/*********************************************************************** * * McStas, neutron ray-tracing package * Copyright 1997-2002, All rights reserved * Risoe National Laboratory, Roskilde, Denmark * Institut Laue Langevin, Grenoble, France * * Component: Filter_gen * %I * Written by: E. Farhi * Date: Dec, 15th, 2002 * Version: $Revision$ * Origin: ILL * Release: McStas 1.6 * * This components may either set the flux or change it (filter-like), using * an external data filename. * * %D * This 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. * *%P * 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 * 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. * thickness: [1] relative thickness. D = D^(thickness). * scaling: [1] scaling factor. D = D*scaling. * xmin: [m] dimension of filter * xmax: [m] dimension of filter * ymin: [m] dimension of filter * ymax: [m] dimension of filter * xwidth: [m] Width/diameter of filter). Overrides xmin,xmax. * yheight: [m] Height of filter. Overrides ymin,ymax. * verbose: [1] Flag to select verbose output. * * %L * HOPG.trm filename as an example. *%E ***********************************************************************/ DEFINE COMPONENT Filter_gen DEFINITION PARAMETERS () SETTING PARAMETERS (string filename=0, string options=0, xmin=-0.05, xmax=0.05, ymin=-0.05, ymax=0.05, xwidth=0, yheight=0, thickness=1, scaling=1, verbose=0) OUTPUT PARAMETERS () /* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */ SHARE %{ #ifndef FILTER_GEN #define FILTER_GEN $Revision$ #define UNKNOWN_TABLE 0 #define ENERGY_TABLE 1 #define WAVEVECTOR_TABLE 2 #define WAVELENGTH_TABLE 3 #define FLUX_ADAPT_SET 0 #define FLUX_ADAPT_MULT 1 #define FLUX_ADAPT_ADD 2 char FilterGen_Mode(char *str, char *Mode, char *Type, double *verbose) { long i; char *c; if (!str || !strlen(str)) return(0); c = malloc(strlen(str)); for (i=0; i 0) { xmax = xwidth/2; xmin = -xmax; } if (yheight > 0) { ymax = yheight/2; ymin = -ymax; } FilterGen_Mode(options, &Mode_Table, &Type_Table, &verbose); if (filename != NULL && strlen(filename) && strcmp(filename,"NULL") && strcmp(filename,"0")) { if (Table_Read(&pTable, filename, 1) <= 0) /* read 1st block data from filename into pTable */ exit(fprintf(stderr,"Filter_gen: %s: can not read filename %s\n", NAME_CURRENT_COMP, filename)); Table_Rebin(&pTable); /* rebin as evenly, increasing array */ if (pTable.rows < 2 || !pTable.step_x) { Table_Free(&pTable); } if (pTable.data) { FilterGen_Mode(pTable.header, &Mode_Table, &Type_Table, &verbose); if (verbose) { Table_Info(pTable); printf("Filter_gen: %s: Filter data [", NAME_CURRENT_COMP); if (Type_Table == ENERGY_TABLE) printf("Energy"); if (Type_Table == WAVEVECTOR_TABLE) printf("Wavevector"); if (Type_Table == WAVELENGTH_TABLE) printf("Wavelength"); if (Type_Table == UNKNOWN_TABLE) printf("UNKNOWN (not used)"); printf(", Flux] in "); if (Mode_Table == FLUX_ADAPT_MULT) printf("multiply"); else if (Mode_Table == FLUX_ADAPT_ADD) printf("add"); else printf("set"); printf(" mode\n"); } } else fprintf(stderr,"Filter_gen: %s: file %s contains no data.\n", NAME_CURRENT_COMP, filename); } else pTable.data = NULL; %} TRACE %{ double v2, K, L, E, X, new_p; PROP_Z0; if (Type_Table && (x>xmin && xymin && y