D20
High-intensity two-axis diffractometer with variable resolution
Position-sensitive multidetector
Assembly of the microstrip gas-chamber position sensitive detector (2000). The advantages of this technology are a very homogeneous response, a very high stability and the possibility of very high counting rates.
The movie (page 2) shows the construction of this large one-dimensional multidetector. With the micro-strip gas-chamber (MSGC) technology, the delicate streched wires of classic gas multidetectors are replaced by metallic strips engraved on a special glass substratum.
Micro-strip plates are made of chromium sputtered onto the polished surface of an electronically conducting glass. The chromium is etched to create conductive micro-strip electrodes (alternately 4 cathodes and 4 thin anodes per detection cell). The detection plates have each 32 cells of 2.568 mm (0.1˚) each, covering in total 3.2˚.
The current PSD covers 153.6˚, with 48 plates mounted in a curved aluminium housing providing a detection zone about 4 m long by 150 mm high.