Vector-based feedback of continuous wave radiofrequency compression cavity for ultrafast electron diffraction

Abstract

The temporal resolution of ultrafast electron diffraction (UED) at weakly relativistic beam energies ($\lesssim$ 100 keV) suffers from space-charge induced electron pulse broadening. We describe the implementation of a radio frequency (RF) cavity operating in the continuous wave regime to compress high repetition rate electron bunches from a 40.4 kV DC photoinjector for ultrafast electron diffraction applications. Active stabilization of the RF amplitude and phase through a feedback loop based on the demodulated in-phase and quadrature components of the RF signal is demonstrated. This scheme yields 144$\pm$19 fs RMS temporal resolution in pump-probe studies.

11 pages, 10 figures

References in corpus (9)

• New electron source concept for single-shot sub-100 fs electron diffraction in the 100 keV range
• Coherent and incoherent electron-phonon coupling in graphite observed with radio-frequency compressed ultrafast electron diffraction
• Achieving 50 femtosecond resolution in MeV ultrafast electron diffraction with a double bend achromat compressor
• Solving the Jitter Problem in Microwave Compressed Ultrafast Electron Diffraction Instruments: Robust Sub-50 fs Cavity-Laser Phase Stabilization
• A kiloelectron-volt ultrafast electron micro-diffraction apparatus using low emittance semiconductor photocathodes
• Lossless monochromation for electron microscopy with pulsed photoemission sources and rf cavities
• Relativistic ultrafast electron diffraction at high repetition rates
• Virtual-Diagnostic-Based Time Stamping for Ultrafast Electron Diffraction
• Feedback and control systems for future linear colliders: White Paper for Snowmass 2021 Topical Group AF07-RF