Session 3 High Intensity Beams and Radiation Issues chair D.Forkel -Wirth secretary B.Mikulec

1. Session 3 High Intensity Beams and Radiation Issues chair D.Forkel-Wirth secretary B.Mikulec

2. Review of the machine protection system in the SPS J.Wenninger recommendations: Upgrade electronics for ring and TT10 BLMs to obtain faster reaction time and to have multiple time integration thresholds; optimum integration time needs to be defined. Perform simulations to optimise BLM coverage and install additional BLMs in the insufficiently covered regions. Perform simulation studies to redefine thresholds for all installed BLMs. Install fast BPMs to interlock also the vertical plane (in work).

3. Review of the machine protection system in the PS complex K.Hanke recommendations: Perform study on how to prohibit full NTOF beam to be sent to EAST Area for parasitic cycles. New implementation of ISOLDE and Linac2 watchdog systems has to be carefully prepared - involvement of all concerned parties (BI, CO, OP) ideally already in design phase desirable. Clear procedures have to be provided to operation in case of new interlocks(PSB elevator, ISOLDE ventilation alarm, interlock for Linac4 construction). Extensive testing of all failure scenarios for new equipment connected to interlock system is required, as well as interlock functionalities reviewed to avoid potential changes with INCA.

4. RF limitations while running at high intensities in the injectors E.Jensen recommendations: PSB: Feasibility study of water-cooling for PSB C04 system to prepare a possible 900 ms cycle operation. PSB: Study if PSB C02 needs hardware upgrade for Linac4 or if new digital LL RF system could be sufficient (if control of LL RF loops would be included in design). PSB: Implement power upgrade of PSB transverse damper in view of Linac4 (highest priority in the white paper!). PS: With parallel proton and ion operation there will be no more hot spare 80 MHz cavity available. It should also be clarified if high and low intensity beams (nominal LHC and probe) can run in the same supercycle with the new slow 80 MHz tuning loop. [SPS: 800 MHz system essential for LHC operation; strong support for renovation project.] SPS: 200 MHz: Purchase of a sufficient number of tubes, tubes need to be considered as ‘consumables’ required for a reliable RF operation - Philips: 1 tube = 60 kCHF, 5 tubes per year required - Siemens: tubes very expensive, too: 7 – 9 tubes per year for 4 – 5 years, then 5 per year – is a function of CNGS ‘statistics’ - allow for a regular 4 months annual maintenance (mandatory for reliability) 7. SPS: Improve the connections between power coupler and the 200 MHz cavities

5. ISOLDE radioactive air handling R.Catherall recommendations: All activities exceeding operational limits defined at ISOLDE start in 1993 need Radiation Safety and Radiation Protection assessment and approval. The same holds for major modification to installation with impact on radiation safety and radiation protection like changes in target design, ventilation schemes etc. The same principle should be applied to all other CERN installations. Radiation safety and radiation protection studies similar to SPS, CNGS and LHC are required as part of HIE approval procedure.

6. Status of RAMSES and ARCON radiation monitoring systems M.Widorski recommendations: Prepare clear procedures for operation before 2009 startup for the case of ARCON failures. Clarify fast access to RAMSES from CCC.

7. Where do we stand 3 years after the recommendations from the BLRWG S.Gilardoni recommendations: Perform BT/BTP line alignment as soon as possible involving BTM and BTY alignment (not feasible with short shutdown). Install remote TCC2 monitoring (TCC2: mixed-field radiation area in North Area). Publish BLRWG report. Revive BLRWG.