1 files changed, 10 insertions, 0 deletions
diff --git a/src/path.h b/src/path.h
index 0c97f18..1e40061 100644
--- a/src/path.h
+++ b/src/path.h
@@ -3,6 +3,16 @@
 
 #include <gsl/gsl_spline.h>
 
+/* Minimum value for the scattering RMS `theta0`.
+ *
+ * This is a bit of a hack to correct for the fact that we assume the
+ * probability of a photon hitting a PMT is uniform across the face of a PMT.
+ * By introducing a minimum value for the scattering RMS we broaden the angular
+ * distribution such that it effectively averages across the face of a PMT.
+ *
+ * FIXME: Should do some tests to figure out what is the best value. */
+#define MIN_THETA0 0.01
+
 typedef double getKineticEnergyFunc(double x, double T0);
 
 typedef struct path {