HiLumi-LHC / LARP Conductor and Cable Internal ReviewOctober 16th and 17th 2013

H. Felice

LARP Short MagnetsFabrication and Test experience

relevant to QXF conductor and cable specifications

H. Felice 2

What is a successful magnet?

A magnet in which every single stage of fabrication has been successful

A magnet will be considered successful when I quench > 90 % Iss

10/17/2013

LARP history illustrates the involvement of each of these steps in magnet success and failures…

Cable Coil Fabrication Assembly - PreloadStrandDesign

H. Felice 3

Successful LARP Magnets

10/17/2013

Large parameter space covered by short models

H. Felice 4

From TQS02 series to TQS03 series

TQS02c •High RRR (>200)• 70 microns filament• 47 % Cu fraction• Jc (12T, 4.3 K) 2925 A/mm2

Tested at CERN

TQS03• High RRR (>200)• 50 microns filament• 54 % Cu fraction• Jc (12T, 4.3 K) 2770 A/mm2

Tested at CERN

205 – 210 T/m

220T/m

Moving from 54/61 to 108/127 improved performances at 1.9 KIn TQ

10/17/2013

220 T/m 238 T/m

H. Felice 5

TQS03 series and stress limit

-280-260-240-220-200-180-160-140-120-100

-80-60-40-20

0

Ti pole L1 pole L1 mp L2 pole L2 mp

Azi

mut

hal s

tres

s (M

Pa)

TQS03a

TQS03b

TQS03c

TQS03d

With Lorentz forces at 12 kA

10/17/2013

4 tests: TQS03 a, b, c and d

• performed with variable pre-stress• TQS03a: 120 MPa• TQS03b: 160 MPa• TQS03c : 200 Mpa• TQS03d: 120 MPa

After cool-down

-260-240-220-200-180-160-140-120-100

-80-60-40-20

0

Ti pole L1 pole L1 mp L2 pole L2 mp

Azim

utha

l str

ess (

MPa

)

TQS03a

TQS03b

TQS03c

TQS03d

H. Felice 6

TQS03 training

10/17/2013

TQS03 series demonstrated- Progressive degradation: but only 5 % from a to c- Permanent degradation beyond 200 MPa preload- QXF should have margin

• Magnet: pole turn (preload) / max midplane stress (excitation)• TQS03a: - 120 / -190 MPa• TQS03b: - 160 / -240 MPa• TQS03c : - 200 / -260 Mpa• TQS03d: - 120 / -190 Mpa

• Quench location:Midplane area

H. Felice 7

HQ series overview

HQ01 a-b-c-d-eMagnets with mixed coilsCoils 1-2-8-9 => 54/61Coils 3-4-5-6-7 => 108/127

Performance (LBNL and CERN)• 4 magnets => 70 to 85 % Iss at 4.4 K• HQ01e test at CERN => 85 % at 1.9

K

HQ02a and a2Same conductor in all coilsCoils 15-16-17-20 => 108/127

Performance (FNAL)• 98 % at 4.5 K• 89 % at 2.2 K

A. GodekeA. Godeke

10/17/2013

2 of each / magnet

H. Felice 8

HQ series performance overview

HQ01 series

HQ02

Reached 80% in 2 quenches

Good memory

What changed? • The coil fabrication

• Cable with Stainless steel core

HQM04

97% at 4.5 K

94% at 2.2 K

Maxim Marchevsky Guram Chladidze

10/17/2013

H. Felice 9

Impact of coil fabrication

Review of the coil fabrication process and designÞ High compaction of the winding during fabricationÞ Tooling and coil design oversight: no margin to allow for cable expansionÞ Risky end design

Suspected to be the cause of conductor degradation in potted coils

Main requirement for HQ02 coils: using the same tooling as HQ01•Accounting for dimensional changes and interlayer insulation

Smaller cable with smaller strand => 0.778 mm diameter strand => 14.8 mm x 1.375 mm

Axial gap size 4 mm/m•Revision of the end parts design

10/17/2013

Lead end

R, Hafalia, S, Caspi

H. Felice 10

HQ experience applied to QXFconductor

• Cable dimensional change accounted for in the magnetic design and tooling design

• 4.5 % in thickness and 2 % in width in ROXIE cross-section• Design made with reacted cable dimensions• Based on HQ and LQ experimental data

Importance to provide actual cable dimensional changes data for QXF cable to magnet designers

10/17/2013

H. Felice 11

Impact on coil fabrication schedule

Last HQ01 coil #9 completed end of 2010HQ01d and e tested starting April 2011

1st Mirror test at FNAL HQM01

2nd Mirror test at FNAL HQM02• 1 less turn• 91 % Iss at 4.6 K• 89 % Iss at 2.2 K

3rd Mirror test at FNAL HQM04• New end parts• New cable

HQ02 tested at FNAL

To validate compaction theory09/2011

05/2013

05/2012

04/2011

• Unforeseen change of cable in the case of HQ02 delayed strongly the magnet production

• QXF 2nd generation cable should be defined very early to facilitate implementation

10/17/2013

H. Felice 12

HQ Winding Experience

HQ01: 1st generation of coils• 2 pass cable• Mechanically stable

HQ02: 2nd generation of coils

• 1 pass cable to implement the stainless steel core• “Easy” popped strands noticed by technicians in some coils

• Easily fixable

HQ02 experience => Learning experience on how to handle less mechanically stable cables

10/17/2013

D. Dietderich - F. Borgnolutti

H. Felice 13

Impact of SS core in HQ performance

10/17/2013

X. Wang, J. DiMarco, M. Marchevsky – Guram Chladidze

HQ01 / HQ02 performance

• Beneficial effect on ramp rate dependence

• Beneficial effect on field quality

H. Felice 14

Summary

10/17/2013

• LARP short models performance widely influenced by all the production chain

• Best examples: HQ01 to HQM04 / HQ02• With coil fabrication improvement => performance improvement

• despite low RRR in coil 15

• What to remember from short model program for QXF

• Cable• Beneficial effect of the core cable on field quality and ramp rate dependence• let’s keep in mind the potential delay to implement a new cable design

• Coil fabrication / tooling design: • Data for Effective dimensional changes in the design

• Assembly: Stress level in conductor => TQS03 is a good guideline