diff --git a/MOT Capture Process Simulation/@MOTSimulator/computeTimeSpentInInteractionRegion.m b/MOT Capture Process Simulation/@MOTSimulator/computeTimeSpentInInteractionRegion.m
index b7d9705..4fae3f8 100644
--- a/MOT Capture Process Simulation/@MOTSimulator/computeTimeSpentInInteractionRegion.m	
+++ b/MOT Capture Process Simulation/@MOTSimulator/computeTimeSpentInInteractionRegion.m	
@@ -9,7 +9,7 @@ function T = computeTimeSpentInInteractionRegion(this, r)
     T = 0;
     NumberOfTimeSteps    = int64(this.SimulationTime/this.TimeStep);
     for n = 1:(NumberOfTimeSteps - 1)
-        dr = Helper.calculateDistanceFromPointToLine(r(n+1, :), [0 0 0], [1 0 0]);
+        dr = Helper.calculateDistanceFromPointToLine(r(n+1, :), [0 0 0], [0 0 1]);
         if dr < this.CoolingBeamRadius
             A = 1;
         else