Changeset 1725f90 in sasview


Ignore:
Timestamp:
Sep 18, 2013 5:59:30 AM (10 years ago)
Author:
Peter Parker
Branches:
master, ESS_GUI, ESS_GUI_Docs, ESS_GUI_batch_fitting, ESS_GUI_bumps_abstraction, ESS_GUI_iss1116, ESS_GUI_iss879, ESS_GUI_iss959, ESS_GUI_opencl, ESS_GUI_ordering, ESS_GUI_sync_sascalc, costrafo411, magnetic_scatt, release-4.1.1, release-4.1.2, release-4.2.2, release_4.0.1, ticket-1009, ticket-1094-headless, ticket-1242-2d-resolution, ticket-1243, ticket-1249, ticket885, unittest-saveload
Children:
d2dfafd
Parents:
16cd735
Message:

Reviewed documentation for:

DAB Model
Sphere Model
Mass Fractal Model
CorrLength?
BroadPeak?

Location:
sansmodels/src/sans/models/media
Files:
3 edited

Legend:

Unmodified
Added
Removed
  • sansmodels/src/sans/models/media/model_functions.html

    ree74edd r1725f90  
    3333<p>The 1D scattering intensity is calculated in the following way (Guinier, 1955):</p> 
    3434<p style="text-align: center;" align="center"><span style="position: relative; top: 16pt;"><img src="img/image004.PNG" alt="" /></span></p> 
    35 <p>where scale is a scale factor* volume fraction, V is the volume of the scatterer, r is the radius of the sphere, bkg is the background level and sldXXX is the scattering length density (SLD) of the scatterer or the solvent.</p> 
    36 <p>Note that if your data is in absolute scale, the 'scale' should represent the volume fraction (unitless) if you have a good fit. If not, it should represent the volume fraction * a factor (by which your data might need to be rescaled).</p> 
    37 <p>The 2D scattering intensity is the same as P(q) above, regardless of the orientation of the q vector.</p> 
     35<p>where r is the radius of the sphere, bkg is the background level and sldXXX is the scattering length density (SLD) of the scatterer or the solvent.<\p> 
     36<p>Note that if your data is on an absolute scale, the 'scale' should represent the volume fraction (unitless) * volume of a scatterer, V.</p> 
     37<p>The 2D scattering intensity is the same as above, regardless of the orientation of the q vector.</p> 
    3838<p>The returned value is scaled to units of [cm-1] and the parameters of the sphere model are the following:</p> 
    3939<div align="center"> 
     
    115115<p style="text-align: center; page-break-after: avoid;" align="center">&nbsp;</p> 
    116116<p>Figure 1: Comparison of the DANSE scattering intensity for a sphere with the output of the NIST SANS analysis software. The parameters were set to: Scale=1.0, Radius=60 &Aring;, Contrast=1e-6 &Aring; -2, and Background=0.01 cm -1.</p> 
     117<p style="margin-left: 0.25in;"><i>2013/09/09 - Description reviewed by King, S. and Parker, P.</i></p> 
    117118<p style="margin-left: 0.55in; text-indent: -0.3in;"><b><span style="font-size: 14pt;">2.2.</span></b><b><span style="font-size: 7pt;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></b><a name="BinaryHSModel"></a><b><span style="font-size: 14pt;">BinaryHSModel</span></b></p> 
    118119<p>This model (binary hard sphere model) provides the scattering intensity, for binary mixture of spheres including hard sphere interaction between those particles. Using Percus-Yevick closure, the calculation is an exact multi-component solution:</p> 
     
    48054806<tr style="height: 19.25pt;"> 
    48064807<td style="border-width: medium 1pt 1pt; width: 107pt; height: 19.25pt;" valign="top" width="143"> 
    4807 <p>exponent_l (=n)</p> 
     4808<p>exponent_p (=n)</p> 
    48084809</td> 
    48094810<td style="border-width: medium 1pt 1pt medium; width: 107pt; height: 19.25pt;" valign="top" width="143">&nbsp;</td> 
     
    48144815<tr style="height: 19.25pt;"> 
    48154816<td style="border-width: medium 1pt 1pt; width: 107pt; height: 19.25pt;" valign="top" width="143"> 
    4816 <p>exponent_p (=m)</p> 
     4817<p>exponent_l (=m)</p> 
    48174818</td> 
    48184819<td style="border-width: medium 1pt 1pt medium; width: 107pt; height: 19.25pt;" valign="top" width="143">&nbsp;</td> 
     
