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FTABLE

Tracks through a magnetic field which is expressed by a SDDS table.
Parallel capable? : yes
Parameter Name Units Type Default Description
L $M$ double 0.0 The effective field length measured along a straight line.
ANGLE $RAD$ double 0.0 The designed bending angle
L1 $M$ double 0.0 The left fringe field length.
L2 $M$ double 0.0 The right fringe field length. L1+L+L2=Total z span in the input field table.
E1 $RAD$ double 0.0 The designed entrance edge angle
E2 $RAD$ double 0.0 The designed exit edge angle
TILT $RAD$ double 0.0 rotation about incoming longitudinal axis
DX $M$ double 0.0 misalignment
DY $M$ double 0.0 misalignment
DZ $M$ double 0.0 misalignment
INPUT_FILE   STRING NULL Name of SDDS file which contains field data.
N_KICKS   long 1 Number of kicks into which to split the element.
VERBOSE   long 0 Used for debugging code. Not applicable to Pelegant
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





This element is used for tracking through an arbitrary magnetic field when its values are known at regularly spaced grid points and it is hard to find a suitable model to describe it. The input magnet parameter and coordinate system definition are illustrated in Fig:1. The field data is saved in a 3 pages ($B_x$, $B_y$, $B_z$) 3D histogram SDDS table (see MHISTOGRAM for detail). An example is shown in Fig:2. This SDDS file must have one column Frequency to store the field data in Tesla, and following parameters:

Figure 1: Illustration of coordinate system and magnet definition.
\includegraphics[width=3in,height=2.5in]{ftable-fig1.eps}

Figure 2: Example of SDDS input file. The column x_index, y_index, z_index is not the necessary part, it's shown here just for clarifying how the data is arranged
\includegraphics[width=6.5in,height=5.5in]{ftable-fig2.eps}

next up previous
Next: FTRFMODE Up: Element Dictionary Previous: FRFMODE
Robert Soliday 2014-06-26