10.57 MARK—A marker, equivalent to a zero-length drift space.

A marker, equivalent to a zero-length drift space.
Parallel capable? : yes
GPU capable? : no
Back-tracking capable? : yes

Parameter NameUnitsType Default


DX M double0.0

non-functional misalignment (e.g., for girder)

DY M double0.0

non-functional misalignment (e.g., for girder)

FITPOINT short 0

Supply local values of Twiss parameters, moments, floor coordinates, matrices, etc. for optimization?


Optionally used to assign an element to a group, with a user-defined name. Group names will appear in the parameter output file in the column ElementGroup

If FITPOINT=0, this element results only in generation of additional output rows in the various files that contain output vs s. For example, Twiss parameters, closed orbits, and matrices vs s will all contain a row for each occurrence of each marker element.

If FITPOINT=1, the element has additional functionality in the context of optimizations. In particular, for occurrence N of the defined element Element, a series of symbols are created of the form Element#N.quantity, where quantity has the following values:

The misalignment controls for this element are non-functional, in the sense that they do not affect the beam. However, when combined with external scripts and the GROUP parameter, one can use this feature to implement girder misalignments using pairs of markers to indicate the ends of the girders. A future version of elegant will implement this internally.