mit testing results

MIT Testing Results

V.B. Graves

MUTAC ReviewBrookhaven National LaboratoryApril 18, 2007

2

OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY

MUTAC Review BNL 18 Apr 2007

High Field Pulsed Solenoid

• 80K Operation

• 15T with 5.5 MVA pulsed power

• 15 cm warm bore

• 1 m long beam pipe

• 15T reached at MIT March 2006 Peter Titus, MIT

3



Hg System Equipment

• Syringe pump

• Hydraulic power unit w/control system

• Optical diagnostic system

• Baseplate support structures

4



MERIT Side View

1234

Syringe PumpSecondaryContainment

Jet Chamber

ProtonBeam

Solenoid

BeamWindow

Hg Jet

5



Hg System Schematic

Sumptank

CV1

VT

VDHgCylinder

Secondary Containment

QD1

QD2

QD3

QD4

CV2

F1

F2

F3

Hg Containment Schematic8Feb2007

P1

T1L1

F4

B1

VV

6



T.Tsang, BNL

Optical Diagnostic Tool: High-Speed Camera to Fast Record Transient Phenomena• Back-illuminated laser shadow photography technique

• Freeze the image of events using high speed camera (up to 1 µs/frame)

• Synchronized arrival of short laser light pulses illuminate onto the target

• The motion of the target after proton impact is frozen by high intensity short (150 ns) laser pulses

• 2-dimensional image

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One set of opticsper viewport

T.Tsang, BNL

Optical Diagnostics in Secondary Containment

FastVision 1 FastVision 2SMD video camera

20 m/s Hg jet, 7 Tesla magnetic field all images have a horizontal flip2 ms/frame 0.1 ms/frame 2 ms/frame 30 frames/s

1st Hg jet runs with 15T magnet on March 3, 2007 @ MIT

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Syringe Pump System

• Primary containment− Hg-wetted components− Capacity 23liters Hg (~760

lbs)− Jet duration up to 12 sec

• Secondary containment− Hg leak/vapor containment− Ports for instruments, Hg

fill/drain, hydraulics

• Optical diagnostic components− Passive optics− Shadow photography

• Beam Windows− Ti alloy components that

directly interact with beam− Single windows on

primary, double windows on secondary

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Syringe Statistics

• 30hp / 4000psi (260 bar) / 12.9gpm hydraulic pump

• 40 gal vegetable-oil based hydraulic fluid

• Hg flow rate 1.6liter/s (24.9gpm)

• Piston velocity 3.0cm/s (1.2in/sec)

• Up to 100 bar (1500 psi) Hg pressure in cylinder

• Hg cylinder force 525kN (118kip)

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MIT Testing Result Summary

• Completed 14 runs with field (10-15-20 m/s jets, 5-10-15 Tesla fields)

• Syringe pump performed as expected, no leaks

• Expected increased Hg pressure due to field, but no effects observed

• Water vapor issues inside jet chamber resulted in addition of strip heater on exterior of chamber

• External bore heater had to be reconfigured due to clearance issues

12



Solenoid Current Traces

15T

15T

15T

10T

10T

7.5T

10T

3T

5T

5T

5T

7T

10T

P.Titus, MIT

• 9-sec ramp up

• 4-sec ramp down

• 30 MJ heating →30K temperature rise

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Jet/Solenoid Time Sequence

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

0.0 5.0 10.0 15.0 20.0 25.0

Time (sec)

Fiel

d (T

esla

)

0

500

1000

1500

2000

2500

Noz

zle

Velo

city

(cm

/sec

)

Magnet FieldNominal Nozzle VelocityMeasured Nozzle VelocityTime of Image Capture

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Hg & Hydraulic Pressure Comparison - 0T vs. 15T20m/s Hg Jets

0.000

20.000

40.000

60.000

80.000

100.000

120.000

140.000

160.000

180.000

200.000

0 2000 4000 6000 8000 10000 12000 14000Time (ms)

Pres

sure

(bar

)

PortA-0T PortA-15T PortB-0T PortB-15T Hg-0T Hg-15T

Design Pressures:Hg Cylinder - 100 bar

Hydraulic Cylinders - 200 bar

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Nozzle Velocity Comparison - 0T vs. 15T

0 2000 4000 6000 8000 10000 12000 14000Time (ms)

Syrin

ge C

omm

and

Sign

al

0.000

500.000

1000.000

1500.000

2000.000

2500.000

Noz

zle

Velo

city

(cm

/sec

)

Syringe Command 0T Syringe Command 15T Nozzle Velocity 0T Nozzle Velocity 15T

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0 T

15 T

H.Park, BNL

Images of Mercury Jet vs. Magnetic Field (V=10m/s)

Viewport 1 Viewport 2 Viewport 3

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0 T

15 T

H.Park, BNL



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0 T

15 T

H.Park, BNL



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Visual Observations

•Magneto hydro-dynamic motion of Hg jet was observed at viewport 1,2,3,4 and was measured at viewport 2.

