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Employment of Bragg scattering for enhancement of vacuum polarization effects and of pair production for an ultra-short gamma-ray characterization. K. Z. Hatsagortsyan , G. Yu. Kryuchkyan*, A. Ipp, J. Evers and C. H. Keitel. Max-Planck-Institut für Kernphysik, Heidelberg, Germany
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Employment of Bragg scattering for enhancement of vacuum polarization effects and of pair production for an ultra-short gamma-ray characterization • K. Z. Hatsagortsyan, G. Yu. Kryuchkyan*, • A. Ipp, J. Eversand C. H. Keitel Max-Planck-Institut für Kernphysik, Heidelberg, Germany *Yerevan State University, Yerevan , Armenia "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Outline • Photon-photon scattering in a periodically modulated vacuum: Bragg scattering • Characterization of ultra-short pulses of γ-rays of GeV energies. Streaking method based on the strong field pair production: from femtosecond time-scale up to zeptoseconds. [SHEEP - streaking at high energies with electrons and positrons] FROG…..RABBITT…..SPIDER "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Vacuum polarization/photon-photon scattering Uniform medium Vacuum birefringence photon-photon scattering Moulin et al. ZPC 1996 Bernard et al. EPJD 2000 Lundström et al. PRL 2006 M=0 in B=const Nonuniform medium Diffraction Kaplan, Ding, PRA 2000 Di Piazza, KZH, Keitel, PRL 2005 Second harmonic generation with "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Modulated vacuum: Bragg scattering Bragg-scattering condition: "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Bragg scattering vs. Photon-photon scattering Lundström et al. PRL 2006 phase-matching factor Bragg-scattering condition: "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Bragg scattering of light in vacuum with multiple laser beams z y enhancement factor with respect to photon-photon scattering • Kryuchkyan, KZH, PRL 107, 053604 (2011) "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Outline • Photon-photon scattering in a periodically modulated vacuum: Bragg scattering • Characterization of ultra-short pulses of γ-rays of GeV energies. Streaking method based on the strong field pair production: from femtosecond time-scale up to zeptoseconds. [SHEEP - streaking at high energies with electrons and positrons] "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Time-resolved intra-nuclear dynamics Why ultra-short pulses of GeV γ-rays are important? Probe Pump Quark system Probe MeV-GeV excitation energy Zeptosecond time-scale Pump "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Yoctosecond double pulses of γ-rays heavy-ion collisions A. Ipp, C. H. Keitel, J. Evers, PRL103, 152301 (2009) "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Characterization of ultra-short pulses Streak-camera "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Streaking mechanism Conversion photons to electrons For XUV 100 eV - 1 KeV: Photoionization For hard x-rays 10 KeV - 1MeV: Compton ionization For γ-rays >MeV: e+e- pair production "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Streak-camera for γ-rays via strong field e+e- pair production SLAC experiment D. Burke et al., PRL 79, 1626 (1997) Ipp, Evers, Keitel, KZH, PLB 702, 383 (2011) "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Streak-camera for γ-rays via strong field e+e- pair production IP+SP should not create e+e- Fast oscillations due to IP Photoemission is negligible "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Streak-camera for γ-rays: Parameters Photoemission is negligible: "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Streak-camera for γ-rays: 0.3-30 GeV from fs up to zs resolution "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Conlcusion • Bragg scattering can enhance photon-photon scattering • A detection scheme has been proposed for the characterization of short γ-ray pulses in the GeV energy range based on pair creation. Sub-attosecond time resolution could be achieved with high-order harmonic generation in the upcoming ELI facility. "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011
Thank you for your attention! "PW Lasers at Hard X-ray Sources" Dresden-Rossendorf, 7 Sep 2011