7.22 elastic_scattering
- type: major action command
- function: perform simulation of elastic scattering at multiple s locations, for use in computing
elastic gas scattering lifetime and loss distribution
- sequence: must follow run_control.
- Command syntax, including use of equations and subcommands, is discussed in 7.2.
- notes:
- Only available in Pelegant.
- Data may be postprocessed with the command elasticScatteringAnalysis.
&elastic_scattering
STRING losses = NULL;
STRING output = NULL;
STRING log_file = NULL;
double theta_min = 0.001;
double theta_max = 0.010;
long n_theta = 11;
long n_phi = 37;
long twiss_scaling = 0;
double s_start = 0;
double s_end = DBL_MAX;
STRING include_name_pattern = NULL;
STRING include_type_pattern = NULL;
long verbosity = 1;
&end
- losses — The (incomplete) name of an SDDS file to which the record of initial scattering
location, initial scattering angle, and loss coordinates will be written.
- output — The (incomplete) name of an SDDS file to which the final coordinates of all
surviving particles will be written.
- log_file — The (incomplete) name of an SDDS file to which statistical data will be written
as the simulations run. Users should check the MinParticles and MaxParticles columns
as the simulation runs to ensure reasonable load balance (e.g., within 10-20%). If balance
is poor, consider changing the values of n_phi and n_theta slightly. The product of these
values should not evenly divide the number of working cores (which is one less than the total
number of cores).
- theta_min — Minimum polar scattering angle in radians. Should be small enough that
no particle scattered by this angle are lost, regardless of the scattering location. See also
twiss_scaling.
- theta_max — Maximum polar scattering angle in radians. Should be large enough that no
particle scattered by this angle survives, regardless of scattering location.
- n_theta — Number of polar scattering angle values on the range theta_min to theta_max.
- n_phi — Number of azimuthal scattering angles on the range [0,π].
- twiss_scaling — If nonzero, then theta_min is scaled
by min(,), where s is the location of the scattering location and
s = 0 is the start of the lattice.
- s_start, s_end — Range of s location for simulated scattering sites.
- include_name_pattern — Wildcard-containing string to match to element names in selecting
scattering sites.
- include_type_pattern — Wildcard-containing string to match to element types in selecting
scattering sites.
- verbosity — Higher values may result in more verbose informational output.