Minutes of the ICE section
73rd meeting on Wednesday 12/12/2012 (08:40-10:30, 6/2-004)
ICE members: Benoit Salvant (BS), Carlo Zannini (CZ), Danilo Banfi (DB), Hugo Alistair Day (HD), Elias Metral (EM), Elena Wildner (EW), Frank Schmidt (FS), Giovanni Iadarola (GI), Giovanni Rumolo (GR), Jean-Luc Nougaret (JLN), Kevin Shing Bruce Li (KL), Nicolo Biancacci (NB), Nicolas Mounet (NM), Olav Ejner Berrig (OB), Serena Persichelli (SP), Sergio Rioja Fuentelsaz (SRF), Tatiana Pieloni (TP), Werner Herr (WH), Xavier Buffat (XB).
Present/Excused: BS, CZ, DB, HD, EB, EM, EW, FS, GI, GR, JLN, KL, NB, NM, OB, SP, SRF, TP, WH, XB, Alessandro Vivoli, Alexander Molodozhentsev (from KEK), Alexej Grudiev, Alexey Burov (from FNAL), Andy Butterworth, Bettina Mikulec, Cedric Hernalsteens, Chandrashekhara Bhat (from FNAL), Christian Carli, Christine Vollinger, Daniel Valuch, Daniel Wollmann, Eirini Koukovini Platia, Elena Shaposhnikova, Fanouria Antoniou, Frank Zimmermann, Fritz Caspers, Gabriel Mueller, Gerad Tranquille, Gersende Prior, Giulia Papotti, Giuliano Franchetti (from GSI), Georges Trad, Hannes Bartosik, Harry Renshall, Haryo Sumowidagdo, Helmut Burkhardt, Humberto Maury Cuna, Javier Fernando Cardona, Ji Qiang (from LBNL), John Jowett, Kazuhito Ohmi (from KEK), Lajos Bojtar, Massimo Giovannozzi, Mathilde Favier, Michel Martini, Miriam Fiterrer, Octavio Dominguez Sanchez de la Blanca, Rama Calaga, Raymond Veness, Raymond Wasef, Riccardo de Maria, Roderik Bruce, Rogelio Tomas, Sandra Aumon, Simon White, Stephane Fartoukh, Tatiana Libera Rijoff, Theodoros Argyropoulos, Tom Mertens, Uli Wienands (from SLAC), Valeri Lebedev (from FNAL), Vittorio Vaccaro (from Naples), Wolfgang Hofle, William Andreazza, Yannis Papaphilippou, Yuri Alexahin (from FNAL).
1) Newcomers / visitors
- None.
2) Comments on the previous meeting + Actions
- No comment.
3) General infos
- SL meeting:
- Travel reimbursements should be done before the end of the year.
- Reminder: IPAC14 will take place in Dresden and recently the decision was taken for the next IPAC17 => Copenhagen (as there will be MAX4 which will start and ESS).
- News from LHC:
- Some results with tune split => See slides.
- Scrubbing run => Will be summarized at the LMC this afternoon.
- Evian workshop next week:
- Any clear message we should pass?
- Impedance team:
- 2 reviews: 1 for new design for kickers and 1 for ZS + work for the PSB.
- LMC talk this afternoon for the LHCb velo.
- Quite a few issues with TDI.
- SP is organising a meeting for finemet cavities.
4) Scrubbing run overview by GR: => See slides at afternoon's LMC.
- Maximum # bunches of 2748 bunches / beam was reached very rapidly.
- Instability at injection damped by increasing octupoles' current.
5) StephaneF on tune split effects: Picture 1 and picture 2
- StephaneF presented the recent analysis.
- EM showed the pictures from TP: Pictures 1-2-3-4-5.
6) Ecloud in IRs by AlexeyB: pdf
- Discussion about the assumption of an electron beam which is the same shape as the proton beam.
- FC mentioned that ecloud has the potential to give cooling => To be discussed more in the future.
- Reminder: Any sort of coupled-beam instabilities is refuted by AlexeyB: the damper sees the same as the other beam, it sees the centre of mass, which is set to 0 by the damper.
- Can ecloud be the reason for the discrepancy?
- It is integrated over the length.
- We see here a reason of collapse of the stability diagram due to compensation between BB and ecloud.
- Low-Q resonator model was already proposed by AlexeyB-Dikansky in 1997!
- If phase advance is ~ 10 then the corresponding head-tail modes are stabilised by longitudinal plane.
- If phase advance is ~ 2 then the corresponding head-tail modes can be excited => Consistent with expectations of instabilities are the end of the squeeze.
- Expected e- at the locations of large betas, i.e. triplet and D1.
- 2 questions asked for ecloud team => To be followed up.
7) Actions to be taken for the next meeting
- Old actions.
8) Miscellaneous
- Deadlines and important dates for ICE.
- The next (74th) meeting will take place on 23/01/2013 => Agenda:
1) Review of the 2012 activities and current plan for the 2013 ones for 3 working groups: BB (WH), HD (GR) and Imped (BS),
2) Impedance localization update for PS, SPS and LHC (NB).
- See preliminary agendas for the next meetings.
Minutes by E. Metral, 16/01/2013.
