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DOE OSTI · 1307514

Femtosecond time-resolved MeV electron diffraction

Zhu, Pengfei·Zhu, Y.·Hidaka, Y.·Wu, L.·Cao, J.·Berger, H.·Geck, J.·Kraus, R.·Pjerov, S.·Shen, Y.·Tobey, R. I.·Hill, J. P.·Wang, X. J.
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Abstract

We report the experimental demonstration of femtosecond electron diffraction using high-brightness MeV electron beams. High-quality, single-shot electron diffraction patterns for both polycrystalline aluminum and single-crystal 1T-TaS 2 are obtained utilizing a 5 fC (~3 × 10 4 electrons) pulse of electrons at 2.8 MeV. The high quality of the electron diffraction patterns confirms that electron beam has a normalized emittance of ~50 nm rad. The transverse and longitudinal coherence length is ~11 and ~2.5 nm, respectively. The timing jitter between the pump laser and probe electron beam was found to be ~100 fs (rms). The temporal resolution is demonstrated by observing the evolution of Bragg and superlattice peaks of 1T-TaS 2 following an 800 nm optical pump and was found to be 130 fs. Lastly, our results demonstrate the advantages of MeV electrons, including large elastic differential scattering cross-section and access to high-order reflections, and the feasibility of ultimately realizing below 10 fs time-resolved electron diffraction.

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74 ATOMIC AND MOLECULAR PHYSICScoherent lengthhigh-brightness electron beamultrafast electron diffractionultrafast electron imaging

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Zhu, Pengfei, Zhu, Y., Hidaka, Y., Wu, L., Cao, J., Berger, H., Geck, J., Kraus, R., Pjerov, S., Shen, Y., Tobey, R. I., Hill, J. P., Wang, X. J.. 2015-06-02. Femtosecond time-resolved MeV electron diffraction. https://doi.org/10.1088/1367-2630%2F17%2F6%2F063004

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