Evidence for competition modes in a partially guided far-infrared free-electron laser

Autor: J.-M. Ortega, J.-P. Berthet, F. Glotin, R. Prazeres
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Physical Review Special Topics. Accelerators and Beams, Vol 17, Iss 10, p 100701 (2014)
Druh dokumentu: article
ISSN: 1098-4402
DOI: 10.1103/PhysRevSTAB.17.100701
Popis: The infrared free-electron laser (FEL) offers a large tunability since the FEL gain remains high throughout the infrared spectral range, and the reflectivity of metal mirrors remains also close to unity. The main limitation comes from the diffraction of the optical beam due to the finite size of the vacuum chamber of the undulator. A solution is to use this chamber as a waveguide by adapting the radius of curvature of the cavity mirrors to this regime. Then, as has been shown before, a minimum appears in the spectrum that can be produced by the FEL. We discuss the physical mechanism of this particular regime and compare it to experiments using vacuum chambers of different transverse sizes. A good agreement is found with results of simulations and with a simple analytical formula.
Databáze: Directory of Open Access Journals