code is presented. For most of the quantities we find agreement with the experimental results showing that the derived force has a reasonable momentum dependence.
Mori, M; Daito, I; Kotaki, H; Hayashi, Y; Yamazaki, A; Ogura, K; Sagisaka, A; Koga, J; Nakajima, K; Daido, H; Bulanov, S V; Kimura, T
2006-01-01
The regimes of quasi-mono-energetic electron beam generation were experimentally studied in the sub-relativistic intensity laser plasma interaction. The observed electron acceleration regime is unfolded with two-dimensional-particle-in-cell simulations of laser-wakefield generation in the self-modulation regime.
INVERSE CASCADE OF NONHELICAL MAGNETIC TURBULENCE IN A RELATIVISTIC FLUID
Zrake, Jonathan [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Menlo Park, CA 94025 (United States)
2014-10-20
The free decay of nonhelical relativistic magnetohydrodynamic turbulence is studied numerically, and found to exhibit cascading of magnetic energy toward large scales. Evolution of the magnetic energy spectrum P{sub M} (k, t) is self-similar in time and well modeled by a broken power law with subinertial and inertial range indices very close to 7/2 and –2, respectively. The magnetic coherence scale is found to grow in time as t {sup 2/5}, much too slow to account for optical polarization of gamma-ray burst afterglow emission if magnetic energy is to be supplied only at microphysical length scales. No bursty or explosive energy loss is observed in relativistic MHD turbulence having modest magnetization, which constrains magnetic reconnection models for rapid time variability of GRB prompt emission, blazars, and the Crab nebula.
Relativistic non-equilibrium thermodynamics revisited
García-Colin, L S
2006-01-01
Relativistic irreversible thermodynamics is reformulated following the conventional approach proposed by Meixner in the non-relativistic case. Clear separation between mechanical and non-mechanical energy fluxes is made. The resulting equations for the entropy production and the local internal energy have the same structure as the non-relativistic ones. Assuming linear constitutive laws, it is shown that consistency is obtained both with the laws of thermodynamics and causality.
Collisional Energy Loss of a Heavy Quark in an Anisotropic Quark-Gluon Plasma
Romatschke, P; Romatschke, Paul; Strickland, Michael
2004-01-01
We compute the leading-order collisional energy loss of a heavy quark propagating through a quark-gluon plasma in which the quark and gluon distributions are anisotropic in momentum space. Following the calculation outlined for QED in an earlier work we indicate the differences encountered in QCD and their effect on the collisional energy loss results. For a 20 GeV bottom quark we show that momentum space anisotropies can result in the collisional heavy quark energy loss varying with the angle of propagation by up to 50%. For low velocity quarks we show that anisotropies result in energy gain instead of energy loss with the energy gain focused in such a way as to accelerate particles along the anisotropy direction thereby reducing the momentum-space anisotropy. The origin of this negative energy loss is explicitly identified as being related to the presence of plasma instabilities in the system.
Stellar energy loss rates in the pair-annihilation process beyond the standard model
Hernández-Ruíz, M. A.; Gutiérrez-Rodríguez, A.; González-Sánchez, A.
2017-01-01
We calculate the stellar energy loss due to neutrino-pair production in e+e- annihilation in the context of a 331 model, a left-right symmetric model and a simplest little Higgs model in a way that can be used in supernova calculations. We also present some simple estimates which show that such process can act as an efficient energy loss mechanism in the shocked supernova core. We find that the stellar energy loss is almost independent of the parameters of the models in the allowed range for these parameters. This work complements other studies on the stellar energy loss rate in e+e- annihilation.
Wagner, F; Deppert, O; Brabetz, C; Fiala, P; Kleinschmidt, A; Poth, P; Schanz, V A; Tebartz, A; Zielbauer, B; Roth, M; Stöhlker, T; Bagnoud, V
2016-05-20
We present a study of laser-driven ion acceleration with micrometer and submicrometer thick plastic targets. Using laser pulses with high temporal contrast and an intensity of the order of 10^{20} W/cm^{2} we observe proton beams with cutoff energies in excess of 85 MeV and particle numbers of 10^{9} in an energy bin of 1 MeV around this maximum. We show that applying the target normal sheath acceleration mechanism with submicrometer thick targets is a very robust way to achieve such high ion energies and particle fluxes. Our results are backed with 2D particle in cell simulations furthermore predicting cutoff energies above 200 MeV for acceleration based on relativistic transparency. This predicted regime can be probed after a few technically feasible adjustments of the laser and target parameters.
Kotikov, A V
2013-01-01
We compute the two-loop fermion self-energy in massless reduced quantum electrodynamics for an arbitrary gauge using the method of integration by parts. Focusing on the limit where the photon field is four-dimensional, our formula involves only recursively one-loop integrals and can therefore be evaluated exactly. From this formula, we deduce the anomalous scaling dimension of the fermion field as well as the renormalized fermion propagator up to two loops. The results are then applied to the ultra-relativistic limit of graphene and compared with similar results obtained for four-dimensional and three-dimensional quantum electrodynamics.
Buehring, W.
1983-03-01
Non-relativistic scattering phase shifts, bound state energies, and wave function normalization factors for a screened Coulomb potential of the Hulthen type are presented in the form of relatively simple analytic expressions. These formulae have been obtained by a suitable renormalization procedure applied to the quantities derived from an approximate Schroedinger equation which contains the exact Hulthen potential together with an approximate angular momentum term. When the screening exponent vanishes, our formulae reduce to the exact Coulomb expresions. The interrelation between our formulae and Pratt's analytic perturbation theory for screened Coulomb potentials' is discussed.
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.
Ulf Elbelt
2015-07-01
Full Text Available Reduced physical activity and almost unlimited availability of food are major contributors to the development of obesity. With the decline of strenuous work, energy expenditure due to spontaneous physical activity has attracted increasing attention. Our aim was to assess changes in energy expenditure, physical activity patterns and nutritional habits in obese subjects aiming at self-directed weight loss. Methods: Energy expenditure and physical activity patterns were measured with a portable armband device. Nutritional habits were assessed with a food frequency questionnaire. Results: Data on weight development, energy expenditure, physical activity patterns and nutritional habits were obtained for 105 patients over a six-month period from an initial cohort of 160 outpatients aiming at weight loss. Mean weight loss was −1.5 ± 7.0 kg (p = 0.028. Patients with weight maintenance (n = 75, with substantial weight loss (>5% body weight, n = 20 and with substantial weight gain (>5% body weight, n = 10 did not differ in regard to changes of body weight adjusted energy expenditure components (total energy expenditure: −0.2 kcal/kg/day; non-exercise activity thermogenesis: −0.3 kcal/kg/day; exercise-related activity thermogenesis (EAT: −0.2 kcal/kg/day or patterns of physical activity (duration of EAT: −2 min/day; steps/day: −156; metabolic equivalent unchanged measured objectively with a portable armband device. Self-reported consumption frequency of unfavorable food decreased significantly (p = 0.019 over the six-month period. Conclusions: An increase in energy expenditure or changes of physical activity patterns (objectively assessed with a portable armband device are not employed by obese subjects to achieve self-directed weight loss. However, modified nutritional habits could be detected with the use of a food frequency questionnaire.
Jones, Bernard J. T.; Markovic, Dragoljub
1997-06-01
Preface; Prologue: Conference overview Bernard Carr; Part I. The Universe At Large and Very Large Redshifts: 2. The size and age of the Universe Gustav A. Tammann; 3. Active galaxies at large redshifts Malcolm S. Longair; 4. Observational cosmology with the cosmic microwave background George F. Smoot; 5. Future prospects in measuring the CMB power spectrum Philip M. Lubin; 6. Inflationary cosmology Michael S. Turner; 7. The signature of the Universe Bernard J. T. Jones; 8. Theory of large-scale structure Sergei F. Shandarin; 9. The origin of matter in the universe Lev A. Kofman; 10. New guises for cold-dark matter suspects Edward W. Kolb; Part II. Physics and Astrophysics Of Relativistic Compact Objects: 11. On the unification of gravitational and inertial forces Donald Lynden-Bell; 12. Internal structure of astrophysical black holes Werner Israel; 13. Black hole entropy: external facade and internal reality Valery Frolov; 14. Accretion disks around black holes Marek A. Abramowicz; 15. Black hole X-ray transients J. Craig Wheeler; 16. X-rays and gamma rays from active galactic nuclei Roland Svensson; 17. Gamma-ray bursts: a challenge to relativistic astrophysics Martin Rees; 18. Probing black holes and other exotic objects with gravitational waves Kip Thorne; Epilogue: the past and future of relativistic astrophysics Igor D. Novikov; I. D. Novikov's scientific papers and books.
Trajectory-dependent energy loss for swift He atoms axially scattered off a silver surface
Ríos Rubiano, C.A. [Instituto de Astronomía y Física del Espacio (CONICET-UBA), Casilla de correo 67, sucursal 28, 1428 Buenos Aires (Argentina); Bocan, G.A. [Centro Atómico Bariloche, Comisión Nacional de Energía Ató mica, and Consejo Nacional de Investigaciones Científicas y Técnicas, S.C. de Bariloche, Río Negro (Argentina); Juaristi, J.I. [Departamento de Física de Materiales, Facultad de Químicas, UPV/EHU, 20018 San Sebastián (Spain); Donostia International Physics Center (DIPC) and Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 San Sebastián (Spain); Gravielle, M.S., E-mail: msilvia@iafe.uba.ar [Instituto de Astronomía y Física del Espacio (CONICET-UBA), Casilla de correo 67, sucursal 28, 1428 Buenos Aires (Argentina)
2014-12-01
Angle- and energy-loss-resolved distributions of helium atoms grazingly scattered from a Ag(110) surface along low indexed crystallographic directions are investigated considering impact energies in the few keV range. Final projectile distributions are evaluated within a semi-classical formalism that includes dissipative effects due to electron–hole excitations through a friction force. For mono-energetic beams impinging along the [11{sup ¯}0],[11{sup ¯}2] and [001] directions, the model predicts the presence of multiple peak structures in energy-loss spectra. Such structures provide detailed information about the trajectory-dependent energy loss. However, when the experimental dispersion of the incident beam is taken into account, these energy-loss peaks are completely washed out, giving rise to a smooth energy-loss distribution, in fairly good agreement with available experimental data.
Sikler, Ferenc
2012-01-01
The energy loss distribution of charged particles in silicon is approximated by a simple analytical parametrization. Its use is demonstrated through several examples. With the help of energy deposits in sensing elements of the detector, the position of track segments and the corresponding deposited energy are estimated with improved accuracy and less bias. The parametrization is successfully used to estimate the energy loss rate of charged particles, and it is applied to detector gain calibration tasks.
Magnetic Dissipation in Relativistic Jets
Yosuke Mizuno
2016-10-01
Full Text Available The most promising mechanisms for producing and accelerating relativistic jets, and maintaining collimated structure of relativistic jets involve magnetohydrodynamical (MHD processes. We have investigated the magnetic dissipation mechanism in relativistic jets via relativistic MHD simulations. We found that the relativistic jets involving a helical magnetic field are unstable for the current-driven kink instability, which leads to helically distorted structure in relativistic jets. We identified the regions of high current density in filamentary current sheets, indicative of magnetic reconnection, which are associated to the kink unstable regions and correlated to the converted regions of magnetic to kinetic energies of the jets. We also found that an over-pressured relativistic jet leads to the generation of a series of stationary recollimation shocks and rarefaction structures by the nonlinear interaction of shocks and rarefaction waves. The differences in the recollimation shock structure due to the difference of the magnetic field topologies and strengths may be observable through mm-VLBI observations and space-VLBI mission.
A reduced model for relativistic electron beam transport in solids and dense plasmas
Touati, M.; Feugeas, J.-L.; Nicolaï, Ph; Santos, J. J.; Gremillet, L.; Tikhonchuk, V. T.
2014-07-01
A hybrid reduced model for relativistic electron beam transport based on the angular moments of the relativistic kinetic equation with a special closure is presented. It takes into account collective effects with the self-generated electromagnetic fields as well as collisional effects with the slowing down of the relativistic electrons by plasmons, bound and free electrons and their angular scattering on both ions and electrons. This model allows for fast computations of relativistic electron beam transport while describing their energy distribution evolution. Despite the loss of information concerning the angular distribution of the electron beam, the model reproduces analytical estimates in the academic case of a monodirectional and monoenergetic electron beam propagating through a warm and dense plasma and hybrid particle-in-cell simulation results in a realistic laser-generated electron beam transport case.
Zapp, Edward Neal
Simulation of energetic, colliding nuclear systems at energies between 100 AMeV and 5 AGeV has utility in fields as diverse as the design and construction of fundamental particle physics experiments, patient treatment by radiation exposure, and in the protection of astronaut crews from the risks of exposure to natural radiation sources during spaceflight. Descriptions of these colliding systems which are derived from theoretical principles are necessary in order to provide confidence in describing systems outside the scope of existing data, which is sparse. The system size and velocity dictate descriptions which include both special relativistic and quantum effects, and the currently incomplete state of understanding with respect to the basic processes at work within nuclear matter dictate that any description will exist at some level of approximation. Models commonly found in the literature employ approximations to theory which lead to simulation results which demonstrate departure from fundamental physical principles, most notably conservation of system energy. The HMD (Hamiltonian Molecular Dynamics) mode is developed as a phase-space description of colliding nuclear system on the level of hadrons, inclusive of the necessary quantum and relativistic elements. Evaluation of model simulations shows that the HMD model shows the necessary conservations throughout system simulation. HMD model predictions are compared to both the RQMD (Relativistic Quantum Molecular Dynamics) and JQMD (Jaeri-Quantum Molecular Dynamics) codes, both commonly employed for the purpose of simulating nucleus-nucleus collisions. Comparison is also provided between all three codes and measurement. The HMD model is shown to perform well in light of both measurement and model calculation, while providing for a physically self-consistent description of the system throughout.
Safronova, M S; Derevianko, S A
1999-01-01
Removal energies and hyperfine constants of the lowest four $ns, np_{1/2}$ and $np_{3/2}$ states in Na, K, Rb and Cs are calculated; removal energies of the n=7--10 states and hyperfine constants of the n=7 and 8 states in Fr are also calculated. The calculations are based on the relativistic single-double (SD) approximation in which single and double excitations of Dirac-Hartree-Fock (DHF) wave functions are included to all-orders in perturbation theory. Using SD wave functions, accurate values of removal energies, electric-dipole matrix elements and static polarizabilities are obtained, however, SD wave functions give poor values of magnetic-dipole hyperfine constants for heavy atoms. To obtain accurate values of hyperfine constants for heavy atoms, we include triple excitations partially in the wave functions. The present calculations provide the basis for reevaluating PNC amplitudes in Cs and Fr.
Comparison of radiative energy loss models in a hot QCD medium
Verweij, M.
2010-01-01
The suppression of high $p_{T}$ hadron production in heavy ion collisions is thought to be due to energy loss by gluon radiation off hard partons in a QCD medium. Existing models of QCD radiative energy loss in a color-charged medium give estimates of the coupling strength of the parton to the
REFINED ALGORITHMS OF ELECTRICAL ENERGY LOSSES CALCULATION IN 0,38 KV NETWORKS IN REAL TIME
Miroshnyk A.
2010-08-01
Full Text Available An approach for closer definition of electrical energy losses size in air lines due to the accounting of environment temperature influence and flowing current size on the wire resistance is offered. Multifunctional microprocessor devices for energy losses calculation are elaborated.
Electron loss from multiply protonated lysozyme ions in high energy collisions with molecular oxygen
Hvelplund, P; Nielsen, SB; Sørensen, M
2001-01-01
We report on the electron loss from multiply protonated lysozyme ions Lys-Hn(n)+ (n = 7 - 17) and the concomitant formation of Lys-Hn(n+1)+. in high-energy collisions with molecular oxygen (laboratory kinetic energy = 50 x n keV). The cross section for electron loss increases with the charge stat...
Comparison of radiative energy loss models in a hot QCD medium
Verweij, M.
2010-01-01
The suppression of high $p_{T}$ hadron production in heavy ion collisions is thought to be due to energy loss by gluon radiation off hard partons in a QCD medium. Existing models of QCD radiative energy loss in a color-charged medium give estimates of the coupling strength of the parton to the mediu
Energy loss of a heavy particle near 3D charged rotating hairy black hole
Naji, Jalil [Ilam University, Physics Department, P.O.Box 69315-516, Ilam (Iran, Islamic Republic of)
2014-01-15
In this paper we consider a charged rotating black hole in three dimensions with a scalar charge and discuss the energy loss of a heavy particle moving near the black-hole horizon. We also study quasi-normal modes and find the dispersion relations. We find that the effect of scalar charge and electric charge increases the energy loss. (orig.)
Energy loss of a heavy particle near 3D charged rotating hairy black hole
Naji, Jalil
2014-01-01
In this paper we consider a charged rotating black hole in three dimensions with a scalar charge and discuss the energy loss of a heavy particle moving near the black-hole horizon. We also study quasi-normal modes and find the dispersion relations. We find that the effect of scalar charge and electric charge increases the energy loss.
Evaluation of economic loss from energy-related environmental pollution: a case study of Beijing
Chen, Chen; Su, Meirong; Liu, Gengyuan; Yang, Zhifeng
2013-09-01
With the growth of energy consumption, energy-related environmental pollution has become increasingly serious, which in turn causes enormous economic loss because of public health damage, corrosion of materials, crop yield reduction, and other factors. Evaluating economic loss caused by energy-related environmental pollution can contribute to decision making in energy management. A framework for evaluating economic loss from environmental pollution produced during energy production, transportation, and consumption is proposed in this paper. Regarding SO2, PM10, and solid waste as the main pollutants, economic losses from health damage, materials corrosion, crop yield reduction, and solid waste pollution are estimated based on multiple concentration-response relationships and dose-response functions. The proposed framework and evaluation methods are applied to Beijing, China. It is evident that total economic loss attributable to energy-related environmental pollution fluctuated during 2000-2011 but had a general growth trend, with the highest value reaching 2.3 × 108 CNY (China Yuan) in 2006. Economic loss caused by health damage contributes most to the total loss among the four measured damage types. The total economic loss strongly correlates with the amount of energy consumption, especially for oil and electricity. Our evaluation framework and methods can be used widely to measure the potential impact of environmental pollution in the energy lifecycle.
Geometric Models of the Relativistic Harmonic Oscillator
Cotaescu, I I
1997-01-01
A family of relativistic geometric models is defined as a generalization of the actual anti-de Sitter (1+1) model of the relativistic harmonic oscillator. It is shown that all these models lead to the usual harmonic oscillator in the non-relativistic limit, even though their relativistic behavior is quite different. Among quantum models we find a set of models with countable energy spectra, and another one having only a finite number of energy levels and in addition a continuous spectrum.
Electromagnetic therapeutic coils design to reduce energy loss
Syrek Przemyslaw
2016-01-01
Full Text Available The article introduces the problem of power loss reduction in applicators used in magnetotherapy. To generate magnetic field whose distribution is optimal and to reduce the power loss, the authors establish a set of parameters to evaluate the model of device. Results make it possible to infer that the real power input necessary to operate the magnetic field generator properly may vary significantly depending on construction and localization. The issues raised in this paper should be treated as a basis for further discussion on the construction of applicators used, e.g., in Transcranial Magnetic Stimulation.
