Minutes of the ICE section
15th meeting on Wednesday 26/01/2011 (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
- None.
2) Comments on the minutes of the 14th meeting + Actions
- No comments.
3) General infos
- Comment from OB (urgent!): The aperture of the vacuum chambers connected to the SPS collimators in position 51651 is too small! (it was proposed recently to move the SPS collimator BRCZ.52105 to the position 51651 in the EDMS document "UA9 LSS5 Shutdown 2010-2011 Upgrades"). It seems that we have 3 options to solve the problem: (1) make new vacuum chambers, connected to the SPS collimators, with a diameter of 100mm; (2) move the SPS collimators downstream, close to the quadrupole "QD.51710". Probably close to the "BPMB.51705" will also be fine; OB will determine the exact position; (3) move the SPS collimator to a completely new position (unthinkable for the moment).
- Should we change the time as it seems difficult to start the meeting at 08:40?
- SL meeting last week:
- All the MARS interviews have to be done and completed for March 11. As I will be in vacation between March 5 and 12, it has to be done before March 5! => Start to prepare them.
- For summer students' supervisors: Complete the project proposal form for 2011, by 14 February at the latest. The estimated number of students BE Department can accommodate this year is 8.
- Chamonix2011 workshop this week.
4) (Nufact10 and) Beta Beams for the Euronu mid term (EW): ppt
- EUROnu Mid Term news:
- We can now produce enough 18Ne (at least on paper. A factor ~ 20 was missing before)! Low-Q option feasible now, if experimentally confirmed (planned to be checked soon at ISOLDE).
- Ample amounts of antineutrino emitters: 6He and 8Li can be produced (experimented)
- EUROnu proposal for production 8Li/8B very difficult: Indirect kinematics gas jet target not (yet) a possible option
- Modifications in 8Li/8B production scenario: Direct kinematics case (simulations)
- Not same acceleration scheme as EURISOL FP6:
- Not fully stripped ions at ECR exit: new RFQ-design (losses?)
- SPS RF
- Adaptation of decay Ring Design
- 5-10 times more useful neutrinos needed for high-Q isotopes:
- Important work on collective effects
- Radiation (may not scale, but certainly > 3 times)
- Cocktail approach (WP6)
- Acceleration scheme is the same for both FP6 and FP7 projects.
- 22 reports on EUROnu web + publications ECR source.
- New associated partners like GSI with Oliver Boine-Frankenheim.
- Ion Cocktails 1 and 2 (from WP6).
- Greenfield beta-beams (Greenfield scenario by Michel Martini) => CERN-Canfranc setup: gamma = 350 for 6He with L = 730 km.
- Options for production (courtesy of T. Stora and P. Valko).
- Experiments with 18Ne for beta beams:
- Measure production and release from a sodium target at ISOLDE => Proposal sent to INTC
- Manpower for experimental setup and measurements => 2 years of scientific associateship agreed by CERN
- Experiments at small decay ring at ISOLDE => LOI (Letter Of Intent) sent to INTC
- 8Li X-sections and distributions => X-sections still need some more work. One of the beta beams team will go to Legenaro for few weeks to do some shifts.
- 3He is expensive and difficult to find.
- Duty factor and RF cavities => Work on HW feasibility will start in 2011: Cockroft Institute / Lancaster University.
- Radiation issues => Work on collimation system to be continued.
- 28 GHz-10 kW gyrotron at LPSC (Laboratoire de Physique Subatomique et de Cosmologie) Grenoble is available for first SEISM Euro-nu experiment. 60 GHz gyrotron will be finished at IAP: installation is funding dependent.
- Costing and safety.
- Parameter lists => Go to http://heplnv135.pp.rl.ac.uk/joomla/index.php?option=com_content&view=category&id=9&Itemid=12. Then click on Data Base: Beta-Beam-Parameters.
- Future work:
- Experiments on 18Ne
- Direct kinematics for 8B and 8Li production: targets
- Cooling and production simulations for Production Ring (8Li/8B)
- Cross-section measurements of 8B (in Legnaro)
- 8B collection setup
- ECR fields for plasma -> 30 000A (structures supra), Gyrotron tests, beam extraction, low cost solutions, Proto -> ECR Source
- Finalizing collective effects studies, all ions, all machines
- CERN complex: RFQ and PS-upgrade
- Decay Ring updates for collective effects (phase slip factor/RF)
- Decay Ring RF, technical feasibility
- Good physics case green-field realistic & cheap beta beams
- Parameter lists update for all ions
- Costing/Safety?
- Modifications:
- Partners continue according to plans
- CERN:
- New RFQ
- Very work-intense study on collective effects, FP6 not working
- Results affect machines: we have already indications for DR
- DR redesign is a consequence, work done
- Technical help with impedance (HW specialists available for beta beams?)
- The old machines need to be adapted: we will follow the PS upgrade
- Production ring: inverse to direct kinematics -> collection device ?
- SC-Magnet shielding not complete, radiation for high-Q needs more work
- Costing/Safety?
- Partners are ready to work, where are the clear EUROnu guidelines
- CERN: no costing support (Magnets, vacuum, civil engineering, RF.)
5) The Production Ring for Beta Beams: status, news and future plans (EB): pdf
- The new scenario (with the new ion production) could even be better for the physics research due to the higher energy => We could use it for the mass hierarchy.
- For the ionization cooling, in analogy with synchrotron radiation, partition numbers are introduced.
