Summary notes of the HSS meeting on 31/03/2014

Present: HB, SF, MF, MG, JJ, DM, AS, CT, RT, FZ, MM

Report from meetings

• SLM and general information -> MG
  The general part was rather short : a discussion on the 2015 optics with Mike and Joerg is planned for tomorrow.
• LBS -> HB
  LBS#52 on the 10 March was mostly on the Monte Carlo studies aiming at a minimization of background and remnant radiation relevant for shutdown work, slides and minutes can be found on indico.
  Helmut also said that the recent EIC'14 conference which Oliver Brüning, Alessandra Valloni and he attended for our group, was very interesting and recommends to consult the slides, which can be found here.

Linear optics measurements and preparations for nonlinear optics measurements in the PSB -> Meghan McAteer (slides)

After briefly recalling the main parameters of the PS booster, Meghan described the status and interpretation of optics related measurements.
Turn by turn measurements were attempted, but currently suffer from noise which is believed to originate in electrical noise on the focusing quadrupoles. The power convertor group with F. Boattini et al. reported they found a potential noise source an plan a reduction by active filtering. This should resulted in more stable tunes and improve measurements.
A transverse instability occurring after about 400 ms from injection has been observed. The origin is currently not well understood.

Linear optics measurements have been successfully performed and were analyzed with LOCO. The orbit response matrices and dispersion where measured for each booster ring.

Beta beating is less than 10% for all rings.

Noise reduction and full performance of all BPMs should allow in future for improved linear and non-linear optics measurements.

For the non-linear measurements, excitation of large amplitudes can be obtained with the tune kicker or the transverse damper used as AC dipole.

Impact of known NCR on machine operation -> MG (slides)

Massimo presented the known non-conformities in the LHC after LS1 and their consequences. This presentation was given in preparation of his presentation to the LMC on Wednesday.

The impact of these non-conformities should be minimal in normal operation and not limit the LHC performance.
Actual current limits are available from /afs/cern.ch/eng/lhc/optics/V6.503/Imax.madx updated today. For further details see the slides and LMC#177.

AOB 

Last update: 13-April-2014

MG & HB

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