Slow-wave induction plasma transport

• US 6,897,616 B2
• Filed: 06/20/2002
• Issued: 05/24/2005
• Est. Priority Date: 06/20/2002
• Status: Expired due to Fees

• Current Assignee: Raphael A. Dandl
• Original Assignee: Raphael A. Dandl
• Inventors: Dandl, Raphael A.
• Primary Examiner(s): TRAN, THUY V
• Application Number:
  US10/175,676
• Publication Number:
  US 20030234616A1
• Time in Patent Office: 1,069 Days
• Field of Search: 315/111.21, 315/111.41, 315/111.51, 315/111.61, 219671-672, 219/674, 156/345.33, 156/345.41, 156/345.42, 156/345.48
• US Class Current: 315/111.41
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01J 37/3266 Magnetic control means

Abstract

A plasma transport system uses a slow-wave power signal in external radio-frequency (RF) inductors to force plasmas to flow through ducts, such as from a plasma generator to a point of use. A magneto-hydrodynamic force is deliberately created by the RF inductors to displace plasma electrons down along the inside of the ductwork. A charge separation results that both drags the ions along and slows down the electrons with the ion drag. The consequence is that both electrons and ions are motivated down the ductwork and the overall plasma charge stays neutral. A directed stream of energetic ions and neutral gas atoms can be realized. The RF electric fields induced in the plasma tend to counteract any electron cooling and help maintains the plasma electron temperature enough to reduce later reionization power demands.

Claims

1. A method for transporting a plasma down a duct, the method comprising the steps of:

inducing an electron current in said plasma;

inducing an RF magnetic field in said plasma through a set of coil inductors coaxially and equally spaced disposed along the duct;

wherein, an interaction between said electron current and said RF magnetic field is such that a magnetohydrodynamic (MHD), j×

B, is created that moves said plasma down the duct in one direction.

2. The method of claim 1, further comprising a step of:

generating said RF magnetic field with an alternating current RF power signal applied to a series of inductors disposed along said duct.

3. The method of claim 2, further comprising a step of:

sequencing said alternating current RF power signal applied to said series of inductors such that when electrons in said plasma move they leave behind excess ions that set up a local electric field that drags ions along;

wherein, a background neutral gas is moved by successive charge exchanges with transporting ions.

4. A method for transporting ionized gas plasmas, the method comprising the steps of:

generating a progressive, inductive slow wave;

passing a plasma coaxially through a cylindrical conduit from an input to an output;

winding said conduit with a number of progressively phased inductors; and

powering successive ones of said inductors with samples of said inductive slow wave such that said plasma is longitudinally motivated in one direction inside said cylindrical conduit;

wherein, a phased array of inductors induce RF electric currents inside the conduit that drives currents in the plasma electrons that are synchronously phased with induced RF magnetic fields so that a force on the electron currents has the same direction at all times of operation.

5. The method of claim 4, further comprising a step of:

choosing a direction in which to move the plasma and adjusting said inductive slow wave to effectuate the chosen direction.

6. The method of claim 4, further comprising a step of:

exerting a unidirectional transportation force on electrons in a ionized gas plasma with the induced RF magnetic fields from a proximate phased-array of inductors.

7. The method of claim 4, further comprising a step of:

forcing electrons in a ionized gas plasma to constantly move in a single direction with the induced RF magnetic fields generated from a proximate and coaxial phased-array of inductors;

wherein, said electrons when moved leave an excess of positive ions behind in their wakes that sets up local electric fields which drag said ions along with said electrons to move at a common velocity.

8. The method of claim 4, further comprising a step of:

varying the power to each of said inductors in the step of powering.

9. A peristaltic plasma transporter, comprising:

a duct for conducting a plasma;

a phased-array of RF inductors linearly disposed between first and second points of the duct; and

a power source for electrically driving individual ones of the RF inductors with a phase that increases with each succeeding inductor to create a peristaltic motion on said plasma;

wherein, said phased-array of RF inductors are synchronously phased to induce an RF electric current inside said duct that drives plasma electron currents with induced RF magnetic fields that a force on the electron currents has the same direction at all times of operation.

10. A plasma transporter, comprising:

a hollow cylindrical conduit comprised of dielectric material;

a plasma-source opening at a first end of the cylindrical conduit;

a plasma-output opening at a second, opposite end of the cylindrical conduit;

a longitudinal phased-array of ring-shaped inductors coaxially disposed about the cylindrical conduit between said first and second ends; and

a power source for electrically driving individual ones of the ring-shaped inductors with a phase that increases with each succeeding inductor;

wherein, said phased array of inductors are synchronously phased to induce an RF electric current inside said conduit that drives plasma electron currents with induced RF magnetic fields that a force on the electron currents has the same direction at all times of operation.

11. A method for transporting a plasma, the method comprising the steps of:

inducing an electron current in a plasma;

inducing an RF magnetic field in said plasma;

wherein, an interaction between said electron current and said RF magnetic field is such that a magnetohydrodynamic (MHD), j×

B, is created that moves said plasma down a duct in one direction; and

generating said RF magnetic field with a phased array of inductors disposed along said duct.