Studies of Coupled Cavity Linac (CCL) Accelerating Structures with 3-D Codes

摘要

The cw CCL being designed for the Accelerator Production of Tritium (AFT) projectaccelerates protons from 96MeV to 211MeV. It consists of 99 segments each containing up to seven accelerating cavities. Segments are coupled by intersegment coupling cavities and grouped into supermodules. The design method needs to address not only basic cavity sizing for a given coupling and pi/2 mode frequency, but also the effects of high power densities on the cavity frequency, mechanical stresses, and the structure's stop band during operation. On the AFT project, 3-D RF (Ansoft Corp.'s HFSS) and coupled RF/structural (Ansys Inc.'s ANSYS) codes are being used to develop tools to address the above issues and guide cooling channel design. The code's predictions are being checked against available low power Aluminurn models. Stop band behavior under power will be checked once the tools are extended to CCDTL structures that have been tested at high power. A summary of calculations made to date and agreement with measured results will be presented.