[ Identification | Description | Input parameters | Links ]
Filter_gen ComponentThis component changes the neutron flux (weight) in order to match a reference table in a filename. Typically you may set the neutron flux (source-like), or multiply it using a transmission table (filter-like). The component may be placed after a source, in order to e.g. simulate a real source from a reference table, or used as a filter (BeO) or as a window (Al). The behaviour of the component is specified using the 'options' parameter, or from the filename itself (see below) If the thickness for the transmission data filename D was t0, and a different thickness t1 would be required, then the resulting transmission is: D^(t1/t0). You may use the 'thickness' and 'scaling' parameter for that purpose. File format: This filename may be of any 2-columns free format (k[Angs-1],p), (omega[meV],p) and (lambda[Angs],p) where p is the weight. The type of the filename may be written explicitely in the filename, as a comment, or using the 'options' parameter. Non mumerical content in filename is treated as comment (e.g. lines starting with '#' character). A table rebinning and linear interpolation are performed. EXAMPLE : in order to simulate a PG filter, using the lib/data/HOPG.trm file Filter_gen(xwidth=.1 yheight=.1, filename="HOPG.trm") A Sapphire filter, using the lib/data/Al2O3_sapphire.trm file Filter_gen(xwidth=.1 yheight=.1, filename="Al2O3_sapphire.trm") A Berylium filter, using the lib/data/Be.trm file Filter_gen(xwidth=.1 yheight=.1, filename="Be.trm") an other possibility to simulate a Be filter is to use the PowderN component: PowderN(xwidth=.1, yheight=.1, zdepth=.1, reflections="Be.laz", p_inc=1e-4) in this filename, the comment line # wavevector multiply sets the behaviour of the component. One may as well have used options="wavevector multiply" in the component instance parameters.
| Name | Unit | Description | Default | |
| filename | str | name of the filename to look at (first two columns data). Data D should rather be sorted (ascending order) and monotonic filename may contain options (see below) as comment | 0 | |
| options | str | string that can contain: "[ k p ]" or "wavevector" for filename type, "[ omega p]" or "energy", "[ lambda p ]" or "wavelength", "set" to set the weight according to the table,"multiply" to multiply (instead of set) the weight by factor,"add" to add to current flux,"verbose" to display additional informations. | 0 | |
| xmin | m | dimension of filter | -0.05 | |
| xmax | m | dimension of filter | 0.05 | |
| ymin | m | dimension of filter | -0.05 | |
| ymax | m | dimension of filter | 0.05 | |
| xwidth | m | Width/diameter of filter). Overrides xmin,xmax. | 0 | |
| yheight | m | Height of filter. Overrides ymin,ymax. | 0 | |
| thickness | 1 | relative thickness. D = D^(thickness). | 1 | |
| scaling | 1 | scaling factor. D = D*scaling. | 1 | |
| verbose | 0 |
| AT ( | , | , | ) RELATIVE | |||
|---|---|---|---|---|---|---|
| ROTATED ( | , | , | ) RELATIVE |
Filter_gen.comp.
[ Identification | Description | Input parameters | Links ]
Generated on 2024-01-03 11:47:43