After determining the r, z, and focus off set values, you need to add 180° to the stated azimuthal (phi) value given in the port position menu to make the beam cross over the z axis before hitting the halfraum wall (Figures 5 and 6)

Figure 5: Beam position with beam’s original azimuthal value.

Figure 6: Beam position after adding 180° to the stated azimuthal value.  Note that is crosses the z-axis.  (z-axis is into the page)