초록 ▼

A radio frequency wave ion generating apparatus which provides a thin disc shaped plasma adjacent an ion attracting means is described. The radio frequency waves are preferably microwaves. Several improvements to microwave plasma generation are described including the steps of generation of a resona

A radio frequency wave ion generating apparatus which provides a thin disc shaped plasma adjacent an ion attracting means is described. The radio frequency waves are preferably microwaves. Several improvements to microwave plasma generation are described including the steps of generation of a resonantly sustained microwave discharge inside a microwave/plasma coupler or cavity (11) to ignite the plasma; probe (14) and length tuning of the microwave/plasma coupler by means of a sliding short (12) during operation of the plasma and minimization of the plasma volume inside the coupler in a chamber (15) to produce the disc plasma. The apparatus is particularly useful for internal ion or free radical irradiation of various materials provided in the plasma or for ion acceleration outside the cavity for use as an ion engine or as an ion source for irradiation of the materials.

대표청구항 ▼

In an ion generating apparatus including a plasma source employing a radio frequency wave coupler which is excited in one or more of its TE or TM modes of resonance to produce the plasma in the coupler and optionally including a static magnetic field which aids in confining the ions in the coupler i

In an ion generating apparatus including a plasma source employing a radio frequency wave coupler which is excited in one or more of its TE or TM modes of resonance to produce the plasma in the coupler and optionally including a static magnetic field which aids in confining the ions in the coupler including a probe inside the coupler which couples the radio frequency waves to the coupler and including ion attracting means for attracting the ions from said plasma preferably by means of a suitable voltage potential which accelerates the ions, the improvement which comprises: (a) an electrically insulated plasma defining chamber (15) having a central longitudinal axis and mounted in closely spaced relationship to an area (16) of a metallic radio frequency wave coupler which is in the shape of a hollow cavity (11); (b) at least one metallic ion attracting means (17a) mounted adjacent to and electrically insulated from the insulated chamber which ion attracting means forms part of the radio frequency coupler; (c) gas supply means (18, 19) for providing a gas which is ionized to form the plasma in the plasma defining chamber, wherein the radio frequency wave applied to the coupler creates and then maintains the plasma in the shape of an elongate, thin disk adjacent to the ion attracting means and perpendicular and surrounding to the axis in the chamber during steady state operation of the apparatus; and (d) movable metal plate means (12) in the cavity mounted perpendicular to the axis and movable towards and away from the plasma disk; and (e) a movable probe (14) connected to and extending inside the coupler for coupling the radio frequency waves to the coupler wherein movement of the plate means and the probe in the coupler achieves a selected TE or TM mode of resonance of the radio frequency wave in the coupler and varies the resonance of the mode. The method of claim 13 wherein the ion attracting means is a plate (30) mounted adjacent the chamber and wherein the ions are attracted to the plate.