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A Joint Proposal for US-Japan Cooperation Program

• Proposal to JSPS US-Japan collaboration fund• R&D of superconducting magnet technology for high

intensity muon beam line• KEK

– ARL, Cryogenics Science Center• T. Ogitsu, N. Kimura, T. Nakamoto, K. Sasaki, K. Tanaka, A. Yamamoto,

– IPNS, Cryogenics Group• Y. Makida, T. Okamura

• FNAL– Technical Div.

• M. Lamm, A. Zlobin, V. Kashikhin, E. Barzi, S. Feher, J. Tompkins

Term• 2009~2014• Phase I (mainly 2009~2011)

– Near term – Projected for Mu2e and COMET

• Phase II (mainly 2011~2014)– Long term– Projected for future high intensity muon beam line– Eventually for Neutrino Factory and Muon Collider

Phase I R&D12206

25687

Mu2eCOMET

Pion Capture SolenoidR&D forMu2e and COMET

Requirement• High Field

– More pion to capture– More (better) conductor– Larger stored energy ~5T for COMET and Mu2e

• High Radiation – High Power Beam– Heat Load– Radiation Damage~10 W for COMET

High yield strength

Al stabilized conductor

NbTi

base for field

up to

5

T

• Superconductor requires good normal conductor as stabilizer and quench protection

• Copper is the standard– Density: 8920 Kg/m3

• Aluminum is also a good normal conductor– Density: 2700 Kg/m3

– More transparent against radiation– Can provide less heat load with the same

stabilization property

High Yield Strength Al stabilized Conductor R&D

• For High Energy Physics– Higher Field ：　 > 5 Tesla– Larger Size ：　 Diameter 〜 10m

• Combination of Various Technology

– ATLAS Al Ni Alloy• Ni-0.5 ~ 1 %

– CMS-Hybrid Support • A6058 -->> A7020

Y.S.(0.2%) = 400 MPaRRR = ~ 400

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An R&D Work using ATLAS-CS Conductor + A6061-T6

• T.S. is > 50 % reinforced with A6061using Electron Beam, and Laser Beam Welding

• LBW may be a potential technology EBW, LBW

Laser Beam Welding

Phase I R&D: Prototype Solenoid

• Fabricate prototype pion capture solenoid• Test items

– Mechanical stability– Heat load stability– Quench protection

• including coupling

Phase I R&D Plan2009 2010 2011

Conductor R&D Design Proto Conductor Fab.

Coil R&D Conceptual Design Proto Coil Fab. Proto Coil Test

Real Magnet Detail Design Magnet Production

Phase II R&D• Aim for future high intensity muon beam line

– Eventually neutrino factory or muon collider• More Muon

– Higher Field (20 T and more)– Higher Beam Intensity = Higher Heat Load

• Advance conductor– Nb3Sn, Nb3Al, MgB2, YBCO, BSCCO– Aluminum stabilizer or aluminum jacket cable in

conduit cable• Study on Design Issues associated with using

advanced conductor

Conductor Choice for Higher Field and Higher Stability

Material Tc Hc2 ( T= 4.2 K) Mass Density

Nb-Ti 9 K 10 T 6000 Kg/m3

Nb3Sn 18 K 28 T 7800 Kg/m3

Nb3Al 18.5 K 30 T 7200 Kg/m3

MgB2 39 K 60 T 2500 Kg/m3

YBCO 90 K > 50 T 5400 Kg/m3

BSCCO 110 K > 50 T 6300 Kg/m3

A15 (Nb3Al, Nb3Sn)For now the best candidate for high field application

05001000150020002500300035004000

02468101214161820222426

NbTi(4.2K)NbTi(1.9K)(NbTa)3Sn(PIT)Nb3Sn(RRP)Nb3Al(RHQT)Nb3Al(RHQT)Jc (A/mm2)

B(T)

Nb3Sn strand Nb3Al strand

Al stabilizedNb3Al Conductor(NIFS)

Toward Higher Beam Power

• Cable in conduit– Removal of large

heat load

Nb3SnRutherford cable

MgB2

Monel 400 sheathed

Diameter: 1.13mmComposition MgB2 (Vol %) 14.6Fe (Vol %) 10.8Cu (Vol %) 13.8Ni (Vol %) 15.8Monel 400 (Vol %) 45.0

Cost: 3€/m

Commercial products are now being available.Low field performances are good up to 20 K, 2 THigh field field performance are under development

0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8

0

50

100

150

200

250

300

350

400

Crit

ical

cur

rent

(A)

Magnetic field (T)

16 K 20 K 24 K 30 K

High Tc Conductors

• 22 T already achieved• Possibility to go beyond

Issue

• Needs stabilizer for stability and quench protection

• Need large conductor for higher operation current, i.e. less inductance

• Aluminum stabilizer?• Aluminum jacket cable in conduit?• Hybrid magnet structure for efficiency

R&D Schedule & Budget2009 2010 2011 2012 2013 2014

Phase I Conductor R&D20MJYen

Proto Coil

25MJYen

Proto Coil Test10MJYen

Proto Coil Test2MJYen

Test Analysis1MJYen

Test Analysis1MJYen

Phase II Conductor Basic R&D5MJYen

Conductor Basic R&D5MJYen

Conductor R&D20MJYen

Proto Cond.Fab.28MJYen

Proto Coil Fab.29MJPYen

Proto Coil Test20MJYen

Cont. 10MJYen 5MJYen 5MJYen 5MJYen 5MJYen 4MJYen

Travel 3MJYen 3MJYen 3MJYen 3MJYen 3MJYen 3MJYen

Total 38MJYen 38MJYen 38MJYen 38MJYen 38MJYen 28MJYen

Other staff

Transport SolenoidR&D at KEK

J-PARC Muon Beam Line

• Field; ~2T• Aparture; ~0.4 m

• Limited Access to shielded area– Refrigerator must be

outside of shield– Limited Space for the

refrigerators– Long distance to cold head

to coil front– Conduction Cooling with

Higher Temperature

Trial Winding of Curved Section with MgB2 conductor

• Purchase two kinds of MgB2 conductor from Columbus SC– 1 is the 1.13 mm diameter round wire

• Will be wound by a company

– 2 is the 1.5 * 2.5 mm square wire• Will be wound by Nakahara and Adachi at KEK

• They will be wound this winter and Tested in next spring

R&D Coil made at KEK in houseNbTiAlready woundTest just startedMgB2 version is also planned

R&D on Transport SCSolenoid Coil by company

will be wound till Mar.

R&D on trim dipole coil