UA1 magnet sets off for a second new life

13 March 2008

A magnet built originally for the UA1 detector at CERN and later used by the NOMAD experiment has set sail for a new life in Japan. Thirty-five containers carrying 150 pieces departed CERN in the last two weeks of January, with the last components – the large aluminium coils – following in March.

In 2005, at the request of European physicists involved in the international Tokai to Kamioka (T2K) long-baseline neutrino experiment, CERN decided to donate the former UA1 magnet, its coils and other equipment to KEK in Japan. For T2K, which will start in autumn 2009, the Japan Proton Accelerator Research Complex at Tokai will use a 40 GeV proton beam to produce an intense low-energy neutrino beam directed towards the Super-Kamiokande neutrino observatory 300 km away.

Built in 1979, the UA1 magnet was later given a second lease of life with the NOMAD neutrino-oscillation experiment at CERN. Since NOMAD was dismantled in 2000, the magnet has been stored in the open air, exposed to the elements, at CERN’s Prévessin site. All the parts were cleaned, polished and repainted before shipment to Japan, including a general overhaul in readiness for transport. However, many of the parts could not be transported in one piece, especially by sea, so much of the equipment had to be dismantled before being loaded into containers.

The general overhaul, and other work needed to prepare the parts for shipping, took almost a year. On 14 January, one by one, 35 sea-going containers began their long journey to Tokai, 60 km north of Tokyo. They first travelled by train to Antwerp, from where they were bound for the port of Hitachinaka via Pusan, in South Korea. The final, and largest, component – consisting of the four very fragile coils – was scheduled to leave CERN at the end of March. With a height of 4.75 m, the aluminium coils weigh close to 40 tonnes and have been packaged into two 1.70 m wide consignments for transport as an exceptional lorry load to Basel, then by barge to Rotterdam to set sail for Japan.

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