11 T Nb3Sn Demonstrator Dipole R&D Strategy and Status

A. Zlobin, Fermilab

1st FNAL-CERN Collaboration Meeting Fermilab, May 13, 2011

Outline

• 11 T Nb3Sn Dipole R&D Program• R&D phases, goals, design constraints• Comparison with other R&D programs• Single-aperture demonstrator R&D

– Status– Schedule

• Conclusions

13 May 2011, FNAL-CERN CM1 2 A. Zlobin - R&D Strategy

• In FY2011 Fermilab and CERN have started a joint R&D program with the goal of building a long twin-aperture Nb3Sn 11 T dipole by 2014.

• This R&D relies on the results of Nb3Sn magnet R&D programs at FNAL and Nb-Ti LHC magnet development at CERN.

• To meet the tight project schedule within the available budget, magnets are designed to make maximum use of the existing tooling, infrastructure, and magnet components at both laboratories.

• Practical orientation is a key feature for any sound Nb3Sn accelerator magnet R&D program at the present time.

11 T Nb3Sn Dipole R&D

13 May 2011, FNAL-CERN CM1 3A. Zlobin - R&D Strategy

Result Application

• LHC collimation system upgrade. – 11 T 11-m long twin-aperture Nb3Sn dipoles

compatible with the LHC lattice and major systems can provide the required space for cold collimators

• additional design constrains • Space in the LHC lattice for different insertion

devices – dynamic collimators, correctors, instrumentation, etc.

A. Zlobin - R&D Strategy413 May 2011, FNAL-CERN CM1

R&D Phases and Goals

Productive CERN-FNAL collaboration is a key to success!

Dates Description Comments R&D goals

December 2011

2-m single-aperture demonstrator dipole

Original design (cable, coil, collar) Construction and test at FNAL

Cable technology Coil technology Coil pre-load techniques Quench performance Margins Field quality (coil magnetization) Quench protection (heater study)

December 2012 June 2013

2-m twin-aperture demonstrator 1

Design iteration (cable, coil, collar) FNAL collared coils (2) Cold mass assembly and test at CERN

Technology transfer to CERN (cable, coil, collared coil) Coil pre-load techniques in 2-in-1 configuration Quench performance Margins Field quality (geometrical harmonics, coil magnetization, iron saturation, aperture cross-talk, end field quality) Quench protection (heater study) Performance reproducibility Two cold mass and collimator integration (alignment)

2-m twin-aperture demonstrator 2

CERN collared coils (2) Cold mass assembly and test at CERN

July 2013 5.5-m coil scale up

Coil 1 at FNAL Coil 2 at CERN Structure assembly and test at CERN (FNAL)

Long cable technology Long coil technology Long coil performance Long heater design and performance

December 2013

5.5-m twin-aperture prototype

Collared coil 1 at FNAL Collared coil 2 at CERN Prototype assembly and test at CERN

Accelerator quality performance

13 May 2011, FNAL-CERN CM1 5 A. Zlobin - R&D Strategy

Constraints

11m Magnet

5.5 m Dipole Cold Mass

FNALFNAL

CERN CERN

• 11+ T at the LHC nominal current and operation temperature, 20% margin, field quality, quench protection

• Compatibility with MB cold mass and cryostat designs– aperture diameter and separation, cold mass OD, heat exchanger

• Nominal field >11 T => Nb3Sn• 20% operational margin at 1.9 K => Bmax=13.2 T• Common yoke and separate collared coils

– collaring press capability limit at FNAL, lower risk• Magnet length ~11 m, coil length ~5.5 m

– Tooling limitations at FNAL, shorter strand and cable length, lower scale up risk

13 May 2011, FNAL-CERN CM1 6 A. Zlobin - R&D Strategy

Single-bore Demonstrator

• Challenges: aperture, length, Bmax, W, schedule

Parameter MSUT (UT)

D20 (LBNL)

HFDA (FNAL)

HD2 (LBNL)

Demo-1 (FNAL/CERN)

Cross-section

Design Cos-theta Cos-theta Cos-theta Block Cos-theta Technology W&R W&R W&R W&R W&R Aperture [mm] 50 50 43.5 36-43 60 Length [m] ~1 ~1 ~1 ~1 ~2 Bmax (Bq_max) [T] 11.5(11.4) 13.35 (13.5) 12.2 (10.2) 15.4 (13.8) 13.62 Wmax [MJ/m] 0.46 0.88 0.30 0.87 0.744 L [mH/m] 2.5 46 1.5 7.3 5.6 Fx/quadrant [MN/m] 3.2 5.2 3.4 5.9 4.6 Fy/quadrant [MN/m] -1.5 -2.6 -1.4 -2.4 -2.5 Design published 1989 1993 1999 2005 2011 First test published 1995 1997 2005 2008 2012

13 May 2011, FNAL-CERN CM1 7 A. Zlobin - R&D Strategy

Twin-bore Demonstrator

• Challenges: 2-in-1 horizontal configuration, aperture, aperture separation, Bmax, length, schedule

Parameter RD3c (LBNL)

HFDC01 (FNAL)

DCC017 (BNL)

Demo-2 (FNAL/CERN)

Cross-section

Design Common coil Common coil Common coil Cos-theta Technology W&R R&W R&W W&R Aperture separation [mm] 220 (vertical) 290 (vertical) 220 (vertical) 197 (horizontal) Aperture [mm] 35 40 31 60 Length [m] ~1 ~1 ~1 ~2

