Answers are grounded in this paper and cite their sources.
Frequency-resolved measurements of the emission of a collective free-electron laser operating at millimeter wavelengths have shown emission spectra that agree well with theoretical predictions for the collective free-electron laser instability. Broad tunability, moderate emission linewidths, and high single-frequency gain have been observed. In addition, adjusting the axial field in the end region of the interaction has been found in some cases to cause a large increase in measured power and efficiency.
No takes yet. Share an insight, caveat, or question.
Gold et al. (1983) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: