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
- 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.
- 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.