Chairman: Karsten Riisager

Scientific Secretary: Mats Lindroos

Present: Juha Äystö, Peter Butler, Luis Fraile, Roland Garoby, Jacques Lettry, Mats Lindroos, Reiner Krücken (replacing Dieter Habs), Mats Lindroos, K. Riisager, Thierry Stora (invited for point 3), Yacine Kadi (invited for point 8)

Excused: Piet van Duppen, Thomas Otto

1. Minutes of last meeting

• The minutes from the last meeting were approved.

2. Status of CERN injector upgrades (RG)

• Roland Garoby gave a report (see file below) for the present plans for the upgrades of the CERN injectors. The need of protons at CERN in the mid- and long-term future has been analyzed and the performance of the present injectors is not sufficient to satisfy all requests. In a first stage a cycling of the PSB at 900 ms (now 1.2 s) is being tested. First results from an on-going test are very positive but there is still a lot of work to make this operational for the complete CERN injector complex. Further tests and modifications are planned for 2006 and the 900 ms cycling could earliest be made operational for all Users in 2007. The next step is to replace the present PSB injector with a new H- linac, linac 4. Development work is progress on this linac with support from Russia through several ISTC contracts. A decision on linac 4 is expected in 2006 and it could be operational for the run in 2010. The long term plan is to replace the PSB with a superconducting proton linac (SPL)  for which the new linac 4 would serve as the first acceleration stage. The SPL will deliver protons at 3.5 GeV, an energy chosen as optimal for a super neutrino beam to a possible future Megaton detector at Frejus in France. Peter Butler asked about costs of the SPL at 3.5 GeV compared to the previous 2.2 Gev version. Roland replied that the increase in energy is cost  neutral due to new technology permitting a shorter linac. He also pointed out that above a certain energy the cost can be calculated as a cost per GeV. Furthermore, it is possible that beam could be extracted to ISOLDE at lower energies if required. Juha Aysto pointed out that there is a strategy decision to be taken at CERN for the future program which probably will mean choosing between the SPL and CLIC.
• Roland and Peter told the meeting that a new working group named PAF has been created at CERN (reporting to the DG) to analyze all options for future proton injector. To analyze the physics requirements a second working group, POFPA, has been created (also reporting to the DG). The mandate and membership of these two new working groups will soon be known.

3. Priorities for target & ion source development (LF, JL)

• The priority lists (priority 1, 2 and 3) for target and REX development at ISOLDE has been updated. New items in priority 1 are negative ion source for Br (experiments IS431 and proposal I59). For priority 2 RILIS developments for Po beams (I57), Ge beams (GeS for I58) and Au beams (I60) has been added. A number of items have been completed and have been deleted.
• Jacques Lettry and Thierry Stora are in the process of making a list of targets, ion sources and resulting beams to be developed within the EURISOL DS study. The target tasks within EURISOL has a web page.

4. Status of REX consolidation (ML)

• The REX integration in the AB department is making good progress. There are problems with the control system migration which will require action by the CO group. However, a first test with a new AB standard front-end for the power supplies will be tested already this summer and the work on a new generation of application programs will start this autumn. The BDI group  has hired a Russian project associate to work on the control part of the instrumentation. A meeting is planned for June with Paul Van der Bergh from IKS Leuven to assure that the BDI group gets a proper introduction to the REX instrumentation hardware and that all existing documentation is made available. The first REX run in 2005 started as scheduled.
• The BMBF grants for two of the REX posts are up for renewal. Peter Butler will write a letter to Dieter Habs and Gerhard Huber to ask them to submit an application for a second two grants. The long term future of REX will be discussed at the INTC meeting for the future of Nuclear and Astrophysics at CERN 10-12 October 2005. A decision is expected by the CERN management and the research board in the months following this meeting.

5. Priorities for REX low-energy development (LF, ML)

• The REX system has been modified for 100 Hz operation in 2005. Many improvements have been made to both the linac and the low energy stage to improve reliability. The REX trap has been migrated to a version of the GSI and ISOLTRAP control system for penning traps. This will assure compatibility between two groups at ISOLDE working with penning traps and a more reliable (in the long term) operation of REX trap.
• The RFQ cooler grant in UK submitted by Jonathan Billows was approved and the work to assembly the RFQ cooler has started. The system will be commissioned in 2006.

6. EU projects:

• EURONS overview (PB)
  • The two EURONS staff posts at ISOLDE have been filled (scientific administrative support and access programme). Fellows will be appointed with partial CERN funding to assure two year contracts for TRAPSPEC, INTAG and CHARGEBREEDING. 
• EURISOL overview (ML)
  • The three CERN EURISOL posts (beam preparation, beam intensity calculations, direct target and beta-beam) have all been appointed. One fellow for the direct target has also been appointed and a second fellow for the beta-beam will be appointed in January.

7. Status of HIE-ISOLDE project (ML)

• Peter Butler and Mats Lindroos reported that a short note (see file below) describing the main elements of the HIE-ISOLDE project proposal has been written and sent to the heads of the AB and PH departments. The total project cost is just over 15 MCHF with 5 MCHF expected to come from external contributors. Some of these external contributions have already been secured and a first meeting of representatives of the original REX proponents will be held 7 July to discuss immediate actions for the upgrade of REX-ISOLDE. The MINBALL detector array is expected to be moved into the new hall extension in the shutdown in 2006.

8. Fission fragment production using LINAC4 (YK)

• The proposed new PSB injector linac 4 could possibly deliver up to 12 kW of proton beam directly to ISOLDE at 160 MeV. This could be an interesting option to improve the efficiency of the ISOLDE facility as it would permit ISOLDE to take protons during PSB operation for other users. To be of physics interest the fission fragment production should at least match the present fission yield of 3 10¹² fissions in a standard ISOLDE UC target (2.5 g/cm²). Yacine Kadi gave a presentation (see file below) of a similar development for ADS systems using a 160 MeV proton beam. It seems feasible that a similar target and converter design together with linac4 could deliver at least the same number of fissions as we have today in a standard ISOLDE target.
• Jacques Lettry, the new group leader of the ATB group, asked Mats Lindroos and Yacine Kadi (both ATB) to make a proposal for such a development. He also pointed out that first tests could be done at the present ISOLDE facility using a 160 MeV proton beam from the PSB. It is possible that some of the MC fellows could work on this project. 

9. AOB

• Peter Butler will leave ISOLDE at the end of August. Peter was congratulated for his excellent work as ISOLDE physics group leader and upgrade group chairman by the INTC and ISCC chairmen and the ISOLDE technical coordinator. The new ISOLDE physics group leader, Karsten Riisager, was elected new chairman for the ISOLDE upgrade group for the duration of his CERN contract.
• Reiner Krücken was elected member of the upgrade group for the duration of his INTC appointment.
• Thierry Stora (ATB-IF) was elected member of the upgrade group for ISOLDE and EURISOL DS target and ion source developments.
• The next meeting of the upgrade group will be held 1 November 2005.

Minutes by Mats Lindroos, 31/05/05