Time and frequencydomain models for SmithPurcell radiation from a twodimensional charge moving above a finite length grating
Abstract
SmithPurcell 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 twodimensional bunch of relativistic electrons passing above a grating of finite length. The first calculation uses the finitedifference timedomain approach with the totalfield/scatteredfield 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 electricfield 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 infinitelength 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 infinitegrating approximation. It is shown that this error disappears asymptotically as the number of periods increases. The WoodRayleigh anomalies, predicted in the infinitegrating approximation, were not seen in our finitegrating calculations. The SPR resonance condition is the same in all three formalisms. Numerical examples are presented for anmore »
 Authors:

 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 1063651X
 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 10100; PERIODICITY; RELATIVISTIC RANGE; RESONANCE; TWODIMENSIONAL CALCULATIONS
Citation Formats
Kesar, Amit S, Hess, Mark, Korbly, Stephen E, and Temkin, Richard J. Time and frequencydomain models for SmithPurcell radiation from a twodimensional 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 frequencydomain models for SmithPurcell radiation from a twodimensional 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 frequencydomain models for SmithPurcell radiation from a twodimensional charge moving above a finite length grating". United States. https://doi.org/10.1103/PhysRevE.71.016501.
@article{osti_20641360,
title = {Time and frequencydomain models for SmithPurcell radiation from a twodimensional charge moving above a finite length grating},
author = {Kesar, Amit S and Hess, Mark and Korbly, Stephen E and Temkin, Richard J},
abstractNote = {SmithPurcell 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 twodimensional bunch of relativistic electrons passing above a grating of finite length. The first calculation uses the finitedifference timedomain approach with the totalfield/scatteredfield 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 electricfield 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 infinitelength 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 infinitegrating approximation. It is shown that this error disappears asymptotically as the number of periods increases. The WoodRayleigh anomalies, predicted in the infinitegrating approximation, were not seen in our finitegrating 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 tenperiod echelle grating having a 2.1mm 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 = {1063651X},
number = 1,
volume = 71,
place = {United States},
year = {2005},
month = {1}
}