Formation of field-reversed configuration using an in-vessel odd-parity rotating magnetic field antenna in a linear device.

A Field-Reversed Configuration (FRC) is formed by an in-vessel odd-parity rotating magnetic field (RMF) antenna in a tandem mirror device, Keda mirror with axisymmetricity. The 40-cm diameter antenna is fed independently by four IGBT-based power units with an output current of 1500 A each at 84 kHz, and their phases are adjustable to launch odd or even parity RMFs. A medium-sized washer gun is utilized to generate a highly ionized seed hydrogen plasma. Driven by RMF, the resultant FRC is formed with a separatrix radius of ∼17 cm, external field of ∼50 G, and trapped poloidal flux of ∼0.15 mWb. The formation process of FRCs is evidenced by the measurement of an array of internal two-dimensional probes; a comparison with the rigid rotor model is presented in this paper. In addition, substantial toroidal electron current is found to be driven, despite the partial RMF penetration. Moreover, the dependence of the driven current on the antenna current is reported and is found to be consistent with the RMF current driving model.

[1]  Q. Lu,et al.  Characterization of a medium-sized washer-gun for an axisymmetric mirror. , 2018, The Review of scientific instruments.

[2]  Q. Lu,et al.  Field-reversed configuration formed by in-vessel θ-pinch in a tandem mirror device. , 2017, The Review of scientific instruments.

[3]  Ming Liu,et al.  Ion cyclotron resonance heating (ICRH) systems for the Keda Mirror with AXisymmetry (KMAX). , 2017, The Review of scientific instruments.

[4]  F. Wessel,et al.  Rigid-rotor, field-reversed configuration , 2014 .

[5]  K. Velas,et al.  Probe measurements of the three-dimensional magnetic field structure in a rotating magnetic field sustained field-reversed configuration , 2014 .

[6]  A. Glasser,et al.  Formation of field-reversed-configuration plasma with punctuated-betatron-orbit electrons. , 2010, Physical review letters.

[7]  Charlson C. Kim,et al.  Extended magnetohydrodynamic simulations of field reversed configuration formation and sustainment with rotating magnetic field current drive , 2010 .

[8]  H. Guo,et al.  Achievement of a New High-Confinement, Collisionless FRC State in TCS-Upgrade , 2009 .

[9]  M. Inomoto,et al.  Azimuthally non-uniform equilibrium of field-reversed configuration sustained by rotating magnetic field with spatial high-harmonic components , 2009 .

[10]  Y. Petrov,et al.  Magnetic field structure evolution in rotating magnetic field plasmas , 2008 .

[11]  M. Inomoto,et al.  Field-reversed configuration maintained by rotating magnetic field with high spatial harmonics. , 2007, Physical review letters.

[12]  A. Glasser,et al.  Formation of collisionless high-beta plasmas by odd-parity rotating magnetic fields. , 2007, Physical review letters.

[13]  Y. Petrov,et al.  Comparison of rotamak plasmas in FRC and ST configurations , 2005 .

[14]  H. Guo,et al.  Observations of improved confinement in field reversed configurations sustained by antisymmetric rotating magnetic fields , 2005 .

[15]  A. Hoffman,et al.  Sustainment of elongated field reversed configurations with localized rotating magnetic field current drive , 2004 .

[16]  J. Slough,et al.  The TCS Rotating Magnetic Field FRC Current-Drive Experiment , 2002 .

[17]  Z. Pietrzyk,et al.  Formation and steady-state maintenance of field reversed configuration using rotating magnetic field current drive , 2002 .

[18]  Cohen,et al.  Ion heating in the field-reversed configuration by rotating magnetic fields near the ion-cyclotron resonance , 2000, Physical review letters.

[19]  Stephen J Tobin,et al.  THE ROTATING MAGNETIC FIELD OSCILLATOR SYSTEM FOR CURRENT DRIVE IN THE TRANSLATION, CONFINEMENT AND SUSTAINMENT EXPERIMENT , 2000 .

[20]  A. Hoffman.  Rotating magnetic field current drive of FRCs subject to equilibrium constraints , 2000 .

[21]  R. Milroy,et al.  Maintaining the closed magnetic-field-line topology of a field-reversed configuration with the addition of static transverse magnetic fields , 2000 .

[22]  J. Slough,et al.  Flux generation and sustainment of a field reversed configuration with rotating magnetic field current drive , 2000 .

[23]  I. Jones,et al.  Operation of the Rotamak as a Spherical Tokamak: The Flinders Rotamak-ST , 1998 .

[24]  J. Slough,et al.  Observation of tilt stability of field reversed configurations at large s , 1988 .

[25]  W. Hugrass,et al.  Steady-state solutions for the penetration of a rotating magnetic field into a plasma column , 1981, Journal of Plasma Physics.

[26]  W. Hugrass,et al.  An experimental investigation of current production by means of rotating magnetic fields , 1980, Journal of Plasma Physics.

[27]  W. T. Cowhig,et al.  Interaction of Travelling Magnetic Fields with Ionized Gases , 1952, Nature.