HQ01e3 test summaryDecember 2012

M. Marchevsky, LBNL

Original test plan

• Verify training and magnet status after CERN test - The primary objective for HQ01e3

- Correct operation of the newly installed SCRs, safety equipment (new valves), detection and acquisition systems (CryoDAC, fast event DAQ, acoustic piezo-sensors) following the upgrades will be verified.

• Validate and extend the magnetic measurements The plan is to use updated injection levels, test new MM probe and study connection between the flux jumps and field quality. AC loss studies with varying ramp rates will be conducted. • Heater efficiency and MIITs studies We have several proposals that address: - heater efficiency through measuring quench delay and MIITs evolution as

function of magnet current- resistance development in the magnet during fast rampdown and using

provoked quenches - spontaneous quenches with increasing detection/protection delays,

gradually increasing the MIITs - Study of self-protection capabilities of the magnet; also important for

establishing operational margins of the MTF.

- SCR operational issue has been discovered

- Indirect assessment of magnet state has been done through flux jump analysis

- FastDAC, acoustic data have been collected

- Magnetic measurements have been conducted as planned, but only up to 9 kA current.

- AC loss data analysis are underway

- No dedicated MIITS studies were conducted, but the 2 high MIITS provoked extractions and one ramp-rate quench were conducted with effectively absent dump resistor.

Heater configuration

PHA01 PHA02 PHB01 PHB02

Coil 9 1000 / 1000/100

1000 /1000/1000

851 /660/686

922(**)/1000/890

Coil 8 1000 /960/706

1000 /1000/1000

1000 /1000/960

567 / 590/590

Coil 7 797 (*) / 750/895

1000/1000/1000

1000 / 1000/1000

1000 /450/366

Coil 5 1000 / 1000/1000

1000 / 1000/1000

1000 /550/718

921 / 550/0

PHs to Coil Hi-Pot: LBL data (HQ01e) / CERN data (HQ01e2)/ HQ01e3

F5: C9A01+C8A02+C5A01+C7A01 -> powered to 190 VF6: C9A02+R+C7A02+C5A02 -> powered to 270 VF7: R+C8B01+C5B01+C9B02 -> powered to 150 V

Heater circuits formed:

->Heater degradation since the CERN test:May be related to the - high MIITS quench- testing at 1.9 KHowever, some degradation was seen already in HQ01

01: 500 A Vdump = 51 V02: 995 A Vdump = 101 V04: 1000 A Vdump = 94 V05: 2000 A Vdump = 181 V06: 3000 A Vdump = 274 V08: 4000 A Vdump = 378 V09: 5000 A Vdump = 406 V10: 5700 A Vdump = 407 V11: 5717 A Vdump = 408 V12: 175 A Vdump = 24V13: 300 A Vdump = 32 V15: 498 A Vdump = 50 V16: 1052 A Vdump = 98 V17: 1552 A Vdump = 137 V18: 2065 A Vdump = 172 V19: 3141 A Vdump = 256 V20: 3083 A Vdump = 274 V21: 3567 A Vdump = 326 V22: 3064 A Vdump = 275 V23: 5598 A Vdump = 409 V24: 5086 A Vdump = 163 V25: 3743 A Vdump = 119 V26: 1202 A Vdump = 39 V27: 3344 A Vdump = 74 V28: 2995 A Vdump = 96 V29: 998 A Vdump = 34 V

24: 5086 A Vdump = 163 V25: 3743 A Vdump = 119 V26: 1202 A Vdump = 39 V27: 3344 A Vdump = 74 V28: 2995 A Vdump = 96 V29: 998 A Vdump = 34 V

MM02: 1629 A Vdump = 54 VMM07: 6642 A Vdump = 218 VMM08: 5583 A Vdump = 178 V

RR01 (100 A/s): 7144 A Vdump = 234 VRR02 (100 A/s): 7154 A Vdump = 234 VRR04 (75 A/s): 10871 A Vdump = 406 V

