Author: Tyukhtin, A.V.
Paper Title Page
TUPC122 Use of a Grid Waveguide for Particle Energy Determination 1302
 
  • A.V. Tyukhtin
    Saint-Petersburg State University, Saint-Petersburg, Russia
 
  Funding: The Education Agency of Russian Federation and the Russian Foundation for Basic Research (09-02-00921).
We consider prospect of use of a grid waveguide for determination of energy of charge particles in bunches. The method under consideration is based on measurement of a waveguide mode frequency. Earlier we developed two variants of this method*. One of them is based on use of a thin dielectric layer in a waveguide. Other variant is based on use of a waveguide loading with a system of wires coated with a dielectric material. In this paper we offer a new version of the method under consideration. It consists in application of a circular waveguide having a grid wall instead a solid one. The grid cells are assumed to be small. The particle bunch moves along the waveguide axis. The analytical solution of the problem is obtained by means of the averaged boundary conditions. It is shown that there is the single propagating mode. The main advantage of the method consists in an enough strong dependency of particle energy on the mode frequency in some wide frequency range. Note as well that this structure is easy for manufacture and can be embedded in the accelerator channel without big difficulty.
* A.V.Tyukhtin et al., PAC’07, p.4156; A.V. Tyukhtin, EPAC’08, p.1302; A.V. Tyukhtin, Tech. Phys. Lett. 35, p.263 (2009); A.V. Tyukhtin et al., IPAC’10, p.1071.
 
 
WEPZ012 Influence of Transition Radiation on Formation of a Bunch Wakefield in a Circular Waveguide 2793
 
  • T.Yu. Alekhina, A.V. Tyukhtin
    Saint-Petersburg State University, Saint-Petersburg, Russia
 
  Funding: The Education Agency of Russian Federation.
Investigation of a field of a particle bunch in a waveguide loaded with a dielectric is important for the wakefield acceleration (WFA) technique and other problems in the accelerator physics. One of subjects of investigation in this area consists in analysis of transition radiation generated by the bunch flying into (out of) the dielectric structure. This radiation can be both destructive (for WFA) and useful (for diagnostics of bunch or material). We investigate the total field of small bunch crossing a boundary between two dielectrics in the waveguide. It includes a “forced” field and a “free” one. The “forced” field is the field of the charge in the unbounded waveguide (it can contain the wakefield). The “free” field is connected with influence of the boundary (it includes transition radiation). Two cases are analyzed in detail: the bunch flies from vacuum into dielectric and from dielectric into vacuum. The behavior of the field depending on distance and time is explored analytically and numerically. Some interesting physical effects are noted. As well, we make a comparison with the case of intersection between vacuum and cold plasma.