Present: Peter Butler (chair), Roland Garoby, Bjoern Jonson, Oliver Kester, Jacques Lettry, Mats Lindroos, Thomas Nilsson, Thomas Otto, Piet Van Duppen

1. Minutes of last meeting

The minutes from the last meeting 25th February 2003 were approved.

2. Report from ISCC on REX integration and hall extension

Bjoern Jonsson reported that the extension of the hall is going ahead with a major part of the cost shouldered by the ISOLDE collaboration. A laboratory for solid state physics will be part of the extension. This large project will put heavy financial strain on the collaboration for the coming few years, a situation that not has improved with the delay of any EU financing through the EURONS proposal. A decision on any money from the EU through that source will earliest come in the spring 2004. Bjoern also reported that the plans for a class A radioactive laboratory for the ISOLDE target area and the construction of UC and ThC targets have been approved by the AB division management and that the construction will start this autumn. The collaboration committee also listened to a status report for the RILIS system and decided to look for external grants to finance a major upgrade of the ISOLDE RILIS to a solid state laser system (500 kCHF) within a three year period.

3. REX-ISOLDE upgrade

Oliver Kester (see below) told the group that REX ISOLDE still is running at 2.2 MeV with new settings giving a very high beam quality at the interaction point. The amplifiers for the 3.1 MeV/u upgrade have been further delayed but good progress is being made on the main-amplifier at the manufacturer. The pre-amp will not be developed at Bertonix in Munich but will be bought directly from another supplier. As this pre-amplifier was part of the original offer a special deal has been made to compensate the REX collaboration for this unexpected cost by the main supplier in the form of cancelled bills for repairs executed at ISOLDE on existing equipment during the 2002-2003 runs. The cavities have already been conditioned at nominal voltages but not yet at full power. However, that should only require the cooling to work as designed and should not involve any lengthy conditioning procedure.

Oliver is now working on detailed plans for the further energy upgrades of REX ISOLDE. The first step aims to bring the energy to 4.3 MeV/u and will already require the hall extension to be in place. The funding for this part is close to 1 MEuros and consists mainly of the cost for the amplifiers. There are two grant application in progress to finance this upgrade, one well advanced application in Belgium as part of a special ministerial program for the financing of expensive equipment, and one in UK. The Belgium grant application is being coordinated by Piet Van Duppen and Mark Huyse and the UK grant application is being coordinated by Dave Warner. The upgrade will take almost one year to implement and the group felt that it should be done after the run in 2005. The time from order of the amplifiers to delivery is 2.5 years so Oliver is hoping to at least launch the design phase with the manufacturer towards the end of this year. The full system could then be ready for January 2007. Roland pointed out that the additional work and possible increase of operational costs has to be negotiated with the AB division.

4. REX-STAR

Mats Lindroos reported that a meeting was held 27 August on a proposal to use an ECR source combined with a low energy accelerator e.g. a simple high voltage platform for the acceleration of multiply charged radioactive ions to energies of a few 100 KeV/u. This energy range is not available at existing facilities and is of special interest for the solid state physics community and for some specific measurements in astrophysics. Since the meeting Heinz Haas has started to work as a consultant for the ISOLDE team and he will present a plan for such a facility in December 2003. The plans for linking a high voltage platform to the two available charge breeders at ISOLDE, the ECR source and the REX-EBIS source.

5. Proton beam availability to 2010

Roland Garoby reported (see below) that the High Intensity Proton project in the CERN AB division already has given its midterm report and that it will submit its final report towards the end of the year. The main findings are that a faster pulsing of the PS Booster could gain ISOLDE a factor of 1.6 and combined with a new H- linac (linac 4) it could give a factor of four. The main users to benefit from linac 4 is CNGS and ISOLDE. The latest date when linac 4 would be an interesting upgrade for ISOLDE was discussed.  Linac 4 is an integral part of the future Superconducting Linac project and if the date between completion of linac 4 and SPL becomes too short it makes little sense to install linac 4 at the present booster at all. The AB management has endorsed the recommendations made by the HIP study in the intermediate report and negotiations are in progress with ISTC for linac 4. It also has to be proven through detailed simulation work that linac 4 really gives the improvements that simple calculations based on scaling laws for injection and space charge issues yields for the PS Booster.

