Il Nuovo Cimento D

, Volume 12, Issue 1, pp 21–34 | Cite as

FEL gain in the pulsed regime: a comparison between numerical and analytical results

  • G. Dattoli
  • L. Giannessi
  • T. Hermsen
  • A. Renieri
  • M. Richetta
  • A. Torre
Article

Summary

In this paper we present simple and general formulae for the FEL gain in the pulsed regime including both the longitudinal mode coupling and the lethargy effect. Such relations, obtained from a numerical integration of the pulse propagation equations, are then compared to similar expressions obtained analitycally in the limiting case of the long bunch approximation and the agreement is shown to be excellent.

PACS 85.60

Photoelectric and optoelectronic devices and systems 

Riassunto

In questo lavoro vengono derivate formule semplici e generali relative al guadagno FEL in regime impulsato. Tali formule tengono conto dell'accoppiamento tra i modi longitudinali e dell'effetto di letargia. Le relazioni di cui sopra sono ottenute nell'ambito di una trattazione numerica delle equazioni di propagazione degli impulsi e sono poi comparate ad analoghe espressioni ottenute per via analitica nel caso limite di pacchetto di elettroni lungo. Si dimostra come l'accordo sia particolarmente buono.

Резюме

В зтой статье мы приводим простые и общие формулы для усиления для лазера на свободных злектронах в импульсном режиме, учитывая связь продольных мод и зффект летаргии. Зти соотношения, полченные с помощью численного интегрирования уравнений распространения импульса, затем сравниваются с аналогичными выражениями, полученными аналитически в предельном случае приближения длинного сгустка, и получается хорошее согласие.

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References

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Copyright information

© Societá Italiana di Fisica 1990

Authors and Affiliations

  • G. Dattoli
    • 1
  • L. Giannessi
    • 1
  • T. Hermsen
    • 1
  • A. Renieri
    • 1
  • M. Richetta
    • 1
  • A. Torre
    • 1
  1. 1.ENEA, Dip. TIB, U.S., Fisica Applicata, CRE FrascatiFrascati (Roma)Italia

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