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Electrical and calorimetric measurements and related software. N. Catalan Lasheras, Z. Charifoulline, M. Koratzinos, A. Rijllart, A. Siemko, J. Strait, L. Tavian, R. Wolf. Outline. What did we see on 19 September 2008? Data from the final ramp - PowerPoint PPT Presentation
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Electrical and calorimetric measurements and related software
N. Catalan Lasheras, Z. Charifoulline, M. Koratzinos, A. Rijllart, A. Siemko, J. Strait, L. Tavian, R. Wolf
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Outline
What did we see on 19 September 2008?
– Data from the final ramp
– Data from the hardware commissioning powering tests
Investigation in other sectors of the machine
– Calorimetric method, calibration
– Sector 1-2 results
– Electrical measurements: across the splices
– Electrical measurements: inside the magnets
– Verification from SM18 data
Summary for all sectors
– Suspected cases
Conclusions
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19 September 2009 Sector 34
Expected temperature increase around 8mK.
Some sensors show between 10 mK and 13 mk increase
Ramping on 19 September
LBBLA_24R3
LBBLA_25R3
LBBLA_29R3
LQASB_23R3
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
2008-09-1911:02:24.000
2008-09-1911:05:16.800
2008-09-1911:08:09.600
2008-09-1911:11:02.400
2008-09-1911:13:55.200
2008-09-1911:16:48.000
2008-09-1911:19:40.800
Time
Del
ta T
in T
T821
Ramping on 19 September
LBBLA_24R3
LBBLA_25R3
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
2008-09-1911:02:24.000
2008-09-1911:05:16.800
2008-09-1911:08:09.600
2008-09-1911:11:02.400
2008-09-1911:13:55.200
2008-09-1911:16:48.000
2008-09-1911:19:40.800
Time
Del
ta T
in T
T821
LBALA_12R3LBALA_14R3LBALA_16R3LBALA_18R3LBALA_20R3LBALA_22R3LBALA_24R3LBALA_26R3LBALA_30R3LBALA_34R3LBALB_12R3LBBLA_12R3LBBLA_13R3LBBLA_14R3LBBLA_15R3LBBLA_16R3LBBLA_17R3LBBLA_18R3LBBLA_19R3LBBLA_20R3LBBLA_21R3LBBLA_22R3LBBLA_23R3LBBLA_24R3LBBLA_25R3LBBLA_26R3LBBLA_27R3LBBLA_28R3LBBLA_29R3LBBLA_30R3LBBLA_31R3LBBLA_32R3LQOAA_25R3LBBLA_33R3LBBLA_34R3LBBLD_13R3LBBLD_17R3LBBLD_15R3LBBLD_19R3LBBLD_21R3LQATD_15R3LBBLD_23R3LBBLD_25R3LBBLD_27R3LBBLD_29R3LBBLD_31R3LBBLD_33R3LQASB_23R3LQASB_27R3LQATA_13R3LQATA_17R3LQATA_21R3LQATD_19R3LQOAC_31R3LQOAI_29R3LQOAK_33R3
Parabolic dependence with time (hence current).
All of them around cell 24R3
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7kA cycle in sector 3-4 on 15 September
Sector 3-4. Plateau at 7 kA on 15th September.
Temperature increase about 30 mK in one hour
Valves blocked at 57.5% limit
Strong temperature gradient across the cryogenic sub-sector
Resistance estimated somewhere between 180 nOhms and 270 nOhms
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All sectors quick comparison
All the current plateaux scrutinized for suspect temperature increase
Unstable conditions and dynamic temperature control prevent accurate calculations.
-10 mK
S1-2 S2-3 S3-4 S4-5
S5-6 S6-7 S7-8 S8-1
7 kA 7 kA 7 kA 9.3 kA
7 kA 7 kA 8.5 kA 7 kA
+40 mK
-10 mK
Rel
ativ
e te
mp
+40 mK
Rel
ativ
e te
mp
1-2 hour flat tops
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Sector 1-2 PGC tests at 8.5 kA. Sub-sector 15R1
Powering a group of circuits tests at the end of the sector commissioning
– Endurance test of 8 hours
– All circuits powered
The cryogenic sub-sector 15R1 shows an excessive heating with current
JT valve opens from 41% to 52% and is effective 3 to 5 h into the flat top
The sector is overcooled after the powering
Temperature
JT valve opening
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Procedures for repowering sector 1-2
Dedicated procedure to assess the quality of the bus-bars joints
– test sequence
– risk analysis
– conditions to go ahead with the next step
Two investigation methods
– Calorimetric
– ElectricEDMS Document No. 973396
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Q Q DDDD
Bayonet HXSupply pipe
Saturated LHeIIDD D D Q Q DDDDDD D D
HX
CV910
TT911
Hydraulic restriction(cutting conduction in HeII
w/r to adjacent sub-sectors)
Calorimetric measurements principle
The JT valve (CV910) is blocked at the right value to compensate the static heat loses before the powering
