MDI workshop, Jan.5,2005, SLAC

An application of high Tc

Rare Earth-QMG material to ILC Final Doublet

Masayuki KUMADA, NIRS Mitsuru MORITA, Nippon Steel Corporation

Introduction:

Motivation; to design the most compact SC Quadrupole magnet

Critical current density of Rare Earth QMG (Quench Melt and Growth) material is extremely high

Technology of processing of a coil made of a high Tc QMG crystal was developed at Nippon Steel corporation

Model QMG coil was made and tested.

Preliminary model of a Quadrupole suitable for ILC final doublet

Introduction:

Motivation; to design the most compact SC Quadrupole magnet

Critical current density of Rare Earth QMG (Quench Melt and Growth) material is extremely high

Technology of processing of a coil made of a high Tc QMG crystal was developed at Nippon Steel corporation

Model QMG coil was made and tested.

Preliminary model of a Quadrupole suitable for ILC final doublet

MDI workshop, Jan.5,2005, SLAC

SINGLE CRYSTAL with of RE-QMG

1cm

MDI workshop, Jan.5,2005, SLAC

10

100

1000

104

105

1 2 3 4 5 6 7 8 9

Jc(B)comparisonBi2212 4K parallel fieldNbTiNb3SnQMG77KQMG63KQMG4.2K

B(T)

30K

40K

50K

Jc

(A/mm2)

New material

Standard SC cable

Latest high Tc

Comparison of RE- QMG with latest high Tc

cable and standard superconducting cable

Comparison of RE- QMG with latest high Tc

cable and standard superconducting cable

MDI workshop, Jan.5,2005, SLAC

- How to make a QMG coil -- How to make a QMG coil -

Strong temperature dependence Strong temperature dependence

Ag sputtering

Precise machining

Slice cutting

Spiral coil processed

wafer

MDI workshop, Jan.5,2005, SLAC

How to assemble a QMG magnet How to assemble a QMG magnet

＋

電流 II

I

II

Coil magnet

Power supply

cryostat

QMG current lead

77K

63K

Reduced pressure94mmHg

Cooling power： 35W(longer than 8h)77K→63K： 45 minutes

assembling

55mm diameter,7 turns6 layers

MDI workshop, Jan.5,2005, SLAC

A very compact RE-QMG QuadrupoleA simple model for a final doublet

A very compact RE-QMG QuadrupoleA simple model for a final doublet

　 5mm

10mm

　 5mm

QMG coil

Median planeCoil surface(2.2T)

２０ｍｍ

+

－－

－－

－ +

+

+

－

－

+

+

++

Note median plane is on the 45 degree plane

4 ０ｍｍ

MDI workshop, Jan.5,2005, SLAC

Simple RE-QMG Quadrupole Model(see previous page) courtsy of Koji Takano

(http://www.tomagnet.com)

Simple RE-QMG Quadrupole Model(see previous page) courtsy of Koji Takano

(http://www.tomagnet.com)

磁場計算

0

0.2

0.4

0.6

0.8

1

1.2

0 5 10 15

mm

tesl

a

1系列

Field distributionContour plot

r

Tesla

G=120T/m

Jc=500 A/ mm2

MDI workshop, Jan.5,2005, SLAC

How much is the field gradient?Simple scaling rule

How much is the field gradient?Simple scaling rule

B of Toroidal coil: B= I/(4r) J =500 A/mm2,r=10mm, B=4T

Thick rectangular conductor: factor 2 smaller.

B of Toroidal coil: B= I/(4r) J =500 A/mm2,r=10mm, B=4T

Thick rectangular conductor: factor 2 smaller.

MDI workshop, Jan.5,2005, SLAC

SummarySummary Jc of RE-QMG coil could be as high as 5kA/mm2

Jc greater than any other existing materials. Better for winding in an application of small curvatures i

nto small coils. Can make the most compact quad with required gradient

with this material (could be smaller than the BNL “compact SC”)

RE-QMG behaves better under high external solenoid field of the detector than standard S-C or high Tccable.

Jc of RE-QMG coil could be as high as 5kA/mm2

Jc greater than any other existing materials. Better for winding in an application of small curvatures i

nto small coils. Can make the most compact quad with required gradient

with this material (could be smaller than the BNL “compact SC”)

RE-QMG behaves better under high external solenoid field of the detector than standard S-C or high Tccable.

MDI workshop, Jan.5,2005, SLAC

AcknowledgementAcknowledgement

Thanks to:

K.Takano(Takano Original Magnet Inc.) E.Antokhin(JST/BINP) F.Kircher(Saclay) Y.Iwashita (Kyoto University) C.Spencer(SLAC)

Thanks to:

K.Takano(Takano Original Magnet Inc.) E.Antokhin(JST/BINP) F.Kircher(Saclay) Y.Iwashita (Kyoto University) C.Spencer(SLAC)

MDI workshop, Jan.5,2005, SLAC

Comparison of Low temperature and existing high temperature superconducting material(appendix)

provided by F.Kircher(Saclay)

Comparison of Low temperature and existing high temperature superconducting material(appendix)

provided by F.Kircher(Saclay)

QuickTimeý DzTIFFÅiLZWÅj êLí£ÉvÉçÉOÉâÉÄ

ǙDZÇÃÉsÉNÉ`ÉÉǾå©ÇÈǞǽDžÇÕïKóvÇ ÇÅB