Chairman: Yorick Blumenfeld
Scientific secretary: Thierry Stora
Present: Yorick Blumenfeld, Peter Butler, Pierre Delahaye (on phone), Nathal Severins (replacing Piet van Duppen), Nobu Imai (for point 3), Magdalena Kowalska, Roberto Losito, Klaus Hanke, Erwin Siesling (for point 5), Thierry Stora, Karsten Riisager, Joachim Vollaire
Excused: Richard Catherall, Klaus Blaum, Maria Garcia Borge, John Billowes.
Presentations are uploaded there.
1. Approval of Minutes of last meeting (YB)
The minutes from the last meeting were approved.
2. Priorities for Target and Ion Source developments in 2012 (MK, TS)
The following results were reported:
The 30Na historical yields could be recovered using a Re ion source instead of the traditionnal Ta or W surface ion sources. 72Kr beams could be delivered to REX and MiniBall for IS478. Carbon beams produced from HfO felts combined with an Helicon source could be delivered to IS445. The rates are still too low, however stable mode of operation and short lived 17C as CO+ beams could be delivered succesfully. Yields need to be further increased to become usefull for physics results. A 3rd target nanomaterial (after SiC and Y2O3) was developped for CaO targets, to deliver n-defficient Ar isotopes, and also for 9C beams as CO+. Constant and high yields could be delivered for several days, operating the target at much lower temperatures than usual ones. Also, the new RILIS scheme for 142Sm will be tested with a low work function cavity made of GdB6, so that if positive results are obtained the planned physics can be performed later in 2012.
Additional results not set in the priority list were obtained this year: x5 improvements of n-defficient Hg yields could be observed, replacing the traditionnal MK3 FEBIAD ion sources by the VADIS sources. No instabilities related to metal vapors were to be reported. Also n-rich Lu (178Lu) could be observed from a Ta/W/Ir-surf(W) unit.
New priorities for beam developments include the Pb/Bi loop target for EURISOL, 44Ti beams to be delivered to REX, 19O, 144Ba, 37K, 52-55Sc (yield assessment), 169Yb, 147-149Gd, 57Co, 77Br, 48Cr, 72,73As, 75Se. Also n-defficient Ba beams need to be added as priority 1 developments.
The Group decided to select the following beams as highest priority for 2012: 57Co, 9C, 142Sm, the neutron converter, the Pb/Bi loop target, 37K, 118Te, 144Ba, the number of achievements (from 3 to 5) depending on the available ressources and on the scheduling constrains.
3. Beams of refractory elements : Laser break-up molecules and ionization (N. Imai)
N. Imai reported on the ongoing activities dealing with the production of refractory elements, using lasers for molecular break-up and ionization in a VADIS cavity. Zr and ZrFx are used as model chemical element and molecule. Results obtained in the LARIS laboratoty on the production of Zr+, ZrO+ and ZrF+ ions were reported. The Zr element is 1st produced by laser ablation of a Zr rod in an Ar gas stream. Zr+ and ZrO+ ions are observed in the TOF -MCP diagnostic box. Upon injection of some % CF4 fraction in the gas phase, large enhancement of the Zr+ ions are observed, together with ZrO+ and ZrF+ moleclar ions. Both the Zr+ ionization and ZrF molecular break-up energies are comparable (6.6 and 6.3eV respectively), whereas some catalytic effect has been documented in the litterature on the dissociation energies of flourine molecule when mixed with other compounds. The project is progressing along three lines : best conditions to provide molecular evaporation of ZrFx molecules, development of the RILIS scheme for Zr+ ion production and tests in a VADIS cavity to confine the break-up ion products before extraction to form the secondary beam.
4. PS Booster upgrade (KH)
K. Hanke presented the status of the LIU (LHC injectors upgrade) project dealing with the future of PSB. The RCS option has now been abandoned, the PSB will undergo an upgrade to accomodate the increased proton intensity, an H- energy increase from 50 to 160MeV at injection from Linac 4 and to reach an ejection energy of 2 GeV. The aim of the project is to reduce the space charge bottleneck from PSB intoe PS to meet the specifications of HL-LHC. The present timeline foresees the commissioning of the upgraded PSB in 2018, and availability for physics after LS2. K.H. went on presenting a pre-study made by D. Voulot on the upgrade of the BTY line to accomodate 2GeV protons for the ISOLDE facility. Since thee BT and BTM sections are already covered by the LIU project, this pre-study is restricted on the specific investigation of the suitablity of the BTY section for an energy increase to 2 GeV protons, keeping 1.4GeV protons available and dropping the 1GeV proton energy option which is not and won't be much requested for the future physics program. The investigation was first focused on the different magnets and associated power supplies. The study on the suitability to switch from a dc to ppm mode of operation is being finalized. If the magnet stability is found satisfactory, only 9 new power converters are required. A first budget estimate for this part amounts to about 2.8 MiCHF, assuming the present magnet designs can sustain the new operation conditions. In terms of shielding requirements, especially under Route Democrite, the initial specifications and observed ambient dose rates seem to be apropriate to sustain a fourfold increase in intensity and an energy of 2GeV. A formal request through INTC in November 2012 should be fomulated.
This pre-study is however not covered by the LIU-PSB project as confirmed by S. Myers, and requires an independant source of funding. (note added after the meeting: After the SGUI meeting, S. Myers suggested to let K. Hanke draft a proposal in the non-LHC physics strategy paper, in preparation at the A&T sector level, to be submitted to the Council for the next Midterm Plan).
5. Plans and schedule for long shutdown (E. Siesling)
E. Siesling reported on the planned activities related to HIE-ISOLDE and to the infrastructures of Bld 170 in 2012 and during LS1 up to 2014. The civil engineering related to the HIE-ISOLDE cryoplant has already started. The covered vehicles parking lot has been removed, the access gate is being moved, and work has started for the cryoplant building. Important works related to cooling and ventilation, and electrical services, will take place end of 2012-beginning 2013. For this, the physics program at ISOLDE must finish strictly on 3rd December 2012. The commissioning of the cryogenics circuits and operation whould be finished by end of June 2014. Post accelerated beams at 5.5MeV/n are foreseen to take place for Autumn 2014. The new beam transfer lines should also be commissioned for end of 2014. Finally, E. Siesling went on presenting the staged approach both in energy and detectors of HIE-ISOLDE, with the option to receive a storage ring facility, the TSR, from MPIK-Heidelberg. Issues related to Building 115 and for hosting users were finally introduced.
6. AOB
The Group expressed its gratitude to Yorick for acting as chairman of the SGUI for the past 4 years, which position will be taken over by M. Borge at the next SGUI meeting.
7. Next meeting
To be defined in 2012 with the new Chair M. Borge.
Minutes by Thierry Stora