What sets the uncorrelated energy spread of high-brightness electron beams? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title · changed
Revision 1: What sets the uncorrelated energy spread of high-brightness electron beams
Revision 2: What sets the uncorrelated energy spread of high-brightness electron beams?
Plain
Lasing needs electrons of nearly identical energy, and measured energy spreads in x-ray FEL electron beams have come out larger than models predicted.
Precise · changed · core
Revision 1: In photoinjectors with $1e8\ \text{to}\ 1e9$ electrons per bunch, determine the contributions of intrabeam scattering, shot-noise-seeded microbunching instability and cathode emission to the slice energy spread $\sigma_E$ (few keV) at injector exit and after bunch compression, and predict $\sigma_E$ within $20\ \mathrm{percent}$ of measured values at several facilities.
Revision 2: In photoinjectors with $10^{8}\ \text{to}\ 10^{9}$ electrons per bunch, determine the contributions of intrabeam scattering, shot-noise-seeded microbunching instability and cathode emission to the slice energy spread $\sigma_E$ (few keV) at injector exit and after bunch compression, and predict $\sigma_E$ within $20\%$ of measured values at several facilities.
Settled by
High-resolution slice energy spread measurements versus bunch charge and laser-heater setting compared with a start-to-end model including intrabeam scattering.
Kind
well-posed
Answer type
mechanism
References
(empty)
Literature status
partially-resolved
Status note
Measurements at FEL injectors in the early 2020s attributed much of the excess to intrabeam scattering; quantitative agreement across facilities is not established.
Posed since
(empty)

Decisions