The success of the start-up of the LHC on 10th of September was in part due to the preparation without beam and injection tests in 2008. The injection tests allowed debugging and improvement in appropriate portions to allow safe, efficient and state-of-the-art commissioning later on. The usefulness of such an approach for a successful start-up becomes obvious when looking at the problems we...
Following various injection tests, the full LHC beam commissioning started on September 10th. Within three days of beam operation, we established stable and captured circulating beam 2 and achieved circulating beam 1 for many turns. This was made possible by a thorough preparations of all the required accelerator systems, beam instrumentation and control software, which all achieved a...
The constraints in the LHC machine protection impose tighter optics tolerances than in any other hadron collider. A variety of beam-based measurements in the first days of LHC operation was effective to measure aperture clearance, magnet polarities and machine optics. A summary of these measurements is given together with model insights.
Beam commissioning of the SPS to LHC transfer lines performed during the summer 2008 is reported. The emphasis is put on the optical checks measured for the first time in the last part of the lines and into the LHC. In particular, extensive trajectory studies, dispersion measurements and coupling analysis are discussed. These studies were conducted in parallel with hardware checks and the...
The initial commissioning of the LHC injections and beam dumps allowed the basic functionality of the systems to be verified, together with progress to be made on some of the systematic checks and measurements foreseen in the detailed commissioning programme. The observations and measurement results are summarised, including comparisons of element strengths and synchronisation, details of the...
During the 2008 LHC injection synchronisation tests and the subsequent days with circualting beam, the majority of the LHC beam instrumentation systems were capable of measuring their first beam parameters. This included the two large, distributed, beam position and beam loss systems, as well as the scitillating and OTR screen systems, the fast and DC beam current transformer systems, the tune...
A large number of components of the LHC controls infrastructure have been intensively exercised during several dry runs and the injection synchronization tests in 2008, in preparation for the LHC start up with beam. All the prior tests were extremely useful to validate the basic functionality, to identify areas of weakness and to prepare the controls to a stable and well functioning...
The start-up of the LHC has provided the first field test for the concept, functionality and accuracy of FiDeL, the Field Description for the LHC. FiDeL is primarily a parametric model of the transfer function of the main field integrals generated by the series of magnets in the LHC powering circuits, from main optical elements to high-order harmonic correctors, both superconducting and...