    48394840<p style="margin-left: 0.25in; text-align: center;" align="center">&nbsp;</p> 
    48404841<p style="margin-left: 0.25in;">Reference: None.</p> 
     4842<p style="margin-left: 0.25in;"><i>2013/09/09 - Description reviewed by King, S. and Parker, P.</i></p> 
    48414843<p style="margin-left: 0.55in; text-indent: -0.3in;"><b><span style="font-size: 14pt;">3.3.</span></b><b><span style="font-size: 7pt;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></b><b><span style="font-size: 14pt;">&nbsp;<a name="CorrLength"></a>CorrLength (CorrelationLengthModel)</span></b></p> 
    48424844<p style="margin-left: 0.25in;">Calculate an empirical functional form for SANS data characterized by a low-Q signal and a high-Q signal</p> 
     
    48934895<tr style="height: 19.25pt;"> 
    48944896<td style="border-width: medium 1pt 1pt; vertical-align: top; width: 107pt; height: 19.25pt;"> 
    4895 <p>exponent_l (=n)</p> 
     4897<p>exponent_p (=n)</p> 
    48964898</td> 
    48974899<td style="border-width: medium 1pt 1pt medium; width: 107pt; height: 19.25pt;" valign="top" width="143">&nbsp;</td> 
     
    49024904<tr style="height: 19.25pt;"> 
    49034905<td style="border-width: medium 1pt 1pt; width: 107pt; height: 19.25pt;" valign="top" width="143"> 
    4904 <p>exponent_p (=m)</p> 
     4906<p>exponent_l (=m)</p> 
    49054907</td> 
    49064908<td style="border-width: medium 1pt 1pt medium; width: 107pt; height: 19.25pt;" valign="top" width="143">&nbsp;</td> 
     
    49284930<p style="margin-left: 0.25in;">REFERENCE</p> 
    49294931<p style="margin-left: 0.25in;">B. Hammouda, D.L. Ho and S.R. Kline, &ldquo;Insight into Clustering in Poly(ethylene oxide) Solutions&rdquo;, Macromolecules 37, 6932-6937 (2004).</p> 
     4932<p style="margin-left: 0.25in;"><i>2013/09/09 - Description reviewed by King, S. and Parker, P.</i></p> 
    49304933<p style="margin-left: 0.55in; text-indent: -0.3in;"><b><span style="font-size: 14pt;">3.4.</span></b><b><span style="font-size: 7pt;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></b><b><span style="font-size: 14pt;">&nbsp;<a name="Lorentz"></a>(Ornstein-Zernicke) Lorentz (Model)</span></b></p> 
    49314934<p style="text-indent: 0.25in;">The Ornstein-Zernicke model is defined by:</p> 
     
    50555058<p style="margin-left: 0.5in;">&nbsp;</p> 
    50565059<p style="margin-left: 0.5in;">Debye, Bueche, "Scattering by an Inhomogeneous Solid", J. Appl. Phys. 20, 518 (1949).</p> 
     5060<p style="margin-left: 0.25in;"><i>2013/09/09 - Description reviewed by King, S. and Parker, P.</i></p> 
    50575061<p style="margin-left: 0.55in; text-indent: -0.3in;"><b><span style="font-size: 14pt;">3.6.</span></b><b><span style="font-size: 7pt;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></b><b><span style="font-size: 14pt;">&nbsp; <a name="Absolute Power_Law"></a>Absolute Power_Law </span></b></p> 
    50585062<p style="margin-left: 0.25in;">This model describes a power law with background.</p> 
     
    53855389<p style="margin-left: 0.25in;">References:</p> 
    53865390<p style="margin-left: 0.25in; text-indent: 0.25in;">D. Mildner, and P. Hall,&nbsp; J. Phys. D.: Appl. Phys.,&nbsp; 19, 1535-1545&nbsp; (1986), Equation(9).</p> 
     5391<p style="margin-left: 0.25in;"><i>2013/09/09 - Description reviewed by King, S. and Parker, P.</i></p> 
    53875392<p>&nbsp;</p> 
    53885393<p>&nbsp;</p> 
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