Construction of a large one-dimensional multidetector

D20 is a very high intensity neutron 2-axis diffractometer equipped with a large micro-strip detector. Due to the extremely high neutron flux, it opens up new possibilities for real-time experiments on very small samples.

The movie below was recorded in 2000. It shows the construction of the large one-dimensional multidetector.
This position sensitive detector (PSD) is based on the micro-strip gas chamber (MSGC) technology, i.e. the delicate streched wires of classic gas multidetectors are replaced by metallic strips engraved on a special glass substratum. Its advantages are a very homogeneous response, a very high stability and the possibility of very high counting rates.
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.