skip to main content

SciTech ConnectSciTech Connect

Title: Dispersion, spatial growth rate, and start current of a Cherenkov free-electron laser with negative-index material

We present an analysis of a Cherenkov free-electron laser based on a single slab made from negative-index materials. In this system, a flat electron beam with finite thickness travelling close to the surface of the slab interacts with the copropagating electromagnetic surface mode. The dispersion equation for a finitely thick slab is worked out and solved numerically to study the dispersion relation of surface modes supported by negative-index materials, and the calculations are in good agreement with the simulation results from a finite difference time domain code. We find that under suitable conditions there is inherent feedback in such a scheme due to the characteristics of negative-index materials, which means that the system can oscillate without external reflectors when the beam current exceeds a threshold value, i.e., start current. Using the hydrodynamic approach, we setup coupled equations for this system, and solve these equations analytically in the small signal regime to obtain formulas for the spatial growth rate and start current.
Authors:
; ; ; ; ;  [1] ;  [2] ; ;  [3] ;  [4] ;  [5]
  1. National Key Laboratory of Science and Technology on Vacuum Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China)
  2. Institute for Laser Technology, Suita, Osaka 565-0781 (Japan)
  3. Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0781 (Japan)
  4. Beijing Vacuum Electronics Research Institute, Beijing 100016 (China)
  5. Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Ako, Hyogo 678-1205 (Japan)
Publication Date:
OSTI Identifier:
22490081
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CHERENKOV RADIATION; COMPUTERIZED SIMULATION; CURRENTS; DISPERSION RELATIONS; ELECTRON BEAMS; FEEDBACK; FREE ELECTRON LASERS; MATERIALS; SIGNALS; SLABS