Final published version
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Benchmarking semiclassical approaches to strong-field QED
T2 - Nonlinear Compton scattering in intense laser pulses
AU - Blackburn, T.G.
AU - Seipt, D.
AU - Bulanov, S.S.
AU - Marklund, M.
PY - 2018/8
Y1 - 2018/8
N2 - The recoil associated with photon emission is key to the dynamics of ultrarelativistic electrons in strong electromagnetic fields, as found in high-intensity laser-matter interactions and astrophysical environments such as neutron star magnetospheres. When the energy of the photon becomes comparable to that of the electron, it is necessary to use quantum electrodynamics (QED) to describe the dynamics accurately. However, computing the appropriate scattering matrix element from strong-field QED is not generally possible due to multiparticle effects and the complex structure of the electromagnetic fields. Therefore, these interactions are treated semiclassically, coupling probabilistic emission events to classical electrodynamics using rates calculated in the locally constant field approximation. Here, we provide comprehensive benchmarking of this approach against the exact QED calculation for nonlinear Compton scattering of electrons in an intense laser pulse. We find agreement at the percentage level between the photon spectra, as well as between the models' predictions of absorption from the background field, for normalized amplitudes a0 > 5. We discuss possible routes towards improved numerical methods and the implications of our results for the study of QED cascades. © 2018 Author(s).
AB - The recoil associated with photon emission is key to the dynamics of ultrarelativistic electrons in strong electromagnetic fields, as found in high-intensity laser-matter interactions and astrophysical environments such as neutron star magnetospheres. When the energy of the photon becomes comparable to that of the electron, it is necessary to use quantum electrodynamics (QED) to describe the dynamics accurately. However, computing the appropriate scattering matrix element from strong-field QED is not generally possible due to multiparticle effects and the complex structure of the electromagnetic fields. Therefore, these interactions are treated semiclassically, coupling probabilistic emission events to classical electrodynamics using rates calculated in the locally constant field approximation. Here, we provide comprehensive benchmarking of this approach against the exact QED calculation for nonlinear Compton scattering of electrons in an intense laser pulse. We find agreement at the percentage level between the photon spectra, as well as between the models' predictions of absorption from the background field, for normalized amplitudes a0 > 5. We discuss possible routes towards improved numerical methods and the implications of our results for the study of QED cascades. © 2018 Author(s).
KW - Benchmarking
KW - Compton scattering
KW - Electrodynamics
KW - Electromagnetic fields
KW - Laser pulses
KW - Magnetosphere
KW - Numerical methods
KW - Photons
KW - Quantum electronics
KW - Classical electrodynamics
KW - Complex structure
KW - Field approximations
KW - High-intensity laser matter interaction
KW - Intense laser pulse
KW - Quantum electrodynamics
KW - Scattering matrix elements
KW - Semiclassical approaches
KW - Electromagnetic field effects
U2 - 10.1063/1.5037967
DO - 10.1063/1.5037967
M3 - Journal article
VL - 25
JO - Physics of Plasmas
JF - Physics of Plasmas
SN - 1070-664X
IS - 8
M1 - 083108
ER -