Next European Dipole (NED) Status Report

1
Next European Dipole (NED) Status Report
Arnaud Devred CEA/DSM/DAPNIA/SACM
CERN/AT/MAS on behalf of the NED
Collaboration CARE Steering Committee
Meeting 5 September 2005
2
Some very good news
for our American colleagues!

• The DOE has agreed to fund the US-LHC
  Accelerator Research Program (LARP) with a budget
  of 11 M for FY06 (approved by Congress but not
  yet signed by the President.
• This budget level should be kept constant for a
  few years (until 2009?)
• For FY06, it will be divided up into 5 M for
  magnets, 4 M for accelerator-related RD and 2
  M for management (shared between FNAL, BNL, LBNL
  and SLAC).
• The goal of the magnet part of LARP is to build
  by 2009 one or two 4-m-long, 90-mm-aperture, 200
  T/m quadrupole magnet prototypes.

3
Some pretty sad news
for the NED collaboration!

• The EUROMAG NEST Adventure proposal has been
  turned down by the EU on the ground that it was
  not adventurous enough
• Hence, we are back to square one regarding the
  funding of the model magnet manufacturing and
  test

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NED Programme

• The NED Programme is articulated around four
  Work Packages and one Working Group
• 1 Management Communication (MC),
• 2 Thermal Studies and Quench Protection
  (TSQP),
• 3 Conductor Development (CD),
• 4 Insulation Development and Implementation
  (IDI),
• 5 Magnet Design and Optimization (MDO) Working
  Group.
• It is carried out by a collaboration made up of
  8 institutes CCLRC/RAL, CEA, CIEMAT, CERN,
  INFN/Genova and INFN/Milano, Twente University
  (TEU) and Wroclaw University of Technology (WUT).
  

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MC Work Package

• We have held three Steering Committee (SC)
  meetings since the beginning of the year
• 20 January at CERN
• 14 April at CERN
• 7 July at WUT
• Next SC meeting will be held at CERN during the
  CARE general meeting next ESAC meeting will be
  held at CERN before or after the planned
  HHH/WAMDO (April 2005).
• Second quarterly report will be completed by the
  end of the week.
• All relevant documents are stored into EDMS and
  posted on the NED website
• http//lt.tnw.utwente.nl/project.php?projectid9

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TSQP Work Package

• The TSQ Work Package includes two main Tasks
• development and operation of a test facility to
  measure heat transfer to helium through conductor
  insulation
• (CEA and WUT Task Leader B. Baudouy, CEA),
• quench protection computation
• (INFN-Mi Task Leader G. Volpini).

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Heat Transfer Measurement (1/3)

• The first part of the Task was to design and
  build a new double bath cryostat.
• CEA wrote detailed specifications that were
  handed out to WUT in June 2004.
• WUT performed a call for tender in the Summer of
  2004 and selected Kryosystem in Poland to
  manufacture the cryostat.

Schematic of NED cryostat (courtesy F. Michel, B.
Baudouy and B. Hervieu, CEA)
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Heat Transfer Measurement (2/3)

• A first reception test of the cryostat was
  carried out on Kryostems premises the 3rd week
  of April 2005, which revealed a few problems.
• WUT reacted very promptly and worked in close
  collaboration with CEA to correct these problems.
• A second reception test was carried out the 2nd
  week of July 2005 (including thermal and leak
  tests in liquid helium at 4.2 K), which was
  deemed successful.
• The cryostat will be delivered to CEA/Saclay on
  19 September, for final implementation and
  commissioning.
• The 6-month delay with respect to the initial
  schedule is not expected to any deleterious
  impacts on the overall NED Programme.

