Installation of the new helium pressure-release system for the LHC is progressing well. The first sector to be fully completed is 5-6, with all 168 individual pressure-release ports now in place. These ports will allow a greater rate of helium escape in the event of a sudden increase in temperature.
To install the pressure-release ports teams had to cut and open the “bellows” – the large accordion-shaped sleeves that cover the interconnections between two magnets. Once all of the ports were fitted, work on closing the bellows could begin. This marked the end of the consolidation work on this sector and the start of preparations to cool it down. By the end of March the first three vacuum subsectors had been sealed. Each subsector is a 200 m long section of the insulating vacuum chamber that surrounds the magnet cold mass. Once sealed, each subsector is tested for leaks before the air is pumped out.
Meanwhile, teams are working through the night and on weekends to install the replacement magnets in the damaged area of sector 3-4 at a rate of six to seven per week. At the same time, the pace of interconnection work has increased sharply over the past few weeks. For example, within a fortnight, the number of joints being soldered rose from two to eight a week. Elsewhere, a magnet in sector 1-2 that was found to have high internal resistance has now been replaced.
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