The Chamber for Rutherford Backscattering Spectroscopy (RBS) and Channeling was manufactured by Charles Evans and Associates (model RBS-50). The chamber is made of stainless steel and is cylindrically-shaped with a 20-inch diameter. As shown in the attached picture, the incoming particle beam is collimated by means of one adjustable tantalum collimator and one double collimator that are mounted at 35 and 60 cm, respectively, from the entrance of the chamber. The latter collimator consists of two circular tantalum foils. The first one, facing first the incoming beam, has a hole with a 2-mm wide radius at its center, whereas the second a hole with 3-mm radius.
A laser mounted outside the RBS chamber is used for the placement of the detectors at the desired scattering angles and for beam alignment. Samples are loaded through a sample loading door. A glass view port allows for visual monitoring of the chamber’s interior, the sample’s translations and rotations and the beam spot’s location and shape. The target holder is being monitored by a CCD camera placed inside the vacuum chamber. Between the RBS and the PIXE chamber that follows downstream, an isolation valve is mounted.