Relativistic Gravothermal Instabilities
Roupas, Zacharias
2014-01-01
The thermodynamic instabilities of the self-gravitating, classical ideal gas are studied in the case of static, spherically symmetric configurations in General Relativity taking into account the Tolman-Ehrenfest effect. One type of instabilities is found at low energies, where thermal energy becomes too weak to halt gravity and another at high energies, where gravitational attraction of thermal pressure overcomes its stabilizing effect. These turning points of stability are found to depend on the total rest mass $\\mathcal{M}$ over the radius $R$. The low energy instability is the relativistic generalization of Antonov instability, which is recovered in the limit $G\\mathcal{M} \\ll R c^2$ and low temperatures, while in the same limit and high temperatures, the high energy instability recovers the instability of the radiation equation of state. In the temperature versus energy diagram of series of equilibria, the two types of gravothermal instabilities make themselves evident as a double spiral! The two energy l...
Energy loss in unstable QGP - problem of the upper cut-off
Carrington Margaret E.
2014-04-01
Full Text Available The energy loss of a highly energetic parton in a weakly coupled quark-gluon plasma is studied as an initial value problem. An extremely prolate plasma, where the momentum distribution is infinitely elongated along one direction, is considered. The energy loss is strongly time and direction dependent and its magnitude can much exceed the equilibrium value. It is logarithmically ultraviolet divergent. We argue that a good approximation to the energy loss can be obtained if this divergence is cut off with the parton energy.
Channeling energy loss and dechanneling of He along axial and planar directions of Si
Shafiei, S.; Lamehi-Rachti, M.
2016-01-01
In the present work, the energy loss and the dechanneling of He ions in the energy of 1.5 MeV and 2 MeV along the and axial directions as well as the {1 0 0} and {1 1 0} planar directions of Si were studied by the simulation of the channeling Rutherford backscattering spectra. The simulation was done based on the considerations that a fraction of the aligned beam enters the sample as a random component due to the ions scattering from the surface, and the dechanneling starts at the greater penetration depths, xDech. It was presumed that the dechanneling process follows a simple exponential law with a parameter λ which is proportional to the half-thickness. The Levenberg-Marquardt algorithm was used to set the best parameters of energy loss ratio, xDech and λ. The experimental results are well reproduced by this simulation. Differences between various axial and planar channels in the Si crystal and their influence on the energy loss ratio and dechanneling of He ions are described. Moreover, the energy dependence of energy loss ratio and dechanneling of He ions were investigated. It is shown that the dechanneling behavior of ions depends on the energy and energy loss of the ions along a channel. The channeled to random energy loss increases by decreasing ions energy.
A relativistic correction to semiclassical charmonium
Weiss, J.
1995-09-01
It is shown that the relativistic linear potentials, introduced by the author within the particle à la Wheeler-Feynman direct-interaction (AAD) theory, applied to the semiclassically quantized charmonium, yield energy spectrum comparable to that of some known models. Using the expansion of the relativistic linear AAD potentials in powers ofc -1, the charmonium spectrum, given as a rule by Bohr-Sommerfeld quantization of circular orbits, is extended up to the second order of relativistic corrections.
The optimum grain size for minimizing energy losses in iron
Campos, M.F. de [Escola de Engenharia Industrial Metalurgica de Volta Redonda/Universidade Federal Fluminense Av. dos Trabalhadores 420, Vila Santa Cecilia, 27255-125, Volta Redonda, RJ (Brazil)]. E-mail: mcampos@metal.eeimvr.uff.br; Teixeira, J.C. [Instituto de Pesquisas Tecnologicas do Estado de Sao Paulo, Av. Prof. Almeida Prado 532, 05508-901, Sao Paulo, SP (Brazil); Landgraf, F.J.G. [Instituto de Pesquisas Tecnologicas do Estado de Sao Paulo, Av. Prof. Almeida Prado 532, 05508-901, Sao Paulo, SP (Brazil)]. E-mail: landgraf@ipt.br
2006-06-15
A model able to predict the optimum grain size for textured electrical steels used in motors or transformers is presented. The model is based on the Pry and Bean model for the anomalous losses. The validity of the model is restricted to the frequency range of 1-1000 Hz. The model predicts that the optimum grain size decreases as: resistivity decreases or frequency increases or thickness of steel sheet increases. The predictions of the model are compared with experimental results.
Relativistic corrections to the ground state energies of the carbon-like atoms%类碳体系基态能量的相对论修正
马堃; 黄时中; 倪秀波; 吴长义; 胡健
2008-01-01
Based on the tensor expression for the Breit-Pauli Hamiltonian, and with the aid of irreducible tensor theory, the theory of relativistic corrections to the non-relativistic energies of many-electron atoms has been generalized to the case in which Racah wave functions are the linear combinations of multi-Slater wave functions, analytic formulism for calculating the relativistic corrections, which include mass correction, one-and two-body Darwin correction and spin-spin contact interaction, has been derived, all the angular interactions and spin sums involved in the problem have been worked out explicitly by using irreducible theory. The theory is applied to the ground state of carbon-like atoms.%以Breit-Pauli哈密顿的球张量形式为基础,借助不可约张量理论,将多电子原子能量的相对论修正理论拓展到了原子的拉卡波函数为多个Slater基函数的线性组合的情形,导出了此情形下多电子原子能量相对论修正(包括相对论质量修正项、单体和双体迭尔文修正项、自旋-自旋接触相互作用项)的解析表达式,完成了所有角向积分和自旋求和计算.利用所建立的理论,对类碳体系基态能量的相对论修正进行了具体计算.
Effects of rapid weight loss and regain on body composition and energy expenditure.
Sagayama, Hiroyuki; Yoshimura, Eiichi; Yamada, Yosuke; Ichikawa, Mamiko; Ebine, Naoyuki; Higaki, Yasuki; Kiyonaga, Akira; Tanaka, Hiroaki
2014-01-01
Weight-classified athletes need an energy intake plan to accomplish target weight reduction. They have to consider body composition and energy metabolism during rapid weight loss followed by rapid weight regain to achieve their energy intake plan. We investigated the effects of rapid weight loss, followed by weight regain, on body composition and energy expenditure. Ten weight-classified athletes were instructed to reduce their body weight by 5% in 7 days. Following the weight loss, they were asked to try to regain all of their lost weight with an ad libitum diet for 12 h. Food intake was recorded during the baseline, weight loss, and regain periods. Fat mass, total body water, and fat-free dry solids were estimated by underwater weighing and stable isotope dilution methods. A three-component model was calculated using Siri's equation. Basal and sleeping metabolic rates were measured by indirect calorimetry. Body composition and energy expenditure were measured before and after weight loss and after weight regain. Body weight, total body water, and fat-free dry solids were decreased after the weight loss period but recovered after weight regain (p weight loss but recovered after weight regain. Changes in total body water greatly affect body weight during rapid weight loss and regain. In addition, rapid weight loss and regain did not greatly affect the basal metabolic rate in weight-classified athletes.
Vos, M. [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, Australian National University, Canberra ACT (Australia); Marmitt, G. G. [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, Australian National University, Canberra ACT (Australia); Instituto de Fisica da Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Finkelstein, Y. [Nuclear Research Center — Negev, Beer-Sheva 84190 (Israel); Moreh, R. [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)
2015-09-14
Reflection electron energy loss spectra from some insulating materials (CaCO{sub 3}, Li{sub 2}CO{sub 3}, and SiO{sub 2}) taken at relatively high incoming electron energies (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO{sub 2}, good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − E{sub gap}){sup 1.5}. For CaCO{sub 3}, the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li{sub 2}CO{sub 3} (7.5 eV) is the first experimental estimate.
Relativistic and non-relativistic geodesic equations
Giambo' , R.; Mangiarotti, L.; Sardanashvily, G. [Camerino Univ., Camerino, MC (Italy). Dipt. di Matematica e Fisica
1999-07-01
It is shown that any dynamic equation on a configuration space of non-relativistic time-dependent mechanics is associated with connections on its tangent bundle. As a consequence, every non-relativistic dynamic equation can be seen as a geodesic equation with respect to a (non-linear) connection on this tangent bundle. Using this fact, the relationships between relativistic and non-relativistic equations of motion is studied.
Artemiev, A N; Yerokhin, V A
1995-01-01
The relativistic nuclear recoil corrections to the energy levels of low-laying states of hydrogen-like and high Z lithium-like atoms in all orders in \\alpha Z are calculated. The calculations are carried out using the B-spline method for the Dirac equation. For low Z the results of the calculation are in good agreement with the \\alpha Z -expansion results. It is found that the nuclear recoil contribution, additional to the Salpeter's one, to the Lamb shift (n=2) of hydrogen is -1.32(6)\\,kHz. The total nuclear recoil correction to the energy of the (1s)^{2}2p_{\\frac{1}{2}}-(1s)^{2}2s transition in lithium-like uranium constitutes -0.07\\,eV and is largely made up of QED contributions.
Mesospheric energy loss rates by OH and O2 emissions at 23°S
H. Takahashi
Full Text Available The nightglow OH(9, 4 and O2 atmospheric (0,1 band emission intensities and their rotational temperatures T(OH and T(O2, respectively, observed at Cachoeira Paulista (23°S, 45°W, Brazil, during the period from October 1989 to December 1990, have been analyzed to study the nighttime mesospheric energy loss rates through the radiations from the vibrationally excited OH* and electronically excited O2* bands. The total emission rates of the OH Meinel bands, O2 atmospheric (0,0 and O2 infrared atmospheric (1Δg bands were calculated using reported data for the relative band intensities I(ν'',ν'/I(9,4, IO2A(0,0/IO2A(0,1 and IO2(1Δg/IO2A(0,1. It was found that there is a minimum in equivalent energy loss rate by the OH* Meinel bands during December/January (equivalent energy loss rate of 0.39K/day*, where day* means averaged over the night and maximum in equivalent energy loss rate during September (equivalent energy loss rate of 0.98K/day*. Energy loss rate by the O2* radiation, on the other hand, is weaker than that by the OH* Meinel bands, showing equivalent energy loss rates of 0.12K/day* and 0.22K/day* during January and September, respectively.
Addressing student models of energy loss in quantum tunnelling
Wittmann, M C; Bao, L; Wittmann, Micael C.; Morgan, Jeffrey T.; Bao, Lei
2005-01-01
We report on a multi-year, multi-institution study to investigate student reasoning about energy in the context of quantum tunnelling. We use ungraded surveys, graded examination questions, individual clinical interviews, and multiple-choice exams to build a picture of the types of responses that students typically give. We find that two descriptions of tunnelling through a square barrier are particularly common. Students often state that tunnelling particles lose energy while tunnelling. When sketching wave functions, students also show a shift in the axis of oscillation, as if the height of the axis of oscillation indicated the energy of the particle. We find inconsistencies between students' conceptual, mathematical, and graphical models of quantum tunnelling. As part of a curriculum in quantum physics, we have developed instructional materials to help students develop a more robust and less inconsistent picture of tunnelling, and present data suggesting that we have succeeded in doing so.
Energy losses in the Polish power system and possibilities of reducing them
Buchta, F.; Janiczek, R.; Sobieszczanski, S. [Politechnika Slaska, Katowice (Poland). PSE SA
1993-11-01
Analyzes energy losses in power generation and power distribution systems in Poland. The following aspects of power losses in power generation are evaluated: structure of existing power plants in Poland, types of equipment used in coal-fired power plants, efficiency of condensation units (about 36.0% or 11.6-10 MJ/kWxh), efficiency of planned modernization of existing power units, effects of flue gas desulfurization on efficiency of power generation in coal-fired power plants, energy policy of Poland, investment in coal-fired power plants, feasibility of clean coal programs, effects of replacing conventional coal combustion by combined-cycle power plants with coal gasification on energy efficiency and energy losses, energy losses during power transmission and distribution. 19 refs.
Neutrino energy loss by electron capture in magnetic field at the crusts of neutron stars
LIU Jing-Jing; LUO Zhi-Quan
2008-01-01
Based on the p-f shell model,the effect of strong magnetic field on neutrino energy loss rates by electron capture is investigated.The calculations show that the magnetic field has only a slight effect on the neutrino energy loss rates in the range of 108-1013 G on the surfaces of most neutron stars.But for some magnetars,the range of the magnetic field is 1013-1018 G,and the neutrino energy loss rates are greatly reduced,even by more than four orders of magnitude due to the strong magnetic field.
Lokhtin, Igor P
2003-01-01
We discuss the modification of a jet fragmentation function due to medium-induced partonic energy loss in context of leading particle observables in ultrarelativistic nucleus-nucleus interactions. We also analyze the relation between in-medium softening jet fragmentation function and suppression of the jet rates due to energy loss outside the jet cone. The predicted anti-correlation between two effects allows to probe a fraction of partonic energy loss carried out of the jet cone and truly lost to the jet.
Measurement of Quark Energy Loss in Cold Nuclear Matter at Fermilab E906/SeaQuest
Lin, Po-Ju [Colorado U.
2017-01-01
Parton energy loss is a process within QCD that draws considerable interest. The measurement of parton energy loss can provide valuable information for other hard-scattering processes in nuclei, and also serves as an important tool for exploring the properties of the quark-gluon plasma (QGP). Quantifying the energy loss in cold nuclear matter will help to set a baseline relative to energy loss in the QGP. With the Drell-Yan process, the energy loss of incoming quarks in cold nuclear matter can be ideally investigated since the final state interaction is expected to be minimal. E906/SeaQuest is a fixed-target experiment using the 120 GeV proton beam from the Fermilab Main Injector and has been collecting data from p+p, p+d, p+C, p+Fe, and p+W collisions. Within the E906 kinematic coverage of Drell-Yan production via the dimuon channel, the quark energy loss can be measured in a regime where other nuclear effects are expected to be small. In this thesis, the study of quark ener gy loss from different cold nuclear targets is presented.
Relativistic magnetohydrodynamics
Hernandez, Juan; Kovtun, Pavel
2017-05-01
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).
Leardini, Fabrice
2013-01-01
This manuscript presents a problem on special relativity theory (SRT) which embodies an apparent paradox relying on the concept of simultaneity. The problem is represented in the framework of Greek epic poetry and structured in a didactic way. Owing to the characteristic properties of Lorenz transformations, three events which are simultaneous in a given inertial reference system, occur at different times in the other two reference frames. In contrast to the famous twin paradox, in the present case there are three, not two, different inertial observers. This feature provides a better framework to expose some of the main characteristics of SRT, in particular, the concept of velocity and the relativistic rule of addition of velocities.
BIRKHOFF'S EQUATIONS AND GEOMETRICAL THEORY OF ROTATIONAL RELATIVISTIC SYSTEM
LUO SHAO-KAI; CHEN XIANG-WEI; FU JING-LI
2001-01-01
The Birkhoffian and Birkhoff's functions of a rotational relativistic system are constructed, the Pfaff action of rotational relativistic system is defined, the Pfaff-Birkhoff principle of a rotational relativistic system is given, and the Pfaff-Birkhoff-D'Alembert principles and Birkhoff's equations of rotational relativistic system are constructed. The geometrical description of a rotational relativistic system is studied, and the exact properties of Birkhoff's equations and their forms onR × T*M for a rotational relativistic system are obtained. The global analysis of Birkhoff's equations for a rotational relativistic system is studied, the global properties of autonomous, semi-autonomous and non-autonomous rotational relativistic Birkhoff's equations, and the geometrical properties of energy change for rotational relativistic Birkhoff's equations are given.
Limits for Recombination in a Low Energy Loss Organic Heterojunction
Menke, S. Matthew
2016-11-03
Donor-acceptor organic solar cells often show high quantum yields for charge collection, but relatively low open-circuit voltages (VOC) limit power conversion efficiencies to around 12%. We report here the behavior of a system, PIPCP:PC61BM, that exhibits very low electronic disorder (Urbach energy less than 27 meV), very high carrier mobilities in the blend (field-effect mobility for holes >10-2 cm2 V-1 s-1), and a very low driving energy for initial charge separation (50 meV). These characteristics should give excellent performance, and indeed, the VOC is high relative to the donor energy gap. However, we find the overall performance is limited by recombination, with formation of lower-lying triplet excitons on the donor accounting for 90% of the recombination. We find this is a bimolecular process that happens on time scales as short as 100 ps. Thus, although the absence of disorder and the associated high carrier mobility speeds up charge diffusion and extraction at the electrodes, which we measure as early as 1 ns, this also speeds up the recombination channel, giving overall a modest quantum yield of around 60%. We discuss strategies to remove the triplet exciton recombination channel.
Multifragmentation calculated with relativistic forces
Feldmeier, H; Papp, G
1995-01-01
A saturating hamiltonian is presented in a relativistically covariant formalism. The interaction is described by scalar and vector mesons, with coupling strengths adjusted to the nuclear matter. No explicit density depe ndence is assumed. The hamiltonian is applied in a QMD calculation to determine the fragment distribution in O + Br collision at different energies (50 -- 200 MeV/u) to test the applicability of the model at low energies. The results are compared with experiment and with previous non-relativistic calculations. PACS: 25.70Mn, 25.75.+r
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.
Relativistic Radiation Mediated Shocks
Budnik, Ran; Sagiv, Amir; Waxman, Eli
2010-01-01
The structure of relativistic radiation mediated shocks (RRMS) propagating into a cold electron-proton plasma is calculated and analyzed. A qualitative discussion of the physics of relativistic and non relativistic shocks, including order of magnitude estimates for the relevant temperature and length scales, is presented. Detailed numerical solutions are derived for shock Lorentz factors $\\Gamma_u$ in the range $6\\le\\Gamma_u\\le30$, using a novel iteration technique solving the hydrodynamics and radiation transport equations (the protons, electrons and positrons are argued to be coupled by collective plasma processes and are treated as a fluid). The shock transition (deceleration) region, where the Lorentz factor $ \\Gamma $ drops from $ \\Gamma_u $ to $ \\sim 1 $, is characterized by high plasma temperatures $ T\\sim \\Gamma m_ec^2 $ and highly anisotropic radiation, with characteristic shock-frame energy of upstream and downstream going photons of a few~$\\times\\, m_ec^2$ and $\\sim \\Gamma^2 m_ec^2$, respectively.P...
Magnetism and rotation in relativistic field theory
Mameda, Kazuya; Yamamoto, Arata
2016-09-01
We investigate the analogy between magnetism and rotation in relativistic theory. In nonrelativistic theory, the exact correspondence between magnetism and rotation is established in the presence of an external trapping potential. Based on this, we analyze relativistic rotation under external trapping potentials. A Landau-like quantization is obtained by considering an energy-dependent potential.
An investigation of standby energy losses in residential sector: Solutions and policies
Singh Solanki, Parmal [Caledonian (University) College of Engineering, Muscat (Oman); Sarma Mallela, Venkateswara [G. Narayanamma Institute of Technology and Science (for Women), Hyderabad (India); Zhou, Chengke [Glasgow Caledonian University, Glasgow, Scotland (United Kingdom)
2013-07-01
This paper investigates the standby power losses of household appliances and determines these losses by field measurements and bottom-up approaches. It is revealed that average standby power losses of e-appliances at household in Oman is 103.4 Watts and could further increase if other miscellaneous appliances are also taken into account. Calculations show that TV sets alone are responsible to consume 1.89 MW standby powers across the country. The paper considers various technological and socio-economic options to diminish the standby power consumption and signify that 42.72% of energy consumed by appliances can be saved by end-users implementing suitable measures. Energy management programmes like energy efficiency standards, labelling and policy instruments to tackle the standby power losses are also discussed. Finally, paper looks into the barriers and their way-outs to implement the energy efficiency standards and labelling.
