1. Towards jitter-free ultrafast electron diffraction technology
- Author
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Fabian Rotermund, Key Young Oang, Sunjeong Park, Jungwon Kim, Mi Hye Kim, Thomas Feurer, Young Chan Kim, Hyun Woo Kim, Kitae Lee, Junho Shin, In Hyung Baek, Young Uk Jeong, Kyu-Ha Jang, Sunglae Cho, Seong Hee Park, and Nikolay Vinokurov
- Subjects
Materials science ,business.industry ,Terahertz radiation ,Ultrafast electron diffraction ,Attosecond ,02 engineering and technology ,Electron ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,010309 optics ,Root mean square ,Optics ,Temporal resolution ,0103 physical sciences ,0210 nano-technology ,business ,Ultrashort pulse ,Jitter - Abstract
Stroboscopic visualization of nuclear or electron dynamics in atoms, molecules or solids requires ultrafast pump and probe pulses and a close to perfect synchronization between the two. We have developed a 3 MeV ultrafast electron diffraction (UED) probe technology that nominally reduces the electron bunch duration and the arrival time jitter to the subfemtosecond level. This simple configuration uses a radiofrequency photogun and a 90° achromatic bend and is designed to provide effectively jitter-free conditions. Terahertz streaking measurements reveal an electron bunch duration of 25 fs, even for a charge as high as 0.6 pC, and an arrival time jitter of 7.8 fs, the latter limited by only the measurement accuracy. From pump–probe measurements of photoexcited bismuth films, the instrument response function was determined to be 31 fs. This pioneering jitter-free technique paves the way towards UED of attosecond phenomena in atomic, molecular and solid-state dynamics. An ultrafast electron diffraction facility with an overall temporal resolution of 31 fs root mean square is developed. Even for a charge as high as 0.6 pC, the electron bunch duration and timing jitter are 25 fs and less than 10 fs, respectively.
- Published
- 2019