Changeset 597


Ignore:
Timestamp:
Nov 5, 2009 2:11:20 PM (13 years ago)
Author:
srkline
Message:

Updated SASCALC with newly measured flux data for both NG3 and NG7.

-At 6A on NG7, now SASCALC is within +/- 5% of the measured value.
-At 6A on NG3, now SASCALC is +15% compared to the measured value.

The average detector efficiency is now included in the simulation (e=0.75) since the cts/s from SASCALC is flux on sample, not as would be measured at the detector.

Location:
sans/Dev/trunk/NCNR_User_Procedures/Reduction/SANS
Files:
2 edited

Legend:

Unmodified
Added
Removed
  • sans/Dev/trunk/NCNR_User_Procedures/Reduction/SANS/MultScatter_MonteCarlo_2D.ipf

    r596 r597  
    12381238        t0 = (stopMSTimer(-2) - t0)*1e-6 
    12391239        t0 *= imon/1000/ThreadProcessorCount                    //projected time, in seconds (using threads for the calculation) 
    1240         inputWave[0] = imon             //reset 
     1240 
     1241// to correct for detector efficiency, send only the fraction of neutrons that are actually counted      
     1242        NVAR detectorEff = root:Packages:NIST:SAS:g_detectorEff 
     1243 
     1244        inputWave[0] = imon     * detectorEff                   //reset number of input neutrons before full simulation 
    12411245         
    12421246        if(t0>10) 
     
    16871691        NVAR estTrans = root:Packages:NIST:SAS:g_1DEstTrans             // estimated transmission of sample 
    16881692        NVAR mScat = root:Packages:NIST:SAS:g_MultScattFraction 
     1693        NVAR detectorEff = root:Packages:NIST:SAS:g_detectorEff 
    16891694         
    16901695        WAVE rw=root:Packages:NIST:SAS:realsRead 
     
    17491754         
    17501755//                              aveint = (Imon)*prob_i / circle_fraction / nCells_expected 
    1751         aveint = (Imon)*prob_i 
     1756// added correction for detector efficiency, since SASCALC is flux on sample 
     1757        aveint = (Imon)*prob_i*detectorEff 
    17521758 
    17531759        countsInAnnulus = aveint*nCells 
  • sans/Dev/trunk/NCNR_User_Procedures/Reduction/SANS/SASCALC.ipf

    r596 r597  
    136136        Variable/G root:Packages:NIST:SAS:g_1D_AddNoise = 1 
    137137        Variable/G root:Packages:NIST:SAS:g_MultScattFraction=0 
     138        Variable/G root:Packages:NIST:SAS:g_detectorEff=0.75                    //averag value for most wavelengths 
    138139         
    139140        //tick labels for SDD slider 
     
    165166        Variable/G del_r = 0.5 
    166167        Variable/G det_width = 64.0 
    167         Variable/G phi_0 = 2.95e13 
    168168        Variable/G lambda_t = 5.50 
    169169        Variable/G l2r_lower = 132.3 
     
    179179        Variable/G guide_width = 6.0 
    180180        Variable/G idmax = 100.0 
    181         Variable/G b = 0.023 
    182         Variable/G c = 0.023 
     181//      //old values, from 3/2002 
     182//      Variable/G phi_0 = 2.95e13 
     183//      Variable/G b = 0.023 
     184//      Variable/G c = 0.023 
     185 
     186        //new values, from 2/2009 
     187        Variable/G phi_0 = 3.4e13 
     188        Variable/G b = 0.0185 
     189        Variable/G c = 0.0135 
    183190         
    184191        //fwhm values (new variables) (+3, 0, -3, calibrated 2009) 
     
    219226        Variable/G del_r = 0.5 
    220227        Variable/G det_width = 64.0 
    221         Variable/G phi_0 = 2.3e13 
    222228        Variable/G lambda_t = 5.50 
    223229        Variable/G l2r_lower = 100 
     
    233239        Variable/G guide_width = 5.0 
    234240        Variable/G idmax = 100.0 
    235         Variable/G b = 0.028 
    236         Variable/G c = 0.028 
     241         
     242//      //old values, from 3/2002 
     243//      Variable/G phi_0 = 2.3e13 
     244//      Variable/G b = 0.028 
     245//      Variable/G c = 0.028 
     246 
     247        //new values, from 6/2009        
     248        Variable/G phi_0 = 3.2e13 
     249        Variable/G b = 0.0448 
     250        Variable/G c = 0.0463 
    237251         
    238252        //fwhm values (new variables) 
    239253        Variable/G fwhm_narrow = 0.09 
    240         Variable/G fwhm_mid = 0.11 
     254        Variable/G fwhm_mid = 0.115             //2009 
    241255        Variable/G fwhm_wide = 0.22 
    242256         
     
    484498                endswitch 
    485499                 
    486                 dlStr = "0.09;0.11;0.22;" 
     500                dlStr = "0.09;0.115;0.22;" 
    487501                Slider SC_Slider_1,limits={100,1531,1},userTicks={root:Packages:NIST:SAS:tickSDDNG7,root:Packages:NIST:SAS:lblSDDNG7 } 
    488502                SetVariable setvar0,limits={100,1531,1} 
     
    19821996End 
    19831997 
    1984  
     1998// updated with new flux numbers from John Barker 
     1999// NG3 - Feb 2009 
     2000// NG7 - July 2009 
     2001// 
     2002// guide loss has been changed to 0.95 rather than the old value of 0.95 
     2003// 
     2004// other values are changed in the initialization routines 
     2005// 
    19852006Function beamIntensity() 
    19862007 
    19872008    Variable alpha,f,t,t4,t5,t6,as,solid_angle,l1,d2_phi 
    1988     Variable a1,a2,retVal 
     2009    Variable a1,a2,retVal,guide_loss=0.95 
    19892010    SetDataFolder root:Packages:NIST:SAS 
    19902011    NVAR l_gap=l_gap,guide_width =guide_width,ng = gNg 
     
    20012022    f = l_gap*alpha/(2*guide_width) 
    20022023    t4 = (1-f)*(1-f) 
    2003     t5 = exp(ng*ln(0.96))       // trans losses of guides in pre-sample flight 
     2024    t5 = exp(ng*ln(guide_loss)) // trans losses of guides in pre-sample flight 
    20042025    t6 = 1 - lambda*(b-(ng/8)*(b-c))            //experimental correction factor 
    20052026    t = t1*t2*t3*t4*t5*t6 
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