  The cw CCL being designed for the Accelerator Production of Tritium (APT)
project accelerates 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 APT 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 Aluminum 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.