• Jet breakup was observed downstream at zero magnetic field. Jet breakup was not observed when magnetic field was applied but some surface disturbance was still present.

•At nonzero magnetic field, the bottom of the jet was smoother than the top was. The surface perturbations were more prominent at low magnetic field, but still present at 15 T.

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H.Park, BNL

Hg Jet Size at Viewport 2

• Observations− Simulations indicated quadrupole effect -> change in jet cross section from

circular to elliptical− Jet size approximately same at 0T/5T, increased at higher fields− For 20m/s jet, size was smaller at 10T than at 15T

0 5 10 1510

12

14

16

18

20

22

24

26

28

30

Magnetic field (T)

Jet s

ize

(mm

)

Hg jet size vs. the applied magnetic field

Hg:10m/sHg:15m/sHg:20m/s

0 5 10 150.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

Magnetic field (T)R

atio

of j

et s

ize

Ratio of Hg jet size to that at 0 T vs. magnetic field

Hg:10m/sHg:15m/sHg:20m/s

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H.Park, BNL

Hg Jet Size at Viewport 2 (cont’d)

• Observations− In general, size of Hg jet increased as jet velocity increased− 10T case does not follow this trend, possibly due to quadrupole effect

10 11 12 13 14 15 16 17 18 19 2012

14

16

18

20

22

24

26

28

30

Jet velocity (m/s)

Jet s

ize

(mm

)

Hg jet size vs. velocity

B=0TB=5TB=10TB=15T

10 11 12 13 14 15 16 17 18 19 20

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

Jet velocity (m/s)R

atio

of j

et s

ize

Ratio of Hg jet size to that at 0 T vs. velocity

B=0TB=5TB=10TB=15T

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H.Park, BNL

Hg Jet Velocity vs. Magnetic Field

• Observation− Jet velocity independent of magnetic field− Corroborates syringe pump sensor data

0 5 10 1510

12

14

16

18

20

22

24

Magnetic field (T)

Jet v

eloc

ity (m

/s)

Hg jet velocity vs. magnetic field

V=10m/s shotV=15m/s shotV=20m/s shot

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Hg System Operational Experience

•Hg fill/drain process performed twice without incident

•Control system functions as expected− Tested emergency stop conditions

•Small Hg leak occurred at ORNL− Contained within secondary, no problems in cleanup

•Hg vapor detection and capture− Vapor monitors work as expected− Local ventilation system (Scavenger) quickly

removes any vapors within secondary, zero emissions detected at exhaust

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Addition of Strip Heaters

• Approx 0.5L water not removed from system prior to Hg operations at ORNL

• Insertion into magnet caused condensation on viewports

• Modified existing flexible heaters to prevent condensation

• New heaters and controllers procured for CERN operation

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Hg Fill & Drain Procedures Tested

• Two fill and drain cycles completed− MIT cycles observed

by CERN personnel• Peristaltic pump

method works well, minimizes spill risk & vapor generation

• Drain into intermediate container reduces chance of overfilling flask

• Flasks weighed empty & full to track inventory

• No spills or operational problems

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Hg Leak Experienced

• Very high vapor levels inside secondary detected at ORNL− No vapors detected

outside secondary− Scavenger snorkel

successfully removed vapors

• Suspected Hg cylinder bellows & made effort to seal seams− Upon disassembly, no

vapors detected inside bellows

• Small Hg leak discovered in nozzle supply threaded joint

• Successfully removed liquid and tightened joint

Hg Leak

Leak Location

Bellows

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Conclusions

• System operating characteristics have been quantified during ORNL and MIT testing− Hg target, optical diagnostics, solenoid performing as expected− Operational issues with solenoid being resolved

• 15T field induced no additional pressure on Hg piping, system well within design pressures

• Hg leak experienced− Detected with instrumentation, contained within secondary,

successfully mitigated− Secondary containment prevented vapor escape− Valuable operational experience gained

• Further non-beam studies to be conducted during system commissioning at CERN

• On-track for in-beam testing July 2007

mit testing results

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