MBSMH101 11T practise coil Collaboration meeting

MBSMH10111T practise coil

Collaboration meeting

Gerard WilleringTE-MSC-TF 21-07-2014

on behalf of the test team: Jerome Feuvrier, Vincent Desbiolleswith thanks for support during test to Susana Izquierdo, Juho Rysti and Philippe Grosclaude

with thanks to everyone involved in the design and preparation of the coil that deserve the creditsnanos gigantum humeris insidentes

Content

Magnet parameters

Conductor parameters

Short circuit and instrumentation

Training and quench performance

Mechanical measurements

Quench heater efficiency

Magnet Parameters

Identification: MBSMH101Coil 101 – Copper coilCoil 105 – OST RRP 108/127, Ta-Doped

Coil ID: HCMBHSP0003_105 from billets 13925, 13926 Cabled at CERN, cabling run 86A Cable ID: H15OC0127A

Overview of the different design of magnet cross-sectionsThis coil has the CERN type Single-aperturs cross-section

Lots of info during 11T design review on: http://indico.cern.ch/event/273023/

10 kA

6.5 kA

13 kA

Magnetic Field

In the half-coil dipole configuration the outer blocks and Quench Heaters are in rather low field region.

Highest field is in the end turns.

Images by S. Izquierdo

Conductor Parameters

Reference: Internal note to be published, B. Bordini, A. Ballarino, A. Bonasia, L. Oberli, «Cable H15OC0127A for Coil 105 (11 T Magnet Project)»

Strand Type RRP 108/127, Ta-DopedBillets 13925, 13926

Max Ic(4.22 K, 12 T)** 480 AMin Ic(1.9 K, 12 T)** 466 A

Max RRR** 230Min RRR** 88

Transposition Pitch (mm) 100 Mid Thickness (mm) 1.2498 (= 0.0011)*

Width (mm) 14.715 (=0.0026)*

Keystone Angle 0.779° (=0.029)*

Number of Strands 40Core Width (mm) 12

Core Thickness (m) 25

Wire Caracteristics Cable Caracteristics

Similar cable as for SMC_11T coil #1 that had magneto-thermal instabilities

SMC_11T #1 MBSMH10148 hrs 210 °C 48 hrs 210 °C48 hrs 400 °C 48 hrs 400 °C50 hrs 650 °C 50 hrs 640 °C

KeystoneLower T should increase RRR and lower Ic

Measured RRR of full coil 77

Rectangular

Short sample and load line

Reference: Internal note to be published, B. Bordini, A. Ballarino, A. Bonasia, L. Oberli, «Cable H15OC0127A for Coil 105 (11 T Magnet Project)»Loadlines calculated by S. Izquierdo using Roxy.

0 2 4 6 8 10 12 14 160

10

20

30

40

50

60

VAMAS 1 - XS, 1.9 KVAMAS 2 - XS, 1.9 KParam. XS, 1.9 KVAMAS 1 - XS, 4.3 KParam. XS, 4.3 KVAMAS 2 - XS, 4.3 KLoadline Roxie 2D w SFLoadline Roxie 2D wo SFLoadline Roxie 3D w SFLoadline Roxie 3D wo SF

Magnetic field [T]

Cab

le c

urre

nt [k

A]

2 sets of Vamas witness samples measured.

Load lines calculated

Resulting short sample current limits:4.3 K: 15.15 kA ± 1 %1.9 K: 16.69 kA ± 1 %

Variation inbetween 2 samples about 300 A.

Uncertainties on loadline Field modulus is usedTheoretical position of the coil is used3D loadline will be re-evaluated

Cooldown

0

50

100

150

200

250

300

0 10 20 30 40 50

Tem

pera

ture

(K)

Time (hours)

Temperature first cooldownT_bottom

T_top

Inner coil

Outer coil

Rather fast cooldown in 45 hours with a ΔT between top and bottom of the yoke of 100 K.Temperature in the coil (calculated from ρ) follows closely the top temperature.

Short circuit in the coil? First ramp of the magnet led to trip at 2.5 kA. Suspicion of a short circuit in the coil

Jumps in total voltage and inner layer voltage during discharge after the quench

2.52.62.72.82.9

33.13.23.33.43.5

0 1 2 3 4 5

Indu

ctan

ce (m

H)

Current (kA)

Ramp up

Ramp down

Only 3.3 mH instead of 3.8 as was calculated!Strong jumps in voltage from 1 to 3 kA

Only normal behavior: Time constant and inductance during energy extraction: coil inductance around 3.8 mH.

2.2

2.25

2.3

2.35

2.4

2.45

2.5

2300

2305

2310

2315

2320

2325

2330

2335

2340

12.22 12.24 12.26 12.28

Volta

ge (V

)

Curr

ent (

A)Time (s)

I_MEAS

V_MEAS

Changes in load on Power ConverterConclusion: No short between turns, but shorts through instrumentation.Post mortem investigation started last Friday.

Inductive voltage on coil not equal to resistive voltage in the dump (6 kA, no quench)

Instrumentation – outer layer

12 outer layer voltage taps2 outer layer heaters

Instrumentation – Inner layer

15 inner layer voltage tapsMany signals for investigation of events !!

Training Quench performanceTraining at 4.3 K up to 14.3 kA

First quench at 9 kA

After 5 quenches at “nominal” 11.8 kA

After 16 quenches 11 T in the coil ends

Most training quenches seem to initiate in the coil ends, but in both inner and outer layer.

