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Present : Bernhard, Jens, Daniel, Zinour , Arjan , Per, Rudiger , Andrzej , Michele, Ivan, Gerard RD2.R8 (7 TeV =6020 A, 6.5 TeV =5590 A)
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Present: Bernhard, Jens, Daniel, Zinour, Arjan, Per, Rudiger, Andrzej, Michele, Ivan, Gerard RD2.R8(7 TeV=6020 A, 6.5 TeV=5590 A) RD2.R8 is a D2 separation dipole. Cold mass is HBMBRCA001-BL000001 (first of the production). MM available up to 7 kA, so it has been trained up to there. Quench during cold test: 6309 A, 6877 A, then up to 7 kA + one quench at 6309 A after thermal cycle. Quenches in 2007/8: 5816, 5788, 5856, 5854 A Quenches in Feb 2013: 5350, 5723, 5779 A Decision 18/2: perform max 1 quench more. Then perform cycle with plateau for 20 min at I_Q_max-100 A. New results: 4thquench at 5670 A Decision 19/2: Run the circuit for 8 hrs at 5.6 kA. New results: Quench on plateau after 8 min!!!! Decision 20/2: Make sure it is not the BB. If it is the magnet, then perform pyramid 5.4, 5.5, 5.6, 5.7, … with 2 hrs on each plateau, and present a.s.a.p. in TE-TM. New results: Except for the first quench, all quenches are in the BB, very close to the magnet. 21/2: Antonio presented possible cooling problem of the bus if the plug is not at the lowest point. Radios by CRYO foreseen asap. See also picture of positioning of the RD2.R8 bus. Re-alignment foreseen for 25/2 PM. Line lowered by 20 mm. New run foreseen for 25/2 evening. 6020 A reached but PC trip caused heater firing. 2 hr plateau at 6020 A successful. PNO will be done today. Antonio presented results from the radios and re-alignment. Closed Ad-hoc MP3 meeting 26/2/2013
RQ6.R2 (Q at 3896, 4124, 4190 all in B1) Decision 21/2: perform max 2 quenches more New results: 4th Q at 4251 A in B1, 5th Q at 3908 A in B2 (with B1 at nominal) Decision 25/2: max 2 quenches more New results: 6th and 7th quench at 4053 A and 4115 A in B2 (with B1 at nominal) Decision 26/2: perform max 2 quenches more RQTD.A23B1 (550 A): Quench at plateau. Ad-hoc decision 21/2: perform pyramid 500 (20 min), 525 (20 min), 550 (2 hr) New results: Pyramid OK. PNO quenched again on plateau. New plateau to be done (2 hrs at 525 A and 2 hrs at 550 A). Pyramid OK. PNO OK. Closed (but to be followed up). RCS. A81B1 (550 A): Q at 544 A, Quench at plateau after 6 min. Perform pyramid 500 (20 min), 525 (20 min), 550 (2 hr) PNO test OK. Pyramid still to be done. RQTD. A81B1 (550 A): Quench at plateau after 8 sec. Perform pyramid 500 (20 min), 525 (20 min), 550 (2 hr) RSF1. A78B1 (550 A): Quench at plateau Perform pyramid 500 (20 min), 525 (20 min), 550 (2 hr). Pyramid OK.
RCD. A12B2 (550 A): Quench at plateau (-550 A) Perform pyramid 500 (20 min), 525 (20 min), 550 (2 hr) ROD. A78B1 (550 A): Quench at plateau (-550 A) Perform pyramid 500 (20 min), 525 (20 min), 550 (2 hr). Pyramid OK. PNO to be done. RQ9. L2 (5390 A): Quench at plateau in B2 Perform pyramid 5000 (20 min), 5200 (20 min), 5390 (2 hr) RQTF. A78B1 (550 A): Quench at plateau Perform pyramid 500 (20 min), 525 (20 min), 550 (2 hr) Quench at flat top of 550 A after 100 s during pyramid. Perform pyramid 500 (2 hr), 525 (2 hr), 550 (2 hr) IT.R2 and RCBXH1.R1: frequent tripping at 50 A. Need RESET. RCSSX3.L1: Q at 63.5 PGC test, for all remaining sectors: Add a PNO test before the PGC for the IPQ’s with equal currents in B1 and B2. Perform PGC with I_nom-100 A in IT, IPD, IPQ, and I_nom-25 A in 600 A circuits. Closed.
