Nb 3 Sn IR Quadrupoles for HL-LHC GianLuca Sabbi for the LARP - - PowerPoint PPT Presentation

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Nb 3 Sn IR Quadrupoles for HL-LHC GianLuca Sabbi for the LARP - - PowerPoint PPT Presentation

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Nb 3 Sn IR Quadrupoles for HL-LHC GianLuca Sabbi for the LARP HiLumi LHC Collaboration 2012 Applied Superconductivity Conference 1 ASC 2012 Nb 3 Sn IR Quadrupoles for HL-LHC G. Sabbi Contributions M. Anerella, J. Cozzolino, J.

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SLIDE 1

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 1

Nb3Sn IR Quadrupoles for HL-LHC

GianLuca Sabbi

for the LARP – HiLumi LHC Collaboration 2012 Applied Superconductivity Conference

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SLIDE 2

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 2

  • M. Anerella, J. Cozzolino, J. Escallier, A.K. Ghosh, J. Muratore,
  • S. Peggs, J. Schmalzle, P. Wanderer
  • H. Bajas, M. Bajko, L. Bottura, G. DeRijk, O. Dunkel, P. Ferracin,
  • J. Feuvrier, L. Fiscarelli, C. Giloux, J. Perez, L. Rossi,
  • S. Russenschuck, E. Todesco
  • G. Ambrosio, N. Andreev, E. Barzi, R. Bossert, J. DiMarco,
  • G. Chlachidze, F. Nobrega, I. Novitski, V. Kashikhin, J. Kerby,
  • M. Lamm, P. Limon, D. Orris, E. Prebys, M. Tartaglia, D. Turrioni,
  • G. Velev, M. Whitson, R. Yamada, M. Yu, A. Zlobin
  • S. Caspi, D.W. Cheng, D.R. Dietderich, H. Felice, A. Godeke, S.

Gourlay A.R. Hafalia, R. Hannaford, J.M. Joseph, A.F. Lietzke, J. Lizarazo, M. Marchevsky, G. Sabbi, A. Salehi; T. Salmi, R. Scanlan,

  • X. Wang

Contributions

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SLIDE 3

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 3

1. Program motivation and goals 2. Overview of LARP magnet R&D 3. Main achievements to date 4. Outstanding technical issues 5. Prototype design and development plans

Presentation Outline

Related presentations at ASC 2012:

  • G. Ambrosio et al., “Test results and analysis of Long Nb3Sn Quadrupole Series by LARP”
  • H. Bajas et al., “Cold Test Results of the LARP HQ01e Nb3Sn quadrupole magnet at 1.9 K”
  • D. Cheng et al., “Evaluation of insulating coatings for wind-and-react coil fabrication”
  • G. Chlachidze et al., “Test of optimized LARP Nb3Sn quadrupole coil using magnetic mirror structure”
  • A. Ghosh “Perspective on Nb3Sn Conductor for the LHC Upgrade Magnets”
  • A. Godeke et al., “Review of Conductor Performance for the LARP High-Gradient Quadrupole Magnets”
  • E. Todesco et al., “Design studies of NbTi and Nb3Sn Low- Quadrupoles for the High Luminosity LHC”
  • X. Wang et al., “A system for high-field accelerator magnet field quality measurements”
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SLIDE 4

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 4

High Luminosity LHC

Physics goals:

  • Improve measurements of new phenomena seen at the LHC
  • Detect/search low rate phenomena inaccessible at nominal LHC
  • Increase mass range for discovery

Required accelerator upgrades include new IR magnets:

  • Directly increase luminosity through stronger focusing

decrease β*

  • Provide design options for overall system optimization/integration

collimation, optics, vacuum, cryogenics

  • Be compatible with high luminosity operation

Radiation lifetime, thermal margins Figure of merit is integrated luminosity, with a target of 3000 fb-1

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SLIDE 5

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 5

IR Upgrade “Roadmap”

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Complex interplay between different aspects of the machine design: beam dynamics, magnets, energy deposition and shielding, cooling, powering…

  • F. Zimmerman, IR’07 Workshop
  • E. Todesco, 2011 HiLumi-LARP meeting
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SLIDE 6

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 6

Quadrupole Optimization Roadmap

High field technology provides design options to maximize luminosity

Higher Field Larger Aperture

(same/lower gradient)

Thicker absorbers More Operating Margin

(at same gradient / aperture)

Longer Lifetime Lower radiation and heat loads Better Field Quality Stronger focusing Higher Gradient

(same/lower aperture)

Shorter magnets Higher T margin Better IR layout Stable operation Easier cooling More Design Margin

(same gradient / aperture)

Lower risk Faster development Less cost & time

for small production

More luminosity

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SLIDE 7

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 7

LARP Magnet Program

Goal: Develop Nb3Sn quadrupoles for the LHC luminosity upgrade Potential to operate at higher field and larger temperature margin R&D phases:

  • 2005-2010: technology development: conductor, coil, structure
  • 2007-2012: length scale-up from 1 to 4 meters
  • 2009-2014: incorporation of accelerator quality features

