The detrimental effect of spontaneous emission in quantum free electron lasers : a discrete Wigner model

Fares, H. and Piovella, N. and Robb, G. R. M. (2018) The detrimental effect of spontaneous emission in quantum free electron lasers : a discrete Wigner model. Physics of Plasmas, 25 (1). 013111. ISSN 1070-664X (https://doi.org/10.1063/1.5003913)

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Abstract

We study the spontaneous emission in high-gain free-electron lasers operating in the quantum regime and its detrimental effect on coherent emission. A quantum model describing the coherent and spontaneous emission in free electron lasers has been recently proposed and investigated [G. R. M. Robb and R. Bonifacio, Phys. Plasmas 19, 073101 (2012)]. The model is based on a Wigner distribution describing the electron beam dynamics, coupled to Maxwell equations for the emitted radiation field. Here, we rephrase the model in a more rigorous way, considering a discrete Wigner distribution defined for a periodic space coordinate for which the electron momentum is discrete. From its numerical solution, we find good agreement with the approximate continuous model. In the quantum regime of the free-electron laser, we obtain a simple density matrix equation for two momentum states, where the role of the spontaneous emission has a clear interpretation in terms of coherence decay and population transfer.

  • Item type:Article
    ID code:63423
    Dates:
    Date
    Event
    16 January 2018
    Published
    21 December 2017
    Accepted
    Notes:This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in Fares, H, Piovella, N & Robb, GRM 2018, 'The detrimental effect of spontaneous emission in quantum free electron lasers: A discrete Wigner model' Physics of Plasmas, vol 25, no. 1, 013111. and may be found at https://doi.org/10.1063/1.5003913.
    Subjects:Science > Physics > Plasma physics. Ionized gases
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:07 Mar 2018 10:06
    Last modified:25 Apr 2024 00:54
    Related URLs:
    URI:https://strathprints.strath.ac.uk/id/eprint/63423
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