Bmax (Bq_max) [T] 10.9 (10.03, 92%SSL)

10.0 (5.8, 58%SSL)

~10 (10.2, 100%SSL)

13.6 (11+20%margin)

Imax [kA] 11.9 23.6 12.7 15.0 Design published 1999 2001 1997 2011 First test published 2003 2004 2006 2012

13 May 2011, FNAL-CERN CM1 8 A. Zlobin - R&D Strategy

Scale Up ChallengesLARP:• 4-m long single-aperture quadrupole by 2014• Test in vertical dewar at VMTF (Fermilab) at 1.9-

4.5 K11 T Dipole program:• 5.5-m long single coil test in MQXB prototype

cryostat in 2013 (Fermilab or CERN)• 5.5-m long twin-aperture dipole by 2014• Assembly with LHC MB cryostat and test at

CERN MTF at 1.9-4.5 K13 May 2011, FNAL-CERN CM1 9 A. Zlobin - R&D Strategy

11 T R&D Impact• Very interesting and challenging R&D

program• Benefit generic SC accelerator magnet

R&D • Nb3Sn practical application in HL-LHC• Step towards high-field magnets for

HE-LHC

13 May 2011, FNAL-CERN CM1 10 A. Zlobin - R&D Strategy

Demonstrator R&D• R&D status

– Strand and cable – Magnetic design and parameters– Mechanical design and analysis– Quench protection– Magnet design and infrastructure

• Details in the following talks

13 May 2011, FNAL-CERN CM1 11 A. Zlobin - R&D Strategy

Strand and Cable

• Details by Daniele.13 May 2011, FNAL-CERN CM1 A. Zlobin - R&D Strategy12

Table 1: Cable parameters

Strand (OST):• 0.7 mm Nb3Sn RRP-108/127• high-Jc, relatively stable

Cable (FNAL):• 15-mm wide, 40 strands

Cable insulation: • 0.075-mm E-glass tape• 2 layers butt lap • traditional insulation technique Strand procurement• 60 kg RRP-151/169 – R&D (Aug 2011)• 152 kg RRP-108/127 (Dec 2011)• 152 kg RRP-108/127 (Jul 2012)Cable fabrication• Practice cable fabricated and tested• Cable for demonstrator in progress

• Design– 2-layer 6-block design– 60-mm aperture

• Coil winding, curing, reaction and impregnation tooling designed and procured

• Coil components designed and procured– Coil end parts were designed

and fabricated by CERN• Coil fabrication

– 1st practice coil wound and cured• Rectangular copper cable

– 2nd practice coil winding started• RRP-114/127 keystone cable

Coil Design

13 May 2011, FNAL-CERN CM1 13A. Zlobin - R&D Strategy

• Details by Mikko and Fred.

Dipole Parameters

13 May 2011, FNAL-CERN CM1 14A. Zlobin - R&D Strategy

Parameter ValueAperture [m] 60

Nominal current Inom [A] 11850

Nominal bore field [T] 10.86Short-sample bore field at 1.9 K [T] 13.6Margin Bmax/Bnom at 1.9 K [%] 25.4

Maximum design field [T] 12.0

Inductance at Inom [mH/m] 5.6

Stored energy at Inom [kJ/m] 473

Fx per quadrant at Inom [kN/m] 2889

Fy per quadrant at Inom [kN/m] 1570

Coil length [m] 1.8Magnetic length [m] 1.69

Mechanical Structure• Design

– 25-mm thick slightly elliptical stainless steel collar

– Vertically split iron yoke – Al clamps – 12.7-mm stainless steel skin – 50-mm thick end plates

• Structure design and mechanical analysis complete– Maximum stress in coil <160 MPa– stresses in structure are within

limits• Collar design complete and

procurement started.• Assembly tooling design is in

progress.• Details by Igor and Fred.

13 May 2011, FNAL-CERN CM1 A. Zlobin - R&D Strategy15

Quench Protection• Demonstrator quench protection during test will be provided by

extracting the stored magnetic energy on the appropriate external dump resistor.

• In accelerator, the magnet protection is provided by quench heaters.

• Quench protection heaters composed of stainless steel strips will be placed inside the ground insulation, covering the outer-layer coil blocks.

• Quench protection analysis and heater design are in progress (Mikko).

13 May 2011, FNAL-CERN CM1 16 A. Zlobin - R&D Strategy

Schedule, Milestones, QA

A. Zlobin - R&D Strategy17

Structure review

Coil review

Cable review

Winding review

DOE reviewDemonstrator specs

Performance review13 May 2011, FNAL-CERN CM1

• 11 T Nb3Sn demonstrator dipole magnets for possible use in accelerators in particular for the LHC upgrades are being developed by Fermilab/CERN collaboration.

• The engineering design of the 60-mm single-aperture 2-m long magnet and fabrication tooling is nearly complete and practice coil winding is in progress.

• The cold tests are planned towards the end of 2011 – Primary goal: demonstrate the quench performance, nominal field,

and operation margins– Auxiliary studies: field quality, magnet quench protection

• The conceptual design of the twin-aperture 11 T dipole magnet has been started.

Conclusions

13 May 2011, FNAL-CERN CM1 18A. Zlobin - R&D Strategy