Tantalum, Aluminum Beamstop, and air in chamber

Simulation Parameters

Target Matter: Tantalum

Target Length: 0.0508cm

Beamstop Matter: Aluminum

Beamstop Thickness: 1.27cm

Chamber Matter: Air

Tracker Matter: Air

World Matter: Vacuum

Target physically starts at -84.4cm and ends at -84.3492cm

Beamstop starts at -84.3492cm and ends at -83.0792cm

The tracker starts at -83.0792cm and ends at -3.0792cm

Conclusion

The beamstop is not thick enough to prevent electrons from traveling through to brem off of the air in the tracker.