Then, the temperature drift is mainly due to electrical resistive heating dissipated during the powering
After powering the temperature shall remain constant
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9
0
0.2
0.4
0.6
0.8
1
1.2
1.83
1.84
1.85
1.86
1.87
1.88
1.89
0 1 2 3 4
I / I p
late
au [-
]
Tem
pera
ture
[K]
Time [hour]
TemperatureCurrent
U(
T)
Methodology
Assessment of the baseline slope (valve opening mismatch)
Assessment of the temperature increase during powering plateau
Assessment of the internal energy variation (J/kg)
Assessment of the deposited energy assuming a mass of 26 l/m of He
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1.88
1.885
1.89
1.895
1.9
1.905
1.91
1.915
1.92
9:30 10:30 11:30
Tem
pera
ture
evo
lutio
n [K
]
LQATO_15R1_TT821.POSST
LBARA_16R1_TT821.POSST
LBBRA_16R1_TT821.POSST
LBARB_16R1_TT821.POSST
LQATH_16R1_TT821.POSST
LBBRA_17R1_TT821.POSST
LBARA_17R1_TT821.POSST
LBBRD_17R1_TT821.POSST
LQATK_17R1_TT821.POSST
LBARA_18R1_TT821.POSST
LBBRA_18R1_TT821.POSST
LBARB_18R1_TT821.POSST
LQATH_18R1_TT821.POSST
LBBRA_19R1_TT821.POSST
LBARA_19R1_TT821.POSST
LBBRD_19R1_TT821.POSST
Taverage
10 W applied on Q15R1
Experimental validation with en electrical heater
Before heating With heating
U [J/kg] -1.1 78
M [kg] 823
U [kJ] -0.92 64.2
t [s] 2880 6600
W [W] -0.3 9.7
W [W] 10
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Calorimetric measurements in sector 1-2
-10
-5
0
5
10
15
20
25
30
35
40
07R1 11R1 15R1 19R1 23R1 27R1 31R1 29L2 25L2 21L2 17L2 13L2 09L2
Spec
ific r
esis
tive
heati
ng [m
W/m
]
Cryogenic sub-sector
3500 A5000 A7000 A
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12C15.R1
Q15
A16.R1 C16.R1
B16.R1
Q16
B17.R1
C17.R1A17.R1
Q17
A1B1
A2B2
A18.R1
B18.R1
MBA line
MBB line
Lead #5
Pol. A
Lead #6
Pol. B
B2A2
B1A1
B2A2
B1A1
B2A2
B1A1
A1B1
A2B2
A1B1
A2B2
B15.R1
A2B2
B1A1
A1B1
A2B2
B2A2
VUd
CH1
VUd
CH2VUd
CH4
VUd
CH5VUd
CH7
VUd
CH8VUd
CH6
VUd
CH3
Point 1 Point 2
B15.R1
C15.R1A15.R1
Q16
MBA line
MBB line
Q15
Vaccum barrier
Vaccum barrier
Lead #5Pol. A
Lead #6Pol. B
A1B1
A2B2
A16.R1 C16.R1
B16.R1
Q17
B17.R1
C17.R1A17.R1
Q18
A1B1
A2B2
A18.R1 C18.R1
B18.R1
Q19
B19.R1
C19.R1A19.R1
Q20
A1B1
A2B2
A20.R1 C20.R1
B20.R1
Q14
Measuring the dipole bus-bar splice resistance
Mobile system with eight channels
Measure of all the bus-bar segments in the dipole circuit in one cell
Only after analysis of the calorimetric measurements
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Bus-bar Splice Resistance Measurements
Measurement of voltage against current across bus-bar segments
Micro Volt accuracy, resolution in nOhms
No anomalous resistance measured in sector 15R1
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60min @ 7kA
10min @ 6kA,5kA,4kA,…,0kA
“Snapshots”: triggering PM-data collection of individualQPS for the dipoles A15R1 – C19R1 (15 magnets)
“Snapshots” using the QPS acquisition
Uses the magnet instrumentation to measure the internal voltage across the dipole/quadrupole through the QPS acquisition
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0.7mV/7kA=100nOhm0.7mV*7kA=4.9W
Snapshot on 03.09.08 : 0.85mV*8.4kA=7.1W
B16R1 => 2334
Results from cells A15R1 to C19R1
Found 100 nOhms in magnet B16R1
Confirmed by snapshot during powering at 8500 A
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Verification from SM18 data on magnet 2334
Data from SM18 acquired during the cold tests confirms an inter-pole splice of 105 nOhm in magnet 2334 (B16R1)
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Sector 56: RB Sector 56: RQD + RQF
Sector 67: RB Sector 67: RQD + RQF
Calorimetric measurements in other sectors
17
Confirmed electrically B32R6
Confirmed electrically B32R6
Not reproducibleNot reproducible
Local bus-bar elec. measurements missingLocal bus-bar elec. measurements missing
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Snapshot for sector 6-7 on 03-Nov-08
Snapshot on all subsector found a resistance of 49 nOhms in magnet B32R6
Signals noisier than in other sectors
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Verification from SM18 data on magnet 2303
Inter-pole resistance of 53nOhms in magnet 2303 confirmed by SM18 data.
