Work in progress on photon correctness

1 files changed, 18 insertions, 0 deletions

diff --git a/src/ewald.c b/src/ewald.c
index 9d8a0450..e9f36596 100644
--- a/src/ewald.c
+++ b/src/ewald.c
@@ -19,16 +19,30 @@
 #include "cell.h"
 
 
+/* Pulse energy density in J/m^2 */
+#define PULSE_ENERGY_DENSITY (30.0e7)
+
+
 void get_ewald(struct image *image)
 {
 	int x, y;
 	double k;  /* Wavenumber */
+	double i0fac;
 	
 	k = 1/image->lambda;
 	
+	/* How many photons are scattered per electron? */
+	i0fac = PULSE_ENERGY_DENSITY * pow(THOMSON_LENGTH, 2.0)
+	          / image->xray_energy;
+	
+	printf("%e photons are scattered per electron\n", i0fac);
+	
 	image->qvecs = malloc(image->width * image->height
 	                       * sizeof(struct threevec));
 	
+	image->phactors = malloc(image->width * image->height
+	                          * sizeof(double));
+	
 	for ( x=0; x<image->width; x++ ) {
 	for ( y=0; y<image->height; y++ ) {
 	
@@ -36,6 +50,7 @@ void get_ewald(struct image *image)
 		double twothetax, twothetay, twotheta;
 		double qx, qy, qz;
 		
+		/* Calculate q vectors for Ewald sphere */
 		rx = ((double)x - image->x_centre) / image->resolution;
 		ry = ((double)y - image->y_centre) / image->resolution;
 		r = sqrt(pow(rx, 2.0) + pow(ry, 2.0));
@@ -51,6 +66,9 @@ void get_ewald(struct image *image)
 		image->qvecs[x + image->width*y].u = qx;
 		image->qvecs[x + image->width*y].v = qy;
 		image->qvecs[x + image->width*y].w = qz;
+		
+		/* Calculate photon factor ("phactor") */
+		
 	
 	}
 	}