Minutes of the LIS Section meeting held on 1st July 2013
Present: Androula Alekou, Fanouria Antoniou, Gianluigi Arduini, Hannes Bartosik, Elena Benedetto, Michael Bodendorfer, Vincenzo Forte, Adriano Garonna, Simone Gilardoni, Alexander Huschauer, Michel Martini, Meghan McAteer, Yannis Papaphilippou, Guido Sterbini, Rogelio Tomàs, Letizia Ventura
General Information (Gianluigi)
Gianluigi reminded the staff contributing to teaching, training, committees to fill in the web form Tracking KT through Teaching, Technical Trainings and Consultancy. This is available at: https://www.research.net/s/SurveyOnTeachingTrainingAndConsultancy
Gianluigi will be on duty trip (IPAC14 Scientific Programme Committee) from Wednesday 3/7 to Friday 5/7 included and then he will be on holidays from Tuesday 9/7 until Tuesday 23/7 included.
Optics Measurements in the PSB (Meghan) - slides
Meghan presented the results of the optics measurements performed in 2012-13 in the PS Booster. The linear optics was qualified from closed orbit measurements while preliminary turn-by-turn measurements have been performed in view of assessing the requirements for non-linear optics measurements.
LOCO measurements have been performed from 160 MeV to 1.4 GeV but only the 160 MeV data have been analyzed so far. The phase advance per cell of approximately 90 degrees is not optimum for beta beating measurements and requires attention in constraining the fit parameters. In that respect performing the measurements with a different working point would be advantageous and it is being considered.
The correction quadrupoles used to compensate beta-beating have been included in the analysis.
The quadrupole tilts measured during the survey performed during the shut-down are consistent with the measured orbit response and have been used to further constrain the fit. The corrector and BPM calibrations are within 10% while the tilts in the orbit correctors can be as large as 20 mrad. The measured dispersion can be fitted well without including any coupling. The resulting beta-beating is in the 10% range.
Simone asked whether the extraction kicker could be used to provide enough kick strength for the turn-by-turn measurements. Meghan replied that this has not been tested yet.
Gianluigi asked whether the same irregular envelope shape is observed with low intensity beams. Meghan replied that at low intensity the measurements are noisy.
Update on space charge simulations in the PSB (Elena)
Elena presented an update of the space charge simulations performed to study the effect of the installation of an inconel vacuum chamber in the chicane magnets. The plots presenting the emittance evolution vs. time refer to the physical emittance (not to the normalized one) and for that reason the emittance is decreasing. Emittance blow-up is observed if the quadrupolar error resulting from feed-down effects is not corrected properly. The blow-up is reduced if extra-trims (on top of those required to compensate the varying edge effects of the chicane magnets during the injection bump decay) are applied.
The MADX model of the aperture has been included in the estimations.
Most of the simulations have been performed with an extremely bright beam. Simulations need to be performed with HL-LHC parameters as well as for ISOLDE beams. Tune scans should be tried too. Action: Elena, Vincenzo.
The absence of spikes in the emittance evolution in the absence of aperture constraints is not yet understood. Action: Elena, Vincenzo.
Notes are being written for the MDs in the PSB and for the corresponding simulations
Short Round Table (all)
PS (Alexander, Guido, Letizia, Simone)
Civil engineering work in the Septum 16 area has started. Gianluigi asked whether there were any more issues with asbestos contamination in the tunnel during the work for the ventilation. Simone relied in the negative. The asbestos contamination outside the fenced areas was negligible and in any case was not exceeding the limits.
Neutrino activities (Androula, Fanouria, Yannis)
HP-PS dynamic aperture and collimation studies ongoing. The requirements on instrumentation for such a high intensity machine needs to be addressed.
The preparation of the Low Emittance workshop (approximately 80 participants) at CERN (8-10 July) is ongoing
BIO-LEIR (Adriano, Christian)
The option of using a cyclotron as injector for BIO-LEIR has been discussed with R. Ostojic but it does not provide sufficient flexibility as a linac.
ELENA (Christian, Tatiana)
A second version of the layout is now available. The contributions to the technical design report for electron cooling and beam instrumentation are still missing.
Monday, 29th May 2013 at 14:00 in room 6-R-012
Agenda:
General information (Gianluigi)
LSS2 fast extraction measurements and analysis (Androula)
Round Table (all)
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