1. MPP Meeting 07/03/2007 MPP Main Ring Magnet Performance Panel Meeting Wednesday 7th March 2007 Agenda: 1)Matters arising 2)Recommendations for the case of MB1055(26R7) 3)Recommendations for the HWC of 600A in Sector 7-8 4) A.O.B.

2. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Hardware Commissioning Training  In March we will start to power cold LHC circuits. The first activity will be to commission the equipment safety systems which are mainly the responsibility of the QPS, PIC and Power Converter teams. Commissioning will involve these experts as well as Hardware Commissioning Coordination, the CCC Operations Engineers and Technicians as well as key support services such as cryogenics, technical services and accelerator controls.  In order to prepare an efficient approach to this activity a one day training session on March 15th is being organised for the people involved. Looking towards parallel commissioning of the LHC sectors later this year we are aiming to spread the knowledge rather widely. As a first estimate we believe about 60 - 80 people should be familiarised with LHC powering and the systems involved.

3. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Hardware Commissioning Training  First half day Introduction (L.Evans) Powering LHC (R.Schmidt) Overview: from Individual System Tests up to Powering to Nominal (B.Perea) - presentation possibly shifted to the afternoon - Superconducting elements (K.H.Mess) Power converters (D.Nisbet) Quench protection (R.Denz) Powering Interlocks (M.Zerlauth)  Second half day Cryogenics and powering (L.Serio) DFBs, Current Leads (A.Ballarino) General services (T.Pettersson) Powering from short circuit test up to nominal (A.Vergara) Overview: software tools for commissioning (R.Lauckner) Risks for personnel during commissioning (P.Proudlock) Organisation of hardware commissioning (R.Saban)

4. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Training Programme  Introduction (L.Evans – 15min) What hardware commissioning? Why is it needed (no such term for LEP). How is it related to other phases: LHC construction, installation and beam commissioning. General schedule.  Powering LHC (R.Schmidt - 30min) Why so many magnets? Magnet types and their function (very brief). Magnets powered individually and magnets powered in series, layout DB. Why so many circuits, 8 sectors, 28 powering sub-sectors, challenges and constraints, circuit DB. Example scenario (to be reused throughout the talks): RB circuit. Introduction of the different elements / systems (QPS, Energy Extraction, PIC, PC,..). Machine Protection: Risk during powering, why equipment protection is required, link between protection during powering and beam operation,  Overview: from Individual System Tests up to Powering to Nominal (B.Perea Solano - 15min, talk possibly shifted to later during the day ) Short Circuit Tests, preparation/execution of cool down, ELQA, PIC1 and PIC2, powering to nominal, … within overall planning

5. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Training Programme  Superconducting system and its elements (K.H.Mess – 20min) what is inside the cryostats: magnets, busbars, current leads, … what is a quench, quench propagation (magnet to magnet, slow quenches in busbars at low current), what parameters have an impact (temperature, field, current density), operation of superconductors at different T what are the constraints during powering? max current, etc., view by the “sc equipment owners”  Power converters (D.Nisbet – 20min) normal conducting part of the circuit, converter and their types (modular), cabling, what is required to switch a power converter ON (water, electricity, controls, powering permit, …), when does it trip, state diagram  Quench protection (R.Denz – 30min) magnet types, busbar types, methods of detection (local and global), methods of protection (diode, heaters, EE) for magnets in series and for stand-alone magnets, cryogenic conditions, what is required for giving powering permit different types of circuits (with/without energy extraction, …) QPS supervision levels, for experts, operators and observers

6. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Training Programme  Powering Interlocks (M.Zerlauth - 20min) why PICs are required? main functionality, interactions with AUG, UPS, cryogenics and QPS introduction to interlock drawings PIC supervision (illustration)  Cryogenics and powering (L.Serio – 20min) what condition to start powering, when do we have to stop powering, protection signals (CryoOK etc), commissioning constraints, how commissioning operators get an overview of the cryo process, how to check that cryo is OK or not OK?, what to do before a (forced) quench and during quench recovery? What does the cryogenic system need to do its job? (vacuum, electricity, water cooling, …)  DFBs and Current Leads (A.Ballarino – 20min) what is inside a DFB, how to commission them for the first time, what can go wrong, what has to be respected during powering, what needs to be watches, constraints to powering  General services (T.Pettersson – 15min) AC distribution, cooling and ventilation, access Water circuits (demineralised / chilled water), how is it distributed? What is required for a smooth operation of the system? How can the correct functioning be verified? Alarms and Logging?

7. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Training Programme  Powering from short circuit test up to nominal (A.Vergara / R.Lauckner) Commissioning of the powering interlock systems: PIC1 and PIC2 Steps foreseen up to nominal powering (e.g. quench features, recovery time) Test in parallel (parallelism of circuits, of powering subsectors) How the schedule will affect the testing, highlighting the expected 'parallel test' scenarios  Overview: software tools for commissioning (A.Vergara / R.Lauckner) HWC sequencer SOC (set of circuits), Alarms, EquipState, Fixed Displays LSA database + operational and configuration data for HWC Software tools available to validate experiments and diagnose problems (post mortem) Recording of tests results: MTF Who need which tool (relation tool – operator/specialist)?

8. MPP Meeting 07/03/2007 A. Siemko/AT-MTM  Case of MB1055

9. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Case of MB1055  The context Case of MB3004 Case of MB2239  Case of MB1055  The risk identification  The risk analysis and evaluation  Recommendations

10. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Predecessors - Case of MB3004 MB3004 Example of normal signals

11. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Predecessors - Case of MB2239  MB2239 First training quench

12. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Predecessors - Case of MB2239 MB2239 1 st 6.5kA provoked QUENCH MB2239 1 st 9kA provoked QUENCH MB2239 2nd 6.5kA provoked QUENCH

13. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Predecessors - Case of MB2239  MB2239 Short location Courtesy of Marta Bajko

14. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Case of MB1055  Abnormal voltage signals similar to known seek cases such as dipoles 3004 and 2239 (i.e. compatible with the turn-to-turn short- circuit during the quench and action of Lorentz forces) were recorded during the first and second training quenches and last provoked quench at nominal current.  The amplitude of the observed oscillations has increased after each quench.

15. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Case of MB1055  1 st training quench

16. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Case of MB1055  2 nd training quench

17. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Case of MB1055  Provoked quench at nominal current

18. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Case of MB1055 - The risk identification  What can happen Further degradation of the electrical integrity of the magnet Damage of the coil preventing powering of the entire MB circuit Break of the electrical integrity of the neighboring magnets (flush of the diodes up to the whole sector) and proximity electronics (QPS) due to uncontrollable HV oscillations Break of the vacuum and cryogenic integrity (contamination of the beam vacuum of the entire sector with He and Carbon debris)  How it can happen Quench of the MB1055 magnet above the critical current level in the coil

19. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Case of MB1055 - The risk analysis  The probability of the risk is proportional to the current level and the amount of stored energy Natural training quench is unlikely below 9kA Natural training quench is highly probable at and above I nominal With beams the quench is probable at any current between I injection and I nominal  Levels of the risks Consequences of a quench below 2kA are limited to the magnet itself Consequences of a quench above 2kA can affect the entire sector 7-8  The controls The current level in the magnet (in the circuit) and resulting stored energy Quench (only provoked quenches for the HWC purpose) in the MB1055 and neighboring magnets

20. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Case of MB1055 - The risk evaluation

21. MPP Meeting 07/03/2007 A. Siemko/AT-MTM Case of MB1055 – MPP Recommendations  No risk scenario Recommendation:  Replace the MB1055 magnet before HWC powering tests  Risk scenario limited to the local damage Recommendation:  Limit powering of the MB circuit to 2kA  Do not provoke quenches in MB1055 and neighboring magnets  Replace the MB1055 magnet after the “engineering run” before the HWC to nominal current  Operation of this magnet with or without beams above 2kA puts the entire sector 7-8 into sizeable risk of a damage necessitating the opening of all interconnects in the sector and possible replacement of the significant part of the equipment

22. MPP Meeting 07/03/2007 A. Siemko/AT-MTM  The MPP Recommendations for HWC current rating in case of 600A circuits in Sector 7-8

23. MPP Meeting 07/03/2007 A. Siemko/AT-MTM HWC current rating for 600A circuits in Sector 7-8