MB 2303 (MB.B32R6, S67, 49 nOhm found in LHC)
y = 5.33E-05x + 3.79E-01
R2 = 9.95E-01
y = 2E-06x + 0.429
R2 = 0.0562
0
0.2
0.4
0.6
0.8
1
1.2
0 2000 4000 6000 8000 10000 12000 14000
Current (A)
Vo
lta
ge
(m
V)
D1_L-Ua D2_U-La
53nOhm
2nOhm
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Sector 78: RB Sector 78: RQD + RQF
Sector 81: RB Sector 81: RQD + RQF
20
Excluded after electrical measurementsExcluded after electrical measurements
Excluded after electrical measurementsExcluded after electrical measurements
Local bus-bar elec. measurements missingLocal bus-bar elec. measurements missing
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-10
0
10
20
30
40
50
6007
R111
R115
R119
R123
R127
R131
R129
L225
L221
L217
L213
L209
L207
R511
R515
R519
R523
R527
R531
R529
L625
L621
L617
L613
L609
L607
R611
R615
R619
R623
R627
R631
R629
L725
L721
L717
L713
L709
L707
R711
R715
R719
R723
R727
R731
R729
L825
L821
L817
L813
L809
L807
R811
R815
R819
R823
R827
R831
R829
L125
L121
L117
L113
L109
L123
R3
Spec
ific r
esis
tive
heati
ng [m
W/m
]
3500 A 5000 A 7000 A
50 n
75 n
100 n
200 n
25 n
S1-2 S6-7 S7-8S5-6
S3-4
S8-1
15R1
31R631R1 ?
Calorimetric measurements for dipole circuits
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-10
0
10
20
30
40
50
6007
R511
R515
R519
R523
R527
R531
R529
L625
L621
L617
L613
L609
L607
R611
R615
R619
R623
R627
R631
R629
L725
L721
L717
L713
L709
L707
R711
R715
R719
R723
R727
R731
R729
L825
L821
L817
L813
L809
L807
R811
R815
R819
R823
R827
R831
R829
L125
L121
L117
L113
L109
L1
Spec
ific r
esis
tive
heati
ng [m
W/m
]
3500 A 5000 A 7000 A
50 n
25 n
S6-7 S7-8S5-6 S8-1
Calorimetric measurements for quadrupole circuits
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31R1 31R6
15R1 23R331R7
0
5
10
15
20
25
-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200
# of
sub-
sect
ors [
-]
Sub-sector resistance variation w/r to baseline [n]
Dipole (5 sectors) Quadrupole (4 sectors)
NNXN: Confirmed by electrical measurements
Summary of the findings in 2008
Two more cases suspected at the limit of 2W in the quadrupole powering
~ 2 W @ 7 kA
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Summary of electrical measurements
Local bus-bar segment measurements done on demand. Not high resistances detected.
Snapshots both inside the magnets and in the bus-bar segments will be implemented from the new QPS system. (See R. Denz talk)
Main Dipoles Circuits, Resistance Measurement SnapshotsSector Date Current CommentsA12* 3-Nov-08 0, 1000, 2000, 3000, 4000, 5000, 6000, 7000 B16R1 -> 100nOhm, all others less than 10nOhm (+ switch open snaphots)A23A34A45A56 28-Nov-08 0, 3500, 5000, 7000 nothing more than 5nOhmA67 14-Nov-08 0, 1000, 2000, 3000, 4000, 5000, 6000, 7000 B32R6 -> 50nOhm, all others less than 10-20nOhm; noisy signalA78 14-Nov-08 0, 1000, 2000, 3000, 4000, 5000, 6000, 7000 nothig more tha 10nOhmA81 2-Dec-08 0, 3500, 5000, 7000 nothig more tha 10nOhm
Main Quads Circuits, Resistance Measurement SnapshotsSector Date Current CommentsA12A23A34A45A56 26-Nov-08 0, 3500, 5000, 7000 nothing more than 5nOhmA67 21-Nov-08 0, 3500, 5000, 7000 nothing more than 5nOhmA78 18-Nov-08 0, 3500, 5000, 7000 nothing more than 5nOhmA81 3-Dec-08 0, 3500, 5000, 7000 nothing more than 5nOhm
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Summary of measurements
(1) suspected cases from calorimetric measurements
1 confirmed cases by electrical measurement.
It may change with current!
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Conclusions
An abnormal temperature rise was seen as a precursor of the incident in sector 3-4.
Accurate/controlled measurements of temperature using the existing equipment can /have spot other potential risks.
Electrical measurements are needed to confirm and quantify the resistive splice but required special equipment and were only local.
Check of internal splices in the magnet is now done during cold tests in SM18.
The main circuits in four sectors have been fully investigated plus the dipole circuit in sector 1-2. Seven suspected cases have been found. Two were excluded, two confirmed and three are pending electrical measurements.
New QPS system will be able to measure the resistance of individual magnets and bus-bar segments in the LHC during dedicated tests. See R. Denz presentation in session 4.
Improved calorimetric measurements in preparation
The new powering procedures will demand mandatory calorimetric and electrical tests in ALL sectors at the beginning of the next LHC powering campaign
