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willendwillend
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Merge pull request #2360 from mccode-dev/patch-issue-2359
Patch issue 2359 - Al_window absorption/scattering
2 parents 0b57bc4 + 24a97be commit cf6a2db

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Lines changed: 178 additions & 7 deletions

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‎mcstas-comps/contrib/Al_window.comp‎

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@@ -64,6 +64,12 @@ SHARE
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#endif
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%}
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INITIALIZE
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%{
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MPI_MASTER (fprintf (stderr, "Al_window %s WARNING: Using simple lo-fi transmission model.\n - Replace with PowderN or NCrystal for bragg edges etc.\n",
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NAME_CURRENT_COMP););
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%}
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TRACE
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%{
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double v; /* Neutron velocity */
@@ -72,22 +78,26 @@ TRACE
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double Al_s_tot_lambda, Al_my_tot, Al_my_a; /* total XS (barn), total scattering length (m-1), absorption scat. length */
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double lambda; /* neutrons wavelength */
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/* Propagate to entry plane */
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PROP_Z0;
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/* Calculate (linear) time to travel in material */
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dt0 = thickness / vz;
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v = sqrt (vx * vx + vy * vy + vz * vz);
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/* Propagate path through material and calculate distance travelled */
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PROP_DT (dt0);
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dist = v * dt0;
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/* Velocity-corrected attentuation */
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Al_my_a = Al_my_a_v / v;
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/* Crude 4th-order polynomial approximation for scattering cross-section */
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lambda = sqrt (81.81 / (VS2E * v * v));
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Al_s_tot_lambda = Al_pf_A + Al_pf_B1 * lambda + Al_pf_B2 * lambda * lambda + Al_pf_B3 * lambda * lambda * lambda;
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Al_s_tot_lambda += Al_pf_B4 * lambda * lambda * lambda * lambda;
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Al_my_tot = Al_rho / Al_mmol * Al_s_tot_lambda * avogadro * 10;
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Al_my_a = Al_my_a_v / v;
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p *= exp (-Al_my_a * dist); /* neutron passes window without any interaction */
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Al_my_tot = Al_rho / Al_mmol * Al_s_tot_lambda * avogadro;
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/* TODO: scatter in Debye-Scherrer cone */
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/* Weight with cross-section */
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p *= exp (-(Al_my_tot + Al_my_a) * dist); /* neutron passes window without any interaction */
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%}
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MCDISPLAY

‎mcstas-comps/examples/ILL/ILL_H143_LADI/ILL_H143_LADI.instr‎

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* Detector: image plate 1250 x 450 mm2
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* Sample: at 2.710 mm from the end of the guide H143.
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*
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* %Example: -y Detector: ImagePlate_I=855288
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* %Example: -y Detector: ImagePlate_I=959000
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*
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* %Parameters
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* lambda: [Angs] wavelength

