TCD (TRIPLE CHARGE DIVISION) - A NOVEL CENTROID FINDING METHOD

A Triple Charge Division (TCD) centroid finding method that uses a zig zag pattern for triple dividing of the cathode plane is introduced for medium length position sensitive detectors. Although the central area of the triple charge division pattern is the widest, both side areas have major roles in position sensing. For the same resolution and line arity, the active region of this pattern is wider than conventional ca thode patterns. For the same width, the linearity of TCD centroid find ing is much better than position sensing with other patterns. Predicte d effects of truncated zigzags are confirmed by experimental results f or the central points of the TCD pattern. A new readout method (graded charge division) is introduced for TCD centroid finding because of di fferent distributions of induced charges on the central area and both sides. This readout method is a combination of charge division readout and position grading for three serial segments. The TCD centroid find ing method and graded charge division readout were tested using double size, triple charge division patterns (200mm and 80mm). Spatial resol ution of about 1% of the detector length was achieved.