Stellar energy loss rates in the pair-annihilation process beyond the standard model
Hernandez-Ruiz, M.A. [Universidad Autonoma de Zacatecas, Unidad Academica de Ciencias Quimicas, Apartado Postal C-585, Zacatecas (Mexico); Gutierrez-Rodriguez, A. [Universidad Autonoma de Zacatecas, Facultad de Fisica, Apartado Postal C-580, Zacatecas (Mexico); Gonzalez-Sanchez, A. [Universidad Autonoma de Zacatecas, Facultad de Fisica, Apartado Postal C-580, Zacatecas (Mexico); PSL Research University, Observatoire de Paris, LERMA, CNRS UMR 8112, Paris (France)
2017-01-15
We calculate the stellar energy loss due to neutrino-pair production in e{sup +}e{sup -} annihilation in the context of a 331 model, a left-right symmetric model and a simplest little Higgs model in a way that can be used in supernova calculations. We also present some simple estimates which show that such process can act as an efficient energy loss mechanism in the shocked supernova core. We find that the stellar energy loss is almost independent of the parameters of the models in the allowed range for these parameters. This work complements other studies on the stellar energy loss rate in e{sup +}e{sup -} annihilation. (orig.)
TFAP2B influences the effect of dietary fat on weight loss under energy restriction
Stocks, Tanja; Angquist, Lars; Banasik, Karina;
2012-01-01
Numerous gene loci are related to single measures of body weight and shape. We investigated if 55 SNPs previously associated with BMI or waist measures, modify the effects of fat intake on weight loss and waist reduction under energy restriction....
Estimation of Power/Energy Losses in Electric Distribution Systems based on an Efficient Method
Gheorghe Grigoras
2013-09-01
Full Text Available Estimation of the power/energy losses constitutes an important tool for an efficient planning and operation of electric distribution systems, especially in a free energy market environment. For further development of plans of energy loss reduction and for determination of the implementation priorities of different measures and investment projects, analysis of the nature and reasons of losses in the system and in its different parts is needed. In the paper, an efficient method concerning the power flow problem of medium voltage distribution networks, under condition of lack of information about the nodal loads, is presented. Using this method it can obtain the power/energy losses in power transformers and the lines. The test results, obtained for a 20 kV real distribution network from Romania, confirmed the validity of the proposed method.
Favareto, Andrea; The ATLAS collaboration
2016-01-01
Many extensions of the Standard Model predict the existence of massive charged long-lived particles (LLPs), such as R-hadrons. These particles, if produced at the Large Hadron Collider (LHC), should be moving non-relativistically and therefore be identifiable through the measurement of an anomalously large specific energy loss in the ATLAS Pixel Detector. Measuring heavy long-lived particles through their track parameters in the vicinity of the interaction vertex allows the investigation of the case where these are metastable with lifetimes in the nanosecond range. A search for such particles, produced in pp collisions at $\\sqrt{s} = 13$ TeV at the LHC with the ATLAS detector, is presented in this poster. The dataset used corresponds to an integrated luminosity of 3.2 fb$^{-1}$.
Energy loss of keV He2+ scattered off an Al(110) surface
Limburg, J; Schlatholter, T; Hoekstra, R; Morgenstern, R; Hausmann, S; Heiland, W; Narmann, A
1998-01-01
This paper presents results of measurements of energy loss suffered by He-projectiles scattered off an Al surface. The measured loss distributions are modeled in terms of the (classical) friction experienced by the projectiles due to their interaction with the electron gas at the Al surface. Simulat
Energy balance and the composition of weight loss during prolonged space flight
Leonard, J. I.
1982-01-01
Integrated metabolic balance analysis, Skylab integrated metabolic balance analysis and computer simulation of fluid-electrolyte responses to zero-g, overall mission weight and tissue losses, energy balance, diet and exercise, continuous changes, electrolyte losses, caloric and exercise requirements, and body composition are discussed.
Henriksen, Matthew Lee; Jensen, Bogi Bech
2013-01-01
Several methods of estimating the annual energy losses for wind turbine generators are investigated in this paper. Utilizing a high amount of transient simulations with motion is first demonstrated. Usage of a space-time transformation for prediction of iron losses is also explored. The methods, ...
Lopatin, Sergei
2017-09-01
The performance of a monochromated transmission electron microscope with Wien type monochromator is optimized to achieve an extremely narrow energy spread of electron beam and an ultrahigh energy resolution with spectroscopy. The energy spread in the beam is improved by almost an order of magnitude as compared to specified values. The optimization involves both the monochromator and the electron energy loss detection system. We demonstrate boosted capability of optimized systems with respect to ultra-low loss EELS and sub-angstrom resolution imaging (in a combination with spherical aberration correction).
The calculation of mechanical energy loss for incompressible steady pipe flow of homogeneous fluid
刘士和; 薛娇; 范敏
2013-01-01
The calculation of the mechanical energy loss is one of the fundamental problems in the field of Hydraulics and Enginee- ring Fluid Mechanics. However, for a non-uniform flow the relation between the mechanical energy loss in a volume of fluid and the kinematical and dynamical characteristics of the flow field is not clearly established. In this paper a new mechanical energy equation for the incompressible steady non-uniform pipe flow of homogeneous fluid is derived, which includes the variation of the mean tur- bulent kinetic energy, and the formula for the calculation of the mechanical energy transformation loss for the non-uniform flow bet- ween two cross sections is obtained based on this equation. This formula can be simplified to the Darcy-Weisbach formula for the uniform flow as widely used in Hydraulics. Furthermore, the contributions of the mechanical energy loss relative to the time avera- ged velocity gradient and the dissipation of the turbulent kinetic energy in the turbulent uniform pipe flow are discussed, and the con- tributions of the mechanical energy loss in the viscous sublayer, the buffer layer and the region above the buffer layer for the turbu- lent uniform flow are also analyzed.
Energy loss of ions by electric-field fluctuations in a magnetized plasma.
Nersisyan, Hrachya B; Deutsch, Claude
2011-06-01
The results of a theoretical investigation of the energy loss of charged particles in a magnetized classical plasma due to the electric-field fluctuations are reported. The energy loss for a test particle is calculated through the linear-response theory. At vanishing magnetic field, the electric-field fluctuations lead to an energy gain of the charged particle for all velocities. It has been shown that in the presence of strong magnetic field, this effect occurs only at low velocities. In the case of high velocities, the test particle systematically loses its energy due to the interaction with a stochastic electric field. The net effect of the fluctuations is the systematic reduction of the total energy loss (i.e., the sum of the polarization and stochastic energy losses) at vanishing magnetic field and reduction or enhancement at strong field, depending on the velocity of the particle. It is found that the energy loss of the slow heavy ion contains an anomalous term that depends logarithmically on the projectile mass. The physical origin of this anomalous term is the coupling between the cyclotron motion of the plasma electrons and the long-wavelength, low-frequency fluctuations produced by the projectile ion. This effect may strongly enhance the stochastic energy gain of the particle.
Toward 10 meV electron energy-loss spectroscopy resolution for plasmonics.
Bellido, Edson P; Rossouw, David; Botton, Gianluigi A
2014-06-01
Energy resolution is one of the most important parameters in electron energy-loss spectroscopy. This is especially true for measurement of surface plasmon resonances, where high-energy resolution is crucial for resolving individual resonance peaks, in particular close to the zero-loss peak. In this work, we improve the energy resolution of electron energy-loss spectra of surface plasmon resonances, acquired with a monochromated beam in a scanning transmission electron microscope, by the use of the Richardson-Lucy deconvolution algorithm. We test the performance of the algorithm in a simulated spectrum and then apply it to experimental energy-loss spectra of a lithographically patterned silver nanorod. By reduction of the point spread function of the spectrum, we are able to identify low-energy surface plasmon peaks in spectra, more localized features, and higher contrast in surface plasmon energy-filtered maps. Thanks to the combination of a monochromated beam and the Richardson-Lucy algorithm, we improve the effective resolution down to 30 meV, and evidence of success up to 10 meV resolution for losses below 1 eV. We also propose, implement, and test two methods to limit the number of iterations in the algorithm. The first method is based on noise measurement and analysis, while in the second we monitor the change of slope in the deconvolved spectrum.
Interdependence of reabsorption and internal energy losses in luminescent solar concentrators
Digaum, Jennefir; Kuebler, Stephen M.
2014-03-01
As a complementary device to photovoltaic (PV) cells, luminescent solar concentrators (LSCs) can reduce the cost of solar energy by replacing the expensive PV material with inexpensive energy-harvesting plastic or glass matrix. However, due to its low efficiency, LSCs are still not commercially viable. The low efficiency is due to the various losses associated with light harvesting and trapping. Most of these losses come from reabsorption and escape of reemitted energy from the LSC device. State-of-the-art LSC technology focuses on decreasing reabsorption loss by employing luminophores with a large Stokes shift. But these materials typically have low quantum yield. Increasing the Stokes shift of the luminophore reduces reabsorption but introduces substantial loss due to low quantum yield and the Stokes shift of the re-emitted photons. The interdependence of these losses is studied computationally using a ray-tracing model that accounts for reabsorption, Stokes shift, escape cone loss, and matrix loss. It is shown that using high Stokesshift luminophores does not give the highest energy efficiency. Higher energy efficiency is obtained by optimizing the Stokes shift. Even greater performance can be achieved by employing high-quantum-yield dyes with intermediate Stokes shift. LSC devices based on this approach could be nearly twice as efficient as those based on conventional luminophores, such as Rhodamine B.
Pang, Long-Gang; Endrődi, Gergely; Petersen, Hannah
2016-04-01
In off-central heavy-ion collisions, quark-gluon plasma (QGP) is exposed to the strongest magnetic fields ever created in the universe. Because of the paramagnetic nature of the QGP at high temperatures, the spatially inhomogeneous magnetic field configuration exerts an anisotropic force density that competes with the pressure gradients resulting from purely geometric effects. In this paper, we simulate (3+1)-dimensional ideal hydrodynamics with external magnetic fields to estimate the effect of this force density on the anisotropic expansion of the QGP in collisions at the Relativistic Heavy Ion Collider and at the Large Hadron Collider (LHC). While negligible for quickly decaying magnetic fields, we find that long-lived fields generate a substantial force density that suppresses the momentum anisotropy of the plasma by up to 20 % at the LHC energy and also leaves its imprint on the elliptic flow v2 of charged pions.
Parton energy loss at strong coupling and the universal bound
Kharzeev, D E
2008-01-01
The apparent universality of jet quenching observed in heavy ion collisions at RHIC for light and heavy quarks, as well as for quarks and gluons, is very puzzling and calls for a theoretical explanation. Recently it has been proposed that the synchrotron--like radiation at strong coupling gives rise to a universal bound on the energy of a parton escaping from the medium. Since this bound appears quite low, almost all of the observed particles at high transverse momentum have to originate from the surface of the hot fireball. Here I make a first attempt of checking this scenario against the RHIC data and formulate a "Universal Bound Model" of jet quenching that can be further tested at RHIC and LHC.
On the use of energy loss mechanisms to constrain Lorentz invariance violations
Mazón, Diego
2014-01-01
In light of recent and probably incoming observations of very high energy astroparticles, such as those reported by the IceCube collaboration, we readdress the energy loss mechanism by Lorentz violating particles. We analytically show that Cohen-Glashow's formula for energy loss is connected with a Poisson distribution for the number of decays, whose large fluctuations prevent from placing bounds on Lorentz invariance violations. However, this model ignores the sharp change in the decay width after each process. We propose replacing Poisson statistics with a new distribution that takes this into account. We study the average final energy and its fluctuations according to the new statistics, contrasting it with Cohen-Glashow's result and discussing the reliability of energy loss mechanisms to constrain violations of Lorentz invariance.
Energy loss and straggling of MeV Si ions in gases
Vockenhuber, C., E-mail: vockenhuber@phys.ethz.ch [Laboratory of Ion Beam Physics, ETH Zurich, Otto-Stern-Weg 5, 8093 Zurich (Switzerland); Arstila, K. [Department of Physics, University of Jyväskylä, 40014 Jyväskylä (Finland); Jensen, J. [Department of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping (Sweden); Julin, J.; Kettunen, H.; Laitinen, M.; Rossi, M.; Sajavaara, T. [Department of Physics, University of Jyväskylä, 40014 Jyväskylä (Finland); Thöni, M. [Laboratory of Ion Beam Physics, ETH Zurich, Otto-Stern-Weg 5, 8093 Zurich (Switzerland); Whitlow, H.J. [Institut des Microtechnologies Appliquées Arc, Haute Ecole Arc Ingénierie, 2300 La Chaux-de-Fonds (Switzerland)
2017-01-15
We present measurements of energy loss and straggling of Si ions in gases. An energy range from 0.5 to 12 MeV/u was covered using the 6 MV EN tandem accelerator at ETH Zurich, Switzerland, and the K130 cyclotron accelerator facility at the University of Jyväskylä, Finland. Our energy-loss data compare well with calculation based on the SRIM and PASS code. The new straggling measurements support a pronounced peak in He gas at around 4 MeV/u predicted by recent theoretical calculations. The straggling curve structure in the other gases (N{sub 2}, Ne, Ar, Kr) is relatively flat in the covered energy range. Although there is a general agreement between the straggling data and the theoretical calculations, the experimental uncertainties are too large to confirm or exclude the predicted weak multi-peak structure in the energy-loss straggling.
Energy loss and straggling of MeV Si ions in gases
Vockenhuber, C.; Arstila, K.; Jensen, J.; Julin, J.; Kettunen, H.; Laitinen, M.; Rossi, M.; Sajavaara, T.; Thöni, M.; Whitlow, H. J.
2017-01-01
We present measurements of energy loss and straggling of Si ions in gases. An energy range from 0.5 to 12 MeV/u was covered using the 6 MV EN tandem accelerator at ETH Zurich, Switzerland, and the K130 cyclotron accelerator facility at the University of Jyväskylä, Finland. Our energy-loss data compare well with calculation based on the SRIM and PASS code. The new straggling measurements support a pronounced peak in He gas at around 4 MeV/u predicted by recent theoretical calculations. The straggling curve structure in the other gases (N2, Ne, Ar, Kr) is relatively flat in the covered energy range. Although there is a general agreement between the straggling data and the theoretical calculations, the experimental uncertainties are too large to confirm or exclude the predicted weak multi-peak structure in the energy-loss straggling.
Relativistic Electron Experiment for the Undergraduate Laboratory
Marvel, Robert E
2011-01-01
We have developed an undergraduate laboratory experiment to make independent measurements of the momentum and kinetic energy of relativistic electrons from a \\beta -source. The momentum measurements are made with a magnetic spectrometer and a silicon surface-barrier detector is used to measure the kinetic energy. A plot of the kinetic energy as a function of momentum compared to the classical and relativistic predictions clearly shows the relativistic nature of the electrons. Accurate values for the rest mass of the electron and the speed of light are also extracted from the data.
Doornenbal, P.
2007-10-23
A two-step fragmentation experiment has been performed at GSI with the RISING setup. It combines the fragment separator FRS, which allows for the production of radioactive heavy ions at relativistic energies, with a high resolution {gamma}-spectrometer. This combination offers unique possibilities for nuclear structure investigations like the test of shell model predictions far from stability. Within the present work the question if the N=14(16) shell stabilisation in Z=8 oxygen isotopes and the N=20 shell quenching in {sup 32}Mg are symmetric with respect to the isospin projection quantum number Tz has been addressed. New {gamma}-ray decays were found in the neutron deficient {sup 36}Ca and {sup 36}K by impinging a radioactive ion beam of {sup 37}Ca on a secondary {sup 9}Be target. The fragmentation products were selected with the calorimeter telescope CATE and the emitted {gamma}-rays were measured with Ge Cluster, MINIBALL, and BaF{sub 2} HECTOR detectors. For {sup 36}Ca the 2{sub 1}{sup +}{yields}0{sub g.s.}{sup +} transition energy was determined to be 3015(16) keV, which is the heaviest T=2 nucleus from which {gamma}-spectroscopic information has been obtained so far. A comparison between the experimental 2{sub 1}{sup +} energies of {sup 36}Ca and its mirror nucleus {sup 36}S yielded a mirror energy difference of {delta}E{sub M}=-276(16) keV. In order to understand the large {delta}E{sub M} value, the experimental single-particle energies from the A=17, T=1/2 mirror nuclei were taken and applied onto modified isospin symmetric USD interactions in shell model calculations. These calculations were in agreement with the experimental result and showed that the experimental single-particle energies may account empirically for the one body part of Thomas-Ehrman and/or Coulomb effects. A method to extract the lifetime of excited states in fragmentation reactions was investigated. Therefore, the dependence between the lifetime of an excited state and the average de
COMPONENTS OF TOTAL ELECTRIC ENERGY LOSSES POWER IN PQR SPATIAL COORDINATES
G.G. Zhemerov
2016-05-01
Full Text Available Purpose. To obtain relations determining the components of the total losses power with p-q-r power theory for three-phase four-wire energy supply systems, uniquely linking four components: the lowest possible losses power, losses power caused by the reactive power, losses power caused by the instantaneous active power pulsations, losses power caused by current flowing in the neutral wire. Methodology. We have applied concepts of p-q-r power theory, the theory of electrical circuits and mathematical simulation in Matlab package. Results. We have obtained the exact relation, which allows to calculate the total losses power in the three-phase four-wire energy supply system using three components corresponding to the projections of the generalized vectors of voltage and current along the pqr axis coordinates. Originality. For the first time, we have established a mathematical relationship between spatial representation of instantaneous values of the vector components and the total losses power in the three-phase four-wire energy supply systems. Practical value. We have elucidated an issue that using the proposed methodology would create a measuring device for determining the current value of the components of total losses power in three-phase systems. The device operates with measuring information about instantaneous values of currents and voltages.
Density measurement of thin layers by electron energy loss spectroscopy (EELS).
Thomas, Jürgen; Ramm, Jürgen; Gemming, Thomas
2013-07-01
A method to measure the density of thin layers is presented which utilizes electron energy loss spectroscopy (EELS) techniques within a transmission electron microscope. The method is based on the acquisition of energy filtered images in the low loss region as well as of an element distribution map using core loss edges. After correction of multiple inelastic scattering effects, the intensity of the element distribution map is proportional to density and thickness. The dependence of the intensities of images with low energy loss electrons on the density is different from that. This difference allows the calculation of the relative density pixel by pixel and to determine lateral density gradients or fluctuations in thin films without relying on a constant specimen thickness. The method is demonstrated at thin carbon layers produced with density gradients.
Hysteresis model and statistical interpretation of energy losses in non-oriented steels
Mănescu, Veronica, E-mail: veronica.paltanea@upb.ro; Păltânea, Gheorghe; Gavrilă, Horia
2016-04-01
In this paper the hysteresis energy losses in two non-oriented industrial steels (M400-65A and M800-65A) were determined, by means of an efficient classical Preisach model, which is based on the Pescetti–Biorci method for the identification of the Preisach density. The excess and the total energy losses were also determined, using a statistical framework, based on magnetic object theory. The hysteresis energy losses, in a non-oriented steel alloy, depend on the peak magnetic polarization and they can be computed using a Preisach model, due to the fact that in these materials there is a direct link between the elementary rectangular loops and the discontinuous character of the magnetization process (Barkhausen jumps). To determine the Preisach density it was necessary to measure the normal magnetization curve and the saturation hysteresis cycle. A system of equations was deduced and the Preisach density was calculated for a magnetic polarization of 1.5 T; then the hysteresis cycle was reconstructed. Using the same pattern for the Preisach distribution, it was computed the hysteresis cycle for 1 T. The classical losses were calculated using a well known formula and the excess energy losses were determined by means of the magnetic object theory. The total energy losses were mathematically reconstructed and compared with those, measured experimentally.
