The Experts below are selected from a list of 47112 Experts worldwide ranked by ideXlab platform
S P Roshchupkin - One of the best experts on this subject based on the ideXlab platform.
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resonant high energy bremsstrahlung of ultrarelativistic electrons in the field of a nucleus and an electromagnetic wave
arXiv: High Energy Physics - Phenomenology, 2019Co-Authors: Alexander Dubov, Victor V Dubov, S P RoshchupkinAbstract:The actual theoretical research investigates the resonant spontaneous bremsstrahlung (RSB) of ultrarelativistic electrons under the condition of scattering on a nucleus in the field of a weak electromagnetic wave. The progression of the functional mechanism indicates the transformation of the intermediate virtual electron into the real particle state. As a result, the initial second order process with accordance to the fine structure constant in the light field productively splits into two consequent first order formations: the laser-stimulated Compton effect and the laser-assisted scattering of an electron on a nucleus. It is important to emphasize that the resonance escalation possesses a possibility to develop within two reaction channels. Therefore, the first channel - delineates the occurrence that correlates to the spontaneous photon emission by an electron with subsequent scattering on a nucleus. The second channel - illustrates the configuration corresponding to the electron scattering on a nucleus with consecutive spontaneous photon emission in the wave field. Moreover, the spontaneous photon radiation angle allocates a single-valued dependency with the resonant frequency for the first channel in contrast to the second displacement that categorizes a composite area with three various resonant frequency magnitudes for the particular emission angle diapason. The project data analysis proposes that the reaction channels do not interfere within the whole range of observation. To summarize, the investigation calculates that the particular cross-section within the resonant ambience significantly exceeds the according cross-section in the approximation of an external field absence. In conclusion, numerous Scientific Facilities with specialization in pulsed laser radiation (SLAC, FAIR, XFEL, ELI, XCELS) may experimentally validate the computational estimations.
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resonant parametric interference effect in spontaneous bremsstrahlung of an electron in the field of a nucleus and two pulsed laser waves
Physical Review A, 2018Co-Authors: A A Lebed, S P Roshchupkin, E A Padusenko, V V DubovAbstract:Electron-nucleus bremsstrahlung in the field of two moderately strong pulsed laser waves in the case of incommensurate frequencies is theoretically studied under resonant conditions. The process is studied in detail in a special kinematic region, where stimulated processes with correlated emission and absorption of photons of the first and second waves become predominant (parametric interference effect). The availability of this region is caused by interference of the first and second laser waves. The correspondence between the emission angle and the final-electron energy is established in this interference kinematic. In this case, the cross-sectional properties are determined by the multiphoton quantum interference parameter, which is proportional to the product of intensities of the first and second waves. The resonant differential cross section of electron-nucleus spontaneous bremsstrahlung with simultaneous registration of both emission angles of the spontaneous photon and the scattered electron can exceed by four or five orders of magnitude the corresponding cross section in the absence of an external field. It was shown for nonrelativistic electrons that the resonant cross section of the studied process in the field of two pulsed laser waves within the interference region in two order of magnitude may exceed corresponding cross sections at other scattering kinematics. The obtained results may be experimentally verified, for example, by Scientific Facilities at sources of pulsed laser radiation (such as SLAC, FAIR, XFEL, ELI).
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parametric interference effect in nonresonant spontaneous bremsstrahlung of an electron in the field of a nucleus and two pulsed laser waves
Physical Review A, 2016Co-Authors: A A Lebed, S P Roshchupkin, E A Padusenko, V V DubovAbstract:Nonresonant spontaneous bremsstrahlung of an electron scattered by a nucleus in the field of two moderately strong pulsed waves is studied theoretically. The process is studied in detail within the interference kinematic region. This region is determined by scattering of particles in the same plane at predetermined angles, at which stimulated absorption and emission of photons of external pulsed waves by an electron occur in a correlated manner. It is shown that the probability of the partial process with correlated emission (absorption) by an electron of the equal number of photons of the both waves is of an order of the magnitude greater than the corresponding probability in any other scattering kinematics. The cross section of spontaneous bremsstrahlung in two pulsed waves may be two times greater than the cross section of a free-field process after summation over all stimulated processes of correlated emission and absorption. Obtained results may be experimentally verified, for example, by Scientific Facilities at sources of pulsed laser radiation (SLAC, FAIR, ELI, XCELS).
