Denys Wilkinson Building

The Denys Wilkinson Building is a prominent 1960s building in Oxford, England, designed by Philip Dowson at Arup in 1967. The building houses the astrophysics and particle physics sub-departments of the Department of Physics at Oxford University, plus the undergraduate teaching laboratories. It was originally built for the then Department of Nuclear Physics and named the Nuclear Physics Laboratory. From 1988, the building was known as the Nuclear and Astrophysics Laboratory (NAPL) after the (Sub-)Department of Astrophysics moved from the University Observatory in the Science Area. In 2001, the building was renamed as the Denys Wilkinson Building, in honour of the British nuclear physicist Sir Denys Wilkinson (1922–2016), who was involved in its original creation. The building is located on the corner of Banbury Road to the west and Keble Road to the south. To the north is the tall Thom Building of Oxford University's Department of Engineering Science, also built in the 1960s. It forms part of the Keble Road Triangle. Attached is a large and distinctive fan-shaped superstructure that was built to house a Van de Graaff generator. Nikolaus Pevsner commented that this marked "the arrival of the 'New Brutalism' in Oxford". The building was originally built to host two small (by today's standards) particle accelerators. The first was a vertical folded tandem electrostatic accelerator (see Tandem accelerators, the top being at floor level in the fan-shaped superstructure, the bottom in the basements. Negatively charged ions were introduced at the bottom and would be accelerated towards the large charge (10 million volts) built up by the Van de Graaff generator by electrostatic attraction. At the top, the ions would pass through a thin foil to strip off electrons, and then their trajectory would be bent 180° by a large magnetic field. The now positively charged nuclei would then be electrostatically repelled by the same charge, accelerating them back down another vacuum tube.