Hysteresis model and statistical interpretation of energy losses in non-oriented steels
Mănescu (Păltânea), Veronica; Păltânea, Gheorghe; Gavrilă, Horia
2016-04-01
In this paper the hysteresis energy losses in two non-oriented industrial steels (M400-65A and M800-65A) were determined, by means of an efficient classical Preisach model, which is based on the Pescetti-Biorci method for the identification of the Preisach density. The excess and the total energy losses were also determined, using a statistical framework, based on magnetic object theory. The hysteresis energy losses, in a non-oriented steel alloy, depend on the peak magnetic polarization and they can be computed using a Preisach model, due to the fact that in these materials there is a direct link between the elementary rectangular loops and the discontinuous character of the magnetization process (Barkhausen jumps). To determine the Preisach density it was necessary to measure the normal magnetization curve and the saturation hysteresis cycle. A system of equations was deduced and the Preisach density was calculated for a magnetic polarization of 1.5 T; then the hysteresis cycle was reconstructed. Using the same pattern for the Preisach distribution, it was computed the hysteresis cycle for 1 T. The classical losses were calculated using a well known formula and the excess energy losses were determined by means of the magnetic object theory. The total energy losses were mathematically reconstructed and compared with those, measured experimentally.
Energy loss of protons in SrTiO{sub 3} studied by medium energy ion scattering
Dedyulin, S.N., E-mail: sdedyuli@uwo.ca [Department of Physics and Astronomy, Western University, London, Ontario, N6A 3K7 (Canada); Singh, M.P.; Razavi, F.S. [Department of Physics, Brock University, St. Catherines, Ontario, L2S 3A1 (Canada); Goncharova, L.V. [Department of Physics and Astronomy, Western University, London, Ontario, N6A 3K7 (Canada)
2012-10-01
The energy loss of medium energy protons (55-170 keV/amu) was studied for a thin SrTiO{sub 3} film on Si. The thickness of the film and the structure of the SrTiO{sub 3}/Si interface was determined by the combination of X-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectrometry (RBS) and medium energy ion scattering (MEIS). These film parameters, together with energy losses extracted from MEIS spectra, were used to calculate stopping cross sections of SrTiO{sub 3} by an iterative procedure. In comparison with Andersen and Ziegler values, the data are systematically lower over the whole energy range.
Gourlaouen, Christophe; Piquemal, Jean-Philip; Saue, Trond; Parisel, Olivier
2006-01-30
Hartree-Fock and DFT (B3LYP) nonrelativistic (scalar relativistic pseudopotentials for the metallic cation) and relativistic (molecular four-component approach coupled to an all-electron basis set) calculations are performed on a series of six nd10 (n+1)s0 [M(H2O)]p+ complexes to investigate their geometry, either planar C2v or nonplanar C(s). These complexes are, formally, entities originating from the complexation of a water molecule to a metallic cation: in the present study, no internal reorganization has been found, which ensures that the complexes can be regarded as a water molecule interacting with a metallic cation. For [Au(H2O)]+ and [Hg(H2O)]2+, it is observed that both electronic correlation and relativistic effects are required to recover the C(s) structures predicted by the four-component relativistic all-electron DFT calculations. However, including the zero-point energy corrections makes these shallow C(s) minima vanish and the systems become floppy. In all other systems, namely [Cu(H2O)]+, [Zn(H2O)]2+, [Ag(H2O)]+, and [Cd(H2O)]2+, all calculations predict a C2v geometry arising from especially flat potential energy surfaces related to the out-of-plane wagging vibration mode. In all cases, our computations point to the quasi-perfect transferability of the atomic pseudopotentials considered toward the molecular species investigated. A rationalization of the shape of the wagging potential energy surfaces (i.e., single well vs. double well) is proposed based on the Constrained Space Orbital Variation decompositions of the complexation energies. Any way of stabilizing the lowest unoccupied orbital of the metallic cation is expected to favor charge-transfer (from the highest occupied orbital(s) of the water ligand), covalence, and, consequently, C(s) structures. The CSOV complexation energy decompositions unambiguously reveal that such stabilizations are achieved by means of relativistic effects for [Au(H2O)]+, and, to a lesser extent, for [Hg(H2O)]2
CMB bounds on dark matter annihilation: Nucleon energy losses after recombination
Weniger, C.; Serpico, P.D.; Iocco, F.; Bertone, G.
2013-01-01
We consider the propagation and energy losses of protons and antiprotons produced by dark matter annihilation at redshifts 100
Refining a relativistic, hydrodynamic solver: Admitting ultra-relativistic flows
Bernstein, J. P.; Hughes, P. A.
2009-09-01
We have undertaken the simulation of hydrodynamic flows with bulk Lorentz factors in the range 102-106. We discuss the application of an existing relativistic, hydrodynamic primitive variable recovery algorithm to a study of pulsar winds, and, in particular, the refinement made to admit such ultra-relativistic flows. We show that an iterative quartic root finder breaks down for Lorentz factors above 102 and employ an analytic root finder as a solution. We find that the former, which is known to be robust for Lorentz factors up to at least 50, offers a 24% speed advantage. We demonstrate the existence of a simple diagnostic allowing for a hybrid primitives recovery algorithm that includes an automatic, real-time toggle between the iterative and analytical methods. We further determine the accuracy of the iterative and hybrid algorithms for a comprehensive selection of input parameters and demonstrate the latter’s capability to elucidate the internal structure of ultra-relativistic plasmas. In particular, we discuss simulations showing that the interaction of a light, ultra-relativistic pulsar wind with a slow, dense ambient medium can give rise to asymmetry reminiscent of the Guitar nebula leading to the formation of a relativistic backflow harboring a series of internal shockwaves. The shockwaves provide thermalized energy that is available for the continued inflation of the PWN bubble. In turn, the bubble enhances the asymmetry, thereby providing positive feedback to the backflow.
Gaudiello, A
2017-01-01
Many extensions of the Standard Model predict the existence of charged and heavy long-lived particles, such as R-hadrons. These particles, if produced at the Large Hadron Collider (LHC), should be non-relativistic and are therefore identifiable through the measurement of an anomalously large energy loss in the ATLAS Pixel Detector. The search for heavy long-lived particles using track information in the vicinity of the interaction vertex is sensitive for values of their lifetime in the nanosecond range. The research of metastable and stable R-hadrons with the ATLAS detector using 2015 LHC data is here reported.
Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Al-Jamel, A.; Aoki, K.; Aphecetche, L.; Armendariz, R. (R.); Aronson, S H; Asai, J.; Atomssa, E. T.; Averbeck, R.
2010-01-01
Transverse momentum (p^e_T) spectra of electrons from semileptonic weak decays of heavy flavor mesons in the range of 0.3 < p^e_T < 9.0 GeV/c have been measured at mid-rapidity (|eta| < 0.35) by the PHENIX experiment at the Relativistic Heavy Ion Collider in p+p and Au+Au collisions at sqrt(s_NN)=200 GeV. The nuclear modification factor R_AA with respect to p+p collisions indicates substantial energy loss of heavy quarks in the produced medium. In addition, the azimuthal anisotropy parameter ...
Quark Energy Loss and Shadowing in Nuclear Drell-Yan Process
DUAN Chun-Gui; CUI Shu-Wen; YAN Zhan-Yuan
2005-01-01
The energy loss effect in nuclear matter is another nuclear effect apart from the nuclear effects on the parton distribution as in deep inelastic scattering process. The quark energy loss can be measured best by the nuclear dependence of the high energy nuclear Drell-Yan process. By means of three kinds of quark energy loss parameterizations given in literature and the nuclear parton distribution extracted only with lepton-nucleus deep inelastic scattering experimental data, measured Drell-Yan production cross sections are analyzed for 800 GeV proton incident on a variety of nuclear targets from FNAL E866. It is shown that our results with considering the energy loss effect are much different from those of the FNAL E866, who analyzes the experimental data with the nuclear parton distribution functions obtained by using the deep inelastic IA collisions and pA nuclear Drell-Yan data. Considering the existence of energy loss effect in Drell-Yan lepton pairs production, we suggest that the extraction of nuclear parton distribution functions should not include Drell-Yan experimental data.
Quark Energy Loss and Shadowing in Nuclear Drell-Yan Process
DUANChun-Gui; CUIShu-Wen; YANZhan-Yuan
2005-01-01
The energy loss effect in nuclear matter is another nuclear effect apart from the nuclear effects on the parton distribution as in deep inelastic scattering process. The quark energy loss can be measured best by the nuclear dependence of the high energy nuclear Dre11-Yan process. By means of three kinds of quark energy loss parameterizations given in literature and the nuclear parton distribution extracted only with lepton-nucleus deep inelastic scattering experimental data, measured Dre11-Yan production cross sections are analyzed for 800 GeV proton incident on a variety of nuclear targets from FNAL E866. It is shown that our results with considering the energy loss effect are much different from those of the FNAL E866, who analyzes the experimental data with the nuclear parton distribution functions obtained by using the deep inelastic IA collisions and pA nuclear Drell-Yan data. Considering the existence of energy loss effect in Drell-Yan lepton pairs production, we suggest that the extraction of nuclear parton distribution functions shoul""""d not include Dre11-Yan experimental data.
A new beam loss detector for low-energy proton and heavy-ion accelerators
Liu, Zhengzheng; Crisp, Jenna; Russo, Tom; Webber, Robert; Zhang, Yan
2014-12-01
The Facility for Rare Isotope Beams (FRIB) to be constructed at Michigan State University shall deliver a continuous, 400 kW heavy ion beam to the isotope production target. This beam is capable of inflicting serious damage on accelerator components, e.g. superconducting RF accelerating cavities. A Beam Loss Monitoring (BLM) System is essential for detecting beam loss with sufficient sensitivity and promptness to inform the machine protection system (MPS) and operations personnel of impending dangerous losses. Radiation transport simulations reveal shortcomings in the use of ionization chambers for the detection of beam losses in low-energy, heavy-ion accelerators. Radiation cross-talk effects due to the folded geometry of the FRIB LINAC pose further complications to locating specific points of beam loss. We propose a newly developed device, named the Loss Monitor Ring (LMR1
Energy Loss of Fast Quarks in Nuclear Drell-Yan Dimuon Production
DUAN Chun-Gui; CUI Shu-Wen; SHEN Peng-Nian; LI Guang-Lie
2004-01-01
@@ The energy loss effect in nuclear matter, which is another nuclear effect apart from the nuclear effects on the parton distribution as in the deep inelastic scattering process, can be measured best by the nuclear dependence of the high energy nuclear Drell-Yan process. By means of the quark energy loss parametrization given in literature and the nuclear parton distribution extracted only with lepton-nucleus deep inelastic scattering experimental data, measured Drell-Yan production cross sections are analysed for 800-GeV protons incident on a variety of nuclear targets from FNAL E866.
Cai, Junping; Jensen, Jørgen Bauck; Skogestad, Sigurd
2008-01-01
This paper studies the trade-off between energy consumption and food quality loss, at varying ambient conditions, in supermarket refrigeration systems. Compared with the traditional operation with pressure control, a large potential for energy savings without extra loss of food quality...... is demonstrated. We also show that by utilizing the relatively slow dynamics of the food temperature, compared with the air temperature, we are able to further lower both the energy consumption and the peak value of power requirement. The Pareto optimal curve is found by off-line optimization....
Energy loss to intravalley acoustic modes in nano-dimensional wire structures at low temperatures
Nag, S.; Das, B.; Basu, A.; Das, J.; Bhattacharya, D. P.; Sarkar, C. K.
2017-03-01
The theory of rate of loss of energy of non-equilibrium electrons due to inelastic interaction with the intravalley acoustic phonons in a nano-dimensional semiconductor wire has been developed under the condition of low lattice temperature, when the approximations of the well known traditional theory are not valid. Numerical results are obtained for narrow-channel GaAs-GaAlAs wires structures. On comparison with other available results it is revealed that the finite energy of the intravalley acoustic phonons and, the use of the full form of the phonon distribution without truncation to the equipartition law, produce significant changes in the energy loss characteristics at low temperatures.
On Energy Diagnosis of Steam Power Plants: A Comparison among Three Global Losses Formulations
Rodolfo Taccani
2002-12-01
Full Text Available
The objectives of energy systems diagnosis are: i identifying components responsible for highest losses increments in comparison with design conditions, ii quantifying energy-efficiency recovery when design conditions are restored in a particular system component. In this paper the energy diagnosis of an existing steam power plant is faced on the basis of three different formulae expressing global losses.
A simulation model of a real 320 MW steam power plant has been implemented with a commercial modular energy systems simulation software (Aspen+. The functional decay of different components of the plant has been simulated using the model. The results show that the components actually responsible for the additional power losses can be identified and the effect of restoring design conditions can be quantified in most cases with sufficient approximation by using the General Formula for the Efficiency or the Lost work Impact Formula (developed in the ambit of thermoeconomics.
Effect of energetic ion loss on ICRF heating efficiency and energy confinement time in heliotrons
Murakami, S.; Nakajima, N.; Okamoto, M. [National Inst. for Fusion Science, Toki, Gifu (Japan); Nuehrenberg, J.
1999-06-01
ICRF heating efficiency and the global energy confinement time during ICRF heating are investigated including the effect of energetic ion loss in heliotrons. The approximate formula of ICRF heating efficiency is derived using the results based on Monte Carlo simulations. The global energy confinement time including energetic ion effect can be expressed in terms of ICRF heating power, plasma density, and magnetic field strength in heliotrons. Our results in the CHS plasma show the systematic decrement of the global energy confinement time due to the energetic ion loss from the assumed energy confinement scaling law, which is consistent with the experimental observations. Also we apply our model to the ICRF minority heating in the LHD plasma in two cases of typical magnetic configurations. The clear increment of the global energy confinement time due to the stored energy of energetic tail ions is obtained in the `orbit improved` configuration, while the decrement is observed in the `standard` configuration. (author)
Steady-state heat losses in pipes for low-energy district heating
Dalla Rosa, Alessandro; Li, Hongwei; Svendsen, Svend
2010-01-01
of low-energy DH systems. Various design concepts are considered in this paper: flexible pre-insulated twin pipes with symmetrical or asymmetrical insulation, double pipes, triple pipes. These technologies are potentially energyefficient and cost-effective solutions for DH networks in low-heat density......The synergy between highly energy efficient buildings and low-energy district heating (DH) systems is a promising concept for the optimal integration of energy saving policies and energy supply systems based on renewable energy (RE). Distribution heat losses represent a key factor in the design...... areas. We start with a review of theories and methods for steady-state heat loss calculation. Next, the article shows how detailed calculations with 2D-modeling of pipes can be carried out by means of computer software based on the finite element method (FEM). The model was validated by comparison...
Relativistic RPA in axial symmetry
Arteaga, D Pena; 10.1103/PhysRevC.77.034317
2009-01-01
Covariant density functional theory, in the framework of self-consistent Relativistic Mean Field (RMF) and Relativistic Random Phase approximation (RPA), is for the first time applied to axially deformed nuclei. The fully self-consistent RMF+RRPA equations are posed for the case of axial symmetry and non-linear energy functionals, and solved with the help of a new parallel code. Formal properties of RPA theory are studied and special care is taken in order to validate the proper decoupling of spurious modes and their influence on the physical response. Sample applications to the magnetic and electric dipole transitions in $^{20}$Ne are presented and analyzed.
Vector Theory in Relativistic Thermodynamics
刘泽文
1994-01-01
It is pointed out that five defects occur in Planck-Einstein’s relativistic thermodynamics (P-E theory). A vector theory in relativistic thermodynamics (VTRT) is established. Defining the internal energy as a 4-vector, and supposing the entropy and the number of. particles to be invariants we have derived the transformations of all quantities, and subsequently got the Lagrangian and 4-D forms of thermodynamic laws. In order to test the new theory, several exact solutions with classical limits are given. The VTRT is free from the defects of the P-E theory.
Hansen, U.
1980-08-26
A mehtod is described for low-loss thermal energy storage in and withdrawal from a heat accumulator connected with an energy source and a heat consumer in a circulatory system through which a heat-carrying flow medium circulates. The method consits of passing the flow medium through the energy source so as to withdraw thermal energy from the energy source and effect absorption of the thermal energy by the flow medium, guiding the flow medium in respective layers within the heat accumulator in a direction from the center of the heat accumulator toward the periphery thereof so as to store the thermal energy in a heat storage mass disposed in the heat accumulator; and guiding the flow medium in the layers thereof through the heat accumulator in a direction from the periphery of the heat accumulator to the center thereof, and passing the flow medium from the heat accumulator through the consumer so as to withdraw thermal energy therefrom and transfer it to the consumer.
Guest, G.E.; Dandl, R.A.; Miller, R.L.
1989-01-17
The Plasma Electron Microwave Source (PEMS) concept is a relativistic-electron plasma confined in a magnetic-mirror device. The stored energy is transformed into microwaves through amplification of whistler waves that can be launched externally for amplifier operation or generated spontaneously for oscillator operation. The anisotropy of the hot-electron temperature governs the maximum plasma energy density that can be stored, the amplification rates, and the saturated power level of the unstable whistler waves. This report summarizes the results of theoretical studies of (1) the critical aspects of hot-electron plasmas generated by ECH techniques, such as the Upper Off-Resonant Heating pioneered by Dandl in the ELMO series of experiments; and, (2) the spatial amplification rates of unstable whistler waves in these plasmas. It is shown that a substantial fraction of the energy stored in a hot-electron plasma can be transformed into repetitive pulses of microwave power by employing the PEMS approach, with typical values of gain, about 40db and bandwidth.
Intermittent Moderate Energy Restriction Improves Weight Loss Efficiency in Diet-Induced Obese Mice
Seimon, Radhika V.; Shi, Yan-Chuan; Slack, Katy; Lee, Kailun; Fernando, Hamish A.; Nguyen, Amy D.; Zhang, Lei; Lin, Shu; Enriquez, Ronaldo F.; Lau, Jackie
2016-01-01
Background Intermittent severe energy restriction is popular for weight management. To investigate whether intermittent moderate energy restriction may improve this approach by enhancing weight loss efficiency, we conducted a study in mice, where energy intake can be controlled. Methods Male C57/Bl6 mice that had been rendered obese by an ad libitum diet high in fat and sugar for 22 weeks were then fed one of two energy-restricted normal chow diets for a 12-week weight loss phase. The continuous diet (CD) provided 82% of the energy intake of age-matched ad libitum chow-fed controls. The intermittent diet (ID) provided cycles of 82% of control intake for 5–6 consecutive days, and ad libitum intake for 1–3 days. Weight loss efficiency during this phase was calculated as (total weight change) ÷ [(total energy intake of mice on CD or ID)–(total average energy intake of controls)]. Subsets of mice then underwent a 3-week weight regain phase involving ad libitum re-feeding. Results Mice on the ID showed transient hyperphagia relative to controls during each 1–3-day ad libitum feeding period, and overall ate significantly more than CD mice (91.1±1.0 versus 82.2±0.5% of control intake respectively, n = 10, Pweight loss or weight regain phases with respect to body weight, fat mass, circulating glucose or insulin concentrations, or the insulin resistance index. Weight loss efficiency was significantly greater with ID than with CD (0.042±0.007 versus 0.018±0.001 g/kJ, n = 10, Pweight loss relative to energy deficit in mice. PMID:26784324
Murphy, G. C.; Dieckmann, M. E.; Bret, A.; Drury, L. O'c.
