Soudan 2's copper cathodes

16 December 1998

Display high resolution image

This week's futuristic image shows the production of a copper cathode board - part of the system that records the passage of charged particles through the Soudan 2 detector. Here members of the Physics Department at Oxford University are seen mounting thin sheets of copper cathode pads on to a 1-m wide by 2.4-m high fibreglass sheet. The cathode pads were produced by subjecting almost 3-km of copper sheets to photofabrication processes.

The Soudan 2 detector was originally designed and built to search for the decay of protons (or more correctly, nucleon decay), predicted by some theories. If such decays do occur they will be extremely rare, so to shield the detector from cosmic rays it is located 713 m underground in an experimental hall on the 27th level of the Soudan Underground Mine State Park in Soudan, Minnesota. Since April 1989, the 963-ton detector has been recording data that have been used to investigate a number of topics, especially the behaviour of neutrinos produced by the interactions of cosmic rays in the Earth's atmosphere.

Credit: Physics Photographic Unit, Oxford University / Soudan

Please contact person or institution named for information about permission for public or commercial use.