Fabrication and test of the LDX levitation coil

Author

Michael, Philip C. ; Zhukovsky, Alexander ; Smith, Bradford A. ; Schultz, Joel H. ; Radovinsky, Alexi ; Minervini, Joseph V. ; Hwang, K. Peter ; Naumovich, Gregory J.

Author_Institution

MIT Plasma Sci. & Fusion Center, Cambridge, MA, USA

Volume

13

Issue

2

fYear

2003

fDate

6/1/2003 12:00:00 AM

Firstpage

1620

Lastpage

1623

Abstract

The Levitated Dipole Experiment (LDX) was designed by Columbia University and the Massachusetts Institute of Technology to investigate plasma confinement within a dipole magnetic field. The experiment consists of a 5 m diameter by 3 m tall vacuum chamber and three superconductor coils: a Nb₃Sn Floating Coil that provides the dipole field for plasma confinement; a NbTi Charging Coil that inductively charges and discharges the Floating Coil current; and a high temperature superconductor (Bi-2223) Levitation Coil that electromagnetically supports the weight of the 620 kg Floating Coil and controls its vertical position within the vacuum chamber. LDX is the first US plasma confinement experiment to use a high temperature superconductor coil. The use of high temperature superconductor minimizes the electrical and cooling power needed for levitation, allowing additional power for plasma heating. The levitation coil is a 2800 turn, 1.3 m outer diameter, double pancake winding. It is designed to operate at up to 150 A current at 20 K and is cooled by a combination of one stage cryocooler and liquid nitrogen cooled radiation shield. This paper provides details for the design, fabrication and test of the coil.

Keywords

high-temperature superconductors; magnetic levitation; magnetic traps; superconducting coils; superconducting magnets; 1.3 m; 150 A; 20 K; 3 m; 5 m; 620 kg; Bi-2223 levitation coil; HTS levitation coil; Levitated Dipole Experiment; Nb₃Sn; Nb₃Sn floating coil; NbTi; NbTi charging coil; coil design; coil fabrication; coil test; dipole magnetic field; double pancake winding; fusion magnets; high temperature superconductor levitation coil; liquid nitrogen cooled radiation shield; one stage cryocooler; plasma confinement; superconductor coils; vacuum chamber; Fabrication; High temperature superconductors; Magnetic fields; Magnetic levitation; Niobium compounds; Plasma confinement; Superconducting coils; Testing; Tin; Titanium compounds;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2003.812808

Filename

1211913