LS1 Report: first beams in the Booster
On Monday, 2 June, the Operations Group injected the first beams into the PS Booster (PSB). The PSB, the second machine in the LHC injector chain to be recommissioned (Linac2 was the first), also provides beams for non-LHC experiments, some of which will need beams for physics as early as this summer.
The PS Booster.
The Operations Group has been back in control of the PS Booster for a month now, having taken over where the engineers and experts of the EN Department, who were responsible for the maintenance work, left off. The group first ran tests with no beam (known as “cold check-out”) to check and requalify all the machine instrumentation, from the control room to the ring itself. Now in beam mode, the Booster is being prepared both to begin supplying the PS at the end of June and, above all, for physics to restart in the ISOLDE experimental area.
The PS Booster console in the CERN Control Centre.
“We have around 15 types of beams to ‘prepare’,” explains Klaus Hanke, Booster Section Leader within the Operations Group. “We actually produce different beams – in terms of the intensity of the proton bunches, the beam size, the time structure – for the LHC and the whole non-LHC physics programme, and we supply the ISOLDE facility directly.” Of course, each of these beams requires a specific injector setup and the right settings have to be found once again after a technical stop of almost a year and a half. “In addition, numerous renovations have been carried out on the PSB and some of its components have been replaced,” Hanke stresses. “So we have to re-parameterise the machine, with the aim of finding the right settings for each beam."
While some debugging was obviously needed during the cold check-out phase, the injection of the first beams on Monday, 2 June went relatively smoothly. The various teams, in particular those in charge of operations, radiofrequency and instrumentation, are now adjusting the settings for beam acceleration and beam extraction to the PS, which should take place in a few weeks. ISOLDE, though, the only experimental area directly connected to the PSB, will be the first user to receive its beams. With physics set to restart in mid-July, the facility will need proton beams very soon.
| Meanwhile, elsewhere... At the LHC, the SMACC project teams, who celebrated reaching the end of the superconducting cable splice consolidation phase on 27 May, have already closed almost all the W bellows and carried out more than 80% of the leak tests across the whole machine.Other tests are also being done at the LHC: the magnets are currently undergoing a series of warm tests, and short-circuit tests on the water-cooled cable systems and quench protection systems are under way. As regards the R2E project, the first installations have already been recommissioned and pressure tests have just been completed in Sector 2-3. Next up are Sectors 5-6, 7-8, 3-4 and 4-5. The temperature of Sector 6-7 has passed below the 80 K threshold, meaning that the teams can once again work in the area. Between 300 K (room temperature) and 80 K, the machine is subject to severe stress as a result of the cooling process, so access is suspended for safety reasons during the cooling phase. Its current thermal stability has notably enabled the surveyors to check the alignment of the magnets, which are sensitive to changes in temperature.In the SPS, the reinstallation of long straight section 1 (LSS1) went well. However, tests revealed a leak in the bellows of the QDA magnet, which was brought to the surface earlier in the week for repair. |
