diff --git a/geant3/src/lemsr/get_direction.F b/geant3/src/lemsr/get_direction.F
index 854506f..09bdad9 100644
--- a/geant3/src/lemsr/get_direction.F
+++ b/geant3/src/lemsr/get_direction.F
@@ -32,12 +32,18 @@ c
       real*4 x,y,z,r
       real*4 t_in_sample,tof,beta,gamma_sqr ! to add relaxation in sample
       real*4 mass, mass_sqr, pz_sqr, z0
+      real*4 arg
 c
 c-----------------------------------------------------------------------------
 c   
         if ( lsets(2) .eq. 0 ) then ! positron created in MCP2 or sample
           t_in_sample = tofg*1.e9   ! time in nsec
-          p = bfield(5) / 100. * exp(-beam_parameter(4)*t_in_sample) ! expo relaxation
+          arg = beam_parameter(4)*t_in_sample
+          if (arg > 10. ) then
+           p = 0.
+          else
+           p = bfield(5) / 100. * dexp(-dble(arg)) ! expo relaxation
+          endif
         else
           x = vect(1)
           y = vect(2)