SIXTRACK Convertor

EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH

SixTrack: Produce input files for tracking in SixTrack

In dynamic aperture studies [SixTrack] is often used because of its speed and controllability. However the input files are notoriously difficult to produce by hand. This command may be used to produce SixTrack files from a sequence in MAD-X's memory.

N.B.: The files contain all information concerning optics, field errors and misalignments. Hence these should all be set and a

TWISS,SAVE;

command should always be issued beforehand.

The generation of the SixTrack input files is then done by the command:

SIXTRACK, CAVALL,
          MULT_AUTO_OFF,
          MAX_MULT_ORD,
          SPLIT,
	  APERTURE,
          RADIUS = ref. radius of magnets;

The parameters are defined as:

CAVALL - (optional flag) This puts a cavity element (SixTrack identifier 12) with Volt, Harmonic Number and Lag attributes at each location in the machine. Since for large hadron machines the cavities are typically all located at one particular spot in the machine and since many cavities slow down the tracking simulations considerably all cavities are lumped into one and located at the first appearance of a cavity. This default is enforced by omitting this flag.
MULT_AUTO_OFF - (optional flag, default = .FALSE.) If .TRUE. this module does not process zero value multipoles. Moreover, multipoles are prepared in SixTrack (file fc.3) to be treated up to the order as specified with MAX_MULT_ORD.
MAX_MULT_ORD - (optional parameter, default = 11) Process up to this order for mult_auto_off = .TRUE..
SPLIT - (optional flag) OBSOLETE. This splits all the elements in two. This is for backwards compatibilty only. The user should now use the MAKETHIN command instead.
APERTURE - (optional flag) Set this to convert the apertures from MAD-X to SixTrack, so SixTrack will track with aperture.
RADIUS - (optional, default value is 1m). This sets the reference radius for the magnets. This argument is optional but should normally be set.
Note: the bv flag is presently ignored
WARNING: SixTrack and c6t are presently set up for names of a maximum of 16 characters!!!!! Therefore, it is mandatory to respect this limit for MAD-X names.

The command will then always produce the following file:

fc.2 - contains the basic structure of the lattice.

and may produce any or all of the following files, depending on the sequence:

fc.3 - contains the multipole mask(s).
fc.3.aux - contains various beam parameters.
fc.8 - contains the misalignments and tilts.
fc.16 - contains the field errors and/or combined multipole kicks.
fc.34 - file with various optics parameters at various locations (not needed by SixTrack but may be used as input to [SODD].)

For a full description of these files see [SixTrack] and for information on running SixTrack see [Run Environment].

Mark Hayes 20.06.02