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Title: Time- and frequency-domain models for Smith-Purcell radiation from a two-dimensional charge moving above a finite length grating

Abstract

Smith-Purcell radiation (SPR), formed by an electron beam traveling above a grating, is a very promising source of coherent radiation from the THz to the optical regime. We present two theoretical calculations of the SPR from a two-dimensional bunch of relativistic electrons passing above a grating of finite length. The first calculation uses the finite-difference time-domain approach with the total-field/scattered-field procedure for fields incident on the grating. This calculation allows good physical insight into the radiation process and also allows arbitrary geometries to be treated. The second calculation uses an electric-field integral equation method. Good agreement is obtained between these two calculations. The results of these theoretical calculations are then compared with a theoretical formalism based on an infinite-length grating. The latter formalism allows periodic boundary conditions to be rigorously applied. For gratings with less than {approx}50 periods, a significant error in the strength of the radiated field is introduced by the infinite-grating approximation. It is shown that this error disappears asymptotically as the number of periods increases. The Wood-Rayleigh anomalies, predicted in the infinite-grating approximation, were not seen in our finite-grating calculations. The SPR resonance condition is the same in all three formalisms. Numerical examples are presented for anmore » {approx}18 MeV, 50 nC/m, 200 {mu}m bunch traveling 0.6 mm above a ten-period echelle grating having a 2.1-mm periodicity.« less

Authors:
; ; ;  [1]
  1. Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
Publication Date:
OSTI Identifier:
20641360
Resource Type:
Journal Article
Journal Name:
Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics
Additional Journal Information:
Journal Volume: 71; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevE.71.016501; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-651X
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BEAM BUNCHING; BOUNDARY CONDITIONS; COHERENT RADIATION; DIFFRACTION GRATINGS; ELECTRIC FIELDS; ELECTRON BEAMS; ELECTRONS; ERRORS; GEOMETRY; GRATINGS; INTEGRAL EQUATIONS; MEV RANGE 10-100; PERIODICITY; RELATIVISTIC RANGE; RESONANCE; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Kesar, Amit S, Hess, Mark, Korbly, Stephen E, and Temkin, Richard J. Time- and frequency-domain models for Smith-Purcell radiation from a two-dimensional charge moving above a finite length grating. United States: N. p., 2005. Web. doi:10.1103/PhysRevE.71.016501.
Kesar, Amit S, Hess, Mark, Korbly, Stephen E, & Temkin, Richard J. Time- and frequency-domain models for Smith-Purcell radiation from a two-dimensional charge moving above a finite length grating. United States. https://doi.org/10.1103/PhysRevE.71.016501
Kesar, Amit S, Hess, Mark, Korbly, Stephen E, and Temkin, Richard J. Sat . "Time- and frequency-domain models for Smith-Purcell radiation from a two-dimensional charge moving above a finite length grating". United States. https://doi.org/10.1103/PhysRevE.71.016501.
@article{osti_20641360,
title = {Time- and frequency-domain models for Smith-Purcell radiation from a two-dimensional charge moving above a finite length grating},
author = {Kesar, Amit S and Hess, Mark and Korbly, Stephen E and Temkin, Richard J},
abstractNote = {Smith-Purcell radiation (SPR), formed by an electron beam traveling above a grating, is a very promising source of coherent radiation from the THz to the optical regime. We present two theoretical calculations of the SPR from a two-dimensional bunch of relativistic electrons passing above a grating of finite length. The first calculation uses the finite-difference time-domain approach with the total-field/scattered-field procedure for fields incident on the grating. This calculation allows good physical insight into the radiation process and also allows arbitrary geometries to be treated. The second calculation uses an electric-field integral equation method. Good agreement is obtained between these two calculations. The results of these theoretical calculations are then compared with a theoretical formalism based on an infinite-length grating. The latter formalism allows periodic boundary conditions to be rigorously applied. For gratings with less than {approx}50 periods, a significant error in the strength of the radiated field is introduced by the infinite-grating approximation. It is shown that this error disappears asymptotically as the number of periods increases. The Wood-Rayleigh anomalies, predicted in the infinite-grating approximation, were not seen in our finite-grating calculations. The SPR resonance condition is the same in all three formalisms. Numerical examples are presented for an {approx}18 MeV, 50 nC/m, 200 {mu}m bunch traveling 0.6 mm above a ten-period echelle grating having a 2.1-mm periodicity.},
doi = {10.1103/PhysRevE.71.016501},
url = {https://www.osti.gov/biblio/20641360}, journal = {Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics},
issn = {1063-651X},
number = 1,
volume = 71,
place = {United States},
year = {2005},
month = {1}
}