Collar Pack 2 Disassembly Incident Coil Inspection report

Collar Pack #2 Disassembly Incident Coil Inspection report Heng Pan 07/29/2015 Heng Pan 1

Inspections on coil 104 Summary • Three major damages (all on the side between coil 104 and 05) a. The insulation at the end of the L 2 splice delaminated. b. A bump was found on the midplane facing coil 05. c. Epoxy cracking around the corner on the end shoe (return end). • Four minor scratches and dents • Those minor scratches were found on both sides of the coil. • Three of them are on the edges of the OD and midplanes; one is a dent on the end shoe (return end). • SG wires were damaged • The gauges are fine, wires were detached from the pad. • Coil 104 passed all of the electrical test • Passed continuity check, sequential R and inductance test. • Passed hi-pot test which shows same results as it was in the preassembly measurement. 07/29/2015 Heng Pan 2

Inspections on coil 104 • Damage (a) Before incident Epoxy delaminated in the L 2 splice area Before incident 15 mm superficial crack 07/29/2015 Heng Pan 3

Inspections on coil 104 • Damage (a) 8. 5 mm 6 mm 17. 5 mm 10. 5 mm 6. 5 mm 138 mm • Visible delamination within the dash line. • Some epoxy cracks were found around the end of the splice. 07/29/2015 Heng Pan 4

Inspections on coil 104 • Damage (b) 3. 5 mm Midplane of coil 104 facing 05 11. 6 mm OD OD RE RE • The coil may have been hit on the OD (in the yellow circle) causing the bump. • Cracks superficial: Hard to see the conductor underneath through the cracks. 07/29/2015 Heng Pan 5

Inspections on coil 104 • Damage (b) • The bump height was measured as 10 mil which is 250 μm. 07/29/2015 Heng Pan 6

Inspections on coil 104 • Damage (c) on the RE end shoe Pre-assembly Return end 07/29/2015 Heng Pan 7

Inspections on coil 104 • Damage (c) on the end shoe Return end 7. 6 mm • The corner of the end shoe may have hit the assembly table first in the incident. • Delamination of the G 10 observed 07/14/2015 8

Inspections on coil 104 • Minor scratches and dents Return end 5. 5 mm 7. 6 mm 5 mm On the edge facing coil 03 07/29/2015 RE RE On the edge facing coil 05 Heng Pan 9

Inspections on coil 104 • Minor scratches and dents Ø 3. 6 mm Return end 5. 5 mm 7. 6 mm On the edge facing coil 03 07/29/2015 Return end RE Heng Pan 10

Inspections on coil 104 • Minor scratches • Those scratches are superficial, only see the epoxy becomes white due to the cracking. • The GPI where the scratches were observed seem may have absorbed some of the impact energy. 07/29/2015 Heng Pan 11

Inspections on coil 104 • SG wires have been repaired Strain gauge wires broken Repaired Temperature compensator pad separated • The temperature compensator strain gauges were inspected, no damage. 07/29/2015 Heng Pan 12

Inspections on coil 05 and 03 Summary • SG wires of the coil 05 were cut off by coil 03 • The gauges are fine, wires (both CERN and LARP SG wires) were cut off. • 1 Minor scratch / coil were found • Coil 05 and 03 passed all of the electrical test • Passed continuity check, sequential R and inductance test. • Passed hi-pot tests which show same results as they were in the preassembly measurement. 03 104 103 07/29/2015 Heng Pan 05 13

Incident pictures • SG wires of coil 05 Coil 03 Coil 05 03 • All strain gauge wires were cut. 07/14/2015 103 05 14

Incident pictures • Minor scratches Coil 03 (RE) Coil 05 5 mm 25 mm • Kapton GPI damage observed, likely due to catching the SG temperature compensator pad of Coil 104. Evidence of epoxy damage underneath. 03 103 05 104 Coils fell off 07/29/2015 Heng Pan 15

Coil inspections • Visual inspections performed • Electrical checks on all coils have been done: • • • Continuity checks with hand-held meter: o between PH and coil o between coil and end shoes o between IL and OL ends at both ends Take sequential R measurements for all coils. Inductance measurements for all coils. Impulse tests and compare with pre-assembly measurements. Full set Hi-pot test (e. g. , coil vs. PH, endshoe vs. endshoe and etc). Coil 104 07/29/2015 Coil 03 Coil 05 Coil 103 Visual inspection √ √ Continuity check √ √ Sequential R √ √ Impulse test √ √ Inductance measurement √ √ Hi pot √ √ Heng Pan 16

Coil inspections MQXFS 104 Pre/Post Event Impulse Test 2500 2000 1500 1000 500 0 0. 00 E+00 -500 1. 00 E-05 2. 00 E-05 3. 00 E-05 4. 00 E-05 5. 00 E-05 6. 00 E-05 -1000 -1500 -2000 V Pre Event 2000 V Post Event MQXFS 03 Pre/Post Event Impulse Test 2500 2000 1500 1000 500 0 0. 00 E+00 -500 1. 00 E-05 2. 00 E-05 3. 00 E-05 4. 00 E-05 5. 00 E-05 6. 00 E-05 -1000 -1500 -2000 V Pre Event 07/29/2015 Heng Pan 2000 V Post Event 17

Coil inspections Impulse Test MQXFS 05 3000 500 V 1000 V 1500 V 1600 V Voltage (V) 2000 1000 0 0. 00 E+00 1. 00 E-05 2. 00 E-05 3. 00 E-05 4. 00 E-05 5. 00 E-05 6. 00 E-05 -1000 -2000 Time (s) Impulse Test MQXFS 03 2500 V 1000 V 1500 V 1600 V 1700 V 1800 V 2000 Voltage (V) 1500 1000 500 0 0. 00 E+00 -500 5. 00 E-06 1. 00 E-05 1. 50 E-05 2. 00 E-05 2. 50 E-05 3. 00 E-05 -1000 -1500 -2000 07/29/2015 Time (s) Heng Pan 18

Coil inspections • Sequential R measurement 200 180 160 140 120 100 80 60 Coil 104 Coil 103 40 Coil 03 20 Coil 05 0 A 01 07/29/2015 A 02 A 03 A 04 A 05 A 06 A 07 A 08 B 08 Heng Pan B 07 B 06 B 05 B 04 B 03 B 02 B 01 19

Inspection conclusion • • 104, 05 and 3 show some damages 103 did not see any impact => no damage The coils pass all the electrical tests. Most of the scratches and dents have been assessed superficial. • GPI layers have been replaced • Repair/dress epoxy • Strain gauge repairs have been done. • Magnet assembly is ongoing. 07/29/2015 Heng Pan 20