2010-12-01
Context. The prompt emissions of gamma-ray bursts (GRBs) are seeded by radiating ultrarelativistic electrons. Kinetic energy dominated internal shocks propagating through a jet launched by a stellar implosion, are expected to dually amplify the magnetic field and accelerate electrons. Aims: We explore the effects of density asymmetry and of a quasi-parallel magnetic field on the collision of two plasma clouds. Methods: A two-dimensional relativistic particle-in-cell (PIC) simulation models the collision with 0.9c of two plasma clouds, in the presence of a quasi-parallel magnetic field. The cloud density ratio is 10. The densities of ions and electrons and the temperature of 131 keV are equal in each cloud, and the mass ratio is 250. The peak Lorentz factor of the electrons is determined, along with the orientation and the strength of the magnetic field at the cloud collision boundary. Results: The magnetic field component orthogonal to the initial plasma flow direction is amplified to values that exceed those expected from the shock compression by over an order of magnitude. The forming shock is quasi-perpendicular due to this amplification, caused by a current sheet which develops in response to the differing deflection of the upstream electrons and ions incident on the magnetised shock transition layer. The electron deflection implies a charge separation of the upstream electrons and ions; the resulting electric field drags the electrons through the magnetic field, whereupon they acquire a relativistic mass comparable to that of the ions. We demonstrate how a magnetic field structure resembling the cross section of a flux tube grows self-consistently in the current sheet of the shock transition layer. Plasma filamentation develops behind the shock front, as well as signatures of orthogonal magnetic field striping, indicative of the filamentation instability. These magnetic fields convect away from the shock boundary and their energy density exceeds by far the
Eljarrat, Alberto; Sastre, Xavier; Peiró, Francesca; Estradé, Sónia
2016-06-01
In the present work, the dielectric response of III-nitride semiconductors is studied using density functional theory (DFT) band structure calculations. The aim of this study is to improve our understanding of the features in the low-loss electron energy-loss spectra of ternary alloys, but the results are also relevant to optical and UV spectroscopy results. In addition, the dependence of the most remarkable features with composition is tested, i.e. applying Vegard's law to band gap and plasmon energy. For this purpose, three wurtzite ternary alloys, from the combination of binaries AlN, GaN, and InN, were simulated through a wide compositional range (i.e., Al x Ga1-x N, In x Al1-x N, and In x Ga1-x N, with x=[0,1]). For this DFT calculations, the standard tools found in Wien2k software were used. In order to improve the band structure description of these semiconductor compounds, the modified Becke-Johnson exchange-correlation potential was also used. Results from these calculations are presented, including band structure, density of states, and complex dielectric function for the whole compositional range. Larger, closer to experimental values, band gap energies are predicted using the novel potential, when compared with standard generalized gradient approximation. Moreover, a detailed analysis of the collective excitation features in the dielectric response reveals their compositional dependence, which sometimes departs from a linear behavior (bowing). Finally, an advantageous method for measuring the plasmon energy dependence from these calculations is explained.
Wernette, Catherine M; White, B Douglas; Zizza, Claire A
2011-06-01
After age 70 to 75 years, average body weight decreases both in ailing and healthy people because of a loss of appetite that results in reduced energy intake and the loss of body fat and lean muscle tissue. This so-called anorexia of aging predisposes elderly people to continued pathologic weight loss and malnutrition-major causes of morbidity and mortality. Health care professionals must understand the many factors involved in the anorexia of aging to help older adults prevent unintentional weight loss. Psychological, social, and cultural factors are important effectors; however, physiological factors are emphasized here because they are not thoroughly understood and they make it inherently difficult for most people to alter their body weight. Monoamines, steroid hormones (glucocorticoids and mineralocorticoids), endocannabinoids, and proteins all influence body weight. This review is an analysis of proteins from the brain, pancreas, adipose tissue, and gastrointestinal tract that are known to affect energy intake and energy balance, with an attempt to identify those factors that may change with aging. The articles included in this review were obtained by a PubMed database search using the keywords mouse OR rat OR human AND aged OR aging OR older OR elderly AND adult AND anorexia OR "unintentional weight loss," and each of the individual proteins discussed, as well as from the reference lists of those articles. The results reveal that some proteins may be important in the development of unintentional weight loss in elderly persons, whereas others may not have a significant role. However, many of the proteins that could conceivably have a role in unintentional weight loss have not yet been studied with that question in mind. Preventing unintentional weight loss in older adults is an important goal and further research on the role of proteins important for the maintenance of energy balance and the development of unintentional weight loss in elderly persons is
Whittaker Order Reduction Method of Relativistic Birkhoffian Systems
LUOShao-Kai; HUANGFei-Jiang; LUYi-Bing
2004-01-01
The order reduction method of the relativistic Birkhollian equations is studied. For a relativistic autonomous Birkhotffian system, if the conservative law of the Birkhotffian holds, the conservative quantity can be called the generalized energy integral. Through the generalized energy integral, the order of the system can be reduced. If the relativisticBirkhoffian system has a generalized energy integral, then the Birkhoffian equations can be reduced by at least twodegrees and the Birkhoffian form can be kept. The relations among the relativistic Birkhoffian mechanics, the relativistic Hamiltonian mechanics and the relativistic Lagrangian mechanics are discussed, and the Whittaker order reduction method of the relativistic Lagrangian system is obtained. And an example is given to illustrate the application of theresult.
Whittaker Order Reduction Method of Relativistic Birkhoffian Systems
LUO Shao-Kai; HUANG Fei-Jiang; LU Yi-Bing
2004-01-01
The order reduction method of the relativistic Birkhoffian equations is studied. For a relativistic autonomous Birkhoffian system, if the conservative law of the Birkhoffian holds, the conservative quantity can be called the generalized energy integral. Through the generalized energy integral, the order of the system can be reduced. If the relativistic Birkhoffian system has a generalized energy integral, then the Birkhoffian equations can be reduced by at least two degrees and the Birkhoffian form can be kept. The relations among the relativistic Birkhoffian mechanics, the relativistic Hamiltonian mechanics and the relativistic Lagrangian mechanics are discussed, and the Whittaker order reduction method of the relativistic Lagrangian system is obtained. And an example is given to illustrate the application of the result.
Diwan, P. K.; Kumar, Sunil; Kumar, Shyam; Sharma, V.; Khan, S. A.; Avasthi, D. K.
2016-02-01
The energy loss straggling of Li and C ions in Al foils of various thicknesses has been measured, within the fractional energy loss limit (∆E/E) ∼ 10-60%. These measurements have been performed using the 15UD Pelletron accelerator facility available at Inter University Accelerator Centre (IUAC), New Delhi, India. The measured straggling values have been compared with the corresponding predicted values adopting popularly used collisional straggling formulations viz Bohr, Lindhard and Scharff, Bethe-Livingston, Titeica. In addition, the experimental data has been compared to the Yang et al. empirical formula and Close Form Model, recently proposed by Montanari et al. The straggling values derived by Titeica theory were found to be in better agreement with the measured values as compared to other straggling formulations. The charge-exchange straggling component has been estimated from the measured data based on Titeica's theory. Finally, a function of the ion effective charge and the energy loss fraction within the target has been fitted to the latter straggling component.
Changes in Energy Expenditure with Weight Gain and Weight Loss in Humans.
Müller, Manfred J; Enderle, Janna; Bosy-Westphal, Anja
2016-12-01
Metabolic adaptation to weight changes relates to body weight control, obesity and malnutrition. Adaptive thermogenesis (AT) refers to changes in resting and non-resting energy expenditure (REE and nREE) which are independent from changes in fat-free mass (FFM) and FFM composition. AT differs in response to changes in energy balance. With negative energy balance, AT is directed towards energy sparing. It relates to a reset of biological defence of body weight and mainly refers to REE. After weight loss, AT of nREE adds to weight maintenance. During overfeeding, energy dissipation is explained by AT of the nREE component only. As to body weight regulation during weight loss, AT relates to two different set points with a settling between them. During early weight loss, the first set is related to depleted glycogen stores associated with the fall in insulin secretion where AT adds to meet brain's energy needs. During maintenance of reduced weight, the second set is related to low leptin levels keeping energy expenditure low to prevent triglyceride stores getting too low which is a risk for some basic biological functions (e.g., reproduction). Innovative topics of AT in humans are on its definition and assessment, its dynamics related to weight loss and its constitutional and neuro-endocrine determinants.
Parshin, A. S.; Igumenov, A. Yu.; Mikhlin, Yu. L.; Pchelyakov, O. P.; Zhigalov, V. S.
2016-05-01
The inelastic electron scattering cross section spectra of Fe have been calculated based on experimental spectra of characteristic reflection electron energy loss as dependences of the product of the inelastic mean free path by the differential inelastic electron scattering cross section on the electron energy loss. It has been shown that the inelastic electron scattering cross-section spectra have certain advantages over the electron energy loss spectra in the analysis of the interaction of electrons with substance. The peaks of energy loss in the spectra of characteristic electron energy loss and inelastic electron scattering cross sections have been determined from the integral and differential spectra. It has been shown that the energy of the bulk plasmon is practically independent of the energy of primary electrons in the characteristic electron energy loss spectra and monotonically increases with increasing energy of primary electrons in the inelastic electron scattering cross-section spectra. The variation in the maximum energy of the inelastic electron scattering cross-section spectra is caused by the redistribution of intensities over the peaks of losses due to various excitations. The inelastic electron scattering cross-section spectra have been analyzed using the decomposition of the spectra into peaks of the energy loss. This method has been used for the quantitative estimation of the contributions from different energy loss processes to the inelastic electron scattering cross-section spectra of Fe and for the determination of the nature of the energy loss peaks.
High-resolution monochromated electron energy-loss spectroscopy of organic photovoltaic materials.
Alexander, Jessica A; Scheltens, Frank J; Drummy, Lawrence F; Durstock, Michael F; Hage, Fredrik S; Ramasse, Quentin M; McComb, David W
2017-09-01
Advances in electron monochromator technology are providing opportunities for high energy resolution (10 - 200meV) electron energy-loss spectroscopy (EELS) to be performed in the scanning transmission electron microscope (STEM). The energy-loss near-edge structure in core-loss spectroscopy is often limited by core-hole lifetimes rather than the energy spread of the incident illumination. However, in the valence-loss region, the reduced width of the zero loss peak makes it possible to resolve clearly and unambiguously spectral features at very low energy-losses (photovoltaics (OPVs): poly(3-hexlythiophene) (P3HT), [6,6] phenyl-C61 butyric acid methyl ester (PCBM), copper phthalocyanine (CuPc), and fullerene (C60). Data was collected on two different monochromated instruments - a Nion UltraSTEM 100 MC 'HERMES' and a FEI Titan(3) 60-300 Image-Corrected S/TEM - using energy resolutions (as defined by the zero loss peak full-width at half-maximum) of 35meV and 175meV, respectively. The data was acquired to allow deconvolution of plural scattering, and Kramers-Kronig analysis was utilized to extract the complex dielectric functions. The real and imaginary parts of the complex dielectric functions obtained from the two instruments were compared to evaluate if the enhanced resolution in the Nion provides new opto-electronic information for these organic materials. The differences between the spectra are discussed, and the implications for STEM-EELS studies of advanced materials are considered. Copyright © 2017 Elsevier B.V. All rights reserved.
Neutrino energy loss by electron capture on strongly screened iron group nuclei
Liu Jing-Jing; Luo Zhi-Quan
2007-01-01
The influences on the neutrino energy loss rates in iron group nuclei at the same density are investigated in the presence of strong electron screening and in the absence of electron screening. The results show that at a temperature of 15 × 109 K, the neutrino energy loss rates which come from the electron capture processfor most iron group nuclei decrease no more than 2 orders of magnitude but for the others (such as 53,55,56,57,58,59,60Co, 56,59Ni) they can decrease about 3 orders of magnitude due to strong electron screening (SES), whereas, at a temperature of 109K the neutrino energy loss rates of the most iron group nuclei can be diminished greatly due to the SES. For example, 61Fe, 60Fe,and 62Ni the neutrino energy loss rates decrease about 4, 15 and 16 orders of magnitude and for 57Cr, 58Cr, and 60Cr decrease about 18, 12, and 10 orders of magnitude respectively. According to our calculations the neutrino energy loss rates of nuclei 58Mn, 59Mn, 60Mn, and 62Mn may decrease about 13 orders of magnitude at a temperature of 109 K due to the SES.
Andersen, K.K.; Esberg, J.; Hansen, K.R.; Knudsen, H.; Lund, M.; Thomsen, H.D. [Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, 8000 Aarhus (Denmark); Uggerhoj, U.I., E-mail: ulrik@phys.au.d [Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, 8000 Aarhus (Denmark); Moller, S.P. [Institute for Storage Ring Facilities, University of Aarhus (Denmark); Sona, P. [University of Florence, Florence (Italy); Mangiarotti, A. [LIP, Universidade de Coimbra (Portugal); Ketel, T.J. [Free University, Amsterdam (Netherlands); Dizdar, A. [University of Istanbul, Istanbul (Turkey); Ballestrero, S. [University of Johannesburg, Johannesburg (South Africa)
2010-05-01
Experimental results for the restricted energy loss of ultrarelativistic electrons, with Lorentz factors up to 3x10{sup 5}, in a 535mum thin silicon detector are presented. The combination of high Lorentz factors and thin targets, opens for the possibility to study two mutually excluding effects, both based upon theory and on scarce experimental observations. One is a disappearance of the density effect when the transit time becomes so short that the effect of plasma-oscillations becomes negligible. This would result in an increased energy loss as the Lorentz factor increases. The other is an effect based on the existence of a coherence length over which there are contributions to the energy loss. This effect leads to a substantially decreased energy loss for thin targets as the Lorentz factor increases. The latter is shown to be incompatible with our measurements, whereas the former may be present with a correction of a few percent to an otherwise constant energy loss. Furthermore, we point to significant effects related to synchrotron and transition radiation, that must be carefully considered in a possible future experiment, and may as well have been of significance for the conclusion in earlier experiments.
Athermal Energy Loss from X-rays Deposited in Thin Superconducting Films on Solid Substrates
Kozorezov, Alexander G.; Lambert, Colin J.; Bandler, Simon R.; Balvin, Manuel A.; Busch, Sarah E.; Sagler, Peter N.; Porst, Jan-Patrick; Smith, Stephen J.; Stevenson, Thomas R.; Sadleir, John E.
2013-01-01
When energy is deposited in a thin-film cryogenic detector, such as from the absorption of an X-ray, an important feature that determines the energy resolution is the amount of athermal energy that can be lost to the heat bath prior to the elementary excitation systems coming into thermal equilibrium. This form of energy loss will be position-dependent and therefore can limit the detector energy resolution. An understanding of the physical processes that occur when elementary excitations are generated in metal films on dielectric substrates is important for the design and optimization of a number of different types of low temperature detector. We have measured the total energy loss in one relatively simple geometry that allows us to study these processes and compare measurements with calculation based upon a model for the various di.erent processes. We have modeled the athermal phonon energy loss in this device by finding an evolving phonon distribution function that solves the system of kinetic equations for the interacting system of electrons and phonons. Using measurements of device parameters such as the Debye energy and the thermal di.usivity we have calculated the expected energy loss from this detector geometry, and also the position-dependent variation of this loss. We have also calculated the predicted impact on measured spectral line-shapes, and shown that they agree well with measurements. In addition, we have tested this model by using it to predict the performance of a number of other types of detector with di.erent geometries, where good agreement is also found.
Calculation of inelastic scattering processes of relativistic electrons in oriented crystals
Hinderks, Dieter; Kohl, Helmut
2015-04-15
The inelastic scattering of electrons in oriented crystals has been used to determine the positions of atoms within a crystal, to obtain site-dependent electron energy loss spectra and, more recently, to obtain an energy loss signal corresponding to the circular dichroism in X-ray absorption spectroscopy. The theoretical approaches currently used for the description of these processes are based on the nonrelativistic Schrödinger equation. Nowadays many experiments, however, are conducted with incident energies of 200 or 300 keV. Therefore it is indispensable to use a relativistic description for such processes based on the Dirac equation. Using the Coulomb gauge it is shown, that the fully relativistic cross sections for plane wave scattering are given by the modulus square of a sum of two terms: one describing the electrostatic interactions similar to the nonrelativistic theory plus one additional term describing the interaction of the specimen with the magnetic field produced by the incident electron. In crystals both terms can interfere leading to large deviations from nonrelativistic theory. - Highlights: • Inelastic scattering of relativistic electrons in oriented crystals is described. • We have derived equations for relativistic Bloch waves. • Strong deviations from nonrelativistic theory have been demonstrated.
Aguila, Alexander; Wilson, Jorge
2017-07-01
This paper develops a methodology to assess a group of measures of electrical improvements in distribution systems, starting from the complementation of technical and economic criteria. In order to solve the problem of energy losses in distribution systems, technical and economic analysis was performed based on a mathematical model to establish a direct relationship between the energy saved by way of minimized losses and the costs of implementing the proposed measures. This paper aims at analysing the feasibility of reducing energy losses in distribution systems, by changing existing network conductors by larger crosssection conductors and distribution voltage change at higher levels. The impact of this methodology provides a highly efficient mathematical tool for analysing the feasibility of implementing improvement projects based on their costs which is a very useful tool for the distribution companies that will serve as a starting point to the analysis for this type of projects in distribution systems.
Energy loss of MeV protons specularly reflected from metal surfaces
Juaristi, J.I. [Departamento Fisica de Materiales, Facultad de Quimicas, Universidad del Pais Vasco/Euskal Herriko Unibersitatea, Apartado Postal 1072, 20080 San Sebastian (Spain); Garcia de Abajo, F.J. [Departamento Ciencias de la Computacion e Inteligencia Artificial, Facultad de Informatica, Universidad del Pais Vasco/Euskal Herriko Unibersitatea, Apartado Postal 649, 20080 San Sebastian (Spain); Echenique, P.M. [Departamento Fisica de Materiales, Facultad de Quimicas, Universidad del Pais Vasco/Euskal Herriko Unibersitatea, Apartado Postal 1072, 20080 San Sebastian (Spain)
1996-05-01
A parameter-free model is presented to study the energy loss of fast protons specularly reflected from metal surfaces. The contributions to the energy loss from excitation of valence-band electrons and ionization of localized target-atom electronic states are calculated separately. The former is calculated from the induced surface wake potential using linear response theory and the specular-reflection model, while the latter is calculated in the first Born approximation. The results obtained are in good agreement with available experimental data. However, the experimental qualitative trend of the energy loss as a function of the angle of incidence is obtained when the valence-band electron model is replaced by localized target atom electron states, though with a worse quantitative agreement. {copyright} {ital 1996 The American Physical Society.}
Xu, H; Toth, J; Tokesi, K; Ding, Z J
2016-01-01
We present an absolute extraction method of optical constants of metal from the measured reflection electron energy loss (REELS) spectra by using the recently developed reverse Monte Carlo (RMC) technique. The method is based on a direct physical modeling of electron elastic and electron inelastic scattering near the surface region where the surface excitation becomes important to fully describe the spectrum loss feature intensity in relative to the elastic peak intensity. An optimization procedure of oscillator parameters appeared in the energy loss function (ELF) for describing electron inelastic scattering due to the bulk- and surface-excitations was performed with the simulated annealing method by a successive comparison between the measured and Monte Carlo simulated REELS spectra. The ELF and corresponding optical constants of Fe were obtained from the REELS spectra measured at incident energies of 1000, 2000 and 3000 eV. The validity of the present optical data has been verified with the f- and ps-sum r...