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amplification of electromagnetic field in electron scattering by ions in a weak light field general relativistic case
Laser Physics, 2013Co-Authors: V A Tsybulnik, S P RoshchupkinAbstract:The gain coefficient for a weak electromagnetic field in the scattering of electrons by ions in an elliptically polarized light wave is theoretically studied in the general relativistic case. A simple analytical expression for the field amplification constant in a logarithmic approach is obtained. It is shown that the gain coefficient for ultrarelativistic electron energies depends on the energy as a cubic power of energy and can be significantly large. This effect results in an increase of the gain coefficient up to quantities of order ????(1?10)?cm?1 for electron energies Ei???(10?20)?GeV. The obtained results may be experimentally verified, for example, by the Scientific Facilities at the SLAC National Accelerator Laboratory and the Facility for Antiproton and Ion Research (FAIR; Darmstadt, Germany).
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nonresonant quantum electrodynamics processes in a pulsed laser field
Laser Physics, 2012Co-Authors: S P Roshchupkin, A A Lebed, E A PadusenkoAbstract:This review contains theoretical study of nonresonant quantum electrodynamics processes of the first and second orders in the fine-structure constant in a pulsed laser field. The approximation is examined when the pulse width is considerably greater than the characteristic time of wave oscillations. It was demonstrated that for nonrelativistic particle energy the differential cross section of a process in a pulsed light fields may considerably difference from the corresponding cross section in an absence of a laser field. Results obtained may be experimentally verified by the Scientific Facilities at the SLAC National Accelerator Laboratory and FAIR (Facility for Antiproton and Ion Research, Darmstadt, Germany) project.
A A Lebed - One of the best experts on this subject based on the ideXlab platform.
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resonant parametric interference effect in spontaneous bremsstrahlung of an electron in the field of a nucleus and two pulsed laser waves
Physical Review A, 2018Co-Authors: A A Lebed, S P Roshchupkin, E A Padusenko, V V DubovAbstract:Electron-nucleus bremsstrahlung in the field of two moderately strong pulsed laser waves in the case of incommensurate frequencies is theoretically studied under resonant conditions. The process is studied in detail in a special kinematic region, where stimulated processes with correlated emission and absorption of photons of the first and second waves become predominant (parametric interference effect). The availability of this region is caused by interference of the first and second laser waves. The correspondence between the emission angle and the final-electron energy is established in this interference kinematic. In this case, the cross-sectional properties are determined by the multiphoton quantum interference parameter, which is proportional to the product of intensities of the first and second waves. The resonant differential cross section of electron-nucleus spontaneous bremsstrahlung with simultaneous registration of both emission angles of the spontaneous photon and the scattered electron can exceed by four or five orders of magnitude the corresponding cross section in the absence of an external field. It was shown for nonrelativistic electrons that the resonant cross section of the studied process in the field of two pulsed laser waves within the interference region in two order of magnitude may exceed corresponding cross sections at other scattering kinematics. The obtained results may be experimentally verified, for example, by Scientific Facilities at sources of pulsed laser radiation (such as SLAC, FAIR, XFEL, ELI).
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parametric interference effect in nonresonant spontaneous bremsstrahlung of an electron in the field of a nucleus and two pulsed laser waves
Physical Review A, 2016Co-Authors: A A Lebed, S P Roshchupkin, E A Padusenko, V V DubovAbstract:Nonresonant spontaneous bremsstrahlung of an electron scattered by a nucleus in the field of two moderately strong pulsed waves is studied theoretically. The process is studied in detail within the interference kinematic region. This region is determined by scattering of particles in the same plane at predetermined angles, at which stimulated absorption and emission of photons of external pulsed waves by an electron occur in a correlated manner. It is shown that the probability of the partial process with correlated emission (absorption) by an electron of the equal number of photons of the both waves is of an order of the magnitude greater than the corresponding probability in any other scattering kinematics. The cross section of spontaneous bremsstrahlung in two pulsed waves may be two times greater than the cross section of a free-field process after summation over all stimulated processes of correlated emission and absorption. Obtained results may be experimentally verified, for example, by Scientific Facilities at sources of pulsed laser radiation (SLAC, FAIR, ELI, XCELS).
