10.35 FMULT—Multipole kick element with coefficient input from an SDDS file.

Multipole kick element with coefficient input from an SDDS file.
Parallel capable? : yes
GPU capable? : no
Back-tracking capable? : no

Parameter Name UnitsType Default


L M double 0.0


TILT RADdouble 0.0

rotation about longitudinal axis

DX M double 0.0


DY M double 0.0


DZ M double 0.0


FSE double 0.0

fractional strength error

FACTOR double 1

factor by which to multiply multipole strengths

N_KICKS long 0

Deprecated. Use N_SLICES.

N_SLICES long 1

Number of slices (full integrator steps).

SYNCH_RAD short 0

include classical, single-particle synchrotron radiation?


name of file containing multipole data

SQRT_ORDER short 0

Ignored, kept for backward compatibility only.


If nonzero, TILT is ignored for purposes of matrix computation.


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

This element simulates a multipole element using a 4th-order sympletic integration. Specification of the multipole strength is through an SDDS file. The file is expected to contain a single page of data with the following elements:

  1. An integer column named order giving the order of the multipole. The order is defined as (Npoles - 2)2, so a quadrupole has order 1, a sextupole has order 2, and so on.
  2. A floating point column named KnL giving the integrated strength of the multipole, KnL, where n is the order. The units are 1∕mn.
  3. A floating point column named JnL giving the integrated strength of the skew multipole, JnL, where n is the order. The units are 1∕mn.

The MULT element is also available, which allows the same functionality without an external file, for a single component.

The transport matrix for FMULT elements is determined by tracking and will affect the tunes, chromaticities, etc. However, in some cases if TILT is nonzero, it may happen that the phase advance jumps by nearly 2π; this anomaly can be suppressed by setting UNTILTED_MATRIX to a nonzero value.