Minutes of the ICE section

14th meeting on Wednesday 19/01/2011 (08:40-10:30, 6/2-004)

ICE members: Benoit Salvant (BS), Christian Hansen (CH), Carlo Zannini (CZ), Diego Quatraro (DQ), Hugo Alistair Day (HD), Elena Benedetto (EB), Ewen Hamish Maclean (EHM), Elias Metral (EM), Elena Wildner (EW), Frank Schmidt (FS), Giovanni Rumolo (GR), Jean-Luc Nougaret (JLN), Kevin Shing Bruce Li (KL), Maria Carmen Alabau Pons (MCAP), Nicolo Biancacci (NB), Nicolas Mounet (NM), Olav Ejner Berrig (OB), Tatiana Pieloni (TP), Werner Herr (WH).

Present/Excused: BS, CH, CZ, DQ, HD, EB, EHM, EM, EW, FS, GR, JLN, KL, MCAP, NB, NM, OB, TP, WH + Rama Calaga + Fritz Caspers.

1) Newcomers / visitors

- 2 visitors have been invited by Frank Zimmermann to work with us on ecloud:

- Two-week visit by Ubaldo Iriso from CELLS for the study of scrubbing scenarios with a map approach (17-29/01/2011),

- 3.5-week visit by Giuliano Franchetti for modeling the incoherent electron-cloud effect (14/02-08/03/2011).

2) Comments on the minutes of the 11-12-13th meeting + Actions

- No comments.

- List of Actions.

3) General infos

- No particular comment from anyone.

- SL meetings on 25/11, 02/12, 28/12 and 12/01:

- The tram line to CERN will be completed in April 2011. There are still discussions concerning the construction of a parking.

- E. Cennini is the CERN link person in and outside CERN on environmental issues.

- Paul Collier will give his department presentation on 15/02/2010.

- Seminar from V. Shiltsev on Monday 13/12/2010 => Its a pity that only few people could attend (a lot of people from OP and LCU attended). EM said that the same day the ICE section had a ski outing day, which explains the ICEs absence. But we should try and attend the seminars/fora etc. in the future.

-  LHC-CC10 (crab cavity) workshop took place at CERN at the end of the year => Some of the conclusions and decisions from Fridays meeting of the LHC-CC Advisory Board chaired by Steve Myers:

- There will be no SPS test with KEKB crab cavities, for a number of reasons (cost, difficulty, extrapolation to LHC, risk).

- The HL-LHC baseline is a local scheme with 400 MHz frequency.

- The situation of machine protection as a possible show stopper is still not absolutely clear.

- There is almost no synergy with CLIC crab cavities.

- No showstopper for compact cavity designs has been found. 3 or 4 promising compact designs exist.

- Additional detailed specifications (transparency, impedance, field quality, fundamental-mode damping, trip rate?) are needed for these cavities.

- What exactly should be tested with beam (machine protection, making cavities invisible, etc. final collimation system will have impact).

- Cavity prototyping should continue. Each cavity may need a special power coupler. A cryomodule time line need to be worked out. There could be generic cryomodule for testing all cavities. A cryostat already exists at CERN.

- Other, additional applications of crab cavities should be investigated.

- A refined roadmap will be sketched.

- All operation budgets are cut by 10% (including travel).

- Alexey Burov should arrive at CERN on April 25, 2011.

- Vittorio Vaccaro should arrive at CERN on February 1, 2011.

- The LHC BCWG should stopped and be replaced (still to be confirmed) by a LPOC (LHC Performance and Operation Committee) chaired by Jorg Wenninger and TP should be the scientific secretary.

- Discussions for a CERN-GSI AccNet EuroLumi 1-day mini-workshop at CERN on 7 March, focused on electron-cloud studies at CERN and GSI (GR).

- The operation of the Tevatron will finally end in FY 2011, as originally scheduled.

- FritzC mentioned that a multipacting test bench is being prepared in building 181 to measure the onset of multipacting => It is an SPS magnet with a vacuum chamber and a wire inside to simulate the beam and therefore be independent of the beam. Should start to make measurements around April (student coming).

- 40th anniversary of the 1st p-p collisions in the CERN ISR on Tuesday 18/01:

- The 1st p-p collisions happened on January 27th 1971.

- Talks in particular by Kurt Hubner and Phyl Bryant for the accelerator part.

- The record luminosity of 1.4E32 (of Dec. 1982) was not beaten until 1991 by CESR at Cornell with 1.7E32.

- Brickwall instability => Shortly after the start of the ISR, a coherent transverse instability limited the beam current. One    explanation invoked dust jumping into the beam, once the beam potential had reached a certain value. However, studies of the shape of the working line in the tune diagram revealed the culprit to be image space charge tune shifts.

- There will be a yellow report.

- Note that the ISR magnets are now used in the LHC beam dump.

4) News on ecloud, beam-beam and impedance for Chamonix => See round table + http://emetral.web.cern.ch/emetral/ICEsection/ICE.htm where the different activities can be followed.

5) Actions to be taken for the next meeting

- Old actions.

6)  Miscellaneous

- The next (15th) meeting will take place on 26/01/2010 => Agenda:

1) Nufact10 and Beta Beams for the Euronu mid term (EW)

2) Update on collective effects studies for beta-beams in the decay ring (CH)

3) Possibility of a I-cooling experiment in rings with internal target (EB)

- See preliminary agendas for the next meetings.

Minutes by E. Metral, 20/01/2011.