Lossless monochromation for electron microscopy with pulsed photoemission sources and rf cavities

Abstract

Resonant radiofrequency cavities enable exquisite time-energy control of electron beams when synchronized with laser driven photoemission. We present a lossless monochromator design that exploits this fine control in the one-electron-per-pulse regime. The theoretically achievable maximum beam current on target is orders of magnitude greater than state-of-the-art monochromators for the same spatial and energy resolution. This improvement is the result of monochromating in the time domain, unconstrained by the transverse brightness of the electron source. We show analytically and confirm numerically that cavity parameters chosen to minimize energy spread perform the additional function of undoing the appreciable effect of chromatic aberration in the upstream optics. We argue that our design has significant applications in both ultra-fast and non-time-resolved microscopy, provided photoelectron sources of sufficiently small size and laser sources of sufficiently high repetition rate. Our design achieves in simulations more than two orders of magnitude reduction in beam energy spread, down to single digit meV. Overcoming the minimum probe-size limit that chromatic aberration imposes, our design clears a path for high-current, high-resolution electron beam applications at primary energies from single to hundreds of keV.

References in corpus (12)

• Ultrafast transmission electron microscopy using a laser-driven field emitter: femtosecond resolution with a high coherence electron beam
• Compression of sub-relativistic space-charge-dominated electron bunches for single-shot femtosecond electron diffraction
• Direct measurement of sub-10 fs relativistic electron beams with ultralow emittance
• Vibrational Spectroscopy at Atomic Resolution with Electron Impact Scattering
• Mapping momentum-dependent electron-phonon coupling and non-equilibrium phonon dynamics with ultrafast electron diffuse scattering
• Terahertz-based attosecond metrology of relativistic electron beams
• Terahertz streaking of few-femtosecond relativistic electron beams
• Cold electron beams from cryo-cooled, alkali antimonide photocathodes
• High quality ultrafast transmission electron microscopy using resonant microwave cavities
• Solving the Jitter Problem in Microwave Compressed Ultrafast Electron Diffraction Instruments: Robust Sub-50 fs Cavity-Laser Phase Stabilization
• Femtosecond Mega-electron-volt Electron Energy-Loss Spectroscopy
• Improving temporal resolution of ultrafast electron diffraction by eliminating arrival time jitter induced by radiofrequency bunch compression cavities

Cited by in corpus (6)

• Bunch Shaping in Electron Linear Accelerators
• Using Electron Energy-Loss Spectroscopy to Measure Nanoscale Electronic and Vibrational Dynamics in a TEM
• Ultimate bunch length and emittance performance of an MeV ultrafast electron diffraction apparatus with a DC gun and a multi-cavity SRF linac
• Vector-based feedback of continuous wave radiofrequency compression cavity for ultrafast electron diffraction
• Ultrafast Electron Diffraction: Visualizing Dynamic States of Matter
• Monochromation of pulsed electron beams with terahertz radiation at a planar mirror