Summary notes of the HSS meeting on 15/09/2014

Present:  LD, SF, MF, SG, MG, RdM, JSM, EM, GR, TP, GV, RW

Report from meetings

• SLM and general information -> MG
  All those who helped with the organisation of the ABP BBQ are warmly thanked!
  In the framework of the optics activities for 2015, Massimo has launched a verification of the triplet gradient value to be used in collision for IR2 and 8.
  The organisation of the annual HiLumi workshop is progressing. The list of participants has been approved by the sector and departments.
  Among the recent requests for new computing hardware, Riccardo proposed to have a new system with large disk space and very fast access to the data. This would be ideal to transfer MD or operational data (LHC or injectors) to this machine for an off-line analysis. This requests seems to interest also other users and Massimo will check whether the service could be requested to, e.g., BE/CO.
• Injectors status and studies -> SG
  The first beams have been injected in the SPS last Friday.
  The MDs in the PS are mainly focusing on: checking of machine impedance and e-cloud measurements using new detectors.
• MAD-X status -> LD
  The executable for MAC OS 10.9 is not working: investigations are in progress.
  PTC_track: an improper initialisation has been found and should be fixed.
  Solenoids: the physics model should be checked.
  Memory corruption has been observed.
  The physics of thick dipoles should be reviewed.
  MAD-X SC: it has been agreed with Frank that a new command to compute space charge will be added to MAD-X. This, however, does not solve the problem of inserting the space charge elements in the lattice (currently these additional elements are included in the lattice by means of external scripts, which should be also embedded into MAD-X).
• SixTrack status -> RdM
  The new environment with new analysis options is being debugged.

Injection Tunes (first experiences) -> RdM (slides, additional material)

The aim of this study is to measure the tune shift vs. intensity at LHC injection using the data from the operational fills. A possible application would be to determine a feed forward correction of the LHC tune at injection.
The first challenge consists of finding data suitable for the analysis. In the end, it was found that the injection oscillations can provide useful information, provided the appropriate analysis technique is applied.
Additional points to be taken into account in the analysis: effect of MQTs at injection, tune decay due to persistent current effects.
Bunch-by-bunch data have been analysed, revealing puzzling effects to be understood.
This preliminary study has also revealed incomplete data stored or unclear logic for the selection of stored data (IQC) and also highlighted the possibility of using the huge amount of data in the post-mortem system for this type of analysis. All this will be also presented at a future LBOC to present the requests for improvement of the data stored.

AOB 

None

Last update: 08-September-2014

MG & HB

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