Effects of self-fields on electron trajectory and gain in planar wiggler free-electron lasers with two-stream and ion-channel guiding

Abstract

The effects of self-fields on electron trajectories and gain in planar wiggler free-electron lasers with two-stream and ion-channel guiding are investigated. An analysis of the two-stream quasi-steady-state electron trajectories is given by solving the equation of motion in the presence of ion-channel guiding and the planar wiggler. The electron trajectories and the gain are derived. The stability of the trajectories, the characteristics of the linear gain, and the normalized maximum gain are studied numerically. The numerical calculations show that there are eight group trajectories rather than the two groups reported in the absence of the self-fields. It is also shown that the normalized gain group seven (G7) decreases while the rest increases with the increase in normalized ion-channel frequency. The two-stream instability and the self-field lead to a decrease in the maximum gain, except for G7.

Formation of Powerful Multiharmonic Electromagnetic Wave by Two Stream Superheterodyne Klystron Free Electron Laser with Helical Electron Beam

“…Двопотокові супергетеродинні лазери на вільних електронах (ЛВЕ) виокремлюються серед інших типів ЛВЕ високими темпами підсилення електромагнітних хвиль [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Такі темпи підсилення обумовлені використанням ефекту супергетеродинного підсилення [1][2][3], у якому як додатковий механізм підсилення використовується двопотокова нестійкість.…”

Space Charge Wave with Broad Frequency Spectrum Formation in Transit Section of Klystron-type Two-stream FEL with Helical Electron Beam

“…Owing to the two-stream instability, the two-stream superheterodyne free-electron lasers (TSFELs) are characterized by exclusively high amplification properties in millimeter-infrared wavelength band [1][2][3][4][5][6][7][8][9][10][11]. However, single-section TSFEL amplifiers have a pronounced tendency to self-excitation due to extremely high amplification level.…”

“…In the majority of works devoted to TSFEL klystrons and TSFEL in general, only monochromatic operation modes are investigated. In such modes the space charge wave (SCW) is excited on the frequency having maximal amplification due to the two-stream instability [1][2][3][4][5][6][7][8][9][10][11]. Lately, there are also works investigating multiharmonic operation modes of TSFELs [1,12,13].…”

Forming of Ultrashort Electromagnetic Clusters by Two-Stream Superheterodyne Free Electron Lasers

“…Two-stream superheterodyne free electron lasers (TSFELs) are characterized by exceptionally high rates of the amplification of electromagnetic waves in the submillimeter-IR range [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Such high rates of the amplification are achieved through the use of the additional amplification mechanism of space-charge wave (SCW) due to the two-stream instability [19][20][21].…”