Program achievements to date:

  • TQ models (90 mm aperture, 1 m length) reached 240 T/m gradient
  • LQ models (90 mm aperture, 4 m length) reached 220 T/m gradient
  • HQ models (120 mm aperture, 1 m length) reached 184 T/m gradient

Current activities:

  • Completion of LQ program to extend TQ results to long models
  • Optimization of HQ, fabrication of LHQ coils and test in mirror
  • Design and planning of the MQXF IR Quadrupole development
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SLIDE 8

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 8

Overview of LARP Magnets

SQ SM TQS LR LQS HQ TQC

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SLIDE 9

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 9

Sub-scale Quadrupoles (SQ)

  • Four “SM” racetrack coils
  • 130 mm bore, length 30 cm

Achieved 97% of SSL at 4.5K & 1.9K

  • Validated conductor for TQ01 models
  • First shell-based quadrupole structure
  • Verification/optimization of FEA models
  • Quench propagation/protection studies

C C

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SLIDE 10

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 10

Long Racetracks (LR)

SG1 SG2 SG3 SG4 SG5 SG6

  • Scale up of “SM” coil and structure: 30 cm to 4 m
  • Coil R&D: first successful length scale-up
  • Structure R&D: friction effects, magnet assembly
  • Achieved 11.5 T, 96% of short sample limit

LRS01b: segmented shell

LRS01a: single shell

  • P. Ferracin, J. Muratore et al.,

IEEE Trans. Appl. Supercond. Vol: 18 (2), 2008, pp. 167-170

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SLIDE 11

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 11

Technology Quadrupoles (TQ)

  • Double-layer, shell-type coil
  • 90 mm aperture, 1 m length
  • Two support structures:
  • TQS (shell based)
  • TQC (collar based)
  • Target gradient 200 T/m

TQC TQS

  • Three coil series using different wire design

MJR 54/61; RRP 54/61; RRP 108/127

  • More than 30 coils fabricated
  • Distributed coil production line
  • 15 magnet tests in different configurations
  • Two models assembled and tested at CERN
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SLIDE 12

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 12

TQ Highlights

Quench performance

  • Maximum gradient 240 T/m
  • 20% above target
  • No retraining

Stress limits

  • TQS03a: 120 MPa at pole, 93% SSL
  • TQS03b: 160 MPa at pole, 91% SSL
  • TQS03c: 200 MPa at pole, 88% SSL
  • Peak stresses are considerably higher
  • Considerably widens design window

Cycling test

  • 1000 cycles
  • No change in mechanical parameters
  • No change in quench levels
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SLIDE 13

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 13

Long Quadrupole (LQ)

S1 (2) D1 (1) S2 (4) S3 (2) S4 (2) D2 (4) D3 (1)

  • TQ length scale-up from 1 m to 4 m
  • Three series of coils
  • All models reached 200 T/m target
  • Recent results and next steps in:
  • G. Ambrosio et al.

4LA-01 (Thursday AM)

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SLIDE 14

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 14

High-Field Quadrupole (HQ)

R&D goals:

  • Explore “new territory” in energy and force levels (~3xTQ)
  • Incorporate field quality and full alignment

Main parameters:

  • 120 mm aperture, 15 T peak field at 220 T/m (1.9K)
  • Coil stresses approaching 200 MPa (if pre-loaded for SSL)
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SLIDE 15

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 15

HQ Highlights – Pre-load control

  • HQ explores stress limits and

test results confirm pre-load window is very narrow

  • HQ01e: asymmetric loading

for better stress uniformity

  • P. Ferracin et al., IEEE Trans.
  • Appl. Supercond. Vol: 22 (3), 2012
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ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 16

HQ Highlights – Field Quality

Discussion of magnetic measurement system by X. Wang et al., 4JE-04 (Thursday PM)

  • Geometric harmonics show good coil uniformity and structure alignment
  • Persistent current effects are large but within limits set by design study
  • Large dynamic effects indicate need to better control inter-strand resistance

Cored cables incorporated in second generation coils

Eddy current harmonics for different ramp rates

1.E-03 1.E-02 1.E-01 1.E+00 1 2 3 4 5 6 7 8 9 10 harmonics σ (units) Harmonic order

fit normal skew

12 kA, R.ref = 21.55 mm

Block positioning error ~29.6 µm.

Analysis of geometric accuracy from random errors

Rc fit 0.2–3.6 µ (LHC target: ~20 µ)

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SLIDE 17

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 17

HQ Highlights – Quench Performance

Latest results from CERN test of HQ01e at 1.9K: H. Bajas, 4LA-02 (Thursday AM)

  • Achieved 184 T/m at 1.9K (85% of SSL) – well above performance target

However, high rate of coil failures (excessive strain and insulation weakness)

  • Flux jump effects appear less severe at 1.9K (5-10 times smaller amplitude)
  • Quench protection studies: energy extraction delay, then removal of IL heaters
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ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 18

  • Large number of insulation failures in coils, coil to parts and coil to heaters
  • Catastrophic failure in HQ01b test due to inter-layer short through end shoe

Remediation steps:

