Minutes of the LIS Section meeting held on 18th March 2013
Present: Javier Alabau, Androula Alekou, Fanouria Antoniou, Gianluigi Arduini, Hannes Bartosik, Elena Benedetto, Christian Carli, Vincenzo Forte, Adriano Garonna, Alexander Huschauer, Guido Sterbini, Letizia Ventura, Raymond Wasef
General Information (Gianluigi)
LHC Run I has finished on Saturday 16th February. After a successful end of the p-Pb run with more than 30 nb-1 delivered to ALICE, ATLAS and CMS an intermediate (1.38 TeV) energy high intensity proton run has taken place followed by quench tests. The results of the quench tests are being analyzed but the preliminary indications are encouraging and showing quench limits higher than those initially estimated. At the end of the operation with beam a period of hardware commissioning tests has followed to identify possible limitations in the circuits to guide the interventions during the shutdown.
A LHC Machine Protection Workshop has taken place in Evian form 11 to 13/3: https://indico.cern.ch/conferenceDisplay.py?confId=227895
The CERN Machine Advisory Committee has taken place on 14/3 (open session) and 15/3 (closed session): https://indico.cern.ch/conferenceDisplay.py?confId=235072
Gianluigi encouraged the team to join the team of guides. There is a strong requests for guided visits in the member states.
On 13/3 an H- beam has been accelerated to 3 MeV through the LINAC4 RFQ in the 3 MeV test-stand.
A LIU meeting will take place on 12/4/2013 to review the progress since the last November meeting (https://indico.cern.ch/conferenceOtherViews.py?view=standard&confId=238152).
Round Table (all)
SPS (Hannes)
Hannes is finalizing the analysis of the SPS data with the Q20 optics. He has attended a workshop of the German Nuclear Physics community (http://www-win.gsi.de/AK-Schleching2013/index.html - in German) where he has given a presentation on the SPS activities. Hannes is also writing his Thesis.
Neutrino Studies (Androula, Fanouria, Javier)
Working on the understanding of the origin of the coupling observed in the trajectory of the beam extracted from LSS2 for the Short Baseline Neutrino Experiment. Gianluigi suggested to use normalized coordinates to localize the observed source of coupling that should appear as the start of a sinusoidal oscillation in the vertical plane.
Fanouria has presented two possible solution for the HP-PS study to produce a beam power of 2 MW at the last LAGUNA meeting held at DESY from 25th to 27th February (http://laguna.ethz.ch/indico/conferenceDisplay.py?confId=8). The baseline is a 50 GeV machine requiring a maximum bending field of 2 T and one for 75 GeV requiring a maximum bending field of 3 T. Both options are based on superferric magnets being studied by J. Alabau in collaboration with TE/MSC.
Next LAGUNA meeting will take place at CERN on 10-12/6.
PS (Alexander, Guido, Letizia, Raymond)
Analysis ongoing in preparation of the Space Charge Workshop (http://indico.cern.ch/conferenceDisplay.py?confId=221441)
Raymond experienced problems running long simulations with ORBIT-PTC. The simulations crash after some time. Gianluigi and Elena suggested to contact Frank Schmidt. Raymond also noticed different final distributions when running simulations having the same parameters and the same initial distribution. It is not clear whether this is due to numerical noise. Frank Schmidt should be informed.
Letizia is studying whether the main mode of the 10 MHz RF cavities can explain the impedance responsible for the coupled bunch longitudinal observations observed in the PS.
Guido has started measurements to characterize the bandwidth of the digital card of the PS Transverse Feedback as a function of the clock frequency with J. Kuczerowski. The first measurements seem to indicate that the card is limited at 40 MHz.
Guido is also looking at the optimum position for the installation of a new electron cloud monitor in the main magnets of the PS. This monitor is measuring the photons (visible range) emitted from the vacuum chamber by the electrons impinging on its surface.
PSB (Elena, Vincenzo)
On 11/4 Elena will present the first results of the simulations to understand the impact of the non-linear fields induced by the eddy currents on the Inconel vacuum chambers of the PSB injection chicane magnets during the injection process. The presentation at the PSB-LIU meeting should be preceded by a presentation at the LIS meeting next Monday 25/3. The first results seem to indicate a small but visible blow-up for the LHC beams.
Vincenzo has started to write some documentation on the use of ORBIT-PTC mostly addressing the tools used for the PSB simulations. He will pass that to Frank Schmidt for publication in the space charge web repository. A new beta version of ORBIT-PTC including some modifications made by A. Molodozhentsev to properly include the aperture has been made available.
LEIR bio-medical (Adriano)
The sextupolar driving terms for LEIR contain a contribution resulting from the LEIR main dipoles. These could be due to the fringe fields. Hannes suggested to switch off the effect of fringe fields. This is possible in PTC.
LEIR (Michael)
Michael is analyzing the data taken with the beam ionization profile monitor (IPM). Discrepancies are observed between the signal measured by the IPM and the total intensity measured with the fast BCT. Michael is trying to understand this with G. Tranquille.
Michael is analyzing the data taken with the tune measurement monitor (BBQ) to measure the chromaticity.
He has also helped K. Li to speed-up the Head-Tail code.
ELENA (Christian)
A new optics of the AD to ELENA transfer line has been provided by P. Belochitskii. It has been decided to proceed with the modifications of the transfer line from AD to the experimental area already during LS1 to prepare the installation of ELENA.
Monday, 25th March 2013 at 14:00 in room 6-R-012
Agenda:
General information (Gianluigi)
Status of the studies on the PSB Inconel Vacuum Chamber in the injection region (Elena)
Status of the measurements at LEIR low energy (Michael)
Round Table (all)
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