THE POLYWELL™: A SPHERICALLY CONVERGENT ION FOCUS CONCEPT

NICHOLAS K. KRALL Krall Associates, 1070 America Way
Del Mar, California 92014

Received December 27, 1990 Accepted for Publication March 7, 1991

D-He(3)/FUSION REACTORS
KEYWORDS: electrostatic confinement, cusp confinement, fusion
Fusion Technology Vol. 22, p. 42-49 (Aug. 1992).

Abstract

The Polywell™ spherically convergent ion focus concept for controlled thermonuclear fusion is described. The device magnetically confines electrons by a quasi-spherical-cusp magnetic field, forming a potential well. Ions are electrostatically confined by this well, converging to a dense focus in the center of the spherical potential, where the fusion rate is large because of the high local density of transient energetic ions. Power balance and critical physics issues are outlined, along with current experimental and theoretical work. The potential of the device for D-He(3) operation is described by the derivation of scaling laws for energy gain.

Section Outline

I. INTRODUCTION
II. ELECTRON CONFINEMENT IN THE POLYWELL SCIF
III. ION CONFINEMENT IN THE POLYWELL SCIF
III.A. Ion Orbits in an Electrostatic and Magnetic Field
III.B. Ion Density from Spherical Convergence
IV. ADVANTAGES OF THE POLYWELL SCIF CONFIGURATION AS A FUSION REACTOR
V. CRITICAL PHYSICS ISSUES
V.A. Electron Physics Issues
V.B. Ion Physics Issues
VI. POWER BALANCE AND A SUCCESSFUL POLYWELL SCIF EQUILIBRIUM
VII. WORK IN PROGRESS ON THE POLYWELL SCIF CONCEPT/b>

List of Figures

  1. Polywell SCIF schematic.
  2. The Polywell magnetic geometry.
  3. Typical potential well and ion density profile.

List of Tables

  1. Polywell SCIF Parameters for D-T Fusion with Classical Loss Rates
  2. DTI Experimental Parameters