Spectrometer Solenoids and Coupling Coils

Primary Activities and Risks Going Forward

Spectrometer Solenoids

Completion of SS#2 magnetic mappingCompletion, test and mapping of SS#2Shipping and installation of SS#1 and 2

Coupling Coils

Test of MuCool coil at FNALCryostat parts fab at LBNLWinding at Qi HuanCryostating at FNALTest of first CC assemblyCoil Prep at LBNLCryostating at FNALTest at FNALRFCC Integration

Spectrometer Solenoid Update

Steve Gourlay For Steve Virostek

Lawrence Berkeley National Lab

LBNL- 3 -

Topics• Latest magnet training results• Summary of 2nd magnet progress• Control system upgrade• Risks and mitigation

LBNL- 4 -

MICE Cooling Channel Layout

Spectrometer Solenoid #1

Spectrometer Solenoid #2

LBNL- 5 -

Current Progress (1st magnet)• The first magnet (designated SS#2) has been successfully

trained to full flip and solenoid mode currents• Current was maintained at full flip mode for a period of

24 hours with no quench• All five power supplies were used at various ramp rates

and under computer control• Numerous improvements and fixes implemented on

control and power supply systems• Improved cold mass heater control loop worked well• Cold mass is being held at 4K and full of LHe in

preparation for upcoming 3D magnetic mapping

LBNL- 6 -

Working on Both Magnets

AssemblyTrainingcomplet

e

LBNL- 7 -

Recent Training Runs

HTS lead failure

After warmup, HTS lead replace and cooldown

After warmup, control sys mods, and cooldown

Vent lineblockage

Target training current achieved (283 A)

LBNL- 8 -

Final Training Progression

LBNL- 9 -

2nd Magnet Progress• The cold mass/shield assembly is complete, MLI

wrapped and suspended in the vacuum vessel• Installation of the cryocooler tower is complete• First stage cooler connections to the thermal

shield are being installed• Vacuum vessel end plates are now being welded• LBNL mechanical technicians playing a key role in

assembly (instrumentation, MLI wrap, HTS leads)

LBNL

- 10

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2nd Magnet Progress

LBNL

- 11

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Control System Upgrade• A control system review was held at LBNL on

December 11th and 12th, 2012• The LBNL/MICE team developed improvements from

the numerous review panel recommendations• The current system is more robust and capable of

protecting the magnet from potential failures• A secondary goal of the upgrade was to move closer

to the final system to be operated in the MICE hall

LBNL

- 12

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Control System UpgradeSeveral of the primary upgrades:• Stand alone PID controller for the cold mass

heater circuit with current monitor• Alarm handler to the control software• Gas bottle backup system prevents negative cold

mass pressure; improved durability of PRV’s• New current shunts directly measure the current

in each coil

LBNL

- 13

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Power Supplies and ControlPower Supplies

• New 500 A supply for center and end coils

• 5 supplies fully integrated

• System verified during recent training runs

Control rack

• Many upgrades installed

• New heater control loop

• UPS added

LBNL

- 14

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Upcoming Tasks• 3D magnetic bore mapping of first unit using

CERN developed system to begin later in May with iron shielding disk in place

• Second unit assembly to be completed in next two to three weeks

• After vacuum pumpout of 2nd magnet, cooldown and training to start in June

• Shipping of fully commissioned magnets to RAL planned for July and September

LBNL

- 15

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Risks and Mitigation

SS controls operational readiness certification• Lack of a complete, fully operational and integrated

control system led to previous system failures• Some risk remains as the final system to be

implemented at RAL is still being developed• Mitigation: numerous upgrades have been implemented

and testing during SS#2 training; additional improvements are under way, and the system will be tested during SS#2 mapping and SS#1 training/mapping

LBNL

- 16

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Risks and Mitigation (cont’d)SS#2 re-train and re-test• Addition of the iron shield for mapping will alter the coil

forces and possibly lead to the need for some re-training• Magnet has always required re-training after warm-up

and subsequent cool-down• Mitigation:

• The cold mass has been maintained at 4K since the completion of the training runs, avoiding any re-training due to thermal expansion/contraction

