Changeset 0d41aeed in sasview for src/sans/models/c_extension/libigor/libSphere.c

Timestamp:

Nov 24, 2014 9:35:22 AM (10 years ago)

Author:

Miguel Gonzalez <onzalezm@…>

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:

2cdcbb5

Parents:

afd42432

Message:

Added model for micelles with spherical cores (from J. Appl. Cryst. (2000) 33, 637-640). C model added to libSphere!

File:

• src/sans/models/c_extension/libigor/libSphere.c (modified) (1 diff)

src/sans/models/c_extension/libigor/libSphere.c

@@ -2330 +2330 @@
 }
 
-
+// Micelle with spherical core 
+// J.S. Pedersen, J. Appl. Cryst. 33, 637 (2000)
+
+double
+MicelleSphericalCore(double dp[], double q)
+{
+        double x, pi;
+        double ndensity, v_core, v_corona, rho_solv, rho_core, rho_corona;      // local names of input params
+        double radius_core, radius_gyr, d_penetration, n_aggreg, bkg, scale;    // local names of input params
+        double beta_core, beta_corona, qr, qrg, qrg2, qrdrg, bes_core, bes_corona; 
+        double term1, term2, term3, term4, debye_chain, chain_ampl, i_micelle;
+
+        x = q;
+        
+        scale = dp[0];
+        ndensity = dp[1];      // number density [1/cm^3]
+        v_core = dp[2];        // volume block in core [A^3]
+        v_corona = dp[3];      // volume block in corona [A^3]
+        rho_solv = dp[4];      // sld of solvent [1/A^2]
+        rho_core = dp[5];      // sld of core [1/A^2]
+        rho_corona = dp[6];    // sld of corona [1/A^2]
+        radius_core = dp[7];   // radius of core [A]
+        radius_gyr = dp[8];    // radius of gyration of chains in corona [A]
+        d_penetration = dp[9]; // close to unity, mimics non-penetration of gaussian chains
+        n_aggreg = dp[10];     // aggregation number of the micelle
+        bkg = dp[11];          // background
+        
+        beta_core = v_core * (rho_core - rho_solv);
+        beta_corona = v_corona * (rho_corona - rho_solv);
+        
+        
+        // Self-correlation term of the core
+
+        qr = x*radius_core;
+        if(qr == 0){bes_core = 1.0;} else {bes_core = 3.0*(sin(qr)-qr*cos(qr))/(qr*qr*qr);}
+        
+        term1 = n_aggreg * n_aggreg * beta_core * beta_core * bes_core * bes_core;
+
+        // Self-correlation term of the chains
+
+        qrg = x*radius_gyr;
+        qrg2 = qrg*qrg;
+        if(qrg2 == 0){debye_chain = 1.0;} else {debye_chain = 2.0*(exp(-qrg2)-1+qrg2)/(qrg2*qrg2);}
+        
+        term2 = n_aggreg * beta_corona * beta_corona * debye_chain;
+
+        // Interference cross-term between core and chains
+
+        if(qrg2 == 0){chain_ampl = 1.0;} else {chain_ampl = (1-exp(-qrg2))/qrg2;}
+
+        qrdrg = x * (radius_core + d_penetration * radius_gyr);
+        if(qrdrg == 0){bes_corona = 1.0;} else {bes_corona = sin(qrdrg)/qrdrg;}
+
+        term3 = 2 * n_aggreg * n_aggreg * beta_core * beta_corona * bes_core * chain_ampl * bes_corona;
+
+        // Interference cross-term between chains
+
+        term4 = n_aggreg * (n_aggreg - 1.0) * beta_corona * beta_corona * chain_ampl * chain_ampl * bes_corona * bes_corona;
+
+        // I(q)_micelle : Sum of 4 terms computed above
+        
+        i_micelle = term1 + term2 + term3 + term4 ; 
+
+        // rescale from [A^2] to [cm^2]
+        
+        i_micelle *= 1.0e-16;
+
+        // "normalize" by number density --> intensity in [cm-1]
+        
+        i_micelle *= ndensity;
+        
+        //scale if desired
+        i_micelle *= scale;
+
+        // add in the background
+        i_micelle += bkg;
+        
+        return(i_micelle);
+        
+}
+