/******************************************************************************* * McStas instrument definition URL=http://mcstas.risoe.dk * * Instrument: ILL_H22_D1B_noenv * * %Identification * Written by: FARHI Emmanuel (farhi@ill.fr) and SANCHEZ Javier (sanchez-montero@ill.fr) * Date: June, 2008 * Origin:ILL * %INSTRUMENT_SITE: ILL * * The D1B diffractometer on the H22 curved thermal guide at the ILL * * %Description * The D1B diffractometer on the H22 curved thermal guide at the ILL. * * D1B is a two-axis spectrometer dedicated to diffraction experiments requesting a * high neutron flux. A great number of experiments performed on D1B concern the * determination of magnetic structures. At small angles where the magnetic peaks * are expected, a high spatial resolution can be achieved, the FWHM reaches 0.2° * (for a sample with = 8 mm). Three pyrolitic graphite monochromators focusing * onto the sample position provide a flux of 6.5·106 n cm-2s-1. A second * wavelength with = 1.28 Å is available by using a germanium monochromator. D1B is * equipped with 3He/Xe position-sensitive detector composed of a system of * multi-electrodes with 400 cells, which span a 2 range of 80°. The detector can * be moved so that an angular range of 2°<2<130° can be covered. The specially * designed cryostat is known for its low background crucial for some experiments * with small intensity changes. Because of its high flux at = 2.52 Å together with * the large multi-detector, surface studies such as adsorbed phases as well as * real-time diffraction experiments are possible. Collecting a diffraction pattern * with sufficient statistics in minutes (1-5 min) even seconds allows in situ * studies of reaction kinetics. A fast detection of phase transitions can also be * obtained by scanning the temperature. A complete thermal variation of the * diffraction patterns (1.5 - 300 K) can be achieved in few hours (3-5h). * * %Example: lambda=2.52 Detector: D1B_BananaTheta_I=5415.58 * * %Parameters: * lambda: [AA] mean incident wavelength. * dlambda: [AA] wavelength full width. * RV: [m] Monochromator vertical curvature, 0 for flat, -1 for automatic setting * L1: [m] Source-Monochromator distance * L2: [m] Monochromator-Sample distance * L3: [m] Sample-Detector distance * Powder: [str] File name for powder description, LAZ/LAU/Fullprof * verbose: [1] Print DIF configuration. 0 to be quiet * R_pitch: [deg] Angular pitch between the absorbing blades * R_ri: [m] Inner radius of the collimator * R_ro: [m] Outer radius of the collimator * R_h: [m] Height of the collimator * R_ttmin: [deg] Lower scattering angle limit * R_ttmax: [deg] Higher scattering angle limit * R_present: [1] Presence flag for the radial collimator. 0: inactivate component. * Inc_Cryo: [1] Cryostat incoherent fraction * Trans_Cryo: [1] Cryostat event transmission * Trans_Spl: [1] Sample event transmission * Inc_Spl: [1] Sample incoherent fraction * TILT: [deg] Monochromator additional tilt, for rocking curves * TRAS_X: [m] Additional monochromator translation along X, left/righ w.r.t beam * TRAS_Z: [m] Additional monochromator translation along Z, along guide * DM: [AA] Mono lattice spacing * THETA_M: [deg] Mono takeoff angle * * %End *******************************************************************************/ DEFINE INSTRUMENT ILL_H22_D1B_noenv(lambda=2.52, dlambda=0.03, DM=0, string Powder="Na2Ca3Al2F14.laz", RV=2.2, L1=0.25, L2=3.0, L3=1.500, TRAS_X=-0, TRAS_Z=0, TILT=0, THETA_M=22.11, R_pitch=.42, R_ri=0.324, R_ro=0.419, R_h=0.090, R_ttmin=-130, R_ttmax=-2, R_present=1, verbose=1, Inc_Cryo=0.02, Trans_Cryo=0.85, Trans_Spl=0.2, Inc_Spl=0.05) /* The DECLARE section allows us to declare variables or small */ /* functions