The latest from the LHC
Sector 4-5 is being warmed to room temperature. The sector was previously warmed to 80 Kelvin in order to perform a test on the copper component of the busbars at non-superconducting temperatures (See previous update). One of the LHC’s electrical interconnections being repaired.
During the test at 80 Kelvin one busbar with potentially high resistance was found. The sector is now being warmed to room temperature in order to perform a more accurate test on all the copper busbars. By comparing the results of the two tests (80 and 300 Kelvin), the accuracy of the 80-Kelvin test can be verified to help interpret data taken from the other cold sectors.
In Sector 1-2 the repairs have been completed to all the electrical interconnections and the last ‘W bellow’ has been closed. After final electrical checks and insulation vacuum checks the sector will be ready to start the cool down process. ---------------
The beam lines in Sector 6-7 have been closed. The sector has been tested with the RF ball, which showed no problems with the interconnections. (More details on RF ball testing available here). Repair work on the electrical interconnections is still ongoing.
Image showing particle tracks reconstructed by the LHCb Vertex Locator (VELO). The particles passed through the LHCb detector in the reverse direction, i.e. passing first through the muon stations and then emerging through the VELO detector.
The LHC’s anti-clockwise beam transfer system was tested on 6 and 7 June. Particle bunches were sent from the SPS through the transfer line towards the LHC where it intersects just before the LHCb cavern.
The beam was sent down the 2.8km transfer line and stopped just before reaching the LHC tunnel with a ‘beam stopper’ (known as a TED) - 4m of graphite that is physically placed in the path of the beam line to prevent the beam from taking the last step into the LHC.
Part of the LHCb detector was turned on during the beam test, and the teams managed to catch a glimpse of the secondary particles produced when the beam hits the ‘beam stopper’.
More pictures are available on the LHCb website
A video of the LHCb test run, including interviews with people in the LHCb control room on the day of the beam test, is available here.
A seminar on the status of the LHC will be given by Steve Myers on 2 July. More details available here.