Snellings, RJM; Hulsbergen, W; Prendergast, EP; van den Brink, A; de Haas, AP; Habets, JJLM; Kamermans, R; Koopmans, M; Kuijer, PG; de Laat, CTAM; Ostendorf, RW; Peghaire, A; Rossewij, M
1999-01-01
Particle identification in intermediate heavy-ion collisions, using a modern 4 pi detector which contains several active layers, relies on a parametrisation or numerical integration of the energy loss in thick layers of detector material for different ions. Here an analytical solution applicable ove
Chaos and Maps in Relativistic Dynamical Systems
Horwitz, L P
1999-01-01
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...
Relativistic Particles in Clusters of Galaxies
Ensslin, T A
2002-01-01
A brief overview on the theory and observations of relativistic particle populations in clusters of galaxies is given. The following topics are addressed: (i) the diffuse relativistic electron population within the intra-cluster medium (ICM) as seen in the cluster wide radio halos and possibly also seen in the high energy X-ray and extreme ultraviolet excess emissions of some clusters, (ii) the observed confined relativistic electrons within fresh and old radio plasma and their connection to cluster radio relics at cluster merger shock waves, (iii) the relativistic proton population within the ICM, and its observable consequences (if it exists), and (iv) the confined relativistic proton population (if it exists) within radio plasma. The importance of upcoming, sensitive gamma-ray telescopes for this research area is highlighted.
Relativistic gas in a Schwarzschild metric
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 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 temperatures) and ultra-relativistic (high temperatures) 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 stat...
Electron energy loss spectroscopy with parallel readout of energy and momentum
Ibach, Harald; Sforzini, Jessica; Soubatch, Serguei; Tautz, F Stefan
2016-01-01
We introduce a high energy resolution electron source that matches the requirements for parallel readout of energy and momentum of modern hemispherical electron energy analyzers. The system is designed as an add-on device to typical photoemission chambers. Due to the multiplex gain, a complete phonon dispersion of a Cu(111) surface was measured in seven minutes with 4 meV energy resolution.
Relativistic Scott correction for atoms and molecules
Solovej, Jan Philip; Sørensen, Thomas Østergaard; Spitzer, Wolfgang Ludwig
2010-01-01
We prove the first correction to the leading Thomas-Fermi energy for the ground state energy of atoms and molecules in a model where the kinetic energy of the electrons is treated relativistically. The leading Thomas-Fermi energy, established in [25], as well as the correction given here, are of ......We prove the first correction to the leading Thomas-Fermi energy for the ground state energy of atoms and molecules in a model where the kinetic energy of the electrons is treated relativistically. The leading Thomas-Fermi energy, established in [25], as well as the correction given here......, are of semiclassical nature. Our result on atoms and molecules is proved from a general semiclassical estimate for relativistic operators with potentials with Coulomb-like singularities. This semiclassical estimate is obtained using the coherent state calculus introduced in [36]. The paper contains a unified treatment...
Lu, Bing-Nan; Zhao, En-Guang; Zhou, Shan-Gui
2013-01-01
We have developed multi-dimensional constrained covariant density functional theories (MDC-CDFT) for finite nuclei in which the shape degrees of freedom \\beta_{\\lambda\\mu} with even \\mu, e.g., \\beta_{20}, \\beta_{22}, \\beta_{30}, \\beta_{32}, \\beta_{40}, etc., can be described simultaneously. The functional can be one of the following four forms: the meson exchange or point-coupling nucleon interactions combined with the non-linear or density-dependent couplings. For the pp channel, either the BCS approach or the Bogoliubov transformation is implemented. The MDC-CDFTs with the BCS approach for the pairing (in the following labelled as MDC-RMF models with RMF standing for "relativistic mean field") have been applied to investigate multi-dimensional potential energy surfaces and the non-axial octupole $Y_{32}$-correlations in N=150 isotones. In this contribution we present briefly the formalism of MDC-RMF models and some results from these models. The potential energy surfaces with and without triaxial deformatio...
Radiation Energy Loss from Laser-Heated Shenguang-Ⅱ Hohlraums
CHANG Tie-Qiang; HUANG Tian-Xuan; SUN Ke-Xu; WANG Guang-Yu; DUAN Qing-Sheng; PEI Wen-Bing; GU Pei-Jun; ZHANG Xing-Hong; DING Yong-Kun; ZHENG Zhi-Jian; YANG Jia-Min
2004-01-01
@@ The x ray energy loss out of laser-heated hohlraum through laser entrance holes (LEH) is discussed in detail according to a simple theoretical model and is compared with the hohlraum experimental data measured at Shenguang Ⅱ laser facility. The radiation loss is considered to be composed of two parts, that is, direct contribution from laser spots and re-emitted part from the x ray-heated hohlraum inner wall, and the former accounts for about 20% of the total loss for the Shenguang Ⅱ hohlraums. Owing to the non-equilibrium characteristics of laser target coupling the direct contribution part is non-equilibrium in spectrum.
Bremsstrahlung from relativistic heavy ions in matter
Sørensen, Allan Hvidkjær
2010-01-01
The emission of electromagnetic radiation by relativistic bare heavy ions penetrating ordinary matter is investigated. Our main aim is to determine the bremsstrahlung which we define as the radiation emitted when the projectile does not break up. It pertains to collisions without nuclear contact...... ("ultraperipheral collisions"). Requirement of coherent action of the nucleons in order to keep the penetrating projectile intact limits bremsstrahlung to relatively soft photons. The spectrum shows a resonance structure with peak position near 2γ times the position of the giant dipole resonance, that is, near 25γ....... As a result of its relative softness, bremsstrahlung never dominates the energy-loss process for heavy ions. As to the emission of electromagnetic radiation in collisions with nuclear break-up, it appears modest when pertaining to incoherent action of the projectile nucleons in noncontact collisions...
Galilean relativistic fluid mechanics
Ván, Péter
2015-01-01
Single component Galilean-relativistic (nonrelativistic) fluids are treated independently of reference frames. The basic fields are given, their balances, thermodynamic relations and the entropy production is calculated. The usual relative basic fields, the mass, momentum and energy densities, the diffusion current density, the pressure tensor and the heat flux are the time- and spacelike components of the third order mass-momentum-energy density tensor according to a velocity field. The transformation rules of the basic fields are derived and prove that the non-equilibrium thermodynamic background theory, that is the Gibbs relation, extensivity condition and the entropy production is absolute, that is independent of the reference frame and also of the fluid velocity. --- Az egykomponensu Galilei-relativisztikus (azaz nemrelativisztikus) disszipativ folyadekokat vonatkoztatasi rendszertol fuggetlenul targyaljuk. Megadjuk az alapmennyisegeket, ezek merlegeit, a termodinamikai osszefuggeseket es kiszamoljuk az ...
Cattaneo, Carlo
2011-01-01
This title includes: Pham Mau Quam: Problemes mathematiques en hydrodynamique relativiste; A. Lichnerowicz: Ondes de choc, ondes infinitesimales et rayons en hydrodynamique et magnetohydrodynamique relativistes; A.H. Taub: Variational principles in general relativity; J. Ehlers: General relativistic kinetic theory of gases; K. Marathe: Abstract Minkowski spaces as fibre bundles; and, G. Boillat: Sur la propagation de la chaleur en relativite.
Stopping of relativistic heavy ions in various media
Waddington, C. J.; Fixsen, D. J.; Crawford, H. J.; Lindstrom, P. J.; Heckman, H. H.
1986-01-01
The residual ranges of (900 + or - 3)-MeV/amu gold nuclei accelerated at the Lawrence Berkeley Laboratory Bevalac have been measured in several different media. The energy of the beam of nuclei was measured directly using a new time-of-flight system. The ranges were measured by absorption in linear wedges of polyethylene, carbon, aluminum, copper, tin, and lead and in circular wedges of polystyrene, aluminum, and gold, and by total absorption in nuclear emulsion. The measured ranges were significantly different from those calculated from the best available theoretical estimates of the energy loss of highly charged nuclei. It is concluded that at present energy losses and residual ranges of relativistic heavy ions in an arbitrary medium cannot be predicted with better than an approximately 2 percent accuracy.
Duskside Relativistic Electron Precipitation in the SAMPEX data set from 1992-2004
Comess, M. D.; Smith, D. M.; Millan, R. M.; Sample, J. G.
2009-12-01
Evidence for duskside relativistic electron precipitation (DREP) within the Earth's outer radiation belt has been seen in several sets of high altitude balloon data (MAXIS, MINIS, INTERBOA). The DREP events have a characteristically short timescale. They are the hardest X-ray events seen from balloons with typical energy around 1MeV. They always occur in the evening hemisphere between 12-24 MLT. These events appear to be intense enough that they may represent the dominant loss mechanism in the outer electron belt for relativistic electrons. However, such evidence has rarely been seen in satellite data as DREP have been hard to distinguish from other forms of precipitation such as band precipitation and microbursts. Statistical evidence for duskside relativistic electron precipitations (DREP) is presented based on a survey of data collected by SAMPEX from 1992-2004. Correlations among event duration, intensity, spectral hardness and duskside MLT are observed in this sample.
Control of Refrigeration Systems for Trade-off between Energy Consumption and Food Quality Loss
Cai, Junping
by applying two main optimization strategies to traditional refrigeration systems. The first strategy is a new defrost-on-demand scheme, which based on an objective function between quality loss and energy consumption, continuously seeks an optimal time interval for defrosting in dynamic situation. The second...... strategy is through utilization of the thermal mass of the refrigerated foodstuffs, the day-night temperature variation and the capacity control of the compressor, to realize a trade-off between system energy consumption and food quality loss....
Intermittent Moderate Energy Restriction Improves Weight Loss Efficiency in Diet-Induced Obese Mice.
Radhika V Seimon
Full Text Available Intermittent severe energy restriction is popular for weight management. To investigate whether intermittent moderate energy restriction may improve this approach by enhancing weight loss efficiency, we conducted a study in mice, where energy intake can be controlled.Male C57/Bl6 mice that had been rendered obese by an ad libitum diet high in fat and sugar for 22 weeks were then fed one of two energy-restricted normal chow diets for a 12-week weight loss phase. The continuous diet (CD provided 82% of the energy intake of age-matched ad libitum chow-fed controls. The intermittent diet (ID provided cycles of 82% of control intake for 5-6 consecutive days, and ad libitum intake for 1-3 days. Weight loss efficiency during this phase was calculated as (total weight change ÷ [(total energy intake of mice on CD or ID-(total average energy intake of controls]. Subsets of mice then underwent a 3-week weight regain phase involving ad libitum re-feeding.Mice on the ID showed transient hyperphagia relative to controls during each 1-3-day ad libitum feeding period, and overall ate significantly more than CD mice (91.1±1.0 versus 82.2±0.5% of control intake respectively, n = 10, P<0.05. There were no significant differences between CD and ID groups at the end of the weight loss or weight regain phases with respect to body weight, fat mass, circulating glucose or insulin concentrations, or the insulin resistance index. Weight loss efficiency was significantly greater with ID than with CD (0.042±0.007 versus 0.018±0.001 g/kJ, n = 10, P<0.01. Mice on the CD exhibited significantly greater hypothalamic mRNA expression of proopiomelanocortin (POMC relative to ID and control mice, with no differences in neuropeptide Y or agouti-related peptide mRNA expression between energy-restricted groups.Intermittent moderate energy restriction may offer an advantage over continuous moderate energy restriction, because it induces significantly greater weight loss relative
Quark energy loss in semi-inclusive deep inelastic scattering of leptons on nuclei
Song, Li-Hua; 10.1103/Phys.RevC.81.035207
2011-01-01
Semi-inclusive deep inelastic scattering on nuclear targets is an ideal tool to study the energy loss effect of an outgoing quark in a nuclear medium. By means of the short hadron formation time, the experimental data with quark hadronization occurring outside the nucleus are picked out. A leading-order analysis is performed for the hadron multiplicity ratios as a function of the energy fraction on helium, neon, and copper nuclei relative to deuteron for the various identified hadrons. It is shown that the nuclear effects on parton distribution functions can be neglected. It is found that the theoretical results considering the nuclear modification of fragmentation functions due to quark energy loss are in good agreement with the experimental data. Whether the quark energy loss is linear or quadratic with the path length is not determined. The obtained energy loss per unit length is 0.38 \\pm 0.03 GeV/fm for an outgoing quark by the global fit.
Andersen, K K; Hansen, K R; Knudsen, H; Lund, M.; Thomsen, H D; Uggerhoj, U I; Moller, S P; Sona, P; Mangiarotti, A; Ketel, T J; Dizdar, A; Ballestrero, S
2010-01-01
Experimental results for the restricted energy loss of ultrarelativistic electrons, with Lorentz factors up to 3x10^5, in a 535@mm thin silicon detector are presented. The combination of high Lorentz factors and thin targets, opens for the possibi lity to study two mutually excluding effects, both based upon theory and on scarce experimental observations. One is a disappearance of the density effect when the transit time becomes so short that the effect of plasma-oscillations becomes negligible. Th is would result in an increased energy loss as the Lorentz factor increases. The other is an effect based on the existence of a coherence length over which there are contributions to the energy loss. This effect leads to a substantially decreased energy l oss for thin targets as the Lorentz factor increases. The latter is shown to be incompatible with our measurements, whereas the former may be present with a correction of a few percent to an otherwise constant energy loss. Furthermore, we point to signifi cant eff...
Tait, E. W.; Ratcliff, L. E.; Payne, M. C.; Haynes, P. D.; Hine, N. D. M.
2016-04-20
Experimental techniques for electron energy loss spectroscopy (EELS) combine high energy resolution with high spatial resolution. They are therefore powerful tools for investigating the local electronic structure of complex systems such as nanostructures, interfaces and even individual defects. Interpretation of experimental electron energy loss spectra is often challenging and can require theoretical modelling of candidate structures, which themselves may be large and complex, beyond the capabilities of traditional cubic-scaling density functional theory. In this work, we present functionality to compute electron energy loss spectra within the onetep linear-scaling density functional theory code. We first demonstrate that simulated spectra agree with those computed using conventional plane wave pseudopotential methods to a high degree of precision. The ability of onetep to tackle large problems is then exploited to investigate convergence of spectra with respect to supercell size. Finally, we apply the novel functionality to a study of the electron energy loss spectra of defects on the (1 0 1) surface of an anatase slab and determine concentrations of defects which might be experimentally detectable.
Van Weyenberg, S; Hesta, M; Buyse, J; Janssens, G P J
2008-10-01
In nine initially obese ponies, a weekly weight loss according to 1% of their ideal body weight was evaluated for its impact on insulin sensitivity and metabolic profile. Weight loss was obtained solely through energy restriction, initially at 70% of maintenance energy requirements, but to maintain constant weight loss, feed amount had to be decreased to 50% and 35% of maintenance energy requirement during the course of the trial. An oral glucose tolerance test (OGTT) was performed at weeks 0, 10 and 17. Fasted blood samples were taken on weeks 0, 3, 10, 17 for analysis of triglycerides (TG), non-esterified fatty acids (NEFA), creatine phosphokinase (CPK), lactate dehydrogenase (LDH), T(3), T(4) and leptin. Total average weight loss was 18.2%. When the OGTT was performed at weeks 0, 10 and 17, ponies had lost 0.22%, 9.9% and 16.3% of their initial weight respectively. Weight loss was associated with a decreased AUC for glucose and insulin. Moreover, greater % weight loss was associated with a significantly lower glucose peak and a lower area under the curve (AUC glucose). The lower glucose response after an OGTT in lean ponies was not the result of an increased insulin secretion, but an improved insulin sensitivity. Restricted feeding led to mobilization of TG and NEFA and to a reduced basal metabolism, with lower LDH, CPK, T(3) and leptin. in obese Shetland ponies, weight loss at a rate of 1% of ideal body weight per week through restricted energy intake, ameliorated insulin sensitivity.
Energy homeostasis and appetite regulating hormones as predictors of weight loss in men and women.
Williams, Rebecca L; Wood, Lisa G; Collins, Clare E; Morgan, Philip J; Callister, Robin
2016-06-01
Sex differences in weight loss are often seen despite using the same weight loss program. There has been relatively little investigation of physiological influences on weight loss success in males and females, such as energy homeostasis and appetite regulating hormones. The aims were to 1) characterise baseline plasma leptin, ghrelin and adiponectin concentrations in overweight and obese males and females, and 2) determine whether baseline concentrations of these hormones predict weight loss in males and females. Subjects were overweight or obese (BMI 25-40 kg/m(2)) adults aged 18-60 years. Weight was measured at baseline, and after three and six months participation in a weight loss program. Baseline concentrations of leptin, adiponectin and ghrelin were determined by enzyme-linked immunosorbent assay (ELISA). An independent t-test or non-parametric equivalent was used to determine any differences between sex. Linear regression determined whether baseline hormone concentrations were predictors of six-month weight change. Females had significantly higher baseline concentrations of leptin, adiponectin and unacylated ghrelin as well as ratios of leptin:adiponectin and leptin:ghrelin. The ratio of acylated:unacylated ghrelin was significantly higher in males. In males and females, a higher baseline concentration of unacylated ghrelin predicted greater weight loss at six months. Additionally in females, higher baseline total ghrelin predicted greater weight loss and a higher ratio of leptin:ghrelin predicted weight gain at six months. A higher pre-weight-loss plasma concentration of unacylated ghrelin is a modest predictor of weight loss success in males and females, while a higher leptin:ghrelin ratio is a predictor of weight loss failure in females. Further investigation is required into what combinations and concentrations of these hormones are optimal for weight loss success.
Relativistic Zitterbewegung in non-Hermitian photonic waveguide systems
Wang, Guanglei; Xu, Hongya; Huang, Liang; Lai, Ying-Cheng
2017-01-01
Zitterbewegung (ZB) is a phenomenon in relativistic quantum systems where the electron wave packet exhibits a trembling or oscillating behavior during its motion, caused by its interaction or coupling with the negative energy state. To directly observe ZB in electronic systems is difficult, due to the challenges associated with the small amplitude of the motion which is of the order of Compton wavelength. Photonic systems offer an alternative paradigm. We exploit the concept of pseudo parity-time (pseudo { P }{ T }) symmetry to study ZB in non-Hermitian quantum systems implemented as an experimentally feasible optical waveguide array. In particular, the non-Hermitian Hamiltonian is realized through evanescent coupling among the waveguides to form a one-dimensional lattice with periodic modulations in gain and loss along the guiding direction. As the modulation frequency is changed, we obtain a number of phenomena including periodically suppressed ZB trembling, spatial energy localization, and Hermitian-like ZB oscillations. We calculate phase diagrams indicating the emergence of different types of dynamical behaviors of the relativistic non-Hermitian quantum system in an experimentally justified parameter space. We provide numerical results and a physical analysis to explain the distinct dynamical behaviors revealed by the phase diagrams. Our findings provide a deeper understanding of both the relativistic ZB phenomenon and non-Hermitian pseudo-{ P }{ T } systems, with potential applications in controlling/harnessing light propagation in waveguide-based optical systems.