RQ5.R1: 2 quenches (3910 and 4086 A) on B1 but not in B2? Sandrine and Ivan analysed and they think it is a PC problem, and not a quench. Huguesshows that the voltages on the leads correspond to the DCCT currents. It seems very likely that the quench was not detected by QPS and the heaters were not fired. Decision 19/2: Jens will check QPS boards in detail, and check in timber if boards were blocked in the past. Lock circuit. We should probably perform an ELQA test. Heaters not fired. Both boards stuck. After reset both boards came back. No signals since aug 21, 2012. Seems software issue, not a hardware problem. Scan boards + reset IPQ/IPD/IT. Decision 20/2: Issue forwarded to QPS. New results: Hot spot of first 2 quenches would have been maximum 350 K. ELQA OK. 3rd quench at 4286 A in B1. Decision 21/2: perform max 2 quenches more New results: 4th and 5th quench at 3718 and 4071 (both in B2 with B1 at 4310 A). Decision 22/2: max 2 quenches more New results: 6th and 7th quench at 4183 and 4267 A (both in B2 with B1 at nominal) Decision 25/2: max 2 quenches more New results: 8th PNO test OK. Closed
RCBYHS5.R8B1: quenches at 64 A “Decision 19/2”: we will discuss tomorrow Decision 20/2:we will discuss tomorrow Decision 21/2:we will discuss tomorrow New results: Gerard and Bernhard looked in detail. Known poblem. Quenched 4 times at 63-64 A. Quench level getting lower wrt previous HWC. 1 hr plateau at 55 A. Trip when ramping down. Decision 22/2: Look also at other cases in the machine. Keep I_nom at 20 A. Perform PNO, but no other tests. Needs follow up with recommendation to fix/replace magnet. RCBXH3.L5: ELQA OK. Tripped in the past at 50 A Decision 22/2: QPS problem. Intervention in tunnel according to proposal Zinour. New results: Some inversion in wiring, possibly with ‘inversion’ in firmware. Magnet has reached nominal in earlier HWC. New results 25/2: compensation now seems to work fine. Complete commissioning to be done. To be cntd. RCO.A78B2: special ELQA to be done Pyramids to 20 A and 58 A done. V(I)=R is not linear, see plot. Diagnostics in the tunnel to better localize the defect(s) foreseen for 26/2 or 27/2.
RCO.A78B2 M. Bednarek
Threshold change (see slides Bernhard) Decision/Conclusion Completely non-compensated boards will be difficult to implement on circuits with high inductive voltages because during ramp the effective voltage threshold will be the resistive threshold plus the inductive component. A new threshold of 400 mV can be implemented on RQTL9.L3B1/B2 and RQTL9.R3B1/B2 today, so that it can be tested tomorrow. Another iteration is needed on possible threshold changes for all the other circuits on Reiner’s wish list. Thresholds on the RCBX circuits cannot be increased at the moment. This needs further analysis.
Closed issues linked to excessive quenching RQX.L2:Closed(3 Q, 4thPNO OK) RD3.L4: Closed (7 quenches, I_nom reduced from 5850 to 5600 A) RQ5.L5: Closed (4 Q, 5th PNO OK) RQ6.R5: Closed (3 Q, 4th PNO OK) RQ5.R2: Closed (3 Q in B1, 1 Q in B2, I_nom reduced to 4100 A, 5thPNO_red OK) RQ5.R5:Closed (1 Q in B1, 2 Q in B2, 4th PNO OK) RQ6.L5:Closed (2 Q in B1, 2 Q in B2, 5th run OK) RQTL11.R5B1: Closed (nominal is 550 A, expected for 7 TeV: 250 A, Q at 487, 506, 514, 543, 498, 545 A, PNO reached, reduced to 450 A) RQTL11.L6B1: Closed (nominal=400 A, expected for 7 TeV: 200 A, Q at 358, 392, 376 A, reduced to 350 A) RQ5.L1: Closed (3 Q, 4th PNO OK)
Closed issues linked to quenches on plateau RQ4.R6: Closed (Q on plateau, PNO.c4 with 2x2 hr OK) RQ7.L4: Closed (Q on plateau, PNO.c4 with 2x2 hr OK) RQ6.L2: Closed (Q on plateau, PNO.c4 with 2x2 hr OK) RQTD.A23B1: Closed (Q at plateau, PNO.c4 with 2x2 hr OK) RCD.A56B2: Closed (Q at plateau, PNO.c4 with 2x2 hr OK) RCD.A45B1: Closed (Q at plateau of 550 A, Pyramid and PNO OK) ROF.A45B2 : Closed (Q at plateau of 550 A, Pyramid and PNO OK) RQTF.A56B1: Closed (Q at 500 A, Q at plateau, Pyramid OK) RQS.A56B2: Closed (Q at 520 A, Q at plateau, Pyramid OK) RQT13.R6B1: Closed (Q at plateau, Pyramid OK) RQS.R5B1: Closed (Q at plateau, Pyramid OK) RCBXV3.L8: Closed (Q at plateau, Pyramid OK)
Closed issues (Various) RQX.R1: Closed (heater firing after PC_failure , PNO OK, Q1 and Q2 on board A the same) RQ4.L5:Closed (QPS A&B frozen) RQ6.L8: Closed (Heater induced quench at 2500 A) RQ7.R4:Closed (repetitive trips during PGC, also one at stable 4.8 kA, PC related) RQS.L5B2: Closed (TT893>324 K, ELQA informed) RQT13.R5B1:Closed (QPS A&B frozen) RSD1.A56B2: Closed (minor issue due to electrical interference) RQS.A56B2: Closed (U_RES saturation, forwarded to QPS) RCBXH2.R5 : Closed (CL cooling problems) RQSX3.R5: Closed (CL cooling problem) RSBXV1.R5 : Closed (CL cooling problem) RQ6.L7B1: Closed (QPS trip due to noise in PC. Forwarded to EPC) PGC in arc alone?: Closed (Everywhere!!!)
New PNO values RD3.L4: reduced from 5850 to 5600 A RQ5.R2: reduced from 4310 to 4100 A RQTL11.R5B1 reduced from 550 to 450 A RQTL11.L6B1 reduced from 400 to 350 A