1. Recommissioning of sector 12 after a short warm-up during eYETS 2016/17
QBT, MP3 – May 2017
S. Le Naour

2. RB.A12 : List of NCR 1775466 : LHC-QN-ELQA-TP4-E-HVQ-RB.A12-Line5-001
EDMS : LHC-QN-ELQA-MIC-C-MBBR2359-A11L2-001

3. RB.A12 : List of NCR (no n°) A31L2 : Heater discharge reference
EE in RR17 : problem with EE power
connector on one fast opening system

4. RB.A12
Two training quenches to recover 11080A A and A) versus 7 during HWC 2014/15.
These 2 magnets never quenched in LHC
2313 (C28R1): Quenched at 8954,10340, 11940, A in SM18
1368 (A25R1) : Quenched at 12343,12433,12683 A in SM18
Graph and tables prepared by G. Willering

5. RB.A12
During the second training quench on A25R1, multiple quenches were propagated in the first second to two neighbouring magnets by iQPS system (dVQS0/dt ~ 1V/s)
C25R1
B25R1
A25R1
268ms
190ms
(1368) (2407) (2380)

6. RQF/RQD. A12 and RQX RQF/RQD.A12
Smooth re-commissioning of these 2 circuits.
Minor issue with the ringing of the micro-switch ST-OPEN-A2  use as is
No training quench to reach 10350A on RQD.A12 and 10580A on RQF.A12.
RQX
Smooth re-commissioning of the triplets
No training quench to declare (neither in S12 after thermal cycle nor in other sectors)

7. IPQ with MQM magnets @4.5K (only S12)

8. IPQ (all sectors) IPQ with MQY magnets @4.5K (18 units)
IPQ with MQM (46 units)

9. List of NCR : Arc 12
EDMS : LHC-QN-ELQA-TP4-E-HVQ-RSD1.A12B1-001
EDMS : LHC-QN-ELQA-TP4-E-HVQ-RQTF.A12B2-001
EDMS : LHC-QN-ELQA-TP4E-HVQ-RQSX3.R1-001

10. 600A circuits of the arcs
Statistics on quenches from 600A magnets
During HWC 16/17, most of circuits with MQT magnets quenched.
Six circuits are from sector 12 and seven circuits from other sectors.
Most of them are in RQTD/F circuits (8 magnets in series).
All of them reached their nominal current.

11. RCBX performance in R1
First individually powered up to 550A, RCBX nested magnets are then powered following the rule I_RCBX2+I_RCBH2= Radius2,

12. RCBX performance in R1

13. RCBX performance in L2

14. RCBX performance
After the warm up of the sector 12, triplet magnets included, a complete HWC was performed on all circuits. Main triplet magnets recovered there previous performance without quenching while all RCBX circuits in R1 needed some training. RCBX circuits in L2 reached their previous performance without quenching
Because some detraining was observed for RCBXH1.R1 and RCBXH3.R1 during HWC 2017 and because these circuits are not used above 250 A in operation, the HWC current was limited to 410 A individually.
The combined powering of RCBXH/V1.R1 needed also some training and reached 410 A (or 290*√2 A). All the other circuits passed this test without quenching.
The warm up of the sector 12 seems to affect the qualification of the corrector magnets in the triplet in R1, but was transparent for L2.
In the other sectors, RCBX circuits were powered only individually during the HWC campaign and no quench was declared.
Reminder : on the base line of the next YETS, triplets in point 5 will be warmed up for alignment with CMS.

15. Summary
Following the warm-up of sector 12, one Vtap of dipole A11L2 was found open, other non conformities were on warm parts of the circuits.
Two training quenches occurred in RB.A12 to recover the performances to 6.5TeV. The second training quench propagated multiple quenches in the first second (electromagnetic coupling phenomena)
No training quench for main triplet magnets, RQF/RQD.A12 or IPDs
For IPQs and 600A, few training quenches to recover their performance but equivalent behaviour than after LS1.
Unexpected behaviour of MCBX magnets in R1 only. One to five quenches occurred in each of the 6 MCBX magnets to reach 550A individually. As they are not powered more than 250A in operation, the commissioning was stopped at 410 A for 2 circuits.
MCBX magnets in L2 reached the nominal current without quenching.

16. List of NCR EDMS 1772023 : LHC-QN-ELQA-TP4E-HVQ-RB.A78.Line#6-001
EDMS : QN-ELQA-MIC-C-IRC-MQ.23R3.001
EDMS : QN-ELQA-MIC-C-IRC-MQ.28L4.001
EDMS : LHC-QN-ELQA-TP4E-HVQ-RCO.A78B2-001