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nonresonant quantum electrodynamics processes in a pulsed laser field
Laser Physics, 2012Co-Authors: S P Roshchupkin, A A Lebed, E A PadusenkoAbstract:This review contains theoretical study of nonresonant quantum electrodynamics processes of the first and second orders in the fine-structure constant in a pulsed laser field. The approximation is examined when the pulse width is considerably greater than the characteristic time of wave oscillations. It was demonstrated that for nonrelativistic particle energy the differential cross section of a process in a pulsed light fields may considerably difference from the corresponding cross section in an absence of a laser field. Results obtained may be experimentally verified by the Scientific Facilities at the SLAC National Accelerator Laboratory and FAIR (Facility for Antiproton and Ion Research, Darmstadt, Germany) project.
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quantum electrodynamics resonances in a pulsed laser field
Laser Physics, 2012Co-Authors: S P Roshchupkin, A A Lebed, E A Padusenko, A I VoroshiloAbstract:This review contains theoretical study of resonant quantum electrodynamics processes in a pulsed laser field. The approximation is examined when the pulse width is considerably greater than the characteristic time of wave oscillations. The lepton’s interaction with the Coulomb potential of a nucleus and each other is considered in the Born approximation. It is demonstrated that the resonant differential cross section of a process in a pulsed light fields may considerably exceed the corresponding cross section in an absence of a laser field. Results obtained may be experimentally verified by the Scientific Facilities at the SLAC National Accelerator Laboratory and FAIR (Facility for Antiproton and Ion Research, Darmstadt, Germany) project.
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resonant spontaneous bremsstrahlung by an electron scattered by a nucleus in the field of a pulsed light wave
Physical Review A, 2010Co-Authors: A A Lebed, S P RoshchupkinAbstract:Resonant spontaneous bremsstrahlung by an electron scattered by a nucleus in the field of a pulsed light wave is theoretically investigated. The approximation is examined when the pulse width is considerably greater than the characteristic time of wave oscillations. The electron interaction with the Coulomb potential of a nucleus is considered in the Born approximation. An analytic expression for the resonant differential cross section of the investigated process was obtained for the range of moderately strong fields. The bremsstrahlung cross section contains a resonant peak. The resonant peak's altitude and width are defined by the external pulsed wave properties. The resonant cross section is studied within the ranges of nonrelativistic, relativistic, and ultrarelativistic electron energies. It is demonstrated that the resonant cross section of spontaneous bremsstrahlung may be several orders of magnitude greater than the corresponding cross section in the absence of an external field. Results obtained may be experimentally verified, for example, by the Scientific Facilities at the SLAC National Accelerator Laboratory.
V V Dubov - One of the best experts on this subject based on the ideXlab platform.
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resonant parametric interference effect in spontaneous bremsstrahlung of an electron in the field of a nucleus and two pulsed laser waves
Physical Review A, 2018Co-Authors: A A Lebed, S P Roshchupkin, E A Padusenko, V V DubovAbstract:Electron-nucleus bremsstrahlung in the field of two moderately strong pulsed laser waves in the case of incommensurate frequencies is theoretically studied under resonant conditions. The process is studied in detail in a special kinematic region, where stimulated processes with correlated emission and absorption of photons of the first and second waves become predominant (parametric interference effect). The availability of this region is caused by interference of the first and second laser waves. The correspondence between the emission angle and the final-electron energy is established in this interference kinematic. In this case, the cross-sectional properties are determined by the multiphoton quantum interference parameter, which is proportional to the product of intensities of the first and second waves. The resonant differential cross section of electron-nucleus spontaneous bremsstrahlung with simultaneous registration of both emission angles of the spontaneous photon and the scattered electron can exceed by four or five orders of magnitude the corresponding cross section in the absence of an external field. It was shown for nonrelativistic electrons that the resonant cross section of the studied process in the field of two pulsed laser waves within the interference region in two order of magnitude may exceed corresponding cross sections at other scattering kinematics. The obtained results may be experimentally verified, for example, by Scientific Facilities at sources of pulsed laser radiation (such as SLAC, FAIR, XFEL, ELI).
