The layout of the accelerator, beam line, and ultra-high vacuum equipment is shown above. The accelerator is a 400 keV Ion Implanter manufactured by High Voltage Engineering in the Netherlands. Ions of virtually any type are created at a source and initially accelerated to 10, 20, or 30 keV. After passing a mass selecting magnet, the ions are accelerated to their final energy in the acceleration tube. Another selecting magnet steers the ion beam into the beam line. Several focussing elements lie along the path of the beam, including two quadrupole lenses. Electrostatic steering elements align the beam along the axis of two beam collimating slits. These slits determine the angular divergence and spot size of the beam on the sample. The beam spot size is 1 mm wide and 0.1 mm high.