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MPP meeting
MPP meeting 31 October 2007
Organizational structure of MPP (A. Siemko)
The list of current MPP members was presented and will be updated accordingly in the web page.
Andrzej proposes structuring MPP in working teams two of which will be:
M. Zerlauth reported the work with the sequencer. Work is already well advanced for the 60 A, 80 A and 120 A circuits. Next in the pipeline is the procedure for the individual powering dipoles (in preparation) and quadrupoles (end of this week).
ELQA is linking all the non conformities found during ELQA to MTF and is working with A. Vergara to solve and close the NCs. The treatment of NC, their distribution and solving procedure is not clear. It should be presented to the next MPP meeting. Action: ELQA team.
For the cooling down of the sector 5-6 ELQA has decided to monitor on-line the insulation of the DFBX. S. Feher objects that this should be discussed.
Three solutions seem possible
General Information
From 25th October problems with compressor stopped the cool-down of sector 4-5. These problems were fixed tonight and the cool-down has restarted. The schedule for the powering tests holds.Organizational structure of MPP (A. Siemko)
The list of current MPP members was presented and will be updated accordingly in the web page. Andrzej proposes structuring MPP in working teams two of which will be:
- MPP expert CCC team: will be present in the control room, assist to the daily meetings of HC, follow the powering procedures and approve the MPP steps. This team will also have to unblock issues appearing during powering, report any issues that need a deeper analysis to the analysis team, and assure detailed reporting in the logbook. Reporting to Maric will also be part of the mandate of this team. The members of this team will work on a weekly rotary basis. Two members will be on each weekly shift and will be declared to the HC team as the representatives of MPP. G. Kirby suggested organizing a training on all circuits for the members of this team. Working in shifts is currently not planned but overlapped extended hours could be considered.
- MPP analysis team: will review the results and release the circuits after the test. They will unblock the performance issues, provide feedback to the MPP CCC team and follow the pending non-conformities. They will document the analysis work and report critical non-conformities affecting the LHC budget, resources or schedule to HWC. They will assist to the 16:30 meeting in the glass-box of the CCC. They will report to MPP and MARIC. K. Dahlerup suggests that a close collaboration between the analysis team and the QPS team is essential. This collaboration already exists for with the MPP CCC team.
Status of the powering procedures and approval process in EDMS (M. Modena)
Three procedures needed for the powering tests of sector 4-5 are still in work. They will start the engineering in check by the end of the week. All the others are in check or released.M. Zerlauth reported the work with the sequencer. Work is already well advanced for the 60 A, 80 A and 120 A circuits. Next in the pipeline is the procedure for the individual powering dipoles (in preparation) and quadrupoles (end of this week).
ELQA issues
D. Bozzini reports that the ELQA team is following the cool-down of 4-5. The insulation is ok.ELQA is linking all the non conformities found during ELQA to MTF and is working with A. Vergara to solve and close the NCs. The treatment of NC, their distribution and solving procedure is not clear. It should be presented to the next MPP meeting. Action: ELQA team.
For the cooling down of the sector 5-6 ELQA has decided to monitor on-line the insulation of the DFBX. S. Feher objects that this should be discussed.
External fault during inner triplet powering
For the special case of the inner triplet, quench heaters will be fired in the case of a fast power abort, a water fault from the magnets or a quench. (For all other circuits, quench heaters are fired only in case a quench is detected). This makes possible for instance, firing the heaters at any moment by human action on the regulation valves or the flow-switches (Elettas). The reason for this logic is that the energy stored in the magnet is too large and could damage the free wheel diode in the power converter. On the other side, repeatedly quenching the magnets, even when the circuit is not powered, could damage the magnets.Three solutions seem possible
- Power as it is (not favoured)
- Set a minimum current level for discharging heaters after a converter fault (implies FGC software modification)
- Prepare an engineering change request and replace the free-wheel diode.
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