CERN Accelerating science

Article
Title	A New Tuning Module for Resonant Coupling Structures
Author(s)	Vaccaro, Vittorio G ; Clauser, Tarcisio ; De Martinis, Carlo ; Giove, Dario ; Masullo, Maria R ; Mauri, Marco ; Rainò, Antonio ; Variale, Vincenzo
Affiliation	(INFN-Bari, Bari) ; (INFN-Milano, Milano) ; (INFN-Napoli, Napoli) ; (INFN/LASA, Segrate (MI) ; (Naples University Federico II and INFN, Napoli) ; (Naples University Federico II, Napoli)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.973
Subject category	Accelerators and Storage Rings
Abstract	In order to have efficient particle acceleration it is fundamental that the particles experience, in the accelerating gap, field amplitudes as uniform and as high as possible from gap to gap. Because of the unavoidable fabrication errors, an accelerating structure, when assembled, exhibits field values lower than the nominal ones and/or not uniform. All the usual procedures developed in order to adjust the parameter deviations responsible of the malfunction of these structures, are based on field amplitude measurements, by using the bead pull technique, which is a very invasive technique. In this paper the philosophy is reversed: it is assumed that all the information can be got by Sounding the Modes of the whole System (SMS) and correct the deviation of each frequency mode from its nominal value by means of an appropriate tuning of the cavities: resorting to a perturbative technique applied to a circuit model representing this kind of structures, it is possible to calculate the amount of tuning to give to the cavities. It will be shown that a very good equalization and maximization of the fields in the cavities can be achieved by using this technique.