Harold A Furth

US Patent:

44366914, Mar 13, 1984

Filed:

Mar 24, 1981

Appl. No.:

6/246976

Inventors:

Stephen C. Jardin - Princeton NJ
Masaaki Yamada - Lawrenceville NJ
Harold P. Furth - Princeton NJ

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

G21B 100

US Classification:

376137

Abstract:

An inductive method and apparatus for forming detached spheromak plasma using a thin-walled metal toroidal ring, with external current leads and internal poloidal and toroidal field coils located inside a vacuum chamber filled with low density hydrogen gas and an external axial field generating coil. The presence of a current in the poloidal field coils, and an externally generated axial field sets up the initial poloidal field configuration in which the field is strongest toward the major axis of the toroid. The internal toroidal-field-generating coil is then pulsed on, ionizing the gas and inducing poloidal current and toroidal magnetic field into the plasma region in the sleeve exterior to and adjacent to the ring and causing the plasma to expand away from the ring and toward the major axis. Next the current in the poloidal field coils in the ring is reversed. This induces toroidal current into the plasma and causes the poloidal magnetic field lines to reconnect.

US Patent:

44306008, Feb 7, 1984

Filed:

Apr 1, 1982

Appl. No.:

6/364276

Inventors:

George V. Sheffield - Hopewell NJ
Harold P. Furth - Princeton NJ

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

H01J 724
G21B 100

US Classification:

31511171

Abstract:

A fusion reactor device in which the toroidal magnetic field and at least a portion of the poloidal magnetic field are provided by a single set of modular coils. The coils are arranged on the surface of a low aspect ratio toroid in planes having the cylindrical coordinate relationship. phi. =. phi. sub. i +kz where k is a constant equal to each coil's pitch and. phi. sub. i is the toroidal angle at which the i'th coil intersects the z=o plane. The device may be described as a modular, high beta torsation whose screw symmetry is pointed along the systems major (z) axis. The toroid defined by the modular coils preferably has a racetrack minor cross section. When vertical field coils and preferably a toroidal plasma current are provided for magnetic field surface closure within the toroid, a vacuum magnetic field of racetrack shaped minor cross section with improved stability and beta valves is obtained.

US Patent:

47132086, Dec 15, 1987

Filed:

May 21, 1986

Appl. No.:

6/866031

Inventors:

Harold P. Furth - Princeton NJ
Alan C. Janos - East Windsor NJ
Tadao Uyama - Osaka, JP
Masaaki Yamada - Lawrenceville NJ

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

G21B 100

US Classification:

376137

Abstract:

An inductive transformer in the form of a solenoidal coils aligned along the major axis of a flux core induces poloidal flux along the flux core's axis. The current in the solenoidal coil is then reversed resulting in a poloidal flux swing and the conversion of a portion of the poloidal flux to a toroidal flux in generating a spheromak plasma wherein equilibrium approaches a force-free, minimum Taylor state during plasma formation, independent of the initial conditions or details of the formation. The spheromak plasma is sustained with the Taylor state maintained by oscillating the currents in the poloidal and toroidal field coils within the plasma-forming flux core. The poloidal flux transformer may be used either as an amplifier stage in a moving plasma reactor scenario for initial production of a spheromak plasma or as a method for sustaining a stationary plasma and further heating it. The solenoidal coil embodiment of the poloidal flux transformer can alternately be used in combination with a center conductive cylinder aligned along the length and outside of the solenoidal coil. This poloidal flux-amplifying inductive transformer approach allows for a relaxation of demanding current carrying requirements on the spheromak reactor's flux core, reduces plasma contamination arising from high voltage electrode discharge, and improves the efficiency of poloidal flux injection.

US Patent:

52251462, Jul 6, 1993

Filed:

Nov 8, 1991

Appl. No.:

7/789519

Inventors:

Masayuki Ono - Princeton Junction NJ
Harold Furth - Princeton NJ

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

G21B 100

US Classification:

376129

Abstract:

An electron injection scheme for controlling transport in a tokamak plasma. Electrons with predominantly perpendicular energy are injected into a ripple field region created by a group of localized poloidal field bending magnets. The trapped electrons then grad-B drift vertically toward the plasma interior until they are detrapped, charging the plasma negative. Calculations indicate that the highly perpendicular velocity electrons can remain stable against kinetic instabilities in the regime of interest for tokamak experiments. The penetration distance can be controlled by controlling the "ripple mirror ratio", the energy of the injected electrons, and their v. sub. perp. /v. sub. 51 ratio. In this scheme, the poloidal torque due to the injected radial current is taken by the magnets and not by the plasma. Injection is accomplished by the flat cathode containing an ECH cavity to pump electrons to high v. sub. perp.

US Patent:

43637760, Dec 14, 1982

Filed:

Jul 30, 1980

Appl. No.:

6/173555

Inventors:

Masaaki Yamada - Lawrenceville NJ
Harold P. Furth - Princeton NJ
Thomas H. Stix - Princeton NJ
Alan M. M. Todd - Princeton Junction NJ

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

G21B 100

US Classification:

376137

Abstract:

A method and apparatus for forming a detached, compact toroidally shaped spheromak plasma by an inductive mechanism. A generally spheroidal vacuum vessel (1) houses a toroidally shaped flux ring or core (2) which contains poloidal and toroidal field generating coils. A plasma discharge occurs with the pulsing of the toroidal field coil, and the plasma is caused to expand away from the core (2) and toward the center of the vacuum vessel (1). When the plasma is in an expanded state, a portion of it is pinched off in order to form a separate, detached spheromak plasma configuration. The detached plasma is supported by a magnetic field generated by externally arranged equilibrium field coils (5).

US Patent:

H4464, Mar 1, 1988

Filed:

Apr 11, 1986

Appl. No.:

6/854667

Inventors:

Russell M. Kulsrud - Princeton NJ
Harold P. Furth - Princeton NJ
Ernest J. Valeo - Princeton Junction NJ
Maurice Goldhaber - Bayport NY

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

G21B 100

US Classification:

376143

Abstract:

A method of controlling the reaction rates of the fuel atoms in a fusion reactor comprises the step of polarizing the nuclei of the fuel atoms in a particular direction relative to the plasma confining magnetic field. Fusion reaction rates can be increased or decreased, and the direction of emission of the reaction products can be controlled, depending on the choice of polarization direction.