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parametric interference effect in nonresonant spontaneous bremsstrahlung of an electron in the field of a nucleus and two pulsed laser waves
Physical Review A, 2016Co-Authors: A A Lebed, S P Roshchupkin, E A Padusenko, V V DubovAbstract:Nonresonant spontaneous bremsstrahlung of an electron scattered by a nucleus in the field of two moderately strong pulsed waves is studied theoretically. The process is studied in detail within the interference kinematic region. This region is determined by scattering of particles in the same plane at predetermined angles, at which stimulated absorption and emission of photons of external pulsed waves by an electron occur in a correlated manner. It is shown that the probability of the partial process with correlated emission (absorption) by an electron of the equal number of photons of the both waves is of an order of the magnitude greater than the corresponding probability in any other scattering kinematics. The cross section of spontaneous bremsstrahlung in two pulsed waves may be two times greater than the cross section of a free-field process after summation over all stimulated processes of correlated emission and absorption. Obtained results may be experimentally verified, for example, by Scientific Facilities at sources of pulsed laser radiation (SLAC, FAIR, ELI, XCELS).
E A Padusenko - One of the best experts on this subject based on the ideXlab platform.
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resonant parametric interference effect in spontaneous bremsstrahlung of an electron in the field of a nucleus and two pulsed laser waves
Physical Review A, 2018Co-Authors: A A Lebed, S P Roshchupkin, E A Padusenko, V V DubovAbstract:Electron-nucleus bremsstrahlung in the field of two moderately strong pulsed laser waves in the case of incommensurate frequencies is theoretically studied under resonant conditions. The process is studied in detail in a special kinematic region, where stimulated processes with correlated emission and absorption of photons of the first and second waves become predominant (parametric interference effect). The availability of this region is caused by interference of the first and second laser waves. The correspondence between the emission angle and the final-electron energy is established in this interference kinematic. In this case, the cross-sectional properties are determined by the multiphoton quantum interference parameter, which is proportional to the product of intensities of the first and second waves. The resonant differential cross section of electron-nucleus spontaneous bremsstrahlung with simultaneous registration of both emission angles of the spontaneous photon and the scattered electron can exceed by four or five orders of magnitude the corresponding cross section in the absence of an external field. It was shown for nonrelativistic electrons that the resonant cross section of the studied process in the field of two pulsed laser waves within the interference region in two order of magnitude may exceed corresponding cross sections at other scattering kinematics. The obtained results may be experimentally verified, for example, by Scientific Facilities at sources of pulsed laser radiation (such as SLAC, FAIR, XFEL, ELI).
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parametric interference effect in nonresonant spontaneous bremsstrahlung of an electron in the field of a nucleus and two pulsed laser waves
Physical Review A, 2016Co-Authors: A A Lebed, S P Roshchupkin, E A Padusenko, V V DubovAbstract:Nonresonant spontaneous bremsstrahlung of an electron scattered by a nucleus in the field of two moderately strong pulsed waves is studied theoretically. The process is studied in detail within the interference kinematic region. This region is determined by scattering of particles in the same plane at predetermined angles, at which stimulated absorption and emission of photons of external pulsed waves by an electron occur in a correlated manner. It is shown that the probability of the partial process with correlated emission (absorption) by an electron of the equal number of photons of the both waves is of an order of the magnitude greater than the corresponding probability in any other scattering kinematics. The cross section of spontaneous bremsstrahlung in two pulsed waves may be two times greater than the cross section of a free-field process after summation over all stimulated processes of correlated emission and absorption. Obtained results may be experimentally verified, for example, by Scientific Facilities at sources of pulsed laser radiation (SLAC, FAIR, ELI, XCELS).