Alt, C; Baatar, B.; Barna, D.; Bartke, J.; Betev, L.; Bialkowska, H.; Blume, C.; Boimska, B.; Botje, M.; Bracinik, J.; Bramm, R.; Buncic, P.; Cerny, V.; Christakoglou, P.; Chvala, O.; Cramer, J.G.; Csato, P.; Dinkelaker, P.; Eckardt, V.; Flierl, D.; Fodor, Z.; Foka, P.; Friese, V.; Gal, J.; Gazdzicki, M.; Genchev, V.; Georgopoulos, G.; Gladysz, E.; Grebieszkow, K.; Hegyi, S.; Hohne, C.; Kadija, K.; Karev, A.; Kliemant, M.; Kniege, S.; Kolesnikov, V.I.; Kornas, E.; Korus, R.; Kowalski, M.; Kraus, I.; Kreps, M.; Laslo, A.; van Leeuwen, M.; Levai, P.; Litov, L.; Lungwitz, B.; Makariev, M.; Malakhov, A.I.; Mateev, M.; Melkumov, G.L.; Mischke, A.; Mitrovski, M.; Molnar, J.; Mrowczynski, St.; Nicolic, V.; Palla, G.; Panagiotou, A.D.; Panayotov, D.; Petridis, A.; Pikna, M.; Prindle, D.; Puhlhofer, F.; Renfordt, R.; Roland, C.; Roland, G.; Rybczynski, M.; Rybicki, A.; Sandoval, A.; Schmitz, N.; Schuster, T.; Seyboth, P.; Sikler, F.; Sitar, B.; Skrzypczak, E.; Stefanek, G.; Stock, R.; Strabel, C.; Strobele, H.; Susa, T.; Szentpetery, I.; Sziklai, J.; Szymanski, P.; Trubnikov, V.; Varga, D.; Vassiliou, M.; Veres, G.I.; Vesztergombi, G.; Vranic, D.; Wetzler, A.; Wlodarczyk, Z.; Yoo, I.K.; Zimanyi, J.
2005-01-01
The transverse mass distributions for antiprotons are measured at midrapidity for minimum bias Pb+Pb collisions at 158A GeV and for central Pb+Pb collisions at 20, 30, 40 and 80 A GeV beam energies in the NA49 experiment at the CERN SPS. The rapidity density, inverse slope parameter and mean transverse mass derived from the transverse mass distributions are studied as a function of the incident energy and the collision centrality and compared to the relevant proton data. The shapes of the m_T distributions of antiprotons and protons are very similar. The ratios of the particle yields, antiproton/proton and antilambda/antiproton, are also analysed. The antiproton/proton ratio exhibits an increase with diminishing centrality and a steep rise with increasing beam energy. The antilambda/antiproton ratio increases beyond unity with decreasing beam energy.
Ayyad, Y.; Benlliure, J.; Casarejos, E. [Group GENP, Dpto. Fisica de Particulas, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Schmidt, K. H. [GSI, Planckstrasse 1, 64941, Darmstadt (Germany); Jurado, B. [Universite Bordeaux I, CNRS/IN2 P3, CENBG, BP 120, F-33175 Gradignan (France); Kelic-Heil, A. [GSI, Planckstrasse 1, 64941, Darmstadt (Germany); Pol, H. A. [Group GENP, Dpto. Fisica de Particulas, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Ricciardi, M. V.; Pleskac, R. [GSI, Planckstrasse 1, 64941, Darmstadt (Germany); Enqvist, T. [CUPP Project, P.O. Box 22, FI-86801, Pyhsalmi (Finland); Rejmund, F. [Grand Accelerateur National D Ions Lourds, BP 55027, F-14076 Caen Cedex 05 (France); Giot, L. [Subatech - Ecole des Mines de Nantes (France); Henzl, V. [Massachusetts Inst. of Technology, 77, Massachusetts Ave, Cambridge, MA 02139 (United States); Lukic, S. [Karlsruhe Inst. of Technology, D-76021 Karlsruhe (Germany); Ngoc, S. N. [Dept. of Nuclear Physics, Inst. of Physics, National Centre for Natural Science and Technology, NgiaDo-TuLiem, Hanoi (Viet Nam); Boudard, A. [DSM/IRFU/CEA, 91191 Gif-sur-Ivette (France); Universite Louis Pasteur, Strasbourg (France); Leray, S. [DSM/IRFU/CEA, 91191 Gif-sur-Ivette (France); Fernandez, M. [Entro de Investigaciones Energticas Medioambientales Y Tecnolgicas, Madrid (Spain); Kurtukian, T. [Universite Bordeaux I, CNRS/IN2 P3, CENBG, BP 120, F-33175 Gradignan (France); Nadtochy, P. [Omsk State Univ., Dept. of Theoretical Physics, RU-644077 Omsk (Russian Federation); Schmitt, C. [Grand Accelerateur National D' Ions Lourds, BP 55027, F-14076 Caen Cedex 05 (France); Henzlova, D. [Los Alamos National Laboratory, Safeguards Science and Technology Group N-1, Los Alamos, NM 87545 (United States); Paradela, C. [Group GENP, Dpto. Fisica de Particulas, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Bacquias, A. [DSM/IRFU/CEA, 91191 Gif-sur-Ivette (France); Universite Louis Pasteur, Strasbourg (France); Loureiro, D. P. [Group GENP, Dpto. Fisica de Particulas, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Foehr, V. [GSI, Planckstrasse 1, 64941, Darmstadt (Germany); Tarrio, D. [Group GENP, Dpto. Fisica de Particulas, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Kezzar, K. [DSM/IRFU/CEA, 91191 Gif-sur-Ivette (France)
2011-07-01
Total fission cross section induced by protons in {sup 181}Ta and {sup 208}Pb at energies in the range of 300 to 1000 A MeV have been measured at GSI (Germany) using the inverse kinematics technique. A dedicated setup with high efficiency made it possible to determine these cross sections with high accuracy. The new data seed light in the controversial results obtained so far and contribute to the understanding of the fission process at high excitation energies. (authors)
Characterization of Solidified Gas Thin Film Targets via $\\alpha$ Particle Energy Loss
Fujiwara, M C; Beveridge, J L; Douglas, J L; Huber, T M; Jacot-Guillarmod, R; Kim, S K; Knowles, P E; Kunselman, A R; Maier, M; Marshall, G M; Mason, G R; Mulhauser, F; Olin, A; Petitjean, C; Porcelli, T A; Zmeskal, J
1996-01-01
A method is reported for measuring the thickness and uniformity of thin films of solidified gas targets. The energy of alpha particles traversing the film is measured and the energy loss is converted to thickness using the stopping power. The uniformity is determined by measuring the thickness at different positions with an array of sources. Monte Carlo simulations have been performed to study the film deposition mechanism. Thickness calibrations for a TRIUMF solid hydrogen target system are presented.
High-resolution proton energy-loss spectrometer for surface analysis
Itoh, Noriaki; Kanasaki, Junichi; Matsunami, Noriaki; Matsuda, Kouji; Aoki, Masahiko.
1988-11-01
We describe a new ion-beam surface analyzer, proton energy loss spectrometer. It analyzes ions incident at 100 keV and scattered by 180degC at solid surfaces with a resolution of 5eV. The results of computer simulation of the energy spectra of scattered ions and the informations on surface electronic and atomic structures possibly derived by the analysis are described. Application of the spectrometer in several areas of science and technology is briefly discussed.
Electron-energy-loss spectral library and its application to materials science
Zaluzec, N.J.
1983-09-01
An electron energy loss spectral library can be an invaluable tool in materials research from a fundamental as well as a practical standpoint. Although it will not alleviate all the complications associated with quantification, this type of library can help to elucidate details of spectral profiles previously found intractable. This work was supported by the US Department of Energy. The author also wishes to express his gratitude to the organizing committee for partial financial support provided to attend this meeting.
Energy losses of charged particles in a finite layer of substance
Chechin, V. A.
1985-04-01
The energy lost by a charged particle as it crosses a plane-parallel plate with dielectric permittivity in a vacuum is calculated theoretically, applying the intermediate transition to the Heaviside transformation and considering various combinations of particle Lorentz factor and plate thickness. The problems encountered in comparing the theoretical predictions with experimental data are examined, and the application of the model of energy loss in very thin layers of Ermilova et al. (1974) is found to explain the observed anomalies.
Ahn, Chang Won; Amarsanaa, Gantsooj; Won, Sung Sik; Chae, Song A; Lee, Dae Su; Kim, Ill Won
2015-12-09
We demonstrate a capacitor with high energy densities, low energy losses, fast discharge times, and high temperature stabilities, based on Pb(0.97)Y(0.02)[(Zr(0.6)Sn(0.4))(0.925)Ti(0.075)]O3 (PYZST) antiferroelectric thin-films. PYZST thin-films exhibited a high recoverable energy density of U(reco) = 21.0 J/cm(3) with a high energy-storage efficiency of η = 91.9% under an electric field of 1300 kV/cm, providing faster microsecond discharge times than those of commercial polypropylene capacitors. Moreover, PYZST thin-films exhibited high temperature stabilities with regard to their energy-storage properties over temperatures ranging from room temperature to 100 °C and also exhibited strong charge-discharge fatigue endurance up to 1 × 10(7) cycles.
Millan, R. M.; Lin, R. P.; Smith, D. M.; McCarthy, M. P.
2007-05-01
We present the first quantitative comparison of precipitating and geomagnetically trapped electron flux during a relativistic electron depletion event. Intense bremsstrahlung X-ray emission from relativistic electron precipitation was observed on January 19-20, 2000 (21:20-00:45 UT) by the germanium spectrometer on the MAXIS balloon payload (-7.2 to -9.3 E, 74 S corresponding to IGRF L = 4.7, 1920-2240 MLT). A rapid decrease in the geosynchronous >2 MeV electron flux was simultaneously observed at GOES-8 and GOES-10, and between 0.34-3.6 MeV by GPS ns33 at L = 4.7. The observations show that electrons were lost to the atmosphere early in the flux depletion event, during a period of magnetic field stretching in the tail. The observed X-ray spectrum is well modeled by an exponential distribution of precipitating electrons with an e-folding energy of 290 keV and a lower-energy cut-off of 400 keV. The duration of the event implies precipitation extended over at least 3 hours of MLT, assuming a source fixed in local time. Comparison of the precipitation rate with the flux decrease measured at GPS implies that the loss cone flux was only ~1% of the equatorial flux. However, precipitation is sufficient to account for the rate of flux decrease if it extended over 2-3 hours of local time.
Double Relativistic Electron Accelerating Mirror
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.
A proximal retarding field analyzer for scanning probe energy loss spectroscopy
Bauer, Karl; Murphy, Shane; Palmer, Richard E.
2017-03-01
A compact proximal retarding field analyzer for scanning probe energy loss spectroscopy measurements is described. Using the scanning tunneling microscope (STM) tip as a field emission (FE) electron source in conjunction with this analyzer, which is placed at a glancing angle to the surface plane, FE sample current and electron reflectivity imaging may be performed simultaneously. This is demonstrated in measurements of Ag nanostructures prepared on graphite by electron-beam lithography, where a material contrast of 13% is observed, with a lateral resolution of 25 nm, between the silver and graphite in electron reflectivity images. Topological contrast mechanisms such as edge enhancement and shadowing are also observed, giving rise to additional features in the electron reflectivity images. The same instrument configuration has been used to measure electron energy loss spectra on bare graphite, where the zero loss peak, π band plasmon loss peak and secondary electron peaks are observed. Using this simple and compact analyzer an STM, with sufficient open access to the tip-sample junction, may easily be augmented to provide simultaneous elemental and topographic mapping, supplementing STM image measurements with FE sample current and electron reflectivity images, as well as electron energy loss spectroscopy measurements, in the same instrument.
Relativistic radiative transfer in relativistic spherical flows
Fukue, Jun
2017-02-01
Relativistic radiative transfer in relativistic spherical flows is numerically examined under the fully special relativistic treatment. We first derive relativistic formal solutions for the relativistic radiative transfer equation in relativistic spherical flows. We then iteratively solve the relativistic radiative transfer equation, using an impact parameter method/tangent ray method, and obtain specific intensities in the inertial and comoving frames, as well as moment quantities, and the Eddington factor. We consider several cases; a scattering wind with a luminous central core, an isothermal wind without a core, a scattering accretion on to a luminous core, and an adiabatic accretion on to a dark core. In the typical wind case with a luminous core, the emergent intensity is enhanced at the center due to the Doppler boost, while it reduces at the outskirts due to the transverse Doppler effect. In contrast to the plane-parallel case, the behavior of the Eddington factor is rather complicated in each case, since the Eddington factor depends on the optical depth, the flow velocity, and other parameters.
Sabyasachi Haldar
2014-07-01
Full Text Available New Free Electrons Wire will enable the use of electrical energy and also energy in various other forms, in a loss free way, at room temperature. Free Electrons confined in vacuum at the order of 10-4 torr or more, at the core of the wire, can move a distance as long as about, to a few kilometers without any collision. The vacuum is maintained in a tube made up of alternate layers of Teflon and Silicon Oxynitride. The columbic repulsion between these free electrons will actually conduct energy without any loss. The free electrons trapped in vacuum tube, should be at a particular density of around 2.02 x 108 electrons per unit area. A metal encapsulation(s over the wire is there to keep the electromagnetic field remain confined within the free electron wire, to make it harmless to the health of living creatures. Apart from loss free energy transportation, the free electron wire is also capable of generating very high electromagnetic field due to the free electrons, simply by removing the metal encapsulation(s, which can be used for various purposes. The materials and techniques adopted will make New Free Electron Wire producible commercially, at the cost of general copper wires.
Zhang, Yanwen [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Varga, Tamas [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Ishimaru, Manabu [Department of Materials Science and Engineering, Kyushu Inst. of Technology, Fukuoka (Japan); Edmondson, P. D. [Univ. of Oxford, (United Kingdom). Dept. of Materials; Xue, H. [Univ. of Tennessee, Knoxville, TN (United States); Liu, Peng [Univ. of Tennessee, Knoxville, TN (United States); School of Physics, Key Laboratory of Particle Physics and Particle Irradiation, Shandong Univ., Jinan (China); Moll, Sandra [TN International/AREVA, Montigny Le Bretonneux (France); Namavar, Fereydoon [Univ. of Nebraska Medical Center, Omaha, NE (United States); Hardiman, Christopher M. [North Carolina State Univ. (United States). Dept. of Nuclear Engineering; Shannon, Steven [North Carolina State Univ. (United States). Dept. of Nuclear Engineering; Weber, William J. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab., Oak Ridge, TN (United States)
2014-05-01
Ever increasing energy needs have raised the demands for advanced fuels and cladding materials that withstand the extreme radiation environments with improved accident tolerance over a long period of time. Ceria (CeO2) is a well known ionic conductor that is isostructural with urania and plutonia-based nuclear fuels. In the context of nuclear fuels, immobilization and transmutation of actinides, CeO2 is a model system for radiation effect studies. Covalent silicon carbide (SiC) is a candidate for use as structural material in fusion, cladding material for fission reactors, and an inert matrix for the transmutation of plutonium and other radioactive actinides. Understanding microstructural change of these ionic-covalent materials to irradiation is important for advanced nuclear energy systems. While displacements from nuclear energy loss may be the primary contribution to damage accumulation in a crystalline matrix and a driving force for the grain boundary evolution in nanostructured materials, local non-equilibrium disorder and excitation through electronic While displacements from nuclear energy loss may be the primary contribution to damage accumulation in a crystalline matrix and a driving force for the grain boundary evolution in nanostructured materials, local non-equilibrium disorder and excitation through electronic energy loss may, however, produce additional damage or anneal pre-existing defect. At intermediate transit energies where electronic and nuclear energy losses are both significant, synergistic, additive or competitive processes may evolve that affect the dynamic response of materials to irradiation. The response of crystalline and nanostructured CeO2 and SiC to ion irradiation are studied under different nuclear and electronic stopping powers to describe some general material response in this transit energy regime. Although fast radiation-induced grain growth in CeO2 is evident with no phase transformation, different fluence and dose dependence
Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy
Zhan, W.; Granerød, C. S.; Venkatachalapathy, V.; Johansen, K. M. H.; Jensen, I. J. T.; Kuznetsov, A. Yu; Prytz, Ø.
2017-03-01
Using monochromated electron energy loss spectroscopy in a probe-corrected scanning transmission electron microscope we demonstrate band gap mapping in ZnO/ZnCdO thin films with a spatial resolution below 10 nm and spectral precision of 20 meV.
Bandgap determination of P(VDF–TrFE) copolymer film by electron energy loss spectroscopy
Dipankar Mandal; K Henkel; K Müller; D Schmeißer
2010-08-01
The ferroelectric of poly(vinylidene fluoride trifluoroethylene), P(VDF–TrFE) is confirmed for 100 nm thickness spin coated copolymer film. The homogeneous coverage of the copolymer film is investigated by the help of X-ray photoelectron spectroscopy (XPS). Most importantly, the existing bandgap in the crystalline phase of the copolymer is determined directly from the electron energy loss spectroscopy (EELS).
Mai Tong; Thomas Liebner
2007-01-01
In a viscous damping device under cyclic loading, after the piston reaches a peak stroke, the reserve movement that follows may sometimes experience a short period of delayed or significantly reduced device force output. A similar delay or reduced device force output may also occur at the damper's initial stroke as it moves away from its neutral position.This phenomenon is referred to as the effect of "deadzone". The deadzone can cause a loss of energy dissipation capacity and less efficient vibration control. It is prominent in small amplitude vibrations. Although there are many potential causes of deadzone such as environmental factors, construction, material aging, and manufacture quality, in this paper, its general effect in linear and nonlinear viscous damping devices is analyzed. Based on classical dynamics and damping theory, a simple model is developed to capture the effect of deadzone in terms of the loss of energy dissipation capacity. The model provides several methods to estimate the loss of energy dissipation within the deadzone in linear and sublinear viscous fluid dampers.An empirical equation of loss of energy dissipation capacity versus deadzone size is formulated, and the equivalent reduction of effective damping in SDOF systems has been obtained. A laboratory experimental evaluation is carried out to verify the effect of deadzone and its numerical approximation. Based on the analysis, a modification is suggested to the corresponding formulas in FEMA 356 for calculation of equivalent damping ifa deadzone is to be considered.
Mapping boron in silicon solar cells using electron energy-loss spectroscopy
Duchamp, Martial; Boothroyd, Chris; Kovács, András
2011-01-01
Electron energy-loss spectroscopy (EELS) is used to study the B distribution in a p-i-n layered solar cell structure. The boron concentration in the p-doped Si layer is expected to be ~1021 cm−3 and should not exceed 1017 cm−3 in the neighbouring intrinsic layer. We show that B concentrations...
