Minutes of the LIS Section meeting held on 15th June 2009

Present: G. Arduini, J. Barranco, H. Bartosik, E. Benedetto, C. Carli, M. Chanel, S. Gilardoni, P. Jackson, G. Lund, M. Martini, S. Maury, G. Prior, D. Quatraro, G. Rumolo, M. Schaumann, M. Scholz, J. Wehner, E. Wildner

General Information (Gianluigi)

Three new students have joined the LIS section for the summer period (G. Lund, M. Schaumann and J. Wehner). They will be working on subjects related to Beta Beams and IBS.

From IEFC:

An oil leak has developed on the 66 kV bushings of one of the two 400 to 66 kV transformer. The transformer has been sent to the manufacturer for repair but it will be available only middle-end of July. The transformer is designed for a maximum power of 160 MVA but last year peaks of 190 MVA have been reached. The load on this transformer could be reduced by powering part of the CERN accelerators form EOS but the electricity price form EOS is double that of EDF. For the moment the power consumption is continuously monitored by the Technical Infrastructure team. Before starting high power equipment TI should be informed so that they can monitor the power consumption and stop the test if needed in order to avoid reaching the interlock level on the transformer.

S. Maury has presented the first ideas for running the NA61 ion fixed target physics experiment in the North area with Ne, Ar and Xe ions. This would imply running the ion injectors for a large fraction of the year in the period 2010-2013 (essentially more than doubling the operation time of source, LINAC3 and LEIR).

It was agreed that a thorough evaluation of the resources required and of the implications of sending primary beams in the North area should be clearly identified. These should be presented at the IEFC before any presentation to the SPSC.

An extension of the LINAC3 run with ions by 3 weeks for ion desorption studies in cryogenic conditions has been recommended by the MSWG and approved by the IEFC. In reply to a question I asked  Stephan said that this possibility has been discussed with Richard and seems feasible.

LHC:

HW commissioning for Sector 23 has started

Measurements at 80 K were conducted in Sector 45 to qualify the continuity of the copper stabilizer in the interconnections. At least an outlier has been observed and it has been decided to warm-up the sector 45 to conduct measurements at room temperature and compare them with the 80 K measurement to validate the latter.

 

An "electrical safety awareness" course is available on the web (http://sir.cern.ch/). This course is NOT an “habilitation électrique” but will be sufficient to grant access to accelerator enclosures. The practical part proposed mentioned on the web will be simply suppressed and there will be no signature required by the supervisor. At the end of the course the success at the quiz tests will be simply registered in the database.

 

Highlights from PAC09 (D. Quatraro) - slides

During the conference there were some discussion on possible upgrades of the ORBIT code. J. Barranco suggested to add the feature of reading the lattice from MADX output files (at present this can only be done from MAD8)

SNS colleagues reported about a failure of the stripping foil support, this seems to be related to the fact that the SNS stripping foil is installed in a region with magnetic field in order to strip electrons from hydrogen atoms in excited states escaping from the stripping foil. The stripped electrons are probably hitting the foil and overheating it. In LINAC4 the fraction of neutrals escaping the foil is expected to be lower as compared to the case of SNS and therefore the stripping foil will not be installed in magnetic field for LINAC4.

Yannis asked what is the maximum magnetic field of the J-PARC dipole magnets. Simone replied that this is 1.8 T. Yannis noted that for the moment the maximum dipole field assumed for PS2 is 1.7 T. So far an intensity of 0.04×1013 p/cycle has been achieved (nominal is 1013 p/cycle).

Round table (all)

Simone mentioned that it has not been possible to optimize the multi-turn extraction due to the unavailability of the wire scanners. Some progress has been done with the instrumentation in the PS although so far the availability has been poor, in particular there are still some doubts about the calibration of the wire scanners in the horizontal plane while the agreement between wire scanners and SEM grid measurements in TT2 is good in the vertical plane. The speed of the scan is limited to 15 m/s due to a limitation in the regulation of wire movement. Weekly follow-up meetings are taking place with the BI expert to sort-out the remaining problems. MTE Extraction should take place towards the end of June and at that time optics measurements in the injection line to the SPS should be possible.

Michel Martini has started simulations of the injection process from LINAC4 to PSB with realistic parameters with ORBIT. Painting and the decay of the injection bump and the effect of the edge focussing of the injection bumpers are included in the simulation. 100000 macroparticles are used for the simulation. The distribution obtained at the end of the injection process can then be used for longer term simulations of the distribution evolution during the ramp.

The ORBIT programme is now installed in the lxclic cluster. The installation has been done mainly by Masamitsu and Christian.

Yannis said that it is planned to freeze the lattice design for the PS2 this autumn. A review of the lattice will be organized. He added that stringent constraints are imposed on the maximum strength of the dipoles and quadrupoles. E. Mahner has provided a very preliminary design of the vacuum system. Carbon coating will be used to minimize the Secondary Electron Yield and NEG strips will be added to provide a good pumping speed.

Yannis added that the vacuum leak that occurred in the PS last week was due to a failure of a by-pass resistor close to an RF cavity. This could be due to the large peak current induced on these resistors by the NToF beam. It seems that a similar failure occurred in 2004.

LEIR cold check-out has started. Beam commissioning is supposed to start on 6th July.

Gersende is continuing the simulation of the Neutrino Factory front-end (CERN scheme) with ICOOL.

Next meeting

Monday, 29th June 2009 at 14:00 in room 354-1-001

Agenda:

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