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Heat Transfer Measurement (3/3)
Cryostat with thermal shields
Lambda plate
Inner view of cryostat with Instrumentation
(Courtesy M. Chorowski, WUT)
He II heat exchanger
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Quench Computation (1/3)

• INFN-Mi has undertaken a detailed analysis of
  the thermal and electrical behaviors of NED-type
  accelerator magnets during a quench.
• The computation was started considering the
  conservative, 88-mm-aperture, cos?, layer
  design developed by D. Leroy.
• It studied the influence of
• magnet length (1, 5 and 10 m),
• operating current (15, 22 and 29 kA),
• external dump resistance (15, 25 and 35 m?),
• quench detection delay (30, 40 and 50 ms),
• quench protection heater length.
• It also compared the results obtained by two
  different codes QLASA at INFN-Mi and QUABER at
  CERN.

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Quench Computation (2/3)

• The results show that, for the entire parameter
  space, the magnet is quite safe to operate,
  thereby justifying the choice of wire and cable
  parameters made early on.

Quench simulation results on 10-m-long,
88-mm-aperture, cos?, layer design (Courtesy M.
Sorbi INFN-Mi)
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Quench Computation (3/3)

• Similar computations have now been started on
  the more innovative, 160-mm-aperture, slot
  design also proposed by D. Leroy.
• The quench computation task is near completion.

88-mm-aperture, layer design (Courtesy D. Leroy,
CERN)
160-mm-aperture, slot design (Courtesy D. Leroy,
CERN)
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CD Work Package

• The CD Work Package includes two main Tasks
• conductor development
• (under CERN supervision L. Oberli has now taken
  over D. Leroy as the official Task Leader),
• conductor characterization
• (CEA, INFN-Ge, INFN-Mi, and TEU Task Leader A.
  den Ouden, TEU).
• It is the core of the programme and absorbs
  about 70 of the EU allocated funding.

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Conductor Development (1/2)

• As a conclusion of preliminary design studies
  carried out in 2003 and 2004 under the
  supervision of D. Leroy, the following
  specifications were derived for NED Nb3Sn strands
  
• diameter 1.250 mm,
• eff. filament diameter lt 50 mm,
• Cu-to-non-Cu ratio 1.25 0.10,
• filament twist pitch 30 mm,
• non-Cu JC 1500 A/mm2 _at_4.2 K 15 T,
• minimum critical current 1636 A at 12 T,
• 818 A at 15 T,
• N-value gt 30 at 4.2 K and 15 T,
• RRR (after heat treatment) gt 200.
• (It is also requested that the billet weight be
  higher than 50 kg.)

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Conductor Development (2/2)

• Based on these specifications, a call for tender
  was issued by CERN in June 2004 and two contracts
  were awarded in November to 2004 to Alstom/MSA in
  France (Enhanced Internal Tin process) and SMI
  in the Netherlands (Powder in Tube Process).
• After discussion with CERN, the two companies
  agreed to work out their development program into
  two successive RD Steps (referred to as STEP 1
  and STEP 2) followed by final cable production.
• A tentative schedule was established as follows
• STEP 1 Summer 2005,
• STEP 2 Summer 2006,
• Final production December 2006.

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Conductor Characterization (1/2)

• The NED-type conductor characterization
  represents a real challenge, given the
  unprecedented performances that are expected
  (e.g., a critical current of 1600 A at 4.2 K and
  12 T on a 1.25-mm wire, to be compared to the
  timid 200 A presently achieved on 0.8 mm ITER
  wires).
• To validate sample preparation and measurement
  processes, the laboratories involved (CEA, TEU
  and INFN) have launched a cross-calibration
  program reminiscent of the ITER/EDA
  cross-calibration program carried out in the
  mid-1990s.
• Since the Summer of 2004, three rounds of
  calibration wires have been prepared and
  circulated among the various partners.

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Conductor Characterization (2/2)

• TEU and INFN have now achieved a good
  convergence.
• The problems at CEA have been identified and are
  being solved.
• All 3 partners should be ready when the first
  wires become available.

SMI/Toshiba Test Wire (results are within 2)
(Courtesy T. Boutboul, CERN)
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FE Wire Model

• In Parallel, INFN-Mi has started to develop an
  ANSYS model of an un-reacted, Alstom/MSA-type
  wire so as to simulate cabling effects.
• Running such a computation requires a detailed
  knowledge of the mechanical properties of the
  materials making up the wire (in the cold work
  state where they end up prior to the cabling
  operation).
• To determine these properties, CERN has carried
  out a series of nano-indentation and
  micro-hardness measurements on various wire
  samples, and compared the results with available
  literature data.
• The next step is to apply this model and the
  appropriate mechanical properties to the wire
  layouts presently considered by Alstom/MSA.

