Calculation of Radiation from a Helically Cut Waveguide for a Gyrotron Mode Converter in the Quasi-Optical Approximation |
| |
Authors: | E M Choi M A Shapiro J R Sirigiri R J Temkin |
| |
Affiliation: | (1) Plasma Science & Fusion Center, Massachusetts Institute of Technology, 167 Albany St., Bldg. NW16, Cambridge, MA 02139, USA |
| |
Abstract: | We present results of calculations of the radiation from a helically cut waveguide launcher, a so-called Vlasov launcher,
which is commonly used either internal or external to a gyrotron for purposes of mode conversion. A gyrotron internal mode
converter consists of such a launcher that radiates the waveguide mode as a nearly Gaussian beam in free space followed by
a set of mirrors to focus and direct the radiation. The radiation from the launcher is first calculated using a geometric
optics representation of the waveguide mode. Then the radiation is calculated in the quasi-optical limit, including diffraction.
These analytic results are compared to a rigorous calculation using the computer code SURF3D, which uses an electric field
integral equation (EFIE) approach. Good agreement is obtained between the quasi-optical theory and the SURF3D calculation.
The present results provide new insights into the accuracy of the quasi-optical theory and may be useful for the design and
improvement of Vlasov-type mode converters. |
| |
Keywords: | Mode converter Vlasov launcher Gyrotron Quasi-optical approximation |
本文献已被 SpringerLink 等数据库收录! |
|