6. Implications of beam intensity upgrade: targets & ion sources

Jacques Lettry told the committee that progress has been made in the last year on e.g. MonoECR sources and thermal load on ISOLDE converters (on-going: Measurement of proton induced shock waves with a laser-vibrometer). The section spent some 160 kCHF + 2.4 FTE for R&D on targets and ion sources (2002-3). The next generation of front-ends is under development and a prototype suppressing the x-y movements of the extraction electrode is now assembled in the off line laboratory. The aim is to create a simplified front-part, which can be disconnected from the first beam optical elements (QP triplet). This part should not cost more than 100 kCHF to build and could be replaced by the O-ring free target coupling or 2 stages extraction standard. The present FE technology was already operated at 4 mA for short periods (weeks) as partly foreseen for the 2005 run, this is however not the case for some of the standard ISOLDE target units (i.e. Molten lead is limited to ~1 mA). To implement further improvements, some additional resources estimated at 1.5 FTE would allow operation (on most target units at intensities up to 10 mA. The planned tasks are beam optics (6 month), engineering of the O-ring free target standard (12 month and 150 kCHF / unit) and eventually development for each target type including cooled n-converter (1-2 month / unit + prototyping costs to be evaluated).

7. Implications of beam intensity upgrade: radiation safety

Thomas Otto (see below) pointed out that radiological safety issues are proportional to number of protons on target. This assumption is based on the fact that targets survive only a given number of protons and that activation by long-lived radionuclides is proportional to intensity. The present levels of personal dose for maintenance at ISOLDE are close to a dose constraint of 5 mSv/year adopted for new facilities at CERN (for LHC for the first time). The meaning of the dose constraint is that facilities have to be planned in a way hat routine operation does not entail higher personal doses to operational, maintenance or experimental personnel. A lowering of the annual reference level (presently 15 mSv) to 6 mSv may also be envisaged. The meaning of the reference level, at 30% of the legal dose limit, is that special permission must be obtained before exposing a person to doses beyond it. These measures are in line with good safety practice in other facilities and workplaces. The focus must be on an improvement of reliability of the facility and to assure that all possible passive protection measures, such as shielding, are optimized. Resources are required within the radiation protection group for calculations and simulations. Another issue is the increased amount of radioactive waste produced, mainly targets. Resources are required within the radiation protection group for estimates of the nuclide composition of used targets and for developing waste handling strategies

8. Status of SPL

Roland Garoby reported (see below) that the SPL project is progressing and an agreement with CEA and CNRS is just being finalized concerning the 3 MeV injector part (IPHI). Three proposals have also been submitted to ISTC for the room temperature part of the linac and the HIPPI proposal within the EU financed CARE integrated initiative was approved with 90% of requested funds made available. The project clearly figures in the CERN long term plan, an example of this is that the CERN director general told the audience at the recent anniversaries of two major discoveries at CERN (neutral currents and W & Z bosons) that the next machine CERN will build is SPL.

9. Status of EURISOL design study

Peter Butler reported on the preparation of the EURISOL proposal. In total 40 expressions of interests have been received by the writing committee. The meeting with the EURISOL steering committee for the 5^th framework RTD study and the writing committee was held during the three days following this upgrade committee meeting. The first meeting with the appointed work package (or task) leaders will be held in Orsay 14 November and a final meeting to discuss the final version of the proposal will be held 16 February at CERN.

10. AOB

Mats Lindroos proposed that the upgrade committee should coordinate the editing of a Technical Design Report (TDR) in the form of a CERN yellow report for the upgrade of the ISOLDE facility. The upgrade group agreed that this should be done and that it should be ready for the Conges meeting on the future of fixed target physics at CERN. The group also agreed that the minutes of this meeting should be sent to all members of the ISOLDE collaboration committee.

11. Next meeting

The next meeting of the upgrade group will take place 24 February 2004 at 13:30.

Minutes by Mats Lindroos