LS1 Report: the electric atmosphere of the LHC
In the LHC, testing of the main magnet (dipole and quadrupole) circuits has been completed. At the same time, the extensive tests of all the other circuits up to current levels corresponding to 7 TeV beam operation have been performed, and now the final ElQA (Electrical Quality Assurance) tests of the electrical circuits are proceeding.
In Sectors 4-5 and 5-6, where the ElQA checks have been finished, the process of removing and storing the helium has started (see the article Heatwave warning for the LHC, in this issue). This is the first step in warming up the whole machine to room temperature so that the main LS1 activities, SMACC (Super Conducting Magnet and Circuit Consolidation) and the R2E (Radiation Two Electronics) programmes, which are scheduled to start on 19 April and 22 March respectively, can get under way.
As far as the LHC injectors are concerned, LINAC2 and the PS Booster are in shutdown mode, having completed their preparatory hardware test programmes, and shutdown work has already started. At the PS, access for LS1 activities also started this week, whilst at the SPS an extensive magnet test programme will continue until 26 March. This programme is aimed at identifying magnets that will need to be repaired or changed during LS1, and preparing the work and maintenance programmes for the magnet group during the coming 18 months.
ElQA tests Electrical Quality Assurance tests aim at detecting magnet non-conformities by measuring the electrical insulation of each magnet with respect to earth. For these tests, engineers apply a high voltage between the magnet coil and earth to ensure it is perfectly electrically insulated. |
by Simon Baird