LARP Magnet Progress

Michael Lamm

For the LARP Collaboration

bnl - fnal - lbnl - slacUS LHC Accelerator Research Program

All Experimenters’ Meeting

Monday, October 8, 2007

All Exp. Meeting - 08 Oct 07 Michael Lamm on LARP Magnets 2

US Accelerator Research Program (LARP)

What is LARP ?

•US Accelerator Specialist to play role in LHC Accelerator, commissioning, operation and performance upgrades

•Fermilab AD/APC/TD play major role

Magnet LARP Motivation

•Existing 70 mm NbTi IR quads will likely be replaced after 4-7 years of operation to increase luminosity

•We want to play a major role with CERN in developing these magnets

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IR Higher Luminosity Replacement Magnets

IR Environment (low , more interactions)Wider beam profile, Larger G*dl, Higher energy deposition, More Radiation

Utilize Nb3Sn SuperconductorImproved Nb3Sn magnet technology

Improved Nb3Sn conductor

Rad Hardened structure

Implications for Magnet Design Wider Aperture, Higher Gradient Higher field on conductor, SC Temperature Margin, Rad Hardened Materials

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Nb3Sn has been around for a while….

• 1960-1990 Nb3Sn/NbTi on parallel path – Alternative for Isabelle– SSC development– LHC 4.2 K Nb3Sn vs. 1.9K NbTi

Nb3Sn Tape BNL W. B. Sampson, circa 1967

NbTi Wins!

• 1990’s Generic R&D to push envelope

Twente, LBNL, achieve up to 14. 7 TOne of a kind

magnets

• 21st Century, Nb3Sn revisited for future VLHC, LHC upgrade

– Conductor improvements in Nb3Sn vs. Field limitations in NbTi– Several participants by now... BNL, FNAL, LBNL,TAMU, CEA, Twente, KEK

– 10’s of 1 meter models magnets successfully built, mostly in the US….

But never used in an actual accelerator

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LARP 2009 Challenge

“Demonstrate that Nb3Sn magnets are a viable choice for an LHC IR upgrade”

Technological Quadrupoles (TQ) for performance reproducibility

1 m long, 90 mm aperture Cos(2), Gnom > 200 T/m, Bcoil > 12T

Scale up to 4 meter long (LQ)

TQs-like cross section and mechanical structure, + experience from two long magnet intermediate studies

Milestone set in agreement with CERN

High gradient quadrupoles (HQ) to explore performance limits

1 m long, 90+ mm aperture, Gnom > 250 T/m, Bcoil > 15 T

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Technological Quadrupoles

Two mechanical designs are under developmentSame coils / Aperture = 90 mm / Gradient > 200 T/m @ 4.2K

2 layers

FillerKeys

4 pads

Bladder

Yoke

Aluminum shell

TQC: using collarsCollar laminations from LHC-IR quads1st time applied to Nb3Sn coils

TQS: using Al-shellPre-loaded by bladders and keys1st time applied to shell-type coils

YokeGap

Collar-YokePreloadShim

ControlSpacer

Skin

Collar

YokeCollaringKey

Inner poleOuter polepiece

Coil MidplaneShim

LBNL: concept, design, development, coils co-fabric., assembly & test

FNAL: concept, design, development, coils co-fabric., assembly & test

FNAL: coils co-fabric, test at 1.9K LBNL: coils co-fabric

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Recent TQ Test Results at Fermilab

TQE02:Build a TQC magnet with TQS02 coilsDirect comparison of mechanical structures To be tested early Oct (this week!)

TQC01b Quench Training at 4.5K and 1.9K

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TQC01b Quench Training at 4.5K and 1.9K

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TQC01b training history

TQC01b (Collar structure):Re-assembly of TQC01 with 2 TQS coils85% ssl at 4.5 K89% at 1.9 KReached G = 200 T/m

Improvement over TQC01 in understanding and process control

TQS02 (Shell Structure): with next generation RRP 54/61 conductor, assembled at LBNLreached ~215 T/m at 4.5 K, little improvement at 1.9K

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TQS02a training history

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Plan for Length Scale-Up

LENGTH SCALE-UP CHALLENGE: No Nb3Sn accelerator magnet longer than 1m has ever been builtLARP should make a successful 4m long quadrupole by end of 09

Design Inputs to LQ:

• TQ results and design studies

• Long mirror

•2 m/4 m Nb3sn Cos () Dipole with COLLAR structure

• Long race track

•4 m Nb3Sn Racetrack coil with SHELL Structure

Scale up quad (LQ) will be a 4 meter longer version of the TQ with TQS, TQC or hybrid structure

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LARP Long Racetrack

The goals of the Long Racetrack (LR): • fabricate and test long Nb3Sn racetrack coils• test an Al-shell-based supporting structure (preloaded using bladders and keys)

From 0.3 m to 3.6 m

Reported in Sept 7, 2007 Fermilab Today

Results:

- Iq> 90% ssl

LBNL Designed

BNL Built/tested

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FNAL Long Mirror

• This magnet is a base program contribution in support of LARP• FNAL “Mirror magnet” is a Nb3Sn cos() dipole where a coil is substituted

by iron blocks.• Long cos() coils fabrication/reaction and collar mechanics prior to LQ

Front view of mirror magnet

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Successful 2m mirror magnet test in May 20074m mirror magnet will be tested in November

LM02 quenchhistory at 4.5Kcompared with 1m model

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LQ Status/Future Plans

• We are developing a plan whose goal is to produce 2 4-meter long LQ’s by the end of CY 2009

• Program leader for LQ has been chosen (Giorgio Ambrosio)

• Program will involve all three participating LARP Magnet Labs

• Major issue to be decided is the mechanical structure• There will be an external review of the LQ program in

late November

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LARP Magnet Status

1) Several TQ Magnets have been built. All of them work well. Performance improves with successive rebuilt due to increased understand of mechanics and coil fabrication.

2) Scaleup to 4 meters is underway. 4 meter long racetrack and 2 meter long mirror dipole (4 meter test soon) LQ plan for 4 meter long cos() underway

3) Beyond LQ several LARP activities toward final goal of Nb3Sn accelerator magnets (local leaders)

1) Conductor Studies for higher Jc better conductor stability (Barzi)

2) Join AP/Magnet IR studies (Zlobin)

3) HQ quad model program (project leaders at LBNL but with contributions from Fermilab on magnetic design for e.g.)

4) 1.9K Test facility and instrumentation upgrades