Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1687508 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms | 2008 | 5 Pages |
Abstract
The radiation from a charge moving along a helical trajectory inside a cylindrical hole in homogeneous dielectric medium is investigated. Prompted by availability of materials with large dielectric permittivity ε and small absorption, we discuss the features of this type of radiation for media with εâ«1. It is shown that there are high peaks in the angular distribution of radiation intensity at well-defined harmonics. The conditions are specified for the cavity-to-helix radii ratio, Ï1/Ï0, under which the angle-integrated radiation intensity on some harmonics exceeds that in the empty space. Though the amplification of radiation intensity increases with increasing ε, the corresponding “resonant” values of Ï1/Ï0 ratio are practically independent of the dielectric permittivity of surrounding medium. It is shown that an analogous amplification of radiation takes place essentially for the same values of Ï1/Ï0 also for the radiation in a cylindrical waveguide with conducting walls. An explanation of this phenomenon is given.
Related Topics
Physical Sciences and Engineering
Materials Science
Surfaces, Coatings and Films
Authors
S.R. Arzumanyan, L.Sh. Grigoryan, H.F. Khachatryan, A.S. Kotanjyan, A.A. Saharian,