Solid angle stuff

1 files changed, 9 insertions, 3 deletions

diff --git a/src/detector.c b/src/detector.c
index 2b0c12d4..339ff626 100644
--- a/src/detector.c
+++ b/src/detector.c
@@ -26,26 +26,32 @@ void record_image(struct image *image)
 {
 	int x, y;
 	double ph_per_e;
+	double twotheta_max, np, sa_per_pixel;
 	
 	/* How many photons are scattered per electron? */
 	ph_per_e = PULSE_ENERGY_DENSITY * pow(THOMSON_LENGTH, 2.0)
 	          / image->xray_energy;
-	
 	printf("%e photons are scattered per electron\n", ph_per_e);
 	
+	twotheta_max = image->twotheta[0];
+	
+	np = sqrt(pow(image->x_centre, 2.0) + pow(image->y_centre, 2.0));
+	sa_per_pixel = pow(2.0 * twotheta_max / np, 2.0);
+	printf("sa per pixel=%e\n", sa_per_pixel);
+	
 	image->data = malloc(image->width * image->height * sizeof(uint16_t));
 	
 	for ( x=0; x<image->width; x++ ) {
 	for ( y=0; y<image->height; y++ ) {
 	
-		uint16_t counts;
+		double counts;
 		double val, intensity;
 		double sa;
 		
 		val = image->sfacs[x + image->width*y];
 		
 		/* What solid angle is subtended by this pixel? */
-		sa = 1.0;
+		sa = sa_per_pixel * cos(image->twotheta[x + image->width*y]);
 		
 		intensity = pow(val, 2.0);
 		counts = intensity * ph_per_e * sa;