70 likes | 160 Views
Present: Sandrine, Per, Jens, Mateusz, Daniel, Bernhard, Rudiger , Mirko RD2.R8 (5350 , 5723 , 5779, 5670 A ) (Quenches in 2007/8: 5816, 5788, 5856, 5854 A) 7 TeV extrapolated value=6020 A and 6.5 TeV =5590 A.
E N D
Present: Sandrine, Per, Jens, Mateusz, Daniel, Bernhard, Rudiger, Mirko RD2.R8 (5350, 5723, 5779, 5670 A) (Quenches in 2007/8: 5816, 5788, 5856, 5854 A) 7 TeV extrapolated value=6020 A and 6.5 TeV=5590 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 done: 5670 A Decision 19/2: Run the circuit for 8 hrs at 5.6 kA. RQX.L2(3 quenches: 6801 A, 6991 A, 7140 A) with RQTX2 at nominal. Decision 18/2: perform max 2 quenches more. New results: Nothing yet. Decision 19/2: approve 3rd quench. Then a 4th run can be performed. Ad-hoc MP3 meeting 19/2/2013
RQ5.L5(4054 in B1, 4294 in B1, 4000 in B2): Note that B1 and B2 on QPS are inversed Decision 18/2: perform max 1 quench more (if quench happens in B2) New results: 4thquench done: 4270 (B2) with B1 at 4310. 5th run OK Issue closed RQ6.R5 (3844 in B1, 4219 inB1, 4251 in B2): Decision 18/2: perform max 2 quenches more (if quench happens in B2) New results: 4th run OK. Issue closed RQ5.R2 slow training in B1: 4067, 4160, 4202 . B2 is still at 2400 A (some problems with QPS files). Decision 18/2: Reduce I_nom on B1 and B2 to 4100 A and do max 2 more quenches to see quench values in B2. E-mail to Massimo. (Arjan) New: Massimo agrees probably. No 4th quench yet. To be cntd.
RQ4.R6 (Q on plateau) Decision 18/2: Analyse and perform a test with 20 min plateau at 90% and 95% and 100% of nominal current. New results: Analysis shows that there were no other related PMs. Quench after 90 s on flattop. PIC claims it was B2, which is at only 2 kA! Pyramid done. SPA during Pyramid. Decision 19/2: MP3 will check SPA test and EPC also. To be cntd. RQ7.L4 (Q on plateau) Decision 18/2: Analyse and perform a test with 20 min plateau at 90% and 95% and 100% of nominal current. New results: Analysis shows that there were no other related PMs. PIC blames B2 at 3 kA, even though QPS PM clearly points to B1. Timing problem? Labeling problem? Pyramid done successfully. Decision 19/2: Perform new PNO with 2x2hrs plateaus. RQ6.L2 (Q on plateau) Decision 18/2: Analyse and perform a test with 20 min plateau at 90% and 95% and 100% of nominal current. New results: QPS PM looks like in RQ7.L4, but PIC does not see a quench!? FPA during pyramid. MP3 will analyse the event. To be cntd.
RQX.R1 heaters fired after PC_failure(Note that one heater is at 850 V). Decision 18/2: Sandrine will do a detailed analysis, checking possible imbalance in QPS. New results: See slides Sandrine. It seems that the heaters are swapped between 2007 and now. Decision 19/2: Small current cycle to be done to confirm QPS signals. Afterwards we have to ask Richard to check proper connections with heaters. RQTD.A23B1 (Q at plateau) Decision 18/2: Perform a test with 20 min plateau at 90% and 95% and 100% of nominal current. New results: sudden rise in U_RES after 40 seconds on flattop. No other related PMs. Pyramid OK. Decision 19/2: repeat PNO test with 2hr plateau. RCD.A56B2 (Q at plateau) Decision 18/2: Perform a test with 20 min plateau at 90% and 95% and 100% of nominal current. New results: Analysis shows quench after 2 seconds, and other related PMs. Pyramid test done and passed. Decision 19/2: repeat PNO test with 2 hr plateau.
RQS.A56B2: 200 ms delay on switch opening New results: Sandrine did very detailed analysis, see slides. All RQS have 190 ms delay. Delay is OK for protection. Carry on tests on the other RQS circuits. Jens will check why U_RES remains saturated for 200 ms even though there is only . RCBX: 550 A with low RR. Decision 18/2: 1st ask for overcooling on leads. If no improvement then reduce I_nom to 450-500 A. New: Mikko gave a list of weak MCBX magnets, that could only work with Q1 magnets. Check correlation. RQ5.R1: Quench on B1 but not in B2? Sandrine and Ivan analysed and they think it is a PC problem, and not a quench. Hugues shows 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.
RSD1.A56B2: apparent quench on plateau. More analysis showed that the event is linked to two other events. Quench propagation or electrical interference? RQ6.L5:quench of B2? Similar event to the one commented by Hugues (RQ5.R1?). No sign of a quench in the PMs (no external abort flag from FGC or QPS PM), but PIC clearly states that QPS triggered first. Check heater discharge in Timber. Lock circuit.
RCBYHS5.R8B1: quenches at 64 A “Decision 19/2”: we will discuss tomorrow Comments from GLM: (Rudiger) RQ.A34 because int. splice resistance of 50 nOhm in Q7? Should circuit be tested to 6.5 TeV. Is the 100 mV on the Q9/Q10 really 100 mV? Lab test + e-mail to Reiner for old QPS IST test. Ad-doc decisions during the afternoon of 19/2 (Sandrine, Bernhard, Mateusz, Zinour, Jens, Arjan): RQ5.R5 (1 quench B1, 2 quenches B2): Perform one more test RQX.L2 (6801, 6991, 7177): Perform one more test RQ6.L2 (Q at plateau, Q at pyramid): Perform PNO with 2 hr plateau