  • Redesigned end parts to improve fit, eliminate high pressure areas
  • Application of insulating coatings to coil parts:
  • Improved winding procedures and QA
  • Redesigned quench heaters to minimize crossings above metallic parts
  • Increased insulation between coil layers and between coil and heaters
  • Enhanced electrical QA during coil and magnet fabrication (impulse testing)

R&D issues – Electrical Integrity

  • D. Cheng et al., 4MA-08

Thursday AM

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SLIDE 19

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 19

R&D issues – Strain during Coil Reaction

  • Results from first HQ models indicated conductor damage in several coils
  • Traced to excessive strain during the coil reaction phase:

No/insufficient gaps in pole segments to limit longitudinal strain Design/tooling did not include space for azimuthal cable expansion

  • G. Chlachidze et al.,

4LA-03 (Thursday AM)

  • HQ02: restored pole gaps and reduced cable size with smaller strand diameter
  • First coil successfully tested in mirror structure:
  • All process improvements incorporated in HQ03 and the Long HQ Coils

Coil spring-back from tooling

“Inverted” ramp-rate dependence in HQ01a-c

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SLIDE 20

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 20

In previous phases of the program, conductor has been adequate to meet the key R&D goals of the model magnets:

  • RRP 54/61 for SQ, LR, and 1st generation TQ/LQ/HQ/HQM models
  • Enabled the 2009 milestone of >200 T/m in TQ and LQ
  • RRP 108/127 for TQS03, LQS03, HQ/HQM, and LHQ

Very good results in TQS03, but lower performance in HQ/HQM and LQ Limitations observed in current density, stability (RRR), piece length

  • Conductor improvements are required for a successful construction project
  • Several developments are underway, but time window is limited
  • Increase and control Jc, RRR, piece length in RRP 108/127
  • Develop/demonstrate possible alternatives (PIT, higher stack RRP)
  • Scale-up to larger billets for faster production an lower cost

R&D Issues – Conductor and Cable

  • A. Ghosh, paper 2SLE-06 (this session)
  • A. Godeke et al., 4JA-07 (Thursday AM)

See presentations by:

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SLIDE 21

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 21

IR Quadrupole Design Specification

  • An aperture increase to 150 mm is expected to result in best overall performance
  • Requires another significant step in energy & force levels with respect to 120 mm

Higher Field Larger Aperture

(same/lower gradient)

Thicker absorbers More Operating Margin

(at same gradient / aperture)

Longer Lifetime Lower radiation and heat loads Better Field Quality Stronger focusing Higher Gradient

(same/lower aperture)

Shorter magnets Higher T margin Better IR layout Stable operation Easier cooling More Design Margin

(same gradient / aperture)

Lower risk Faster development Less cost & time

for small production

  • Max. luminosity
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SLIDE 22

ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 22

Next Phase: IR Quadrupole Prototype

Preliminary layout of HL-LHC final focus using 150 mm bore 140 T/m quadrupoles: Prototype design status:

  • Increased cable size to facilitate coil stress management and quench protection

Cable R&D underway targeting 18.5 mm width, 1.50 mm mid-thickness, 0.65 deg. keystone angle (D. Dietderich) Strand diameter from 0.778 mm (HQ) to 0.85 mm to limit aspect ratio

  • Electrical integrity: increase of cable insulation thickness from 0.1 to 0.15 mm
  • Preliminary cross-sections were developed for evaluation
  • Latest developments presented in: E. Todesco et al., 4LA-05 (Thursday AM)

6.77 m 2 x 3.99 m 6.77 m 2 x 3.99 m

  • R. De Maria et al,

HiLumi meeting, 7/26/12

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ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 23

Design and Construction Planning

  • Full partnership between USLARP and CERN for R&D and production
  • The HL-LHC structure provides the needed collaboration framework for

machine and magnet design optimization: Organized around “work packages” - magnet WP is closely interacting with accelerator physics, powering, energy deposition, cryogenics, vacuum WPs Overall coordination by WP1 (management) through collaboration board, steering committee, parameters and layout committee

  • In the US, LARP is being reorganized to focus on selection, prototyping and

construction of key deliverables Goal: fully address remaining R&D issues and obtain convincing performance demonstration before start of construction project Closer integration of LARP and General Accelerator Development effort (laboratory base programs) is also expected during the next phase

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ASC 2012 Nb3Sn IR Quadrupoles for HL-LHC – G. Sabbi 24

Summary

  • A large knowledge base is available after 7 years of fully integrated

effort involving three US Labs and CERN Steady progress in understanding and addressing R&D issues that were perceived as potential show stoppers: conductor performance, mechanical support, degradation due to stress and cycling, length scale-up, coil/structure alignment, field quality, quench protection

  • Remaining challenges include: control of dynamic effects, electrical

integrity, process documentation and QA, incorporation of rad-hard epoxies, development and selection of production-class conductors

  • Next few years will be critical and much work is still left to do

Integrating LARP effort with CERN, US core programs, EuCARD

  • HL-LHC IR Quads are a key step for future high-field applications

Acknowledgement: