LHC Performance Workshop - Chamonix 2012

Session

S07 - After LS1

9 Feb 2012, 08:30

Chamonix

Conveners

S07 - After LS1

• Rudiger Schmidt (Chair)
• Mirko Pojer (Scientific Secretary)

41. Performance potential of the injectors after LS1

Heiko Damerau (CERN)

09/02/2012, 08:30

The main upgrades of the injector chain in the framework of the LIU project will only be implemented in the second long shutdown (LS2), in particular the increase of the PSB energy to 2 GeV or the implementation of cures/solutions against instabilities/e-cloud effects etc. On the other hand, Linac4 will become available by the end of LS1. Its connection to the PSB can then take place either on...

44. Performance reach of LHC after LS1

Werner Herr (CERN)

09/02/2012, 08:55

Based on past experience (2010/2011), in particular expected limitations from beam-beam effects, and taking into account the expected beam quality from the LHC injectors, the peak and integrated luminosities at top energy are discussed for different scenarios (e.g. bunch spacing, beta*). In particular it will be shown which are the key parameters to reach the nominal luminosity and whether it...

49. Magnet powering with zero downtime - a dream?

Markus Zerlauth (CERN)

09/02/2012, 09:20

Despite a number of improvements already applied in the course of the year, the magnet powering system of the LHC still accounts for around 50% of the premature beam dumps. This number might even further increase when moving to higher beam energies in the next years. With mitigations of radiation effects and the prospects for beam induced magnet quenches being discussed elsewhere, we aim at...

45. Beam systems without failures – what can be done?

Jan Uythoven (CERN), Matteo Solfaroli Camillocci (CERN)

09/02/2012, 09:45

The beam dumps triggered by interlocks not related to the magnet powering are discussed. This concerns the systems like the RF, the transverse feedbacks, beam instrumentation, beam dumping system, collimators and control systems. An analysis of the reasons of these dumps is presented together with a possible strategy to mitigate the effect of these failures.

47. Will we still see SEEs?

Marco Calviani (CERN)

09/02/2012, 10:40

The actions during the first years of the R2E Mitigation Project allowed to drastically reducing the rate of Single Event Errors on radiation sensitive electronic equipment installed in the LHC underground areas. Shielding and relocation activities during LS1 will allow the resolution of the present issues concerning UJs of P1, 5 and 7 as well as the P8 cavern. The parallel development of...

53. UFOs – will they take over?

Tobias Baer (CERN/Hamburg University (DE))

09/02/2012, 11:05

During UFOs are one of the major unexpected performance limitations of the LHC. With large-scale increases of the BLM thresholds, their impact on LHC availability could be mitigated in the second half of 2011. For higher beam energy and lower magnet quench limits, the problem is expected to be considerably worse, though. Therefore, in 2011, the diagnostics for UFO events were significantly...

54. Quenches: will there be any?

Arjan Verweij (CERN)

09/02/2012, 11:30

Quenches in superconducting circuits are part of the normal operation of the LHC, and can never be excluded. Operation at 3.5 TeV resulted in only a small amount of quenches in 2011, especially because most magnets were operated below 20% of the critical current, resulting in a temperature margin of about 5 K. When operating at about 6.5-7 TeV beam energy, the temperature margin will only be...