in C syntax. These may be used in the whole instrument. */ DECLARE %{ %} USERVARS %{ /* flags to separate scattering processes */ double flag_sample; double flag_env; %} /* The INITIALIZE section is executed when the simulation starts */ /* (C code). You may use them as component parameter values. */ INITIALIZE %{ /* transfert instrument parameters for components */ double KI, Vi, EI; if (!THETA_M && lambda && DM) THETA_M =asin(lambda/(2*DM))*RAD2DEG; else if (THETA_M && !lambda && DM) lambda = fabs(sin(THETA_M*DEG2RAD))*2*DM; else if (THETA_M && lambda) DM = fabs(lambda/sin(DEG2RAD*THETA_M)/2.0); /* test input parameters */ if (!THETA_M || !DM || !lambda) exit(fprintf(stderr, "%s: ERROR: Monochromator take-off, d-spacing or wavelength is null (THETA_M=%g, DM=%g, lambda=%g). Abort.\n", NAME_INSTRUMENT, THETA_M, DM, lambda)); if (RV < 0) RV=2*L2*sin(DEG2RAD*THETA_M); KI = 2*PI/lambda; Vi = K2V*fabs(KI); EI = VS2E*Vi*Vi; if (verbose) { printf("%s: Detailed D1B configuration\n", NAME_INSTRUMENT); printf("* Incoming beam: lambda=%.4g [Angs] EI=%.4g [meV] KI=%.4g [Angs-1] Vi=%g [m/s]\n", lambda, EI, KI, Vi); printf("* Monochromator: DM=%.4g [Angs] RV=%.4g [m] %s, take-off THETA_M=%.4g [deg]\n", DM, RV, (!RV ? "flat" : "curved"), THETA_M); printf("* Sample: '%s' in Al cryostat.\n", Powder); } %} /* Here comes the TRACE section, where the actual */ /* instrument is defined as a sequence of components. */ TRACE %include "ILL/ILL_H22/ILL_H22.instr" /* additional horizontal divergence monitor at end of guide */ /* also defines a static position to orient remaining instrument */ COMPONENT D2B_Mono_Dx = Monitor_nD( xwidth=0.03, yheight=0.2, restore_neutron=1, options="dx, all auto, per cm2, slit", restore_neutron=1) AT (0, 0, L1) RELATIVE PREVIOUS EXTEND %{ flag_env=0; flag_sample=0; %} /* TIP: monochromator cradle */ SPLIT COMPONENT mono_cradle = Arm() AT (TRAS_X, 0, TRAS_Z) RELATIVE D2B_Mono_Dx /* TIP: curved monochromator with NH>1 NV>1 et RH>0 RV>0 */ COMPONENT Monok = Monochromator_curved( width = 0.060, height = 0.15, NH = 1, NV = 3, RV=RV, mosaich = 20, mosaicv = 20, DM = DM) AT (0, 0, 0) RELATIVE mono_cradle ROTATED (0, THETA_M+TILT, 0) RELATIVE mono_cradle /* TIP: positioning diffraction direction for monok (order 1) */ COMPONENT mono_out = Arm() AT (0, 0, 0) RELATIVE D2B_Mono_Dx ROTATED (0, 2*THETA_M, 0) RELATIVE D2B_Mono_Dx /* Monitor a la altura del shutter */ COMPONENT D1B_monitor_shutter = Monitor_nD( options="x y", bins=50, xwidth = 0.030, yheight = 0.20) AT (0,0,0.75) RELATIVE mono_out /* filtro de grafito -ocupa toda la linea- */ COMPONENT filtro_D1B = Filter_graphite( xmin=-0.05, xmax=0.05, ymin=-.10, ymax=.10, length=0.20) AT (0,0,0.75) RELATIVE mono_out /* Linea propia de D1B, desde el monocromador hasta Slits*/ /* distancia desde el monocromador ancho alto */ /*slit_fijo 985.5 50 118 */ /*Ventana_1 1176 50 112 */ /*Ventana_2 1436 50 112 */ /*Ventana_3 1753 50 112 */ /* slit fija */ COMPONENT slit_fija = Slit( xmin = -0.025, xmax = 0.025, ymin = -0.059, ymax = 0.059) AT (0, 0, 0.9855) RELATIVE mono_out /* ventana 1 */ COMPONENT ventana_1 = Slit( xmin = -0.025, xmax = 0.025, ymin = -0.056, ymax = 0.056) AT (0, 0, 1.176) RELATIVE mono_out /* ventana 2 */ COMPONENT ventana_2 = Slit( xmin = -0.025, xmax = 0.025, ymin = -0.056, ymax = 0.056) AT (0, 0, 1.436) RELATIVE mono_out /* ventana 3 */ COMPONENT ventana_3 = Slit( xmin = -0.025, xmax = 0.025, ymin = -0.056, ymax = 0.056) AT (0, 0, 1.753) RELATIVE mono_out /* Monitor de control que coincide con las cuentas de monitor del D1B. Se ha introducido el comando SPLIT en los dos siguientes */ COMPONENT monitor_D1B = Monitor_nD( options="auto lambda", bins=50, xwidth = 0.100, yheight = 0.100) AT (0, 0, 