MAD-X/PTC lattice design for DAPHNE at Frascati

In absence of a program that takes as an input the desired or known location of the magnets in the tunnel, accelerator designers have been using MAD that looks at a ring as a sequence of magnets without a connection to the tunnel. In many simple examples that is just fine, but once more complicated structures are treated one is bound to play tricks with MAD. Here PTC comes to the rescue. It is shown how pieces of this machine that exist in MADX format are used in PTC to create this double ring, as found on the accelerator floor, with a proper survey in the forward and backward direction. Special elements have been implemented in MAD-X to allow the full PTC description of the machine.