Superconducting R&D – Now Strand and Cable R&D FERMILAB Magnet Systems Department – Now SC...
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Transcript of Superconducting R&D – Now Strand and Cable R&D FERMILAB Magnet Systems Department – Now SC...
Superconducting R&D – Now Strand and Cable R&D
FERMILAB
Magnet Systems Department – Now SC Materials Department (TD)
HTS Insert Coil Test in External Solenoid Field
Emanuela Barzi
All Experimenters’ Meeting, July 11, 20111
Motivation of R&D
High Temperature Superconductors (HTS) are of interest for Muon Collider and/or Neutrino Factory accelerator magnets
The muons initially occupy a large 6D phase space, which must be cooled by a factor O(106). In the muon ionization cooling channel designs, the muons are confined within a lattice of high-field solenoids. The square-root of the final transverse emittance that is achievable is inversely proportional to the solenoid field at the end of the channel. The achievable luminosity in the collider is therefore proportional to this solenoid field, up to fields of about 50 T, beyond which the beam-beam tune shift is expected to limit the luminosity. 2
0 3 6 9 12 15 18 21 24 27 300
200
400
600
800
1000
1200
1400
1600
YBCO (Bparallel)
YBCO (Bperp)
Nb3Sn
NbTi
Applied Field, T
JE (
4.2
K),
A/m
m2
“Study of HTS Wires at High Magnetic Fields” , D. Turrioni, E. Barzi, M. J. Lamm, R. Yamada, A. V. Zlobin, A. Kikuchi . IEEE Trans. On Appl. Superconductivity 19, No 3, Part 3, 3057-3060 (2009).
Why HTS?
“Angular Measurements of HTS Critical Current for High Field Solenoids”, D. Turrioni et al.. Advances in Cryogenic Engineering, V. 54, AIP, V. 986, pp. 451-458 (2008).
1. Magnet design studies - Since 2007, A. Zlobin, V. V. Kashikhin, E. Barzi, E. Terzini“Study of High Field Superconducting Solenoids for Muon Beam Cooling”, V. V. Kashikhin et al.. IEEE Trans. Appl. Sup., V. 18, No. 2, p. 928 (2008).“Towards 50T Solenoids”, E. Barzi - https://indico.fnal.gov/conferenceDisplay.py?confId=3148.Analytical Study of Stress State in HTS Solenoids – Stress distribution in a solenoid was studied for various constraint configurations, max. stresses were produced as a function of coil self-field, and results compared with Finite Element Models. E Terzini, E. Barzi, FERMILAB-TM-2448-TD.
2. HTS Conductor R&D – Ongoing since 2005, E. Barzi, L. Del Frate, V. Lombardo, D. TurrioniConductor characterization – Studies of Je as a function of B, T, angle, and bending, longitudinal and transverse strains.BSCCO-2212 cable development.YBCO Roebel cable.
3. Insert Coil Development – Since 2008, E. Barzi, G. Norcia, A. Bartalesi, A. Cattabiani, G. Gallo, V. Lombardo
Winding methods and tooling, impregnation techniques, splicing procedures, R&D on thermally conductive insulation.Development of modular test setup.Magnetic models for insert and background field were developed to calculate short sample limits of insert coils.Co-wound and impregnated YBCO coil were represented by meso-mechanic models. A. Bartalesi, FERMILAB-MASTERS-2009-04.
4. Insert Coil Test – Since 2009, D. Turrioni, P. Vicini, V. LombardoDevelopment of instrumentation, DAQ, quench protection and detection systems for insert coil tests. Test pancake assemblies in 14 T/77 mm bore existing magnet and provide feedback to coil technology development.
HTS Work Directions
5
Conductor SuperPower SCS4050-i
Ic (A) Average @77K,0T 113 A
Ic (A) Minimum @77K,0T 107 A
Ic Standard Deviation 2.7%
Turn to Turn Insulation Spiral Wrapped Kapton
Coil Geometry Double Pancake – no inner splice
Coil ID 19 mm
Coil OD 62 mm
Conductor Thickness 0.1 mm
Conductor + Insulation Thickness
0.2 mm
Packing Factor 50%
Turns per Single Coil 108
Conductor length per Coil 13.9 m
Overall Conductor Length 27.8 m
Coil Resistance @ 300K 2.87 Ohm
Coil Inductance @1kHz 1.5 mH
Double-Pancake Units
Modular Insert Test Setup
14 T solenoid with
77 mm bore
Modular Insert Test Facility
6
Coil1
Coil2
Coil3
Coil4
Modular Test Facility for HTS Insert Coils”, V. Lombardo, A. Bartalesi, E. Barzi, M. Lamm, D. Turrioni and A.V. Zlobin”. IEEE Trans. Appl. Sup., V. 20, No. 3, p. 587 (2010).
7
Result - 21.2 T with 14 T Bkg. Field
YBCO Insert Coil
External Magnet
Max Current Reached 335 A
SSL 92%
Peak Field on Conductor
21.5 T
Peak Axial Field 21.2 T
What Next?
This insert coil produced 7.5 T in a 14 T background field (about 9 T at self-field).
This is an intermediate result with respect to our final goal. To develop a technology for 35 T+ solenoid, we need to double (~15 T) the field of the HTS insert in a background field of ~ 20 T provided by Nb3Sn/ NbTi hybrid coils.