Extractions / quenches summary

Rdump 120 mW

Rdump 30 mW

Rdump 30 mW

Extraction system has malfunctioned at Vdump>(406-409) V

System tests

Magnetic measurements

Ramp-rate quenches

SysTest11: extraction at 5.6 kA

~400 A

Only ~0.5% of magnet energywas extracted

Due to SCR malfunction, the extraction was interrupted at +38 ms and magnet re-connected back to the power supply

SysTest23: extraction at 5.7 kA

0 200 400 600 800 1000 1200 1400 16003

4

5

6

7

8

9

10

He

level (in

)Pcr

yo (

psi

)

t (s)

Lost ~ 40L of LHe over ~130 s

~15.7 MIITS

Flux jump statistics

Each flux-jump event was assigned to one particular coil. For every event the selected coil was the one with the largest absolute value of integrated flux imbalance. The histogram shows the number of events assigned to each coil.

Unusually large number of FJ events in Coil 7; was not seen in the HQ01d,e tests when quench antennas we re used to monitor flux jumps – possible degradation in C7

Each flux-jump event was assigned to one particular coil. For every event the selected coil was the one with the largest absolute value of integrated flux imbalance. The histogram shows the sum of the integrated flux imbalance of all the events that were assigned to each coil.

54/61 strands

108/127strands

MM ramp up to 9 kA and back down

Ramp-rate quenches

HQ01e35

8

8

5,

8

8

85

55

5

5,8

Ramp-rate quench current values and also quenching coils are is consistent with the earlier HQ tests

RR04: 10872 A quench at 75 A/s

Quench starts in the outer layer multi-turn of C5

0 200 400 600 8000.0

2.0x107

4.0x107

6.0x107

8.0x107

1.0x108

I2 (

A2 )

Time (ms)

12.3 MIITS

0 100 200 300 4000.00

0.01

0.02

0.03

0.04

R (

Ohm

)

Time (ms)

0 100 200 300 4000.00

0.01

0.02

0.03

0.04

0.05

0.06

Rm

ag (

Oh

m)

Time (ms)

H. Bajas et. al., MT22 presentation

Magnet resistance with no dump

Effective Rdump is very low, can be neglected

𝑅𝑚𝑎𝑔 (𝑡)=− 𝐿(𝐼𝑚𝑎𝑔 (𝑡 ))𝑑 𝐼𝑚𝑎𝑔(𝑡)/𝑑𝑡𝐼𝑚𝑎𝑔(𝑡)

Magnet resistance reached maximum of ~52 m .W - another reference datapoint adding to the CERN data of Rmag~120 mW at 15.9 kA / 18.3 MIITS

Independent coil resistance measurements

0 100 200 300 4000

2000

4000

6000

8000

10000

12000 Sound triggered Imbalance triggered Sound and imbalance

I (A

)

t (s)

0 100 200 300 4000

100

200

300

400

500

Sound triggered Imbalance triggered Sound and imbalance

Um

ax, (

mV

)

t (s)

Current and sound at the triggered events

0.5 1.0 1.5-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.112 ms

Sensor 1 Sensor 2

Usn

d (V

)

t (ms)

-4

-2

0

2

4

6

8

10

Imbalance

Uim

b (V)

Sound signals example at Imag=10036 A

Acoustic emission studies (RR04)

0 10 20 30 40 50 60 70 800.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Sensor 1 (bottom) Sensor 2 (top)

mV

rms2 /

Hz

f (kHz)

Sensor 1 is installed at the bottom load plate; sensor 2 is installed at the top plate

• HQ magnet produces increased acoustic emissions (seemingly unrelated to FJ) and high-frequency (>50 kHz) vibration “bursts” when energized above 9kA. The latter are occasionally correlated with the short imbalance spikes and most likely caused by stick-slip motion of the conductor

• Inductive pickups sensors can be developed and used in conjunction with acoustic devices to improve selectivity for the specific mechanical and electrical events

Also presented at WAMSDO 2013:http://indico.cern.ch/contributionDisplay.py?contribId=34&confId=199910