- Reminder from FritzC: If one wants fast cooling, i.e. must faster than few ms, there is only ionization cooling which can work. If we have more than few ms then we can debate if electron and stochastic coolings can be of any help.
- Energy losses (dE/ds) in the target material given by the Bethe-Bloch plot. Our position in the Bethe-Bloch diagram is not ideal because we are in the negative slope (as highlighted in the slides). We could move to the left but there the energy is too low to have a good stripping. We could go to the right as the slope is better and it is also better as the energy is higher and therefore it provides good stripping, but the X-section is already very low.
- 6D tracking simulations:
- SixTrack (collimation version)
- Target implemented as a special collimator element:
- Analytical formulae for Multiple Coulomb Scattering and Energy Losses (benchmarked with Geant4 simulations (J.Wehner, Aachen))
- Coupling with MonteCarlo code FLUKA ongoing => V.Vlauchoudis, D.Sinuela, E.B. (CERN)
- Rms emittances & Intensity evolution diagnostics
- SixTrack is for protons => Need proton equivalent ring (same Brho, same Dp/p recovered in RF)
- Benckmark with MADX / PTC => OK.
- In conclusion, all the things have been done and benchmarked => Ready to be used!
- Technological issues and feasibility: High density gas-jet target (1E19 atoms/cm2 thick) in vacuum environment => Factor 1E4 larger than existing targets!
- Lithium target:
- Possible solution => Go for a liquid target:
- Energy deposited ~300kW
- Better in direct kinematics: D or 3He beam & Li target
- Investigate optimum projectile energy => Stopping power, target thickness, cross section, rev. frequency
- How to collect 8Li/8B?
- Angle (larger) & velocity (smaller) of produced ions
- Do we still need to stopping + diffusion/effusion?
- or... (electrostatic) separator?
- Implications for the stored beam (i-cooling, lifetime,...)
- Reminder on direct and inverse kinematics:
- Direct kinematics: When we send light ions on a heavy target (ex: D beam on Li target) => This is the new proposition from ElenaB. This method was also proposed by D. Neuffer (2008).
- Inverse kinematics: It is the opposite, i.e. e.g. Li beam on D target (it is what was proposed by C. Rubbia).
- Direct vs. inverse kinematics: pros and cons.
- Some preliminary studies by T. Weber (student from RTWH Aachen, who did a very good job) => Factor 1000 gained! => The direct kinematics approach with a Liquid Lithium target looks very promising. Note that liquid target with ~ 1 mm thickness exist but we need ~ 10 microm and it is R&D, but may be it is better than the gas jet target.
- Next steps:
- Direct kinematics feasibility:
- Identify possible show-stoppers
- Production rates
- Realistic target thickness (and beam energy)
- New collection device (or a separator, if feasible/preferred)
- Lattice optimization and injection design (in either direct/reverse)
- Beam-Target interaction with Monte-Carlo codes:
- Use correct physics inside tracking simulations (since we are at the limits of ionization cooling capabilities...)
- Integration of FLUKA in SixTrack (with V. Vlachoudis, D. Sinuela)
- Cross section measurements for 6Li(3He,n)8B:
- At INFN-Legnaro
- Proposal submitted by V.Kravtchouk and E.Wildner
- 3 weeks beam in April or May
- Prepare meeting w. Carlo Rubbia
- New collaborator for i-cooling simulations
- Gianmaria Collazuol, researcher form Padova University
- Meeting at CERN in February to define work plan
- FFAG option (contacts with Y. Mori and K. Okabe, KURRI, Japan):
- Similar machine, internal target for neutron production, FFAG-ERIT prototype built.
- Invited to visit KURRI in Nov.'10.
- Ongoing => Study how to adapt ERIT to our Beta Beam needs.
- Tracking codes available for FFAG: Zgoubi (F. Meot) and also Scode (S. Machida).
6) Update on collective effects studies for beta-beams in the decay ring (CH): pdf
- A realistic goal for the transverse broad-band impedance of a new machine is ~ 1 MOhm/m. Reminder: ~ 3 in PS, ~ 20 in SPS, ~ 3 at LHC injection but ~ 30 at LHC top energy due to the collimators!
- The decay ring was redesigned (by A. Chance) to raise the TMCI intensity threshold which scales like the slip factor => The farther away from the transition energy the higher the intensity threshold. This helped but the transverse shunt impedance is still a factor ~ 3 below the goal of ~ 1 MOhm/m, but more of the beta-beams scenarios are now allowed.
7) Actions to be taken for the next meeting
- Old actions.
8) Miscellaneous
- The next (16th) meeting will take place on 09/02/2011 => Agenda:
1) Flat beams in SIXTRACK by Emanuele Laface
2) (Short, ~ 10 min) presentations of all the LHC instruments (with the corresponding BI, RF and OP experts) which we used during ecloud MDs in Oct/Nov 2010: Transverse dampers (Riccardo de Maria), HeadTail monitor (Benoit Salvant and Hannes Bartosik), LHC BPM (Nicolas Mounet), Schottky monitor (Tatiana Pieloni), Transverse emittance measurements from BSRT (Christian Hansen), Transverse emittance measurements from FWS (Carlo Zannini), BCT and FBCT (Gersende Prior), BLM (Humberto Maury Cuna and Octavio Dominguez Sanchez de la Blanca) and BBQ (Tatiana and Benoit Salvant): how many equipments? how does it work? Different modes of operation? Data saving? etc.
- See preliminary agendas for the next meetings.
Minutes by E. Metral, 31/01/2010.