Minutes of the LIS Section meeting held on 23rd March 2009

Present: G. Arduini, S. Aumon, J. Barranco, O. Berrig, C. Carli, M. Chanel, A. Franchi, S. Gilardoni, C. Hansen, S. Maury, E. Métral, N. Mounet, Y. Papaphilippou, D. Quatraro, B. Salvant, E. Wildner

General Information (Gianluigi)

The ATOP days summary will take place on 1st April.

The first meeting of the IEFC (LHC Injectors and Experimental Facilities Committee) has taken place on 20th March and it has been dedicated to the presentation of the "modus operandi" of the committee and of the corresponding working groups. A summary of the ATOP days has been given by S. Maury and K. Hanke. (IEFC minutes)

An HW Commissioning day has taken place on 19th March (link) and it has been dedicated to the review of the strategy and plans for the commissioning.

Gianluigi reminded the members of the Section that a a refresher of the course "Habilitation Electrique pour non-electriciens" should be attended every 3 years in order to keep the access rights in the tunnel. A web version of the course is being put in place but the members of the section needing the refresher are encouraged to enrol for the standard course so that they can be informed once the web version is available.

A new European Programme providing additional funds to the CERN fellowship programme has been launched and it allows extending the fellowship to 3 years. The selection of candidates will be done in the frame of the CERN fellowship programme.

The Beta Beam study (Elena Wildner) - slides

Elena gave an overview of the Beta Beam study.  So far 6He and 18Ne have been considered as b emitters. EuroNu will investigate the option of using 8LI and 8B as emitters. The required production rates have been based on the required neutrino annual rates taking into account the length of the cycles required in the different machines. But this is based on the assumption that there will be no other user of the existing accelerator chain and assuming 100%  availability of the whole chain. Gianluigi noted that this is certainly too optimistic.

It is proposed to use a 60 GHz ECR source to ionize the radioactive ions. Christian and Gianluigi noted that so far there is experience with sources running to a frequency up to 18 GHz and it is not easy to get the expected theoretical scaling of intensity with frequency.

CERN will take care of the design of the production ring, and of the decay ring. PS2 is past of the injection chain for the decay ring. C. Hansen will study the option of filling the decay ring using barrier buckets. A possible design of the dipole based on an open mid-plane geometry exists.

Round table (all)

Yannis reported that it is planned to reduce the beam aperture for the PS2. The machine should be mainly designed for the LHC beam. The aperture for the fixed target beam would be defined by the collimators at 3.5 sigma. Gianluigi noted that for an high intensity machines as the PS2 deemed to operate for some decades some margin should be left. He also suggested Yannis to summarize the work done so far in a paper. Elias noted that an aperture of 3 sigma has been considered for the FAIR project. Gianluigi replied that the accelerators of the FAIR facility are operated at low intensity. He also asked what is the design aperture for J-PARC. Yannis replied that this is also small and he will verify the exact value.

The LARP contribution is still very limited.

Sandra reported that for the moment no reasonable solution for matching the dispersion at injection in the PS has been found

Olav reported that the results of the FT61 survey have been made available by T. Dobers. The optics for the different PS energies are being introduced in the optics repository. The optics model are based on measurements taken on the MDPS cycle. Measurements performed on the LHC cycle by Yannis seem to indicate that the chromaticity on this cycle at flat-top was negative.

Christian reported about some problems with LSA discovered during the controls tests performed in LEIR. He is in contact with G. Kruk. The control of the timings is still done with the old application. It will be implemented in INCA.

A pressure rise has been observed in LEIR in Sector 2 (electron cooler). The pressure has started to rise since the end of last year. TE/VSC will make a gas analysis as soon as they hav completed the work in the other injectors. Christian will follow-up this issue.

Gianluigi asked whether we have spares for the component of the electron cooler. Christian replied in the affirmative. If an intervention is needed on the electron cooler about 3 weeks are required to recover the vacuum. Therefore no delay is to be expected for LEIR for the time being.

Diego has made some simulations with HEADTAIL to study the TMCI threshold dependence on space charge in order to test the new space charge module in HEADTAIL. The results seem to be consistent with previous simulations done by Giovanni. Gianluigi reminded that it would be important to summarize in a MD note the analysis of the data taken on the instability observed at low energy in the PSB and the present knowledge of the PSB impedance model.

Andrea is studying the effect of the chirp noise on the capture efficiency for the MTE. This proved to be very effective for increasing the capture efficiency during the MTE commissioning.

 Elias and Benoit reported that the discrepancy (factor 4.4) between theory and simulation for simple geometries (rectangular resistive chambers) is not yet understood. C. Zannini is working on that.

Nicolas is continuing the theoretical work on the derivation of the electromagnetic fields in a cylindrical chamber.

Simone has started the study of the effect of a failure of a PFW in the PS with the help of Sandra.

Elias reported that a new filling scheme is being studied by Elias, Werner Herr, Massimiliano Ferro-Luzzi for ALICE.

Gianluigi asked whether Elias got any feedback from the gSI colleagues after the CERN-GSI workshop. Elias replied in the negative.

Elias reported that no intervention has been done on the TT20 BSI.

Next meeting

Monday, 20th April 2009 at 14:00 in room 354-1-001

Agenda:

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