Workshop Chamonix XV

Session

Session 04 - Magnetic Requirements for Commissioning

04

24 Jan 2006, 14:00

L'Esplanade du Lac, Divonne-les-Bains

60. What is the Impact of Hysteresis on Orbit Correction and Feedback

Ralph Steinhagen (AB/OP)

24/01/2006, 14:00

Orbit correction is a fundamental feedback action that is applied to the beam in order to counteract disturbances due to misalignments, ground motion, dynamics effects, etc. Threading the very first LHC pilot beam though the 26.7 km ring relies on the ability to properly correct the beam trajectory. The requirements for orbit correction on transfer functions and hysteresis of the LHC orbit...

22. Transfer function of quadrupoles and expected beta beating

Stephane Sanfilippo (AT/MTM)

24/01/2006, 14:30

We present data relative to the transfer function of all the quadrupoles in the machine, specifying how many different measurement system are involved, how cross-calibrations are carried out, and what is the final level of absolute and relative accuracy that will be reached according to the present baseline. Other sources of perturbation of the optic fuctions such as the precision of...

25. Hysteresis in magnet correctors versus tune and chromatic correction

Walter Venturini (AT/MTM)

24/01/2006, 15:00

As a follow-up of the discussions initiated at the last LHC Project Workshop, this contribution will concentrate on the aspects of the magnetic behaviour of Trim and Tuning Quadrupoles, as well as spool and lattice Sextupoles, which may be relevant for the machine operation. The measured magnetic hysteresis and its possible influence on setting errors during operation will be...

79. Field model deliverables for sector test and commissioning: when and what ?

Mike Lamont (LFC)

24/01/2006, 16:00

The implemention of an accurate magnetic model will be vital for efficient LHC commissioning with beam and subsequent machine performance. Given the conclusions of the RMS review, and the resource constraints, the proposed implementation of a magnetic model is described. The present state of the implementation is given along with the proposed planning for the deliverables required for the...

21. Sorting the magnets in the machine: what did/will we gain ?

Luca Bottura (AT/MTM)

24/01/2006, 16:20

The criteria for sorting the magnets in the machine are outlined, pointing out which are the most critical and the expected gain in terms of machine performances. The compatibility of the sorting with planning issues experienced in the past year is reviewed. The expected difference or similarity between the sectors is analysed, and the representativity of the first sector that will be...

83. Expected quench levels of the machine without beam: starting at 7 Tev ?

Pierre Pugnat (AT/MTM)

24/01/2006, 16:40

The quench training performance of about 900 LHC main dipoles and 200 main quadrupoles cold tested to date will be presented and commented. From these results an estimate of the number of quenches that could be required to operate the whole machine at nominal energy will be presented without considering beam loss effects. The energy level at which the machine could be operated...

26. Chasing parasitic magnetic fields in the LHC

Arnaud Devred (AT/MAS)

24/01/2006, 17:00

A tnetative summary of the parasitic fields in the LHC machine is presented. The impact on the beam is evaluated. Critical cases, such as the one of the connection cryostat, are reviewed and the solutions to avoid deleterious effects on the beam dynamics are outlined. A first pass at computing in 3D the field created by the busbars in the dipole-to-dipole interconnect is discussed.