New life for CERN's first accelerator
Building 300 right in the middle of the CERN site houses a special "antique": the Laboratory's very first accelerator. After several years in the wilderness following its decommissioning in 1990, the Synchrocyclotron is set to take on a new lease of life in the near future, this time as a visitor attraction.
The Synchrocyclotron as it was in 1975; it will be restored to this configuration for public viewing.
The Synchrocyclotron (SC) began operation in 1957, two years before the PS was commissioned. Running at an energy of 600 MeV and producing beams of protons, neutrons, muons and pions, it helped to further research in the nuclear physics field for no fewer than 33 years, providing beams for various decay experiments as well as the muon capture experiment (*).
Since the SC was decommissioned in 1990, three of its four buildings (160, 161 and 301) have been converted into offices for members of the ALICE collaboration, but the shielded hall housing the machine itself remains as it was, with the Synchrocyclotron still king of all its surveys.
Hence the idea to create an exhibition area. "It was only natural to want to show this major part of the Organization's history to the public," says the project leader, Marco Silari of the DGS/RP group. "The SC was CERN's first accelerator and, as such, is definitely worth seeing. We therefore came up with the idea of making it into a visit point, which we discussed with the Director of Administration and Infrastructure, Sigurd Lettow, and are now putting into practice in collaboration with the Education group."
The 2,500 tonne accelerator complete with magnet, vacuum chamber, vacuum pumps, radiofrequency (RF) system and even a control panel dating back to the 1950s (!) will therefore stay put in Hall 300.
As far as radioactivity considerations are concerned, the level of radiation intensity has had the last twenty years to decrease. "For safety reasons, the Radiation Protection (RP) group has carried out gamma spectrometry measurements on around 120 samples taken all over the building, as well as a full radiological survey of the whole facility," explains Marco Silari. "This will enable it to draw up a radiological evaluation and determine the protective measures that need to be taken."
Renovated to look like it did in 1975, the exhibition room should be ready to welcome members of the public in about two years' time, offering a unique opportunity to visit a complete accelerator. "The project is still in its early stages," Marco Silari points out. "At the end of 2012, once the initial phase of removing all the equipment that is not an integral part of the accelerator has been completed, the whole area will have to be rehabilitated to allow the civil engineering work to begin. The Education group (PH/EDU) will then step in to make the 400 m2 hall into a welcoming space fit to receive visitors."
| A short history of the SC The Synchrocyclotron produced its first 600 MeV proton beam on 1st August 1957. Ten years later, construction began on an underground hall to house the ISOLDE experiment, which was supplied by the SC until 1990. Following a year's technical stop to upgrade the machine, the SC was ready to accelerate 3He2+ ions in October 1974. Acceleration tests with 12C4+, 16O6+, 14N5+ and 20Ne6+ beams were also performed over the next few years. The SC was decommissioned on 17 December 1990. |
*The experiments at the SC can be found in the report on the SC 33 symposium held at CERN in April 1991: Thirty-three years of physics at the CERN Synchrocyclotron, Proc. of the SC 33 Symposium at CERN, G. Fidecaro, ed, CERN, 22 April 1991, Physics Report 225 (1993).
