TITLE

Efficiency enhancement in a single-pass Raman free electron laser

AUTHOR(S)
Rouhani, M. H.; Maraghechi, B.
PUB. DATE
September 2009
SOURCE
Physics of Plasmas;Sep2009, Vol. 16 Issue 9, p093110
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Efficiency enhancement in free electron laser (FEL) with ion channel and axial magnetic field is compared. By using Maxwell’s equations and nonwiggler averaged equation of motion of electron beam, a set of coupled nonlinear differential equations is derived in the slowly varying amplitude and wave number approximation. Because of using nonwiggler averaged equation of motion, it is possible to treat the injection of the beam into the wiggler. The electron beam propagates with a relativistic velocity, ions are assumed immobile and slippage is ignored. The final set of nonlinear first-order differential equations describing the nonlinear evolution of the FEL is solved by the Runge–Kutta method. Efficiency enhancement in group I orbits is almost the same for both ion channel and axial magnetic field cases, with somewhat larger growth rate for the latter. In group II orbits, efficiency enhancement is not possible for the ion-channel guiding; however, the intrinsic efficiency can be larger than that of the axial magnetic field case.
ACCESSION #
44387823

 

Related Articles

  • On steady poloidal and toroidal flows in tokamak plasmas. McClements, K. G.; Hole, M. J. // Physics of Plasmas;Aug2010, Vol. 17 Issue 8, p082509 

    The effects of poloidal and toroidal flows on tokamak plasma equilibria are examined in the magnetohydrodynamic limit. “Transonic” poloidal flows of the order of the sound speed multiplied by the ratio of poloidal magnetic field to total field Bθ/B can cause the (normally...

  • Three-dimensional fluid simulations of a simple magnetized toroidal plasma. Ricci, Paolo; Rogers, B. N. // Physics of Plasmas;Sep2009, Vol. 16 Issue 9, p092307 

    Three-dimensional fluid simulations are performed in a simple magnetized toroidal plasma, in which vertical and toroidal magnetic fields create helicoidal magnetic field lines that terminate on the torus vessel. The simulations are carried out in the three-dimensional flux tube that wraps around...

  • X- and Y-line equilibria. Yoon, P. H.; Lui, A. T. Y. // Physics of Plasmas;Oct2007, Vol. 14 Issue 10, p104504 

    In this Brief Communication, it is shown that an analytical solution for an exact two-dimensional X- or Y-line equilibrium may be constructed quite easily on the basis of the fundamental theoretical equation. The equilibria discussed in the present report show the potential for a rich variety of...

  • Validation of on- and off-axis neutral beam current drive against experiment in DIII-D. Park, J. M.; Murakami, M.; Petty, C. C.; Heidbrink, W. W.; Osborne, T. H.; Holcomb, C. T.; Van Zeeland, M. A.; Prater, R.; Luce, T. C.; Wade, M. R.; Austin, M. E.; Brooks, N. H.; Budny, R. V.; Challis, C. D.; DeBoo, J. C.; deGrassie, J. S.; Ferron, J. R.; Gohil, P.; Hobirk, J.; Hollmann, E. M. // Physics of Plasmas;Sep2009, Vol. 16 Issue 9, p092508 

    Neutral beam current drive (NBCD) experiments in DIII-D using vertically shifted plasmas to move the current drive away from the axis have clearly demonstrated robust off-axis NBCD. Time-dependent measurements of magnetic field pitch angles by the motional Stark effect diagnostic are used to...

  • Effect of magnetic geometry on transport of neutral particles locally entering confined plasma volume. Tokar, M. Z. // Physics of Plasmas;Sep2009, Vol. 16 Issue 9, p094506 

    The effect of the position where neutral particles enter the confined plasma region with closed magnetic surfaces on the radial profiles of the neutral flux and plasma density is numerically investigated. The case of elongated magnetic surfaces with X-point, in whose vicinity the metric...

  • Generation of polarized shear Alfvén waves by a rotating magnetic field source. Gigliotti, A.; Gekelman, W.; Pribyl, P.; Vincena, S.; Karavaev, A.; Shao, X.; Sharma, A. Surjalal; Papadopoulos, D. // Physics of Plasmas;Sep2009, Vol. 16 Issue 9, p092106 

    Experiments are performed in the Large Plasma Device at the University of California, Los Angeles to study the propagation of field-aligned, polarized kinetic shear Alfvén waves radiated from a rotating magnetic field source created via a novel phased orthogonal loop antenna. Both right and...

  • Radial compression and torque-balanced steady states of single-component plasmas in Penning-Malmberg traps. Danielson, J. R.; Surko, C. M. // Physics of Plasmas;May2006, Vol. 13 Issue 5, p057101 

    Penning-Malmberg traps provide an excellent method to confine single-component plasmas. Specially tailored, high-density plasmas can be created in these devices by the application of azimuthally phased rf fields (i.e., the so-called “rotating wall” technique). Recently, we reported a...

  • Quantum effects on Rayleigh–Taylor instability in a vertical inhomogeneous rotating plasma. Hoshoudy, G. A. // Physics of Plasmas;Feb2009, Vol. 16 Issue 2, pN.PAG 

    Quantum effects on Rayleigh–Taylor instability in inhomogeneous plasma rotating uniformly in an external magnetic field have been investigated. Using the exponential density distribution and in the presence of a fixed boundary condition, the linear growth rate is obtained and analyzed. It...

  • Plasma characteristics in a solenoidal inductive/capacitive discharge under a weak dc magnetic field. Min-Hyong Lee; Chin-Wook Chung // Physics of Plasmas;Oct2007, Vol. 14 Issue 10, p103507 

    Plasma parameters such as electron temperatures, plasma potentials, and plasma densities in a solenoidal inductive/capacitive discharge immersed in a weak dc magnetic field are investigated by measuring electron energy distribution functions (EEDF). Measured EEDFs in a dc magnetic field show the...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics