anchor.diff:  ! =================================================================================================
   !  K. Sjobak, V.K. Berglyd Olsen, BE-ABP-HSS
   !  Created: 2017-08
  -!  Updated: 2018-11-12
  +!  Updated: 2019-11-20
   ! =================================================================================================
   subroutine scatter_init
   
  
positive.code: ! ~~~~~~~~~~~~~~~~~~~~~~~~~
  !  V.K. Berglyd Olsen, K.N. Sjobak, H. Burkhardt, BE-ABP-HSS
  !  Created: 2017-08
  !  Updated: 2019-08-26
  !
  !  References
  ! ~~~~~~~~~~~~
  
negative.code:       ! sigmaYeff = abs(sigmaX*cRot - sigmaY*sRot)
  
        ! Compute approximate kinematic factor and the normalisation of the PDF
        kFac    = two*cos_mb(two*(sigmaXeff/scatter_beam2Length))*cos_mb(two*(sigmaYeff/scatter_beam2Length))
        normFac = kFac/(twopi*sqrt(sigmaXeff**2 * sigmaYeff**2))
  
        scatter_proList(idPro)%fParams(10) = sigmaX
        scatter_proList(idPro)%fParams(11) = sigmaY
  