The building in the southwest corner of Harwell Science and Innovation Campus houses the second target station
Link of Isis, the UK's central facility for research with neutrons and muons. The large embankment on the left shows how much bedrock had to be removed to put the building in this location - the OS map still shows the original contour lines in the location of the building.
Isis is a spallation neutron source, i.e. the neutrons (uncharged sub-atomic particles) are generated by hitting a heavy metal (tungsten) target with a pulsed beam of protons, and was the first source in which this concept had been realised when it opened in 1985. In comparison with more conventional neutron sources (nuclear research reactors), the pulsed nature of the neutron beam has advantages for experiments where this time structure can be exploited, e.g. when measuring time-dependent processes. Isis is a user facility, and beamtime is allocated to research groups working in fields as varied as materials science, life sciences and particle physics following a peer review process. A typical experiment takes a few days at a time during which the visiting scientists work on the beamlines and in support laboratories. Each beamline is a highly specialised instrument and supports a different type of experiment. All have in common that the interaction of neutrons with the atoms of a sample is probed - this allows to infer information about the internal structure of the materials studied. The second target came into operation in 2007 alongside the original and has extended the research that can be done at Isis considerably. In addition to Isis, the UK also has a share in the multinational Institut Laue-Langevin in Grenoble in the French Alps (a reactor-based neutron source) and supports the European Spallation Source currently being built in Lund, Sweden.