Minutes of the ICE section
45th meeting on Wednesday 07/12/2011 (08:40-10:30, 6/2-004)
ICE members: Benoit Salvant (BS), Christian Hansen (CH), Carlo Zannini (CZ), Hugo Alistair Day (HD), Elena Benedetto (EB), 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), Tatiana Pieloni (TP), Werner Herr (WH), Xavier Buffat (XB).
Present/Excused: BS, CH, CZ, HD, EB, EM, EW, FS, GI, GR, JLN, KL, NB, NM, OB, TP, WH, XB, Chandrashekhara Bhat, Christian Carli, Haryo Sumowidagdo, Georges Trad.
1) Newcomers / visitors
- Alexander Molodozhentsev (Sasha, from KEK) arrived on Friday 25/11 and will stay with us for 1 month (until Christmas) => Office: 6/2-001 and tel: 75008.
2) Comments on the minutes of the previous 44th meeting + Actions
- None.
3) General infos
- No particular comment from anyone.
- SL meeting:
- The deadline for student grant applications to IPAC 2012 is today (07/12/11). PaulC can sign as "Head of Institute".
- The cost of Mathlab licences for CERN will increase by a factor 8 (info from PaulC. The possibility of having part of the licences as academic was turned down). However it is not clear what is the actual cost, so we cannot compare it with the cost of replacing Mathlab. Further details will be given by IT in a dedicate presentation to the BEMB before taking a decision.
- Plans about the construction of a new building close to the CCC, including an exhibition, were presented (details can be found in the BEMB minutes and in yesterday's talk of PaulC).
- There was a LIS board last Friday: BE-ABP-LIS-2011-166.
- 2 vacancy notices have been published last Thursday 01/12/11:
1) BE-ABP-ICE-2011-268-LD (deadline: 24.01.2012).
2) BE-ABP-ICE-2011-269-LD (deadline: 26.01.2012).
- GR, Miguel and Brennan organised a general review of the status and plans of the electron cloud mitigation activities in the SPS for Wednesday 11 January 2012 in 865-1-D17, 14:00 - 17:30.
- PHD student: PERSICHELLI Serena with BS (01.02.2012) => Interview still to be organised.
- REMINDER: Christmas party to be organised by ICE team on 15/12/11 => Everybody is required! Thanks in advance...
- Evian workshop next week => Rehearsal for NM+BS+GR being organised for Friday at 16:00 (room to be reserved by BS) => Everybody welcome to give feedback.
- IPAC12 => Abstracts approved by PaulC (I sent you already the list) => Next (last) step: Upload the abstract on the IPAC12 site by tonight!
- RolandG and LucioR are planning to have a 2nd LIU HL-LHC brainstorming meeting at the beginning of next year on Tuesday 24th January.
4) The ELENA project and possible ICE studies (OB): pptx
- ELENA = Extra Low ENergy Antiproton ring to be installed in the AD machine.
- OB explained clearly why ELENA was proposed (ChristianC reminded us that the first proposition came in 1982):
- Without ELENA, the beam is decelerated in the AD until 5.3 MeV and then some (thick) degrader slows down the beam even more until 4 keV, but with 99.5% of losses => Not very efficient!
- With ELENA, the beam will be decelerated from 5.3 MeV down to 100 keV, and then some (thin) degrader slows down the beam even more until 4 keV, but with less loss (~ 70%) => Much more efficient! => Huge gain!
- The optics is well advanced (PavelB used MAD8, the preferred scenario still being discussed), 6-fold symmetry, circumference = 30.4 m, Qx / Qy = ~ 2.3 / 2.45, direct space charge tune shift ~ -0.1. Bunch length: 300 ns = 1.3 m (determined by the length of the trap in the experiment).
- Some key elements:
- Electron cooler: Reduces the transverse emittances. When the beam is decelerated, the vertical emittancies grows, because there is less adiabatic damping. Cooling also counteracts multiple Coulomb scattering, which heats the beam. The ecooler creates a lot of coupling between H and V => Main compensation with solenoids (around the ecooler) but also some skew quads to compensate for the residual coupling.
- Longitudinal Schottky PU: BTF tune measurements for intensity measurement and cooling control.
- Ionization profile monitor: Measures beam profiles. Allows the non-destructive monitoring of beam centres and emittances throughout the cycle => Some questions raised about of the effect of the static electric fields which might affect the circulating antiprotons, scattering of pbar and also possible annihilation => See what is the experience of other labs.
- Some impedances sources were discussed and the RW (resistive wall) instability was mentioned to be the most critical (after discussion with Alexey Burov) but other effects need also to be looked at in detail: IBS and Coulomb scattering (with the residual gas). The requirement for ELENA is 3E-12 Torr (it seems that Coulomb scattering is not important for pressures smaller than 5E-11 Torr).
- Most important question: do we need a transverse damper? => If yes, reserve some space, define the requirements (computing the instability rise-times). Reminder: 4 bunches with a total intensity of 6.5E7 pbar. The damper is also useful for blowing up the beam if there are instabilities at extraction.
- Beam impedance definition => A "i" is missing for the transverse impedance.
- Reminder: Diameter for the vacuum chamber = 80 mm.
- Coffee discussion after the meeting with PavelB, StephanM, ChristianC and OlavB => Possible PHD student could work with the ICE team on "Collective effects studies in ELENA" under the supervision of ChristianC => Still to be confirmed.
5) HL-LHC WP2 task 2.4 (EM): pdf
- EM explained what the HL-LHC project, WP2 and task 2.4 are. A SharePoint site was started (thanks RiccardoDM!).
6) HL-LHC WP2 task 2.5 (WH): pdf
- WH explained what the task 2.5 is. A SharePoint site was also started.
7) Actions to be taken for the next meeting
- Old actions.
8) Miscellaneous
- The next (46th) meeting will take place on 21/12/2011 => Agenda:
1) Discussion about the Large Piwinski Angle MD (Frank Zimmermann).
- See preliminary agendas for the next meetings.
Minutes by E. Metral, 07/12/2011.