• The forces due to the shield are only a fraction of the nominal inter-coil forces

• The training procedure is well established

LBNL

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Risks and Mitigation (cont’d)SS#2 operational failure with iron shield• Some risk presented as iron shield has never been fitted

to the vacuum vessel, and magnet has never been operated with the shield in place

• Mitigation: • Iron shield supports designed with conservative safety factors

and adequate adjustment capability; fast turnaround modifications possible using Wang NMR and/or LBNL shop

• Magnetic forces on cold mass supports are only a fraction of the calculated loads present during operation with other MICE magnets in place; cold mass supports designed and load tested 10% beyond operational requirements

LBNL

- 18

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Risks and Mitigation (cont’d)SS#1 train and test• SS#1 represents a newly modified and assembled

system that has never been tested in this configuration• Risk areas include: coil windings, cold leads, HTS lead

connections, heat leaks, other mechanical systems• Mitigation:

• The SS#1 cold mass has been previously trained to ~200 A• The design and as-built configuration of SS#1 is identical to

that of SS#2• The same technician crew that assembled SS#2 is also

working on completing SS#1

LBNL

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Risks and Mitigation (cont’d)SS#1 operational failure with iron shield• The risks and mitigation are the same as those for SS#2• All training and testing of SS#1 will likely be carried out

with the shield in place

LBNL

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Coupling Coils

Steve Gourlay For

Allan DeMello

Coupling Coil Sub-assemblies

Coupling Coil Cold Mass

• Winding of cold mass coils #2, #3 and #4 by QiHuan Company (Beijing, China)

• Preparation cold mass coils #2, #3 and #4 at LBNL

• Magnetic test of cold mass coils #2, #3 and #4 at FNAL

• Risks to schedule• Delay getting superconductor to

China• Problem with winding process at

QiHuan• Leak in cooling pipe after pressure

test at LBNL• Damage during shipping to FNAL• Problem during magnetic testing

Coupling Coil Cryostat

Single Cavity Vacuum Vessel Exploded View

• LBNL mechanical shop is in the process of fabricating the first cryostat

• Estimated completion on 7-1-2013• Drawings will be updated to reflect

the “as built” cryostat• Determine fabricator for the

additional 2 cryostats

• Risks to schedule• Delay in fabrication process• Vessel not vacuum tight• Damage during shipping to FNAL

Coupling Coil Thermal Shield

• Thermal shield design is nearly complete• Drawings have been red lined but not updated• Some SINAP parts/drawings will need to be

revised for better manufacturability• LBNL shops will fabricate the first thermal shield

• Risks to schedule• Delay getting drawings finished• Problem with fabrication process• Damage during shipping to FNAL

Cold Mass Fully Assembled (at FNAL)

• Reservoir/cooling circuit installation complete

• Cold mass support brackets and band installed

• Cold mass wrapped with MLI

• Risks to schedule•Delay getting bands fabricated•Leak in reservoir circuit

Cooling Circuit

• Finalize cooling circuit design • Create detail fabrication drawings • Fabrication of component parts• Assemble components

• Risks to schedule• Delay fabrication of component parts• Unforeseen problem during assembly

CCM Prototype Assembly at FNAL

• Cold mass prepared for integration with cryostat• Mount cold mass support bracket and bands• Wrap cold mass in MLI• Assemble thermal shield around cold mass• Wrap assembly in MLI

• Insert cold mass into cryostat• Attach cold mass support bands to cryostat• Align magnet in the cryostat• Weld on cryostat tower and inner bore

• Risks to schedule• Unforeseen problem during assembly• Vessel not vacuum tight

CCM Prototype Assembly at FNAL

• Weld tower assembly to cryostat• Assemble upper cooling circuit• Attach upper cooling circuit to the

cold mass cooling circuit

• Risks to schedule• Unforeseen problem during

assembly• Cooling circuit leak due to welding

error• Vacuum leak in cryostat

CCM Prototype Assembly at FNAL

• Add cryocoolers to cooling circuit• Coupling coil training and testing

• Risks to schedule• Magnet does not get to cold

enough for superconducting operation with cryocoolers