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MPP meeting
Participants
Amalia Ballarino
Andrzej SIEMKO
Antonio Vergara Fernandez
Davide Bozzini
Giorgio D'Angelo
Glyn Kirby
Knud Dahlerup-Petersen
Michele Modena
Mikko Karppinen
Nuria Catalan Lasheras
Reiner Denz
Richard Mompo
Robert Henry Flora
Sandor Feher
Sandrine Le Naour
Stephan Russenschuck
Vittorio Parma
Walter Venturini Delsolaro
Minutes of the MPP meeting held on the 3 Oct 207
Maximum dI/dt for hardware commissioning powering. G. Kirby.
The maximum ramp rates originally included in the old version of document EDMS 519716 were settled on the basis of power converter requirements. The possibility of increase these ramp rates for low current for the insertion magnets exists and a test during commissioning could be envisaged. The test should take into account the dependence on the ramp rate of the power converter as well as the magnet quench behavior and the QPS system . The fast and slow power abort tests may be used to infer the maximum ramp rate from the QPS and PC point of view but further investigation is needed to check the magnet. Action: G. Kirby.
W. Venturini Delsolaro pointed out that the required ramp rates for the 600 A circuits may be insufficient for fast processes as the snap back. Besides, the QPS system may not be able to deal with larger ramp rates. This should be discussed in a future meeting. Action: W. Venturini Delsolaro.
The interconnection with the DFB has been now re-closed and the magnet will be cooled with the rest of the sector. The corrector circuit can not be powered and has to be blocked for hardware commissioning. ElQA will re-test the magnet at cold and inform MPP. Action: D. Bozzini
A working group chaired by K.-H. Mess and M. Giovannozzi is in charge of estimate the criticality of this particular corrector and study the feasibility of a cryo-magnet containing a single corrector of this type.
V. Parma informed that the cryostat for this kind of assembly does not exist at CERN. However is the design of the undulator cryostat can be easily adapted, manufacturing a new one could be sensibly faster.
K. Dahlerup-Petersen pointed out that similar procedures do not exist yet for parallel powering of circuits in the same DFB. These procedures should also contain tests of the active elements of the DFB.
General information
Sector 4-5 will be the next sector to be cooled down and powered. The powering will not include the inner triplet. Sectors 8-1 and 5-6 will follow depending on the results of vacuum tests. A. Vergara informed that sectors 8-1 and 7-8 will be cooled-down before Christmas for powering at the beginning of next year.ELQA issues concerning MPP.
After the flushing of sector 8-1 a short-circuit was found in cell 11L1 and localized in the diode of dipole MB1158 (EDMS 871858). Tests indicate a debris moving on the diode. The diode is open and the repair is ongoing.Maximum dI/dt for hardware commissioning powering. G. Kirby.
The maximum ramp rates originally included in the old version of document EDMS 519716 were settled on the basis of power converter requirements. The possibility of increase these ramp rates for low current for the insertion magnets exists and a test during commissioning could be envisaged. The test should take into account the dependence on the ramp rate of the power converter as well as the magnet quench behavior and the QPS system . The fast and slow power abort tests may be used to infer the maximum ramp rate from the QPS and PC point of view but further investigation is needed to check the magnet. Action: G. Kirby.W. Venturini Delsolaro pointed out that the required ramp rates for the 600 A circuits may be insufficient for fast processes as the snap back. Besides, the QPS system may not be able to deal with larger ramp rates. This should be discussed in a future meeting. Action: W. Venturini Delsolaro.
Status of MCBC problem in Q5L8 N. Catalan Lasheras.
A resistance of 20 mOhms was detected in a MCBC circuit in Q5L8 during cool-down of sector 7-8. After the warm-up, the ElQA team investigated the fault and exclude the bus-bars and pigtails as well as the joints to the DFB. The MCBC resistance is very high (380 Ohms) and does not allow a direct measurement of any defect resistance. The comparison of measures taken after the cold mass production and after installation in the tunnel are inconclusive. The magnet can not be repaired in situ.The interconnection with the DFB has been now re-closed and the magnet will be cooled with the rest of the sector. The corrector circuit can not be powered and has to be blocked for hardware commissioning. ElQA will re-test the magnet at cold and inform MPP. Action: D. Bozzini
A working group chaired by K.-H. Mess and M. Giovannozzi is in charge of estimate the criticality of this particular corrector and study the feasibility of a cryo-magnet containing a single corrector of this type.
V. Parma informed that the cryostat for this kind of assembly does not exist at CERN. However is the design of the undulator cryostat can be easily adapted, manufacturing a new one could be sensibly faster.
MPP procedures status. M. Modena.
A document EDMS 865957 describing the required procedures for powering during hardware commissioning has been written and is currently under approval. It contains the list of procedures needed, deadlines and people involved for each circuit and system.K. Dahlerup-Petersen pointed out that similar procedures do not exist yet for parallel powering of circuits in the same DFB. These procedures should also contain tests of the active elements of the DFB.
List of pending issues for next meetings
- Maximum dI/dt for insertion magnets and 600 A circuits. G. Kirby and W. Venturini Delsolaro.
- 30 A window for relaxed QPS thresholds in 600 A circuits. A. Verweij and W. Vennturini Delsolaro.
- Pigtails protection parameters A. Verweij.
- MCBY short0circuit in Q5R4. N. Catalan Lasheras.
- Specifications for automatic analysis during hardware commissioning. G. D'angelo.
- MPP e-logbook. D. Nisbet.
- Logging and meter databases. AB/CO.
- Powering of inner triplet quads and quench heaters firing.
- Proceedings for simultaneous powering of all the circuits in a DFB.
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