‎mcstas-comps/examples/Tests_optics/Test_Al_windows/Test_Al_windows.instr‎

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/*******************************************************************************
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* Instrument: Test_Al_windows
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*
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* %I
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* Written by: Peter Willendrup
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* Date: 20260316
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* Origin: ESS
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* %INSTRUMENT_SITE: Tests_optics
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*
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* Small test instrument for studying Al-window performance
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*
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* %D
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* Test instrument for studying transmission through Al-windows.
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*
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* Includes 3 models of increasing complexity / sophistication:
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* 1) Al_window(),:
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* - simple linear absorption + 4th order scattering model
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* - infinite-plane geometry
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* 2) PowderN()
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* - Material specified from Al.laz input-file
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* - Parametrized for 80% statistics -> transmission
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* 3) NCrystal()
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* - Material specified from local Al as .ncmat format input
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* (generated from CIF file COD / 1502689)
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*
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* %Example: Window=1 thickness=0.001 Detector: OutputWL_I=0.099
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* %Example: Window=2 thickness=0.001 Detector: OutputWL_I=0.099
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* %Example: Window=3 thickness=0.001 Detector: OutputWL_I=0.099
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* %Example: Window=1 thickness=0.005 Detector: OutputWL_I=0.098
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* %Example: Window=2 thickness=0.005 Detector: OutputWL_I=0.098
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* %Example: Window=3 thickness=0.005 Detector: OutputWL_I=0.098
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*
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* %P
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* Window: [1] Choice of Al_Window (1), PowderN (2) or NCrystal (3) model
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* thickness: [m] Thickness of Al window
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* %L
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* <reference/HTML link>
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*
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* %E
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*******************************************************************************/
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DEFINE INSTRUMENT Test_Al_windows(int Window=1, double thickness=0.005)
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DECLARE
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%{
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double u=1e-6; // Small distance, 1um
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%}
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USERVARS
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%{
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%}
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INITIALIZE
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%{
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%}
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TRACE
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COMPONENT origin = Progress_bar()
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AT (0, 0, 0) RELATIVE ABSOLUTE
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COMPONENT Source = Source_simple(
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yheight=0.1,
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xwidth=0.1,
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dist=10,
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focus_xw=0.1,
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focus_yh=0.1,
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lambda0=5,
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dlambda=4.99)
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AT (0, 0, 0) RELATIVE PREVIOUS
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COMPONENT InputPSD = PSD_monitor(
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xwidth=0.11,
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yheight=0.11)
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AT (0, 0, u) RELATIVE Source
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COMPONENT InputWL = L_monitor(
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xwidth=0.11,
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yheight=0.11,
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nL=1000, Lmin=0, Lmax=10)
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AT (0, 0, u) RELATIVE Source
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COMPONENT Slit_in = Slit(
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xwidth=0.1,
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yheight=0.1)
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AT (0, 0, 10) RELATIVE Source
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COMPONENT Al_window = Al_window(
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thickness=thickness)
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WHEN Window==1 AT (0, 0, 10+u) RELATIVE Source
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COMPONENT PowderN = PowderN(xwidth=0.11, yheight=0.11, zdepth=thickness, reflections="Al.laz", p_transmit=0.8, p_inc=0.1, p_interact=0.1)
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WHEN Window==2 AT (0, 0, 10+u) RELATIVE Source
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COMPONENT NCrystal_sample = NCrystal_sample(xwidth=0.11, yheight=0.11, zdepth=thickness, cfg="autogen_Al_sg225_cod1502689.ncmat")
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WHEN Window==3 AT (0, 0, 10+u) RELATIVE Source
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COMPONENT Slit_out = Slit(
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xwidth=0.1,
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yheight=0.1)
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AT (0, 0, 10+thickness+2*u) RELATIVE Source
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COMPONENT OutputSD = PSD_monitor(
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xwidth=0.11,
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yheight=0.11)
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AT (0, 0, u) RELATIVE Slit_out
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COMPONENT OutputWL = L_monitor(
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xwidth=0.11,
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yheight=0.11,
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nL=1000, Lmin=0, Lmax=10)
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AT (0, 0, u) RELATIVE Slit_out
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FINALLY
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%{
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%}
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END

‎mcstas-comps/examples/Tests_optics/Test_Al_windows/autogen_Al_sg225_cod1502689.ncmat‎

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NCMAT v7
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#
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# Al (cubic, SG-225)
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#
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# Atoms per unit cell: 4xAl
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#
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# Structure converted (with NCrystal.cifutils module) from:
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#
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# "Hydrogen in the Metal&#x2212;Organic Framework Cr MIL-53"
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# Mulder, Fokko M., et al. [The Journal of Physical Chemistry C, 2010]
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# DOI: https://dx.doi.org/10.1021/jp102463p
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# Crystallography Open Database entry 1502689
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# https://www.crystallography.net/cod/1502689.html
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#
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# IMPORTANT NOTICE: This is a mostly automatic conversion which has not been
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# verified! In particular the @DYNINFO sections might need
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# post-editing. Before distributing this file to other people,
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# please review this, amend the comments here to document,
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# anything done, and remove this notice.
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#
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# Notice: The following WARNINGS were emitted when loading the CIF data:
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#
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# NCrystalUserWarning : ignoring uiso info present in CIF input for "Al" since uiso_temperature parameter value is not provided
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#
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# WARNING: Fallback (dummy) Debye temperature value was used for 1 atom!
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#
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# NOTICE: crystal structure was verified with spglib to be self-consistent.
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#
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@CELL
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cubic 4.0339
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@SPACEGROUP
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225
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@ATOMPOSITIONS
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Al 0 0 0
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Al 0 1/2 1/2
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Al 1/2 0 1/2
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Al 1/2 1/2 0
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@DYNINFO
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# WARNING: Using fallback Debye temperature value!
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element Al
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fraction 1
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type vdosdebye
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debye_temp 300

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