Mismatch Oscillations in High Current Accelerators.

Andersen, O. A.

Technical Information Center Oak Ridge Tennessee

关键词: Accelerators;    Oscillations;    Approximation;    Quadrupoles;    Charge density;   

RP-ID  :  DE2005859933

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

When planning the design of high-current FODO transport for accelerators, it is useful to have simple, accurate tools for calculating quantities such as the phase advances (sigma)(sub 0) and (sigma) given the lattice and beam parameters. Along with the KV beam model, the smooth approximation is often used. It is simple but not very accurate in many cases. Although Struckmeier and Reiser showed that the stable oscillation frequencies of mismatched beams could be obtained accurately, they actually used a hybrid approach where (sigma)(sub 0) and (sigma) were already known precisely. When starting instead with basic quantities such as quadrupole dimensions, field strength, beam line charge density and emittance, the smooth approximation gives substantial errors. Here we derive a simple modification of the smooth approximation formula that improves the accuracy of the predicted frequencies by a factor of five at (sigma)(sub 0) = 83(sup o).