WBS 6:Magnetic Shielding

B. Filippone and B. PlasterCaltech

December 3, 2004

Zeroth-Order Concept

cos θ coil:r ~ 35cm; ℓ ~

300cm

4K ferromagnetic shield: r ~ 40cm; ℓ ~ 300cm

superconducting shield: r ~ 50cm; ℓ ~ 300cm(neither shown here)

4-layer µ-metal shielding

configuration

Large cylindrical µ-metal shields with end-caps:

r ~ 106.7cm, 110.5cm, 114.3cm, 118.1cmℓ ~ 445.8cm, 453.39cm, 461.0cm, 468.6cm

[J. Boissevain]

[J. Boissevain]

Zeroth-Order Concept

cos θ coil:r ~ 61cm; ℓ ~

393cm

4K ferromagnetic shield: r ~ 60cm; ℓ ~ 400cm

superconducting shield: r ~ 63cm; ℓ ~ 400cm(neither shown here)

4-layer µ-metal shielding

configuration

Large cylindrical µ-metal shields with end-caps:

r ~ 106.7cm, 110.5cm, 114.3cm, 118.1cmℓ ~ 445.8cm, 453.39cm, 461.0cm, 468.6cm

[J. Boissevain]

[J. Boissevain]

Estimated Costs• 4K ferromagnetic shield

– Open cylinder with no end caps• 20 mil thickness

– Cryoperm option• Amuneal quote for r ~ 40cm,

ℓ ~ 300cm: $30,000• Scale up to latest reference

design of r ~ 60cm, ℓ ~ 400cm: $60,000

– Metglas option• Honeywell quote: $515/kg

• 20 mils thick will require ~70 kg → $40,000

• Al cylinder support frame: $8,000

• VERY LABOR INTENSIVE: ~5 miles of 2-inch wide Metglas strips !!!

• 300K ferromagnetic shields

– Cylindrical µ-metal shields with end-caps; take baseline 62 mils

• Larry Maltin (President of Technical Products at Amuneal):

– “…confident that we could engineer, fabricate, anneal, and install such a [sized] shield…”

• Cost estimate for largest cylinder with end caps: $60,000 → ~$250,000 for 4

• If want larger spacing between layers: $300,000

• ~3 to 6 month lead time (freight truck shipping) and will require some on-site assembly

• 4-layer structure estimated to weigh ~2.5 English tons

Estimated Costs• Superconducting shield

– Not as well thought out at this point– Proposed idea is to melt lead and pour into a cylindrical Al

casting frame• Will require design engineering efforts

– Estimate: $100,000• $100,000 is estimated cost in pre-proposal• No experience yet; crude guess is $50,000• In-house vs. out-sourcing

• “Room-sized” box-type µ-metal shield or large tri-axial square Helmholtz bucking coils– Estimate for thin (14 mil) box-type (or large cylindrical) shield:

$75,000

Estimated Costs• AC demagnetization circuit for the ferromagnetic shields

– Demagnetizing prototype Cryoperm and µ-metal shields has proven to be difficult (later talk)

– High-power, variable-frequency, programmable AC power supply: $25,000

– Demagnetization circuit supplies: $5,000

• Technical/Engineering/Machining work at Caltech– Support for design engineer and machinist for assistance with integration

of shielding with experiment– Estimated labor costs: $30,000

• Note: We did not include expenses related to materials/construction of support structures for the shielding (only for design engineering)

Costs Roll Up

WBS 6: Magnetic Shielding6.1 5-Layer Ferromagnetic Shield $360,000 2 6.1a 0.3K Ferromagnetic Shield $60,000 2 6.1b 300K 4-Layer Ferromagnetic Shield $300,000 26.2 Superconducting Shield $50,000 36.3 Other Shielding (e.g., “room-sized”) $75,000 26.4 AC Demagnetization Circuit $30,000 16.5 Technical/Engineering/Machining Support

$30,000 2

6 TOTAL $545,000

Risk Level

[ 1 = lowest; 3 = highest ]

[Pre-Proposal: $415,000]

Proposed Schedule• Personnel during construction phase (1.0 FTE): 1 faculty; 1

post-doc; 1 design engineer; 1 machinist; undergraduate student(s) and/or 1 graduate student

