usage:
inputFile is a text file containing a series of namelist commands specifying the parameters of a
quadrupole or sextupole, the type and amplitude of the errors to include, and the filenames for
output. Each namelist command results in a complete computation and generation of output
files.
The namelist command is perturbations. It has the following fields:
- type — A string value, either “quadrupole” (default) or “sextupole”.
- name — An optional string value giving the name of the element. This is used in preparing
data for elegant.
- SDDS_output — An required string value giving the name of an SDDS file to which
data for each seed will be written. This file can be used to compute statistics or perform
histograms.
- elegant_output — An optional string value giving the name of a text file to which
elegant commands and element definitions will be written. Note that this file is a
mixture of commands and element definitions. As such, the user must manually edit the
file and place the appropriate parts in the lattice file and the command file.
- kmult_output — An optional string value giving the name of an SDDS file to which
data will be written in the format accepted by the RANDOM_MULTIPOLES feature of the
KQUAD and KSEXT elements. This is the recommended data to use with elegant.
- effective_length — The effective length of the magnet, in meters.
- bore_radius — The bore radius of the magnet, in meters.
- reference_radius — The reference radius for the multipole output, in meters.
- dx_pole — The rms error, in meters, to be imparted to the horizontal position of each
pole.
- dy_pole — The rms error, in meters, to be imparted to the vertical position of each
pole.
- dradius — The rms error, in meters, in the bore radius.
- dx_split — The rms error, in meters, to be imparted to the horizontal distance between
the left and right sides of the magnet.
- dy_split — The rms error, in meters, to be imparted to the vertical distance between
the top and bottom halves of the magnet.
- dphi_halves — The rms error, in radians, to be imparted to the relative rotation of the
top and bottom halves of the magnet.
- n_cases — The number of cases to simulate (default is 1000).
- n_harm — The number of harmonics to simulate. The default is 0, which results in
computing all the harmonics for which Halbach indicates his treatment applies.
- random_number_seed — The initial seed for the random number generator. Should be
a large integer.
- long suppress_main_error — If non-zero, harmonics for the main multipole and
lower orders are suppressed. It is implicitly assumed that these are correctable through
alignment and calibration.