Advanced Intraundulator Electron Beam Diagnostics Using COTR Techniques

Lumpkin, A.H.; Berg, William J.; Biedron, Sandra; Borland, M.; Chae, Yong-Chul; Dejus, R.; Erdmann, M.; Huang, Zhirong; Kim, K. J. K.; Li, Y. L.; Milton, S.V.; Moog, E.R.; Rule, D.W.; Sajaev, V.; Ye, Bo

doi:10.1063/1.1524403

Cited by 2 publications

(1 citation statement)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have previously reported what appeared to be effects on the transverse COTR intensities in beam size [13] and the far field [8], but for those experiments the 500-nm shortpass filters had not been installed in the filter wheels, so the sorting of OTR and COTR contributions at low gain was difficult.…”

Section: Resultsmentioning

confidence: 99%

Evidence for transverse dependencies in COTR and microbunching in a SASE FEL

Lumpkin¹,

Chae²,

Lewellen³

et al. 2003

Nuclear Instruments and Methods in Physics Research Section A:

View full text Add to dashboard Cite

Using coherent optical transition radiation (COTR) techniques, we have observed transverse dependencies, which in some aspects relate to the electron beam microbunching in a visible wavelength (540 nm) self-amplified spontaneous emission (SASE) free-electron laser (FEL). The experimental COTR observations include the zdependent e-beam sizes, the z-dependent angular distributions, and the z-dependent spectra (which show an x-dependence). A 30-40% narrowing of the observed beam size using COTR is explainable by the mechanism's dependence on the square of the number of microbunched particles. However, additional effects are needed to explain beam size reductions by factors of 2-3 at different z locations. Localized e-beam structure in the gun or induced in the bunch compression process may result in microbunching transverse dependence, and hence the observed COTR effects.

show abstract

Section: Resultsmentioning

confidence: 99%