diff options
| -rw-r--r-- | src/detector.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/src/detector.c b/src/detector.c index fbe2c5f2..a55d6fcc 100644 --- a/src/detector.c +++ b/src/detector.c @@ -146,7 +146,7 @@ void record_image(struct image *image) int x, y; double fluence; double ph_per_e; - double sa_per_pixel; + double pix_area, Lsq; double area; const int do_bloom = 1; @@ -157,10 +157,9 @@ void record_image(struct image *image) printf("Fluence = %5e photons / m^2, %5e photons total\n", fluence, fluence*area); - /* Solid angle subtended by a single pixel at the centre of the CCD */ - sa_per_pixel = pow(1.0/(image->resolution * image->camera_len), 2.0); - printf("Solid angle of one pixel (at centre of CCD) = %e sr\n", - sa_per_pixel); + /* Area of one pixel */ + pix_area = pow(1.0/image->resolution, 2.0); + Lsq = pow(image->camera_len, 2.0); image->hdr = malloc(image->width * image->height * sizeof(double)); @@ -169,6 +168,7 @@ void record_image(struct image *image) double counts, intensity, sa, water; double complex val; + double dsq, proj_area; val = image->sfacs[x + image->width*y]; intensity = pow(cabs(val), 2.0); @@ -181,8 +181,15 @@ void record_image(struct image *image) //printf("%e, %e, ", intensity, water); intensity += water; - /* What solid angle is subtended by this pixel? */ - sa = sa_per_pixel * cos(image->twotheta[x + image->width*y]); + /* Area of pixel as seen from crystal (approximate) */ + proj_area = pix_area * cos(image->twotheta[x + image->width*y]); + + /* Calculate distance from crystal to pixel */ + dsq = pow(((double)x - image->x_centre)/image->resolution, 2.0); + dsq += pow(((double)y - image->y_centre)/image->resolution, 2.0); + + /* Projected area of pixel divided by distance squared */ + sa = proj_area / (dsq + Lsq); counts = intensity * ph_per_e * sa; //printf("%e counts\n", counts); |