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nonresonant quantum electrodynamics processes in a pulsed laser field
Laser Physics, 2012Co-Authors: S P Roshchupkin, A A Lebed, E A PadusenkoAbstract:This review contains theoretical study of nonresonant quantum electrodynamics processes of the first and second orders in the fine-structure constant in a pulsed laser field. The approximation is examined when the pulse width is considerably greater than the characteristic time of wave oscillations. It was demonstrated that for nonrelativistic particle energy the differential cross section of a process in a pulsed light fields may considerably difference from the corresponding cross section in an absence of a laser field. Results obtained may be experimentally verified by the Scientific Facilities at the SLAC National Accelerator Laboratory and FAIR (Facility for Antiproton and Ion Research, Darmstadt, Germany) project.
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quantum electrodynamics resonances in a pulsed laser field
Laser Physics, 2012Co-Authors: S P Roshchupkin, A A Lebed, E A Padusenko, A I VoroshiloAbstract:This review contains theoretical study of resonant quantum electrodynamics processes in a pulsed laser field. The approximation is examined when the pulse width is considerably greater than the characteristic time of wave oscillations. The lepton’s interaction with the Coulomb potential of a nucleus and each other is considered in the Born approximation. It is demonstrated that the resonant differential cross section of a process in a pulsed light fields may considerably exceed the corresponding cross section in an absence of a laser field. Results obtained may be experimentally verified by the Scientific Facilities at the SLAC National Accelerator Laboratory and FAIR (Facility for Antiproton and Ion Research, Darmstadt, Germany) project.
Brendan Mcginty - One of the best experts on this subject based on the ideXlab platform.
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convergence of artificial intelligence and high performance computing on nsf supported cyberinfrastructure
Journal of Big Data, 2020Co-Authors: E A Huerta, Asad Khan, Edward Davis, Colleen Bushell, William Gropp, Daniel S Katz, Volodymyr Kindratenko, Seid Koric, William Kramer, Brendan McgintyAbstract:Significant investments to upgrade and construct large-scale Scientific Facilities demand commensurate investments in R&D to design algorithms and computing approaches to enable Scientific and engineering breakthroughs in the big data era. Innovative Artificial Intelligence (AI) applications have powered transformational solutions for big data challenges in industry and technology that now drive a multi-billion dollar industry, and which play an ever increasing role shaping human social patterns. As AI continues to evolve into a computing paradigm endowed with statistical and mathematical rigor, it has become apparent that single-GPU solutions for training, validation, and testing are no longer sufficient for computational grand challenges brought about by Scientific Facilities that produce data at a rate and volume that outstrip the computing capabilities of available cyberinfrastructure platforms. This realization has been driving the confluence of AI and high performance computing (HPC) to reduce time-to-insight, and to enable a systematic study of domain-inspired AI architectures and optimization schemes to enable data-driven discovery. In this article we present a summary of recent developments in this field, and describe specific advances that authors in this article are spearheading to accelerate and streamline the use of HPC platforms to design and apply accelerated AI algorithms in academia and industry.
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convergence of artificial intelligence and high performance computing on nsf supported cyberinfrastructure
arXiv: Computational Physics, 2020Co-Authors: E A Huerta, Asad Khan, Edward Davis, Colleen Bushell, William Gropp, Daniel S Katz, Volodymyr Kindratenko, Seid Koric, William Kramer, Brendan McgintyAbstract:Significant investments to upgrade or construct large-scale Scientific Facilities demand commensurate investments in R&D to design algorithms and computing approaches to enable Scientific and engineering breakthroughs in the big data era. The remarkable success of Artificial Intelligence (AI) algorithms to turn big-data challenges in industry and technology into transformational digital solutions that drive a multi-billion dollar industry, which play an ever increasing role shaping human social patterns, has promoted AI as the most sought after signal processing tool in big-data research. As AI continues to evolve into a computing tool endowed with statistical and mathematical rigor, and which encodes domain expertise to inform and inspire AI architectures and optimization algorithms, it has become apparent that single-GPU solutions for training, validation, and testing are no longer sufficient. This realization has been driving the confluence of AI and high performance computing (HPC) to reduce time-to-insight and to produce robust, reliable, trustworthy, and computationally efficient AI solutions. In this white paper, we present a summary of recent developments in this field, and discuss avenues to accelerate and streamline the use of HPC platforms to design accelerated AI algorithms.
