Parallel capable? : yes

Parameter Name | Units | Type | Default | Description |

INPUTFILE | STRING | NULL | name of file giving Green functions | |

TCOLUMN | STRING | NULL | column in INPUTFILE containing time data | |

WXCOLUMN | STRING | NULL | column in INPUTFILE containing x Green function | |

WYCOLUMN | STRING | NULL | column in INPUTFILE containing y Green function | |

CHARGE | double | 0.0 | beam charge (or use CHARGE element) | |

FACTOR | double | 1 | factor by which to multiply both wakes | |

XFACTOR | double | 1 | factor by which to multiply x wake | |

YFACTOR | double | 1 | factor by which to multiply y wake | |

N_BINS | long | 128 | number of bins for current histogram | |

INTERPOLATE | long | `0` |
interpolate wake? | |

SMOOTHING | long | `0` |
Use Savitzky-Golay filter to smooth current histogram? | |

SG_HALFWIDTH | long | 4 | Savitzky-Golay filter half-width for smoothing | |

SG_ORDER | long | 1 | Savitzky-Golay filter order for smoothing | |

DX | double | 0.0 | misalignment | |

DY | double | 0.0 | misalignment | |

TILT | double | 0.0 | rotation about longitudinal axis | |

X_DRIVE_EXPONENT | long | 1 | Exponent applied to x coordinates of drive particles | |

Y_DRIVE_EXPONENT | long | 1 | Exponent applied to y coordinates of drive particles | |

X_PROBE_EXPONENT | long | `0` |
Exponent applied to x coordinates of probe particles | |

Y_PROBE_EXPONENT | long | `0` |
Exponent applied to y coordinates of probe particles |

Transverse wake specified as a function of time lag behind the particle.

Parameter Name | Units | Type | Default | Description |

RAMP_PASSES | long | `0` |
Number of passes over which to linearly ramp up the wake to full strength. | |

BUNCHED_BEAM_MODE | long | 1 | If non-zero, then do calculations bunch-by-bunch. | |

GROUP | string | NULL | 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 |

The input file for this element gives the transverse-wake Green
functions, and , versus time behind the particle. The
units of the wakes are V/C/m, so this element simulates the integrated
wake of some structure (e.g., a cell or series of cells). If you
have, for example, the wake for a cell and you need the wake for N
cells, then you may use the `FACTOR` parameter to make the
appropriate multiplication. The values of the time coordinate should
begin at 0 and be equi-spaced. A positive value of time represents
the distance behind the exciting particle. Time values must be equally
spaced.

The sign convention for ( being or ) is as follows: a particle with will impart a positive kick ( ) to a trailing particle following seconds behind if . A physical wake function should be zero at and also be initially positive as increases from 0.

Use of the `CHARGE` parameter on the `TRWAKE` element is
disparaged. It is preferred to use the `CHARGE` element as part
of your beamline to define the charge.

Setting the `N_BINS` paramater to 0 is recommended. This results
in auto-scaling of the number of bins to accomodate the beam. The bin
size is fixed by the spacing of the time points in the wake.

The default degree of smoothing (`SG_HALFWIDTH=4`) may be excessive.
It is suggested that users vary this parameter to verify that results
are reliable if smoothing is employed (`SMOOTHING=1`).

The `XFACTOR` and `YFACTOR` parameters can be used to adjust
the strength of the wakes if the location at which you place the `TRWAKE` element has different beta functions than the location at
which the object that causes the wake actually resides.

The `X_DRIVE_EXPONENT` and `Y_DRIVE_EXPONENT` parameters can be used to change the
dependence of the wake on the x and y coordinates, respectively, of the particles.
Normally, these have the value 1, which corresponds to
an ordinary dipole wake in a symmetric chamber.

If you have an asymmetric chamber, then you will have a transverse
wake kick even if the beam is centered. (Of course, you'll need a 3-D
wake code like GdfidL or MAFIA to compute this wake.) This part of
the transverse wake is modeled by setting `X_DRIVE_EXPONENT=0` and `Y_DRIVE_EXPONENT=0`. It will result in an orbit distortion, but conceivably
could have other effects, such as emittance dilution. In this case,
the units for the x and y wake must be . A negative value of the wake
corresponds to a kick toward negative x (or y).

In addition, a quadrupole wake can be modeled by setting `X_DRIVE_EXPONENT=0`, `Y_DRIVE_EXPONENT=0`, `X_PROBE_EXPONENT=1`, and `Y_PROBE_EXPONENT=1`.
The kick to a particle now depends on *it's* displacement, not on the displacement of
the leading particles.
In this case, the units for the wakes must be .

Bunched-mode application of the short-range wake is possible using specially-prepared input
beams.
See Section 6 for details.
The use of bunched mode for any particular `TRWAKE`

element is controlled using the `BUNCHED_BEAM_MODE`

parameter