2.478) RELATIVE mono_out COMPONENT PSD_D1B = Monitor_nD( options="x y", bins=50, xwidth = 0.100, yheight = 0.100) AT (0, 0, 2.478) RELATIVE mono_out /* Slits ... Valores anteriores ~ xmin=-0.020, xmax=0.020, */ SPLIT COMPONENT slit_D1B = Slit( xmin=-0.010, xmax=0.010, ymin = -0.015, ymax = 0.015) AT (0, 0, 2.5) RELATIVE mono_out EXTEND %{ flag_sample=flag_env=0; %} /* Definicion del entorno. */ /* Se fuerza que la difraccion se concentre en el detector, para aumentar la eficiencia. */ /* COMPONENT Cryo_1 = PowderN(reflections="Al.laz", */ /* radius = 0.061, thickness = 0.001, yheight = 0.10, */ /* concentric = 1, d_phi=RAD2DEG*atan(R_h/L3), */ /* p_inc=Inc_Cryo, p_transmit=Trans_Cryo) */ /* AT (0,0,L2) RELATIVE mono_out */ /* EXTEND */ /* %{ */ /* flag_env+=SCATTERED; */ /* %} */ /* COMPONENT Cryo_2 = COPY(Cryo_1)(radius = 0.0545, thickness = 0.001) */ /* AT (0,0,L2) RELATIVE mono_out */ /* EXTEND */ /* %{ */ /* flag_env+=SCATTERED; */ /* %} */ /* COMPONENT Cryo_3 = COPY(Cryo_1)(radius = 0.039, thickness = 0.001) */ /* AT (0,0,L2) RELATIVE mono_out */ /* EXTEND */ /* %{ */ /* flag_env+=SCATTERED; */ /* %} */ /* COMPONENT Cryo_4 = COPY(Cryo_1)(radius = 0.036, thickness = 0.001) */ /* AT (0,0,L2) RELATIVE mono_out */ /* EXTEND */ /* %{ */ /* flag_env+=SCATTERED; */ /* %} */ COMPONENT Sample = PowderN( reflections = Powder, radius = 0.0030, p_transmit=Trans_Spl, p_inc=Inc_Spl, yheight = 0.040, d_phi=RAD2DEG*atan(R_h/L3)) AT (0, 0, L2) RELATIVE mono_out EXTEND %{ flag_sample=SCATTERED; %} /* COMPONENT COPY(Cryo_4)=COPY(Cryo_4)(concentric = 0) */ /* AT (0,0,L2) RELATIVE mono_out */ /* EXTEND */ /* %{ */ /* flag_env+=SCATTERED; */ /* %} */ /* COMPONENT COPY(Cryo_3)=COPY(Cryo_3)(concentric = 0) */ /* AT (0,0,L2) RELATIVE mono_out */ /* EXTEND */ /* %{ */ /* flag_env+=SCATTERED; */ /* %} */ /* COMPONENT COPY(Cryo_2)=COPY(Cryo_2)(concentric = 0) */ /* AT (0,0,L2) RELATIVE mono_out */ /* EXTEND */ /* %{ */ /* flag_env+=SCATTERED; */ /* %} */ /* COMPONENT COPY(Cryo_1)=COPY(Cryo_1)(concentric = 0) */ /* AT (0,0,L2) RELATIVE mono_out */ /* EXTEND */ /* %{ */ /* flag_env+=SCATTERED; */ /* if (!flag_sample && !flag_env) ABSORB; /\* TIP: perfect beamstop *\/ */ /* %} */ /* se introduce el Collimator radial, he introducido el comando ROC */ /* http://www.mcstas.org/download/components/contrib/Collimator_ROC.comp */ /* ROC_pitch: [deg] Angular pitch between the absorbing blades (1) */ /* ROC_ri: [m] Inner radius of the collimator (0.4) */ /* ROC_ro: [m] Outer radius of the collimator (1.2) */ /* ROC_h: [m] Height of the collimator (0.153) */ /* ROC_ttmin: [deg] Lower scattering angle limit (0) */ /* ROC_ttmax: [deg] Higher scattering angle limit(100) */ /* ROC_sign: [1] Chirality/takeoff sign (1) */ /* ROC_present:[1] Presence flag of this component (1) */ COMPONENT collimador_radial = Exact_radial_coll( nslit=ceil(128/R_pitch), radius=R_ri, length=R_ro-R_ri, h_in=R_h, h_out=R_h, theta_min=R_ttmin, theta_max=R_ttmax, verbose=1) WHEN (R_present) AT (0, 0, 0) RELATIVE Sample /* perfect detector: 1D(theta). Se ha modificado los limites. Originalm ~ [-4 -130]*/ COMPONENT D1B_BananaTheta = Monitor_nD( options = "banana, theta limits=[-130 -2], bins=1280", xwidth = L3*2, yheight = R_h, restore_neutron=1) AT (0, 0, 0) RELATIVE Sample COMPONENT D1B_BananaTheta_Sample = Monitor_nD( options = "banana, theta limits=[-130 -2], bins=1280", xwidth = L3*2, yheight = R_h) WHEN (flag_sample) AT (0, 0, 0) RELATIVE Sample /* perfect detector: 2D(theta,y) to see diffraction rings. Originalmente: y bins=25 */ /* COMPONENT BananaPSD = Monitor_nD( */ /* options = "banana, theta limits=[-130 -2] bins=1280, y bins=150", */ /* xwidth = L3*2*1.005, yheight = 0.3) */ /* AT (0, 0, 0) RELATIVE Sample*/ END