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moments_output

&moments_output
    STRING filename = NULL;
    long output_at_each_step = 0;
    long output_before_tune_correction = 0;
    long final_values_only = 0;
    long verbosity = 0;
    long matched = 1;
    long equilibrium = 1;
    long radiation = 1;
    long n_slices = 10;
    double emit_x = 0;
    double beta_x = 0;
    double alpha_x = 0;
    double eta_x = 0;
    double etap_x = 0;
    double emit_y = 0;
    double beta_y = 0;
    double alpha_y = 0;
    double eta_y = 0;
    double etap_y = 0;
    double emit_z = 0;
    double beta_z = 0;
    double alpha_z = 0;
&end

This command performs several functions. In the most basic form, it propagates beam moments, i.e., the 6x6 sigma matrix, from the beginning to the end of a transport line, including coupling from rotated elements or offset sextupoles. This can be performed with or without synchrotron radiation effects in dipoles, quadrupoles, and sextupoles. These computations include the evolution of the trajectory due to errors and (if included) synchrotron radiation.

If desired, the command will instead compute the periodic beam moments. In this case, the user must include an appropriate rf cavity in the lattice in order to get valid results. (By ``appropriate rf cavity'' we mean that it must have the right voltage, frequency, and phase to support stored beam.) It is also suggested that the user compute the closed orbit using closed_orbit so that the computations are performed on the closed orbit.

The results of moments computation may be subjected to optimization using values at marker elements. See the documentation for MARK for more details.


next up previous
Next: momentum_aperture Up: Namelist Command Dictionary Previous: modulate_elements
Robert Soliday 2014-06-26