Report from Session 2 Main Dipoles
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Transcript of Report from Session 2 Main Dipoles
Report from Session 2 Main Dipoles
Bi-2212(YBCO)
NbTi
?
Nb3Sn
Bi-2212(YBCO)
NbTi
?
Nb3Sn
P. McIntyre 2005 – 24T ss Tripler, a lot of Bi-2212 , Je = 800 A/mm2
0
20
40
60
80
0 20 40 60 80 100 120
y (m
m)
x (mm)
HTS
HTS
Nb3Snlow j
Nb-Ti
Nb-TiNb3Snlow j
Nb3Snlow j
Nb3Snhigh j
Nb3Snhigh j
Nb3Snhigh j
Nb3Snhigh j E. Todesco 2010
20 T, 80% ss30% NbTi55 %NbSn15 %HTS All Je < 400 A/mm2
Conductor• NbSn: 15- 16 T (80% ss !!)
– Developed, existing in moderastre quantities (tons); for ITER (less Jc) 400 tons
– Needs improvement in mechanical, stability– Instability is an issue but we can manage– A reduction 2 in – projected- cost is an asset– 2 manufacturers only: 1 at good level, 1 near
Bi-2212
Ic=348A
Ic=186A
Ic=438A
Ic=488A
Without insulation With insulation
Coil section 1 Coil section 2
Short samples
HTS (Bi-2212): needed for B > 16 T (at 80%) 40% cost of material for 20% fieldJe = 100-200 A/mm2 today; difficult material; HEP is almost only client…Either a strong program or very likely to be abandoned
Ts
T1
Tp
Rc2R
c3
Rc1
Rc4
Time,h
Tem
pera
ture
,o C
Key step!
YBCO
YBCO: may be a great hope: many developersCost is –still- stellarLack of multikA compact cable may be a killer…
The many developers guidfed by othertr applications (Power, electrical devices…)
If we want gain we need to choose between Bi-2212 and Ybco, then push and guide development
New ideas needed…what do they need to be developed?
We might go far to eliminate all of these problems if we could fully texture the powder in the subelements:
But how to do it?
6 mm
Magnet Development Chart
LBL:16 T reached with bladder system…
D20 RD3 HD1
“common-coil”“cos-theta” “block”
13.8T, 199750mm bore
14.5T, 2001 16T, 2003
Adding a bore…
6
7
8
9
10
11
12
13
14
15
16
0 5 10 15 20 25 30 35 40 45 50
Bore
fiel
d (T
)
Training quench #
HD2a
HD2b
HD2c
HD2d
HD2e
Short sample limit
HD2: 43 mm boreTarget @ 4.2 K : 15.6 T
Extensive investigation of superconductor and classical structure
15000
17000
19000
21000
23000
25000
0 10 20 30 40 50 60 70 80
Quench Number
Que
nch
Cur
rent
[A]
Iq(Inner)
Iq(outer)
dI/dt>20
PIT Models: Bmax=9.4/10.2T @4.5/2.2K (100% of SSL).RRP-108/127 coil: Bmax= 11.4T @4.5 K (97% of SSL)
instabilities at ~21kA
Conclusion from NbSn US program…
• @ FERMI• 20 dipole and 35 quadrupole 1-m long coils• Reasonable size reproducibility • Short fabrication time• 2 dipole and 14 quadrupole 4-m long coils• From CORE programs + LARP• 11 T in dipoles and quadrupoles: we can count on
it (but development on conductor and structure still needed…)
• 13-15 T in view, but 3 years needed…
Getting acquainted with HTS in special applications: BNL
• We have successfully designed, built and tested a large number of HTS coils and magnets:– Number of HTS coils built: ~100– Number of magnet structures built and tested: ~10
• We are performing HTS magnet R&D on a wide range of programs: – High T, low B (several, in house)– Medium T, medium B (3 funded programs)– Low T, high B (>20 T, 2 funded programs)
FRIB
Main coil: layer woundBucking: double pancake
YBCO: 25 T – 100 mm solenoids for SMES…
KEK : Nb3Al and more…
Nb3Sn
Compressive Load
Europe: Fresca-2 (2013)
• Making a detailed 3D model is important: the devil is in the detail
• 3D turn by turn model
Hot points…• Radiation facility (HiRadMat @ CERN)• Design : for B>13-14 T consensus toward block design. Proved ? Not yet!• Aperture: needs more than educated guess (small aperture favor block vs
cos)• CONDUCTOR
– Is the performance driver– Is the cost driver– 20 T: 4 G(CHF-$-€)
• Mitigation measure: 15-16 T range• Assess real margin (80%, 90%?)• Needs to drive (and finance) development: Ybco > Bi-2212
• HL-LHC (11 T DS dipole, IR magnets @ 13 T) is a valid test bed• Other specific issues: protection & powering, stress management, small
aperture, two-in-one design