Beam Diagnostics In Superconducting Accelerating Cavities

Beam Diagnostics in Superconducting Accelerating Cavities

An energetic charged particle beam introduced to an rf cavity excites a wakefield therein. This wakefield can be decomposed into a series of higher order modes and multipoles, which for sufficiently small beam offsets are dominated by the dipole component. This work focuses on using these dipole modes to detect the beam position in third harmonic superconducting S-band cavities for light source applications. A rigorous examination of several means of analysing the beam position based on signals radiated to higher order modes ports is presented. Experimental results indicate a position resolution, based on this technique, of 20 microns over a complete module of 4 cavities. Methods are also indicated for improving the resolution and for applying this method to other cavity configurations. This work is distinguished by its clarity and potential for application to several other international facilities. The material is presented in a didactic style and is recommended both for students new to the field, and for scientists well-versed in the field of rf diagnostics.

Measurement and Control of Charged Particle Beams

The intent of this book is to bridge the link between experimental obser vations and theoretical principles in accelerator physics. The methods and concepts, taken primarily from high energy accelerators, have for the most part already been presented in internal reports and proceedings of accelera tor conferences, a portion of which has appeared in refereed journals. In this book we have tried to coherently organize this material so as to be useful to designers and operators in the commissioning and operation of particle accelerators. A point of emphasis has been to provide, wherever possible, experimental data to illustrate the particular concept under discussion. Of the data pre sented, most are collected from presently existing or past accelerators and we regret the problem of providing original data some of which appear in less accessible publications - for possible omissions we apologize. Regarding the uniformity of the text, particularly with respect to symbol definitions, wehave taken the liberty to edit certain representations of the data while trying to maintain the essence of the presented observations. Throughout the text we have attempted to provide references which are readily available for the reader.

Savannah River Site, Accelerator for Production of Tritium