Author: Hovakimyan, L.V.
Paper Title Page
MOP003 Helical Undulator Radiation in Internally Coated Metallic Pipe 26
  • T.L. Vardanyan, A. Grigoryan, L.V. Hovakimyan, M. Ivanyan, A.V. Tsakanian, V.M. Tsakanov
    CANDLE SRI, Yerevan, Armenia
  The vacuum chambers of many advanced undulator sources are coated internally in order to reduce the impedance of the vacuum chamber or improve the vacuum performance. Although the impedances and radiation properties of the internally coated metallic pipes for straightforward moving charge are well studied, the peculiarities of the particles wiggling motion on the radiation characteristics in such structure are missed. In this paper we obtain exact expressions for the fields of a particle moving along a spiral path, as in the single-layer resistive as well as in the two-layer metallic waveguides, modelling NEG coating of the waveguide walls. Based on these results, it will be possible to obtain the necessary characteristics of the radiation of helical undulators, very close to reality. The solution is obtained as a superposition of a particular solution of inhomogeneous Maxwell's equations in a waveguide with perfectly conducting walls, and the solutions of the homogeneous Maxwell equations in the single-layer and double-layer resistive waveguides. Solution in the form of the multipole expansion for inhomogeneous Maxwell's equations for a waveguide with perfectly conducting walls, are also obtained in this study.