More room for ISOLDE
To meet the needs of the new ISOLDE experiments, a new extension has been added to the facility's Building 170.
Moving around the ISOLDE hall was almost like an obstacle course until now. The facility's Building 170 simply didn't have an inch to spare and the ISOLDE team's need to set up new experiments, whose installation could have created difficulties from the safety point of view, only exacerbated the problem. "We had ambitious plans to develop new experiments but no room for them", says Mats Lindroos, ISOLDE's technical coordinator. The only solution was to extend the existing building".
This was how a new building saw the light of day. Measuring 24 metres long, 20 metres wide and 12 metres high, it is an extension to the existing Building 170 and should be ready for use this year.
The new structure makes use of the existing infrastructure, with part of the end wall of Building 170 being kept as a support for steel platforms. The top of this wall had to be cut away to a depth of 40 centimetres to allow the overhead travelling crane of Hall 170 to be used in the extension. Two holes also had to be made in the wall, one to allow people and equipment through and the other for the beams.
The work was done by two civil engineering companies (Zschokke and Losinger) and a company specialising in steel constructions (Revaz). The main difficulty was the existence of a buried service duct near the site of the extension work, which had to be shored up. "In spite of these difficulties, we were able to meet the deadline. The work began in August 2004 and was completed on 15 April as scheduled", explains Natacha Lopez-Hernandez, who was in charge of the civil engineering.
The new building will allow ISOLDE room to move in the next couple of years. The Miniball detector (see Bulletin No. 46/2001) will be transferred to the new extension in the coming months, away from the REX post-accelerator, which will then be able to detect gamma rays from radionuclide reactions at high energies with virtually no background.
In two years' time, the REX post-accelerator will be extended to accelerate nuclei in an energy range of 60 KeV to 5.5 MeV/MeV/u, compared to a maximum of 3 MeV/u today. "For the future experiments at ISOLDE, we will need even more exotic nuclei. Then, to be able to explore new reactions between exotic nuclei and a target, higher energies will be needed", explains Peter Butler, head of the ISOLDE physics group. Logically, therefore, REX will have to be longer". New experiments based on the extended REX accelerator are also to be installed in the new building.