• Rough Timeline (assuming funding available FY2007)200

72008

2009

2010

Finalize shield design/geometryFinalize/integrate support structureProcure ferromagnetic shieldsConstruct/test superconducting shieldProcure AC demagnetization equipmentInstall all magnetic shieldingInstall/test AC demagnetization circuit

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potential hold-ups

300K Four-Layer Shield

r = 106.7cm, 110.5cm, 114.3cm, 118.1cm (nominal design)r = 106.7cm, 115.0cm, 125.0cm, 135.0cm r = 106.7cm, 120.0cm, 135.0cm, 150.0cm

WBS 7:Magnets

B. Filippone and B. PlasterCaltech

December 3, 2004

Overview of Magnets• Magnets to be constructed

– cos θ coil for static field• 1-10 mGauss DC field; ±0.1% spatial uniformity; 10-6 temporal stability

– Solenoid as “π/2 r.f.” 3He and neutron spin-flip coil• 0.1 mGauss AC field; 3.165 Hz; 1.58 second duration

– Spin-dressing cos θ coils• Field parameters to be defined …

• Accompanying instrumentation needs– Highly-stable AC and DC power supplies– Mapping hardware and probes for field monitoring

• Labor costs (design engineering and machining/construction) and raw materials will comprise the core costs for WBS 7 – As opposed to mostly procurement costs for WBS 6

Zeroth-Order Conceptstatic cos θ coil“π/2 r.f.”

solenoid

spin-dressing cos θ coils [180° phase

difference]

4K ferromagnetic shield

Χx

y

superconducting shield

Estimated Costs• Design and construction of static cos θ coil: $130,000

– ¼-scale prototype already constructed at Caltech → have acquired experience with design and machining efforts (later talk)

• Design engineering/integration labor costs: $20,000• Materials and supplies: $30,000• Machining/production labor costs: $80,000

– Assuming out-sourcing; in-house could lead to reduction

• Design and construction of “π/2 r.f.” solenoid: $20,000– Solenoid → design and construction should be simpler (in principle)

• Design engineering/integration labor costs: $5,000• Materials and supplies: $10,000• Machining/production labor costs: $5,000

Estimated Costs• Construction/integration of spin-dressing coils:

$150,000– Prototype AC cos θ coils to be built as part of the 2005-2006

R&D efforts at Caltech• Design engineering/integration labor costs: $20,000• Materials and supplies: $50,000• Machining/production labor costs: $80,000

– Assuming out-sourcing; in-house could lead to reduction

• AC and DC power supplies: $60,000– Require highly-stable power supplies and stabilization circuits

• DC power supply with accompanying stabilization circuit for the static cos θ coil: $30,000

• Low-frequency AC power supply for “π/2 r.f.” spin-flip solenoid: $10,000

• High-frequency AC power supply for spin-dressing coils: $10,000• Computer-controlled interface for all power supplies: $10,000

– Possibly coupled to AC demagnetization circuit in WBS 6

Estimated Costs• Mapping hardware and probes for (possible) in-situ

real-time field monitoring: $80,000– DC field profile independent of 3He co-magnetometry– Appropriate tuning of AC fields

• Computer-controlled positioning/stepping hardware and readout (difficulties due to the cryogenic environment): $50,000

• Engineering for integration: $10,000• Cryogenic 3-axis fluxgate magnetometers and probes: $20,000

Costs Roll Up

WBS 7: Magnets7.1 Static Field cos θ Coil $130,000 27.2 r.f. Spin-Flip Coil $20,000 27.3 Spin Dressing Coils $150,000 27.4 AC and DC Power Supplies $60,000 17.5 Field Monitors $80,000 1 and 37 TOTAL $440,000

Risk Level

[ 1 = lowest; 3 = highest ]

[ Pre-Proposal: $270,000 ]

Proposed Schedule• Personnel during construction phase (2.0 FTE): 1 faculty; 1

post-doc; 1 professional staff member; 1 design engineer; 1 machinist; 1 graduate student (?); undergraduate student(s)

• Rough Timeline (assuming funding available FY2007)2007

2008

2009

2010

Finalize magnet parameters/geometryConstruct/test static cos θ coilConstruct/test “π/2 r.f.” spin-flip coilConstruct/test spin-dressing coilsProcure/test AC and DC power suppliesDesign/construct field monitorsProcure magnetometer/probesInstall all components

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potential hold-ups