  The CCT (Coupled Cavity Tuning) code automates the RF calculations and sizing
of RF cavities for the CCL (Coupled Cavity Linac) structures of APT. It is
planned to extend the code to the CCDTL (Coupled Cavity Drift Tube Linac). The
CCT code controls the CCLFISH code, a member of the Poisson Superfish series of
codes [1]. CCLFISH performs RF calculations and tunes the geometry of
individual cavities, including an accelerating cavity (AC) and a coupling
cavity (CC). CCT also relates the AC and CC by means of equations that describe
the coupling slot between cavities. These equations account for the direct
coupling, the next nearest neighbor coupling between adjacent AC's, and the
frequency shifts in the AC and CC caused by the slot. Given design objectives
of a coupling coefficient k, the pi/2 mode frequency, and the net frequency of
the CC, the CCT code iterates to solve for the geometry of the AC and CC and
the separation distance between them (this controls the slot size), satisfying
the design objectives. The resulting geometry is used to automate CAD drawing
preparation. The code can also be used in "as-designed" mode to calculate the
frequencies and coupling of a specified configuration. An overview of the code
is presented.