Fast-ion Energy Loss During TAE Avalanches in the National Spherical Torus Experiment
Fredrickson, E D; Darrow, D S; Gorelenkov, N N; Kramer, G J; Kubota, S; Podesta, M; White, R B; Bortolon, A; Gerhardt, S P; Bell, R E; Diallo, A; LeBlanc, B; Levinton, F M
2012-07-11
Strong TAE avalanches on NSTX, the National Spherical Torus Experiment [M. Ono, et al., Nucl. Fusion 40 (2000) 557] are typically correlated with drops in the neutron rate in the range of 5% - 15%. In previous studies of avalanches in L-mode plasmas, these neutron drops were found to be consistent with modeled losses of fast ions. Here we expand the study to TAE avalanches in NSTX H-mode plasmas with improved analysis techniques. At the measured TAE mode amplitudes, simulations with the ORBIT code predict that fast ion losses are negligible. However, the simulations predict that the TAE scatter the fast ions in energy, resulting in a small (≈ 6%) drop in fast ion β. The net decrease in energy of the fast ions is sufficient to account for the bulk of the drop in neutron rate, even in the absence of fast ion losses. This loss of energy from the fast ion population is comparable to the estimated energy lost by damping from the Alfven wave during the burst. The previously studied TAE avalanches in L-mode are re-evaluated using an improved calculation of the potential fluctuations in the ORBIT code.
Energy loss caused by shielding effect of steel cage outside source tube
无
2007-01-01
The energy loss, produced by shielding effect of steel cage outside the source tube, is quite considerable.With PENELOPE software package, MC results have been obtained based on the simulation of different source conformations. The result illustrates that the naked source tubes can improve the utilization ratio of the cobalt facilities. It demonstrates the applied value of the naked source tube in engineering.
Ermuratskii V.
2009-12-01
Full Text Available It is studied thermal loss factor of solar energy collector, which absorber represents the register made from polymeric pipes. Input data are results of tests in non-stationary thermal regime at the zero water flow rate and the minimum sunlight.
A Bench Measurement of the Energy Loss of a Stored Beam to a Cavity
Sands, M; Rees, J.; /SLAC
2016-12-19
A rather simple electronic bench experiment is proposed for obtaining a measure of the impulse energy loss of a stored particle bunch to an rf cavity or other vacuum-chamber structure--the so-called "cavity radiation". The proposed method is analyzed in some detail.
A Bench Measurement of the Energy Loss of a Stored Beam to a Cavity
Sands, M.; Rees, John R.; /SLAC
2005-08-08
A rather simple electronic bench experiment is proposed for obtaining a measure of the impulse energy loss of a stored particle bunch to an rf cavity or other vacuum-chamber structure--the so-called ''cavity radiation''. The proposed method is analyzed in some detail.
Moskalenko, Alexander
2010-09-15
This is an opinion of an independent consultant about key sources of energy losses. It differentiates from the one commonly accepted. The main loser of energy is an energy sector - producers of energy and the distribution networks, responsible for transporting of energy, not the housing and the transportation sector. This opinion is based on the GCE Group's experience. The author proposes to focus the work to reduce energy losses on increasing the energy efficiency of energy sector, not on the end consumer. This will allow to reduce the cost of energy unit production and to reduce greenhouse gas emissions.
High-energy irradiation and mass loss rates of hot Jupiters in the solar neighborhood
Salz, M; Czesla, S; Schmitt, J H M M
2015-01-01
Giant gas planets in close proximity to their host stars experience strong irradiation. In extreme cases photoevaporation causes a transonic, planetary wind and the persistent mass loss can possibly affect the planetary evolution. We have identified nine hot Jupiter systems in the vicinity of the Sun, in which expanded planetary atmospheres should be detectable through Lyman alpha transit spectroscopy according to predictions. We use X-ray observations with Chandra and XMM-Newton of seven of these targets to derive the high-energy irradiation level of the planetary atmospheres and the resulting mass loss rates. We further derive improved Lyman alpha luminosity estimates for the host stars including interstellar absorption. According to our estimates WASP-80 b, WASP-77 b, and WASP-43 b experience the strongest mass loss rates, exceeding the mass loss rate of HD 209458 b, where an expanded atmosphere has been confirmed. Furthermore, seven out of nine targets might be amenable to Lyman alpha transit spectroscopy...
Stefańska, Patrycja
2016-01-01
In this paper we present tabulated data for magnetic-dipole-to-electric-quadrupole cross-susceptibilities ($\\chi_{\\textrm{M}1 \\to \\textrm{E}2}$) for Dirac one-electron atoms with a pointlike, spinless and motionless nucleus of charge $Ze$. Numerical values of this susceptibility for the hydrogen atom ($Z=1$) and for hydrogenic ions with $2 \\leqslant Z \\leqslant 137$ are computed from the general analytical formula, recently derived by us [P. Stefa{\\'n}ska, Phys. Rev. A 93 (2016) 022504], valid for an arbitrary discrete energy eigenstate. In this work we provide 30 tables with the values of $\\chi_{\\textrm{M}1 \\to \\textrm{E}2}$ for the ground state, and also for the first, the second and the third set of excited states (i.e.: 2s$_{1/2}$, 2p$_{1/2}$, 2p$_{3/2}$, 3s$_{1/2}$, 3p$_{1/2}$, 3p$_{3/2}$, 3d$_{3/2}$, 3d$_{5/2}$, 4s$_{1/2}$, 4p$_{1/2}$, 4p$_{3/2}$, 4d$_{3/2}$, 4d$_{5/2}$, 4f$_{5/2}$ and 4f$_{7/2}$) of the relativistic hydrogenlike atoms. The value of the inverse of the fine-structure constant used in the...
Modelling moisture content and dry matter loss during storage of logging residues for energy
Filbakk, Tore; Hoeiboe, Olav Albert (Dept. of Ecology and Natural Resource Management, Norwegian Univ. of Life Sciences, Aas (Norway)); Dibdiakova, Janka (Norwegian Forest and Landscape Inst., Aas (Norway)); Nurmi, Juha (Finnish Forest Research Inst., Kannus (Finland))
2011-04-15
To achieve optimal utilisation of logging residues for energy, it is important to know how different handling and storage methods affect fuel properties. The aim of this study was to model how the moisture content and dry matter losses of logging residues develop during storage. Logging residues were collected from five different stands of spruce and pine during different seasons of the year and stored in the same location. The logging residues were stored in covered piles of bundled residues and loose residues. Only minor differences were found in the moisture content profiles between piles of bundles and loose residues. Logging residues located in the centre of both types of piles had considerably lower moisture content than the outer parts. The moisture content significantly affected dry matter loss, with the highest dry matter losses being found in the samples with the least favourable drying conditions. The dry matter losses varied between 1 and 3% per month. Significantly higher dry matter losses were found in the spruce bundles than in the pine bundles. Seasoned logging residues had the lowest dry matter loss, while the logging residues harvested and piled in the autumn had the highest loss
Energy losses in mixed matrix superconducting wires under fast pulsed conditions
Wollan, J.J.
1976-08-17
Energy losses have been measured on a set of mixed matrix (CuNi, Cu, NbTi) superconducting wires at B's up to 1.5 x 10/sup 7/ G/s. The losses have been measured as a function of wire diameter, twist pitch, maximum applied field, and B. Both static and dynamic losses were measured for a field applied perpendicularly to the wire axis. The dynamic losses were measured by slowly applying an external field to a sample and then causing the field to decay exponentially in roughly 1 ms to 10 ms. Under low B (9 kG) and B (10/sup 6/ G/s) conditions the hysteretic loss dominated. At high B (21 kG) and B (1.5 x 10/sup 7/ G/s) the matrix losses became dominant. The systematic variation of the losses with the mentioned parameters will be presented and will be compared to theoretical predictions.
Holographic Aspects of a Relativistic Nonconformal Theory
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.
IMPLICATIONS OF MASS AND ENERGY LOSS DUE TO CORONAL MASS EJECTIONS ON MAGNETICALLY ACTIVE STARS
Drake, Jeremy J.; Cohen, Ofer [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Yashiro, Seiji [Interferometrics Inc., Herndon, VA 20171 (United States); Gopalswamy, Nat, E-mail: jdrake@cfa.harvard.edu [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
2013-02-20
Analysis of a database of solar coronal mass ejections (CMEs) and associated flares over the period 1996-2007 finds well-behaved power-law relationships between the 1-8 A flare X-ray fluence and CME mass and kinetic energy. We extrapolate these relationships to lower and higher flare energies to estimate the mass and energy loss due to CMEs from stellar coronae, assuming that the observed X-ray emission of the latter is dominated by flares with a frequency as a function of energy dn/dE = kE {sup -{alpha}}. For solar-like stars at saturated levels of X-ray activity, the implied losses depend fairly weakly on the assumed value of {alpha} and are very large: M-dot {approx}5 Multiplication-Sign 10{sup -10} M{sub sun} yr{sup -1} and E-dot {approx}0.1 L{sub sun}. In order to avoid such large energy requirements, either the relationships between CME mass and speed and flare energy must flatten for X-ray fluence {approx}> 10{sup 31} erg, or the flare-CME association must drop significantly below 1 for more energetic events. If active coronae are dominated by flares, then the total coronal energy budget is likely to be up to an order of magnitude larger than the canonical 10{sup -3} L {sub bol} X-ray saturation threshold. This raises the question of what is the maximum energy a magnetic dynamo can extract from a star? For an energy budget of 1% of L {sub bol}, the CME mass loss rate is about 5 Multiplication-Sign 10{sup -11} M {sub Sun} yr{sup -1}.
Gemard, M
2014-01-01
The centrality dependence of spectra of identified particles in collisions between ultrarelativistic heavy ions with a center of mass energy ($\\sqrt{s}$) of 39 and 11.5 $AGeV$ is analyzed in the core - corona model. We show that at these energies the spectra can be well understood assuming that they are composed of two components whose relative fraction depends on the centrality of the interaction: The core component which describes an equilibrated quark gluon plasma and the corona component which is caused by nucleons close to the surface of the interaction zone which scatter only once and which is identical to that observed in proton-proton collisions. The success of this approach at 39 and 11.5 $AGeV$ shows that the physics does not change between this energy and $\\sqrt{s}=200~ AGeV$ for which this model has been developed (Aichelin 2008). This presents circumstantial evidence that a quark gluon plasma is also created at center of mass energies as low as 11.5 $AGeV$.
Clumps in large scale relativistic jets
Tavecchio, F; Celotti, A
2003-01-01
The relatively intense X-ray emission from large scale (tens to hundreds kpc) jets discovered with Chandra likely implies that jets (at least in powerful quasars) are still relativistic at that distances from the active nucleus. In this case the emission is due to Compton scattering off seed photons provided by the Cosmic Microwave Background, and this on one hand permits to have magnetic fields close to equipartition with the emitting particles, and on the other hand minimizes the requirements about the total power carried by the jet. The emission comes from compact (kpc scale) knots, and we here investigate what we can predict about the possible emission between the bright knots. This is motivated by the fact that bulk relativistic motion makes Compton scattering off the CMB photons efficient even when electrons are cold or mildly relativistic in the comoving frame. This implies relatively long cooling times, dominated by adiabatic losses. Therefore the relativistically moving plasma can emit, by Compton sc...
Relativistic semi-classical theory of atom ionization in ultra-intense laser
无
2001-01-01
A relativistic semi-classical theory (RSCT) of H-atom ionizationin ultra-intense laser (UIL) is proposed. A relativistic analytical expression for ionization probability of H-atom in its ground state is given. This expression, compared with non-relativistic expression, clearly shows the effects of the magnet vector in the laser, the non-dipole approximation and the relativistic mass-energy relation on the ionization processes. At the same time, we show that under some conditions the relativistic expression reduces to the non-relativistic expression of non-dipole approximation. At last, some possible applications of the relativistic theory are briefly stated.
Effect of EMIC Wave Normal Angle Distribution on Relativistic Electron Scattering
Gamayunov, K. V.; Khazanov, G. V.
2006-01-01
The flux level of outer-zone relativistic electrons (above 1 MeV) is extremely variable during geomagnetic storms, and controlled by a competition between acceleration and loss. Precipitation of these electrons due to resonant pitch-angle scattering by electromagnetic ion cyclotron (EMIC) waves is considered one of the major loss mechanisms. This mechanism was suggested in early theoretical studies more than three decades ago. However, direct experimental evidence of the wave role in relativistic electrons precipitation is difficult to obtain because of lack of concurrent measurements of precipitating electrons at low altitudes and the waves in a magnetically conjugate equatorial region. Recently, the data from balloon-borne X-ray instruments provided indirect but strong evidence on an efficiency of the EMIC wave induced loss for the outer-zone relativistic electrons. These observations stimulated theoretical studies that, particularly, demonstrated that EMIC wave induced pitch-angle diffusion of MeV electrons can operate in the strong diffusion limit and this mechanism can compete with relativistic electron depletion caused by the Dst effect during the initial and main phases of storm. Although an effectiveness of relativistic electron scattering by EMIC waves depends strongly on the wave spectral properties, the most favorable assumptions regarding wave characteristics has been made in all previous theoretical studies. Particularly, only quasi field-aligned EMIC waves have been considered as a driver for relativistic electron loss. At the same time, there is growing experimental and theoretical evidence that these waves can be highly oblique; EMIC wave energy can occupy not only the region of generation, i.e. the region of small wave normal angles, but also the entire wave normal angle region, and even only the region near 90 degrees. The latter can dramatically change he effectiveness of relativistic electron scattering by EMIC waves. In the present study, we
Spin, localization and uncertainty of relativistic fermions
Céleri, Lucas C; Terno, Daniel R
2016-01-01
We describe relations between several relativistic spin observables and derive a Lorentz-invariant characteristic of a reduced spin density matrix. A relativistic position operator that satisfies all the properties of its non-relativistic analogue does not exist. Instead we propose two causality-preserving positive operator-valued measures (POVM) that are based on projections onto one-particle and antiparticle spaces, and on the normalized energy density. They predict identical expectation values for position. The variances differ by less than a quarter of the squared de Broglie wavelength and coincide in the non-relativistic limit. Since the resulting statistical moment operators are not canonical conjugates of momentum, the Heisenberg uncertainty relations need not hold. Indeed, the energy density POVM leads to a lower uncertainty. We reformulate the standard equations of the spin dynamics by explicitly considering the charge-independent acceleration, allowing a consistent treatment of backreaction and incl...
Jet energy loss and bulk parton collectivity in nucleus-nucleus collisions at RHIC
HUANG Huan-Zhong
2009-01-01
Nucleus-nucleus collisions at RHIC produce high temperature and high energy density matter which exhibits paxtonic degrees of freedom. We will discuss measurements of nuclear modification factors for light hadrons and non-photonic electrons from heavy quark decays, which reflect the flavor dependence of energy loss of high momentum partons traversing the dense QCD medium. The dense QCD medium responds to energy loss of high momentum patrons in a pattern consistent with that expected from a hydrodynamic fluid. The hadronization of bulk partonic matter exhibits collectivity with effective partonic degrees of freedom. Nuclear collisions at RHIC provide an intriguing environment, where many constituent quark ingredients are readily available for possible formation of exotic particles through quark coalescence or recombinations.
Energy reduction in buildings in temperate and tropic regions utilizing a heat loss measuring device
Sørensen, Lars Schiøtt
2012-01-01
to ACMV in the "warm countries" contribute to an enormous energy consumption and corresponding CO2 emission. In order to establish the best basis for energy renovation, it is important to have measures of the heat losses on a building façade, for optimizing the energy renovation. This paper will present...... penetration through facades with the aim to reduce the costs to AC. The paper will introduce a common project between NUS (National University of Singapore), AAU (Aalborg University) and HT-Meter, the latter as the U-value Meter developer company. In the project we will measure the heat transfer in the unit W...... of the project. Furthermore this paper present results from already conducted heat loss measurements in the temperate regions....
Jung, Hyunsung; Lee, Ki-Suk; Jeong, Dae-Eun; Choi, Youn-Seok; Yu, Young-Sang; Han, Dong-Soo; Vogel, Andreas; Bocklage, Lars; Meier, Guido; Im, Mi-Young; Fischer, Peter; Kim, Sang-Koog
2011-01-01
A wide variety of coupled harmonic oscillators exist in nature. Coupling between different oscillators allows for the possibility of mutual energy transfer between them and the information-signal propagation. Low-energy input signals and their transport with negligible energy loss are the key technological factors in the design of information-signal processing devices. Here, utilizing the concept of coupled oscillators, we experimentally demonstrated a robust new mechanism for energy transfer between spatially separated dipolar-coupled magnetic disks - stimulated vortex gyration. Direct experimental evidence was obtained by a state-of-the-art experimental time-resolved soft X-ray microscopy probe. The rate of energy transfer from one disk to the other was deduced from the two normal modes' frequency splitting caused by dipolar interaction. This mechanism provides the advantages of tunable energy transfer rates, low-power input signals and negligible energy loss in the case of negligible intrinsic damping. Coupled vortex-state disks might be implemented in applications for information-signal processing.
A low-loss hybrid rectification technique for piezoelectric energy harvesting
Schlichting, A. D.; Fink, E.; Garcia, E.
2013-09-01
Embedded systems have decreased in size and increased in capability; however, small-scale energy storage technologies still significantly limit these advances. Energy neutral operation using small-scale energy harvesting technologies would allow for longer device operation times and smaller energy storage masses. Vibration energy harvesting is an attractive method due to the prevalence of energy sources in many environments. Losses in efficiency due to AC-DC rectification and conditioning circuits limit its application. This work presents a low-loss hybrid rectification technique for piezoelectric vibration energy harvesting using magnetically actuated reed switches and a passive semiconductor full-bridge rectifier. This method shows the capability to have higher efficiency levels and the rectification of low-voltage harvesters without the need for active electrical components. A theoretical model shows that the hybrid rectification technique performance is highly dependent on the proximity delay and the hysteresis behavior of the reed switches. Experimental results validate the model and support the hypothesis of increased performance using the hybrid rectification technique.
Yakovlev, Sergey [Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Misra, Manoj; Shi, Shanling [Unilever Research and Development, Trumbull, CT 06611 (United States); Firlar, Emre [Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Libera, Matthew, E-mail: mlibera@stevens.edu [Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)
2010-06-15
Spatially resolved low-loss electron energy-loss spectroscopy (EELS) is a powerful method to quantitatively determine the water distribution in frozen-hydrated biological materials at high spatial resolution. However, hydrated tissue, particularly its hydrophilic protein-rich component, is very sensitive to electron radiation. This sensitivity has traditionally limited the achievable spatial resolution because of the relatively high noise associated with low-dose data acquisition. We show that the damage caused by high-dose data acquisition affects the accuracy of a multiple-least-squares (MLS) compositional analysis because of inaccuracies in the reference spectrum used to represent the protein. Higher spatial resolution combined with more accurate compositional analysis can be achieved if a reference spectrum is used that better represents the electron-beam-damaged protein component under frozen-hydrated conditions rather than one separately collected from dry protein under low-dose conditions. We thus introduce a method to extract the best-fitting protein reference spectrum from an experimental spectrum dataset. This method can be used when the MLS-fitting problem is sufficiently constrained so that the only unknown is the reference spectrum for the protein component. We apply this approach to map the distribution of water in cryo-sections obtained from frozen-hydrated tissue of porcine skin. The raw spectral data were collected at doses up to 10{sup 5} e/nm{sup 2} despite the fact that observable damage begins at doses as low as 10{sup 3} e/nm{sup 2}. The resulting spatial resolution of 10 nm is 5-10 times better than that in previous studies of frozen-hydrated tissue and is sufficient to resolve sub-cellular water fluctuations as well as the inter-cellular lipid-rich regions of skin where water-mediated processes are believed to play a significant role in the phenotype of keratinocytes in the stratum corneum.