LHC Beam Operation Workshop - Evian 7-9 December 2010

Session

Session 6: Luminosity performance

9 Dec 2010, 09:00

Hilton, Evian

Description

Chair: Malika Meddahi; Scientific Secretary: Verena Kain

Presentation materials

Discussion Summary

LuminositySessionSummary1.docx

LuminositySessionSummary1.pdf

19. Longitudinal and transverse emittance preservation

V. Kain

09/12/2010, 09:00

The preservation of the transverse emittance is crucial for luminosity performance. At the LHC design stage the total allowed emittance increase was set to 7 % throughout the LHC cycle. The injection process is particularly critical in this respect. Results of an analysis quantifying the emittance increase from injection to stable beams will be presented. The luminosity goals of the 2010...

20. LHC Beam-Beam

W. Herr

09/12/2010, 09:20

First experiences with colliding beams have been collected during the 2010 LHC run and some observations of beam-beam effects will be reported. The observations are interpreted and critically compared with the expectations and strategies proposed at the previous workshop. Based on the available information, possible limitations are evaluated and strategies for the optimization are derived.

21. Strategy for luminosity optimisation

S. White

09/12/2010, 09:40

Integrated luminosity is a key parameter for the performance of a particle collider and depends both on beam parameters and operational efficiency. The experimental detectors are turned on and start acquiring useful data only when the machine is declared as stable, it is therefore important to minimize the duration of the activities from the collapsing of the separation bumps until STABLE BEAM...

22. The LHC optics in practice

R. Tomas

09/12/2010, 10:00

During LHC 2010 run, approximately 40 experimental sessions for optics Measurements were carried out. Both local and global corrections were implemented demonstrating the feasibility of achieving 10% peak beta-beating. The long-term optics stability is presented with extrapolations of errors down to beta* of 0.55 m. Operational issues arising during corrections, as the treatment of hysteresis,...

23. Hump: how did it impact the luminosity performance?

G. Arduini

09/12/2010, 10:20

The status of the measurements performed to characterize and identify the origin of the so-called hump will be presented as well as its impact on beam performance and the countermeasures found to mitigate its effects. The directions for future investigations will be outlined.

24. LHC Beam parameters: pushing the envelope?

E. Metral

09/12/2010, 10:40

The goal for 2011 is to deliver an integrated luminosity of one inverse femtobarn to the experiments. This will require to gain an order of magnitude in peak luminosity, i.e. run with values of more than 1E33 cm-2s-1, whereas a maximum of ~2.07E32 cm-2s-1 was achieved so far. Many collective effects were observed this year, first when the intensity per bunch was increased and subsequently when...