Patent Number: 6,251,282

Title: Plasma filter with helical magnetic field

Abstract: A plasma mass filter using a helical magnetic field for separating low-mass particles from high-mass particles in a multi-species plasma includes a cylindrical outer wall located at a distance "a" from a longitudinal axis. Also included is a coaxial cylindrical inner wall positioned to establish a plasma chamber between the inner and outer walls. The magnetic field is generated in this chamber with an axial component (B.sub.z) and an azimuthal component (B.sub..theta.), which interact together with an electric field to create crossed magnetic and electric fields. The electric field has a positive potential, V.sub.ctr, on the inner wall and a zero potential on the outer wall. With these crossed magnetic and electric fields, a multi-species plasma is moved through the chamber with a velocity, v.sub.z, high-mass particles in the plasma (M.sub.2) are ejected into the outer wall and low-mass particles (M.sub.1) are confined in the chamber during transit of the chamber to separate the low-mass particles from the high-mass particles, where M.sub.1 <M.sub.c <M.sub.2, and where M.sub.c =(ea.sup.2 (B.sub.z.sup.2 +B.sub..theta..sup.2)/8v){f(B.sub..theta. /B)}.

Inventors: Putvinski; Sergei (La Jolla, CA), Ohkawa; Tihiro (La Jolla, CA), Freeman; Richard L. (Del Mar, CA)

Assignee: Archimedes Technology Group, Inc.

International Classification: H01J 49/30 (20060101); H01J 49/26 (20060101); B03C 001/00 ()

Expiration Date: 06/26/2018