Modelling elliptically polarised free electron lasers

J R Henderson; L T Campbell; H P Freund; B W J McNeil

doi:10.1088/1367-2630/18/6/062003

Modelling elliptically polarised free electron lasers

J R Henderson, L T Campbell, H P Freund, B W J McNeil

Research output: Contribution to journal › Article

2 Citations (Scopus)

100 Downloads (Pure)

Abstract

A model of a Free Electron Laser operating with an elliptically polarised undulator is presented. The equations describing the FEL interaction, including resonant harmonic radiation fields, are averaged over an undulator period and generate a generalised Bessel function scaling factor, similar to that of planar undulator FEL theory. Comparison between simulations of the averaged model with those of an unaveraged model show very good agreement in the linear regime. Two unexpected results were found. Firstly, an increased coupling to harmonics for elliptical rather than planar polarisarised undulators. Secondly, and thought to be unrelated to the undulator polarisation, a signifcantly different evolution between the averaged and unaveraged simulations of the harmonic radiation evolution approaching FEL saturation.

Original language	English
Article number	062003
Number of pages	14
Journal	New Journal of Physics
Volume	18
DOIs	https://doi.org/10.1088/1367-2630/18/6/062003
Publication status	Published - 20 Jun 2016

Fingerprint

free electron lasers

harmonic radiation

Bessel functions

radiation distribution

simulation

saturation

harmonics

scaling

polarization

interactions

Keywords

free electron laser
harmonic radiation fields
tunable radiation

Cite this

Henderson, J. R., Campbell, L. T., Freund, H. P., & McNeil, B. W. J. (2016). Modelling elliptically polarised free electron lasers. New Journal of Physics, 18, [062003]. https://doi.org/10.1088/1367-2630/18/6/062003

Henderson, J R ; Campbell, L T ; Freund, H P ; McNeil, B W J. / Modelling elliptically polarised free electron lasers. In: New Journal of Physics. 2016 ; Vol. 18.

@article{32fb26075a114b858b3899276f81597f,

title = "Modelling elliptically polarised free electron lasers",

abstract = "A model of a Free Electron Laser operating with an elliptically polarised undulator is presented. The equations describing the FEL interaction, including resonant harmonic radiation fields, are averaged over an undulator period and generate a generalised Bessel function scaling factor, similar to that of planar undulator FEL theory. Comparison between simulations of the averaged model with those of an unaveraged model show very good agreement in the linear regime. Two unexpected results were found. Firstly, an increased coupling to harmonics for elliptical rather than planar polarisarised undulators. Secondly, and thought to be unrelated to the undulator polarisation, a signifcantly different evolution between the averaged and unaveraged simulations of the harmonic radiation evolution approaching FEL saturation.",

keywords = "free electron laser, harmonic radiation fields, tunable radiation",

author = "Henderson, {J R} and Campbell, {L T} and Freund, {H P} and McNeil, {B W J}",

year = "2016",

month = "6",

day = "20",

doi = "10.1088/1367-2630/18/6/062003",

language = "English",

volume = "18",

journal = "New Journal of Physics",

issn = "1367-2630",

}

Henderson, JR, Campbell, LT, Freund, HP & McNeil, BWJ 2016, 'Modelling elliptically polarised free electron lasers', New Journal of Physics, vol. 18, 062003. https://doi.org/10.1088/1367-2630/18/6/062003

Modelling elliptically polarised free electron lasers. / Henderson, J R; Campbell, L T; Freund, H P; McNeil, B W J.

In: New Journal of Physics, Vol. 18, 062003, 20.06.2016.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Modelling elliptically polarised free electron lasers

AU - Henderson, J R

AU - Campbell, L T

AU - Freund, H P

AU - McNeil, B W J

PY - 2016/6/20

Y1 - 2016/6/20

N2 - A model of a Free Electron Laser operating with an elliptically polarised undulator is presented. The equations describing the FEL interaction, including resonant harmonic radiation fields, are averaged over an undulator period and generate a generalised Bessel function scaling factor, similar to that of planar undulator FEL theory. Comparison between simulations of the averaged model with those of an unaveraged model show very good agreement in the linear regime. Two unexpected results were found. Firstly, an increased coupling to harmonics for elliptical rather than planar polarisarised undulators. Secondly, and thought to be unrelated to the undulator polarisation, a signifcantly different evolution between the averaged and unaveraged simulations of the harmonic radiation evolution approaching FEL saturation.

AB - A model of a Free Electron Laser operating with an elliptically polarised undulator is presented. The equations describing the FEL interaction, including resonant harmonic radiation fields, are averaged over an undulator period and generate a generalised Bessel function scaling factor, similar to that of planar undulator FEL theory. Comparison between simulations of the averaged model with those of an unaveraged model show very good agreement in the linear regime. Two unexpected results were found. Firstly, an increased coupling to harmonics for elliptical rather than planar polarisarised undulators. Secondly, and thought to be unrelated to the undulator polarisation, a signifcantly different evolution between the averaged and unaveraged simulations of the harmonic radiation evolution approaching FEL saturation.

KW - free electron laser

KW - harmonic radiation fields

KW - tunable radiation

UR - http://iopscience.iop.org/journal/1367-2630

U2 - 10.1088/1367-2630/18/6/062003

DO - 10.1088/1367-2630/18/6/062003

M3 - Article

VL - 18

JO - New Journal of Physics

JF - New Journal of Physics

SN - 1367-2630

M1 - 062003