Minutes of the LIS Section meeting held on 14^th February 2011

Present: G. Arduini, H. Bartosik, C. Carli, S. Gilardoni, M. Martini, M. Newman, Y. Papaphilippou, G. Prior

General Information (Gianluigi) 

Chamonix outcome: 3.5 TeV operation in 2011 and operation in 2012. New measurements to be performed on the splices during the next Christmas stop to determine the energy for 2012.

• MAC reccomendations:
  • Scrubbing with 50 ns asap
  • Continue with 50 ns for physics and step back to 75 ns only if strictly needed.
  • Agreed with the proposal to delay the first long shut down
  • Encouraged CERN to prepare a resource load long-term planning
  • Encouraged CERN to organise a review for the interconnects and proceed with the thermal amplifier.
  • Encouraged CERN to stay at 3.5 TeV this year.
  • Encouraged CERN to optimise the performance of the injectors for 50 ns and 75 ns.
  • Encouraged CERN to pursue the wire beam-beam compensation in the framework of the HL-LHC project.
  • Encouraged CERN to pursue the analysis of the batch compression scheme, while were not particularly supportive for the RCS option.
• Implications of the Chamonix decisions: can the LINAC4 connection to PSB be advanced? Length of the Christmas stop to be increased. These items will have to be discussed at the IEFC.

New committees: LHC Beam Operation Committee (chairman: J. Wenninger, deputy: Gianluigi, Sc. Secr: T. Pieloni) and LHC Studies Working Group (chairs: R. Assmann and F. Zimmermann)

FOM: a new Scientific Secretary has been appointed (B. Salvant).

• IEFC (11/02/2011):
  • SPS: After consolidation of the water manifolds for the Lintott MBB dipole magnets no more leaks have been observed on these magnets. On the other hand water leaks start now to appear on Alsthom magnets (MBA and MBB). According to the magnets team consolidation is situ should be possible for these magnets and there is no requirement for opening the magnets.
  • Other items in the agenda were:
    • Short summary from Chamonix 2011
    • Report from the SPSC (17.-19. Jan.)
    • Reject water issue
    • HiRadMat - installation progress, commissioning plan.

IEFC workshop is going to take place from 21/3 to 24/3 in the Kjell Johnsen Auditorium.

VIA fellows: 2 requests have been retained (3 MeV test stand, PS Upgrade).

Summer student project list collected by Delphine.

Round Table

Simone

80 MHz cavities in the PS: One problem due to inclination of the tuner tearing some of the RF contacts. Solved by supporting the tuner. Issue with the corrosion of RF contacts in the coupler due to water leaks. Modifications are being prepared for the next Christmas stop. (see some photos here: https://espace.cern.ch/be-dep/FOM/Presentations%202011/08-02-2011/80MHz_cavity_FOM_08022011.pdf )

PS upgrade: Work Packages for the PS being collected. RCS study by June with cost estimate for summer to decide on RCS or PSB Upgrade by the end of the year. In parallel the possibility of advancing the connection of LINAC4 to PSB is being considered.

Consolidation plans are also being reviewed. PS magnets are not an issue according to the magnets experts and can run for 25 years both PS and SPS. Simone stressed that this could not be the case if we change the ramp rate of the magnets as considered for the PS neutrino experiment proposed by C. Rubbia.

POPS is now driving the PS magnets. The following beams have been prepared: CT, LHCINDIV and LHCPROBE (the LHC beams have still to be captured on the 40/80 MHz systems.

 For MTE the first beam to take is single bunch to see whether we can jump the septum blade.

Gianluigi (SPS)

SPS start-up perturbed by an obstacle in 218 (a bump had to be applied) and with a screen in point  4 which was found to be IN

SPS voluntary misalignment to be done today.

Myriam

Analysis of the effect of the low energy quadrupoles as possible sources of the fluctuations in MTE capture efficiency/losses: the data cannot be used because of a time jitter in the acquisition due to the firmware installed in some of the new ADCs. The same ADCs are used for the acquisition of parameters like the FMR of the PSB and PS. The problem is now solved.

Hannes

SPS low gamma transition optics: lower chromaticity sextupoles are required due to the larger dispersion and due to the lower natural chromaticity. This could explain why the dynamic aperture is larger than that calculated for the nominal optics.

ORBIT-PTC tests done by Hannes for studying space charge in the SPS. To be discussed with Christian, Michel and F. Schmidt.

Gersende

New MARS version on a CERN machine (64 bit version). Need to run again the simulations to see the differences. Working with Ilias's student to optimize the tapering of the solenoid of the front-end.

Christian

Measurement line being studied by Lutz Heine with A. Lombardi.

Next meeting

Monday, 14^th March 2011 at 14:00 in room 354-1-001

Agenda

• General information (Gianluigi)

• MTE for PS2 (Antoine)

• Injection losses in the PS - summary of the findings (Sandra)

• Round table (all)

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