diff --git a/heliosmatics.js b/heliosmatics.js
index 0971903..fae1f46 100644
--- a/heliosmatics.js
+++ b/heliosmatics.js
@@ -210,7 +210,8 @@ function CalConstants(){
   
   ez_slope = Math.abs(BField) * c * light[1]*beta/2/Math.PI/1000; // MeV/mm
   alpha = ez_slope/beta;
-  alpha_B = alpha * heavy[1]/light[1];
+  //alpha_B = alpha * heavy[1]/light[1];
+  alpha_B = Math.abs(BField) * c * heavy[1]*beta/2/Math.PI/1000 / beta;
 
 }