Modified PARMILA code for new accelerating structures

The PARMILA code was originally developed as a numerical tool to design and simulate the beam performance of the drift-tube linac (DTL). We have extended PARMILA to the design of both the coupled-cavity linac (CCL) and the coupled-cavity drift-tube linac (CCDTL). We describe the new design and simulation features associated with these linac structures and improvements to the code that facilitate a seamless linac design process.