SOME PHYSICS CONSIDERATIONS OF MAGNETIC INERTIAL-ELECTROSTATIC CONFINEMENT: A NEW CONCEPT FOR SPHERICAL CONVERGING-FLOW FUSION

ROBERT W. BUSSARD* Pacific-Sierra Research Corporation
2340 Santa Monica Blvd., Los Angeles, California 90025

Received October 12, 1989 Accepted for Publication June 26, 1990

FUSION REACTORS
KEYWORDS: inertial-electrostatic, converging flow, confinement
Fusion Technology Vol. 19, p. 273-293 (Mar. 1991).

Abstract

A new concept for inertial-electrostatic spherical colliding beam fusion (POLYWELL™) is based on the use of magnetohydrodynamically stable quasi-spherical polyhedral magnetic fields to contain energetic electrons that are injected to form a negative potential well that is capable of ion confinement. A simple phenomenological model for this system shows that

  1. It is grossly stable against internal and global perturbations by virtue of the effects of both the external magnetic fields (typically 1 to 5 kG) and the large central azimuthally isotropic power flow due to conservation of transverse momentum in the recirculating ion flow.

  2. Electron current recirculation ratios must be of the order of 10^5 for net fusion power operation, which is found to be possible within limits set by energy-exchange self-collisions.

  3. Losses due to bremsstrahlung and synchrotron radiation can be kept small relative to fusion power generation, and ion energy Maxwellianization by two-body collisional upscattering can be kept to acceptable levels by operation at sufficiently large well depth.

  4. System gains of 10 to 100 seem possible from several fusion fuels.

  5. No zero-order impediments have yet been found to this highly speculative concept; feasibility must be determined by study of more complex and detailed phenomena.

Section Outline

I. INTRODUCTION AND BACKGROUND
I.A. The Basic Concept
I.B. Prior Work
II. SUMMARY OF TECHNICAL FEATURES AND CHARACTERISTICS
III. NEGATIVE POTENTIAL WELL FORMATION BY ELECTRON INJECTION
III.A. Constant Charge Density and Inertial Effects
III.B. MHD and Aspherical Deformation Stability
III.C. Electron Collisional Transport and Particle-Cusp Losses
IV. POSITIVE ION TRAPPING, STABILITY, AND RADIATION LOSSES
IV.A. Convergent Ion Flow, Momentum Transformation, and Pressure Balance
IV.B. Electrostatic Waves, Dynamic Pressure, and Core Stability
IV.C. Synchrotron Radiation and Bremsstrahlung Losses
V. REACTION POWER GENERATION AND COLLISIONAL EFFECTS
V.A. Reaction Rate Density and Power Generation
V.B. Energy Distributions, Multibody Collisions, and Upscattering
VI. POWER BALANCE, LOSSES, AND SYSTEM PERFORMANCE GAIN
VI.A. Cusp Electron and Magnet Coil Ohmic Power Losses
VI.B. Power Balance and System Gain Considerations

List of Figures

  1. Inertial-electrostatic confinement: deep negative electric potential well (1) traps positive ion fuels (2) in spherical radial oscillations (3) until they make fusion reactions (4).
  2. Inertial-electrostatic confinement: trapping well formed by energetic electron injection (1) into cusps of polyhedral magnetic fields (2) and ions fall into the well and remain until reacted (3).
  3. Direct electric conversion: reaction products (1) are energetic charged particles, which escape against spherically symmetric radial voltage gradient (2) to yield radiation-free direct electric power output (3).
  4. Octahedral and truncated cube polyhedral geometries, showing face-center magnetic fields (A,C,D), field direction on face-symmetry lines, and axes of null field (B,E). Arrows on polyhedron edges indicate direction of current flow in edge conductors to product [sic] desired fields.
  5. Monoenergetic fusion reaction cross sections in CM coordinate frame for several candidate fuels.
  6. Energy and velocity distributions for central collisions in radially monoenergetic converging ion flow: CM and CG are coincident in the system.

List of Tables

  1. Minimum Well Depth for Equal Bremsstrahlung and Fusion Power Densities
  2. Reaction Energy and Synthetic Gain at Peak Cross Section for Fusion Fuels