Layer Voltage taps1 Inner I13-I142 Outer O02-O033 Inner I13-I144 Inner I03-I045 Inner I06-I076 Inner I03-I047 Outer O05-O068 Inner I09-I109 Outer O07-O0810 Outer O02-O0311 Outer O02-O0312 Outer O03-O0413 Outer O06-O0714 Outer O03-O0415 Inner I10-I1116 Outer O05-O0617    18 Outer O07-O0819 Inner I11-I1220 Inner I13-I1421 Outer O07-O0822 Outer O04-O0523 Inner I10-I1124 Outer O07-O0825 Inner I02-I0326 Outer O07-O0827 Outer O07-O0828 Inner I14-I1529 Inner I03-I0430 Outer O07-O0831 Outer O07-O0832 Inner I04-I0533 Outer O07-O0834 Outer O07-O0835 Outer O07-O0836 Outer O07-O0837 Inner I14-O0238 Outer O07-O0839 Outer O07-O0840 Inner I07-I0841 Inner I09-I1042 Inner I02-I0343 Outer O07-O0844 Outer O07-O0845 Inner I09-I1046 Outer O06-O0747 Outer O07-O08

“Holding quenches”: no quench during 40 minutes at 15 kA at 1.9 K.

6.5

7.3

8.1

8.9

9.7

10.5

11.3

12.1

12.9

13.8

14.6

8000

9000

10000

11000

12000

13000

14000

15000

16000

17000

18000

0 10 20 30 40 50

Mag

netic

fiel

d in

the

pole

end

s (T)

Curr

ent (

A)

Quenches

Training quenches 11T practise model - mirror configuration single coil

4.3 K, 10 A/s

Short sample 4.3 K

1.9 K, 10 A/s

Short sample 1.9 K

1.9 K, 50 A/s

Thermal cycle

Comparison SMC 11T_2

SMC 11T_2 and 11T practise coil are made from the same cable.

SMC 11T_2 suffered from conductor instabilities at 1.9 K between 14.1 and 16 kA.

11T practise coil seems to have a “smooth training” up to 16 kA.8000

9000

10000

11000

12000

13000

14000

15000

16000

0 10 20 30 40 50

Curr

ent (

A)

Quench number

Comparison 11 T practise coil with SCM11T_2

4.3 K, 10 A/s

1.9 K, 10 A/s

1.9 K, 50 A/s

4.3 K SMC 11T_2

1.9 K, SMC 11T_2

Comparison with MBHSM01 tested at FNAL

Single coil versus magnetic mirrorCERN coil has a higher I_ss

7000

8000

9000

10000

11000

12000

13000

14000

15000

16000

17000

0 10 20 30 40 50 60 70

Cur

rent

(A)

Quench number (-)

4.3 K, 10 A/s

1.9 K, 10 A/s

1.9 K, 50 A/s

Plots for comparison, but between two coils with different characteristics.

0.5

0.55

0.6

0.65

0.7

0.75

0.8

0.85

0.9

0.95

1

0 10 20 30 40 50

I/Is

s (-)

Quench number

Comparison training quenches FNAL mirror to CERN 11T practise coil

CERN 4.3K Ic=15560 A

CERN 1.9 K Ic=17270 A

FNAL 4.3 K Ic=13000 A

FNAL 1.9K Ic= 14514 A

Mechanical Measurements LaboratoryM.Guinchard/P. GrosclaudeMechanical measurements

Reference: https://edms.cern.ch/file/1352279/1/11T_results.pptxhttps://edms.cern.ch/file/1387744/1/11T-2_Measurements_on_the_instrumented_collar_packs_report.pdf

Capa Gauge size 120 by 15 mm

Strong fluctuations seen from 15 to 16 kA. Needs further explanation

Pole wedge compression stressesRamp to 16 kA

0255075

100125150175200225250275300325

Initial 686 t ofcharge

Welding 4.2K 293K 4.2K 1.9K 293K

Stre

ss (M

Pa)

Bottom Shell - Traction Stress

Shell_0

Shell_1

Shell_2

Shell_3

FEA Results

Good correlation calculations with measurements on traction stress in the shell in the different stages of coil life.

Many probes did not perform as expected, instrumentation is already revised for the next coil.

Quench Heater studies

0

10

20

30

40

50

60

70

80

90

0 2 4 6 8 10 12 14

Que

nch

dela

y (m

s)

Current (kA)

I_QH = 150 A, T = 1.9 KQuench heater response time within calculated range, except at 14 kA

Calculations by S. Izquierdo

Resistance growth comparison between model and measurements is progressing

0

20

40

60

80

100

120

5 7 9 11 13 15

Que

nch

dela

y (m

s)

Current (kA)

150 A - 1.9 K

100 A - 1.9 K

80 A - 1.9 K

150 A - 4.3 K

Quench Heater studies

QH delay at 4.3 K is very consistent up to 14 kA.

QH delay at 1.9 K is very fast at 13 and 14 kA, faster than at 4.3 K.

Confirmed for multiple cases

Cannot be explained with “normal” heat transfer from heater to coil.

In addition the quench starts in interlayer jump, far from Quench heaters

Small benefit in resistance growth, but not an effect to count on for protection.

Quench Heater studies

Resistive voltage in the coil at 1.9 K following QH discharge

Large set of data acquired for model validation and futher QH efficiency studies

Resistive voltage different coil blocks at 12 kA at 1.9 K

Example 1 Example 2

Preliminary conclusions

- Good training performance up to 16 kA, 13 T- Very good memory after thermal cycle- No “Holding quenches”- No degradation during testing- Quench heater delays as expected- QH efficiency studies is work in progress, in the right direction

Gives a good motivation to keep on going….

End of presentation