The evolution of ultrafast electron microscope instrumentation.
Extrapolating from a brief survey of the literature, we outline a vision for the future development of time-resolved electron probe instruments that could offer levels of performance and flexibility that push the limits of physical possibility. This includes a discussion of the electron beam parameters (brightness and emittance) that limit performance, the identification of a dimensionless invariant figure of merit for pulsed electron guns (the number of electrons per lateral coherence area, per pulse), and calculations of how this figure of merit determines the trade-off of spatial against temporal resolution for different imaging modes. Modern photonics' ability to control its fundamental particles at the quantum level, while enjoying extreme flexibility and a very large variety of operating modes, is held up as an example and a goal. We argue that this goal may be approached by combining ideas already in the literature, suggesting the need for large-scale collaborative development of next-generation time-resolved instruments.
Reed
B W
BW
Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA. reed12@llnl.gov
Armstrong
M R
MR
Browning
N D
ND
Campbell
G H
GH
Evans
J E
JE
LaGrange
T
T
Masiel
D J
DJ
D008854:Microscopy, Electron / Q000379:methods* / Q000639:trends*