Generation of sub-100 fs electron pulses for time-resolved electron diffraction using a direct synchronization method

Area of Science:

• Materials Science
• Physical Chemistry
• Condensed Matter Physics

Background:

• Investigating photoinduced phenomena requires ultrashort pulsed X-ray and electron sources.
• Electron and X-ray wavelengths are shorter than material lattice constants, enabling direct observation of dynamics.
• Femtosecond to picosecond timescales of photoinduced structural dynamics are key research areas.

Purpose of the Study:

• To develop a tabletop ultrashort pulsed electron diffraction setup.
• To achieve high brightness and high repetition rates for electron sources.
• To enable direct observation of photoinduced structural dynamics in materials and molecules.

Main Methods:

• Utilized a femtosecond laser and electron pulse compression cavity.
• Synchronized the setup to a microwave master oscillator (∼3 GHz).
• Estimated electron pulse duration (<100 fs) using photoinduced lattice changes in silicon films.

Main Results:

• Created a tabletop ultrashort pulsed electron diffraction setup.
• Achieved a 1 kHz repetition rate with compressed electron pulses containing 228,000 electrons.
• Demonstrated an electron pulse duration of less than 100 fs at the sample position.

Conclusions:

• The developed time-resolved electron diffraction setup offers sub-100 fs temporal resolution.
• This setup is comparable to femtosecond laser pulse widths and suitable for quantum materials research.
• The tool will advance material science when combined with optical pump-probe and X-ray measurements.