CERN Accelerating science

Article
Title	Experimental Investigation of an X-Band Tunable Dielectric Accelerating Structure
Author(s)	Kanareykin, Alex ; Gai, Wei ; Karmanenko, Sergei F ; Nenasheva, Elisaveta ; Power, John G ; Schoessow, Paul ; Semenov, Alexei
Affiliation	(ANL, Argonne, Illinois) ; (Euclid Concepts, LLC, Solon, Ohio)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.3529
Subject category	Accelerators and Storage Rings
Abstract	Experimental study of a new scheme to tune the resonant frequency for dielectric based accelerating structure (driven either by the wakefield of a beam or an external rf source) is underway. The structure consists of a single layer of conventional dielectric surrounded by a very thin layer of ferroelectric material situated on the outside. Carefully designed electrodes are attached to a thin layer of ferroelectric material. A DC bias can be applied to the electrodes to change the permittivity of the ferroelectric layer and therefore, the dielectric overall resonant frequency can be tuned. In this paper, we present the test results for an 11.424 GHz rectangular DLA prototype structure that the ferroelectric material's dielectric constant of 500 and show that a frequency tuning range of 2% can be achieved. If successful, this scheme would compensate for structure errors caused by ceramic waveguide machining tolerances and dielectric constant heterogeneity.