Accelerator and Element Description

As mentioned in the introduction, elegant uses a variant of the MAD input format for describing accelerators. With some exceptions, the accelerator description for one program can be read by the other with no modification. Among the differences:

• elegant does not support the use of MAD-style equations to compute the value of a quantity. The link_element namelist command can be used for this purpose, and is actually more flexible than the method used by MAD. Also, rpn-style equations may be given in double-quotes; these are evaluated once only when the lattice is parsed.
• elegant does not support substitution of parameters in beamline definitions.
• elegant contains many elements that MAD does not have, such as kick elements, wake fields, and numerically integrated elements.
• The length of an input line is not limited to 80 characters in elegant, as it is in MAD. However, for compatibility, any lattice created by elegant will conform to this limit.

elegant's print_dictionary command allows the user to obtain a list of names and short descriptions of all accelerator elements recognized by the program, along with the names, units, types, and default values of all parameters of each element. The present output of this command is listed in the next section. The reader is referred to the MAD manual[2] for details on sign conventions for angles, focusing strength, and so forth.