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IDI Work Package

• The IDI Work Package includes two main Tasks
• studies on conventional insulation systems
  relying on ceramic or glass fiber tape and
  vacuum-impregnation by epoxy resin
• (CCLRC Task Leader E. Baynham),
• studies on innovative insulation systems
  relying on pre-impregnated fiber tapes and
  eliminating the need for a vacuum impregnation
• (CEA Task Leader F. Rondeaux).

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Conventional Insulation (1/2)

• CCLRC and CEA have developed in collaboration an
  engineering specification (issued in July 2004)
  and a coordinated test programme (issued in
  October 2004).
• Since then, CCLRC has carried out a number of
  screening tests of candidate materials.
• The tests are applied to standardized laminates
  representative of inter-turn insulation and
  include
• electrical breakdown test,
• short beam shear test,
• inter-laminar fracture test.

Example of Double Cantilever Beam (DCB) fracture
test (courtesy S. Canfer, CCLRC)
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Conventional Insulation (2/2)

• CCLRC has also investigated the issue of
  sizing (a lubricant, usually organic, coated
  onto the fibers of tapes, that need to be removed
  prior to conductor wrapping and winding, thereby
  rendering the fiber tape fragile and easy to tear
  off).
• Very promising results have been obtained with
  an improved polyimide sizing, produced by
  Hydrosize, NC, and applied by JPS, SC, which
  seems to be able to sustain the required Nb3Sn
  heat treatment without carbonization (thereby
  eliminating the need for de-sizing).
• More complete evaluation tests are underway.

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Innovative Insulation

• The work on innovative insulation has not
  started yet, pending the hiring of a technician
  at the CEA chemistry laboratory, which has been
  delayed until early next year.
• To compensate for this lack, it was decided last
  spring to reallocate the EU funding of this task
  to hire a postdoc at CEA.
• A candidate has been identified, who is expected
  to start working this fall.
• The timing of this task is now becoming critical
  with respect to the overall NED program.

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MDO Working Group (1/3)

• The MDO Working Group is made up of
  representatives from CCLRC, CEA, CERN and CIEMAT,
  under the Leadership of F. Toral, CIEMAT.
• Its main charge is to compare different magnet
  configurations so as to assess their efficiency
  in terms of manufacturability, performance and
  cost.

Cos???layer design (courtesy D. Leroy, CERN)
Intersecting-Ellipses design (courtesy H.
Felice, CEA)
Motor-type design (courtesy F. Toral, CIEMAT)
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MDO Working Group (2/3)

• In parallel, work is pursued at CERN so as to
  optimize the baseline, 88-mm-aperture, cos? layer
  design with respect to
• conductor geometry,
• iron shape (to reduce saturation effects),
• ferromagnetic shims (to compensate magnetization
  effects).

(courtesy N. Schwerg, CERN)
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MDO Working Group (3/3)

• CCLRC/RAL is also developing a 2D ANSYS model of
  the 88-mm-aperture, cos? layer design so as to
  optimize mechanical support.
• This model includes sub-models of individual
  coil turns to compute peak stresses in cable
  strands and cable insulation.

(courtesy P. Loveridge, CCLRC)
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Conclusion

• A great deal of progress has been made since my
  last presentation (at the CARE general meeting in
  Hamburg last year), leading to a number papers
  presented at various conferences (1 at CEC/ICMC,
  1 at EUCAS and 4 at MT).
• The cryostat for heat transfer measurements is
  completed and will be delivered to CEA next week.
  
• The next few months will be critical for the
  Conductor Development program with the results of
  the STEP 1 wires.
• The only Task that has not started is the
  Innovative Insulation Task at CEA, but the hiring
  of a Postdoc should help.
• The funding of the model magnet manufacturing
  remains an open question.