An ECR sheet plasma device employing a 2.45 GHz microwave source and combination of permanent magnets and field coils is being developed. The combined field realized a linear magnetic field that sustained a rectilinear confinement of the plasma. The ECR condition effectively lowered the plasma ignition power to below 500 W and minimum plasma sustaining power to 94 W while also increasing the pressure range of low power ignition. Low ignition power is observed while plasma density is highest at 0.7 -0.3 Pa pressure range. Stable plasma operation at input microwave power of up to 3 kW was achieved without overheating in the quartz window region with the aid of a gas feed mechanism on the quartz window.

A 280 G linear magnetic field sustained a 2.5 mm diameter stable hydrogen plasma column produced by a duoplasmatron plasma cathode. A high-intensity magnetic field created by a pair of permanent magnets and the field compression structure realized the passage of a dense plasma flow through a 2 mm diameter hole. Both ions and electrons can be extracted from the downstream plasma where a linear magnetic field can be induced to guide the plasma for striking a tungsten target. Luminous intensity distribution around a tungsten target located at another end of the magnetic field confronting to the plasma cathode was examined. A substantial reduction in the Hα line spectral broadening was observed that enabled a precise spectroscopic study of the hydrogen particle reflection at the solid target surface.

A 2.45 GHz microwave power injected through a quartz glass window produced a stable sheet-shaped plasma with the 11 cm wide and 4 cm high rectangular cross section in a static linear magnetic field. A thin slot gas conduit opened near the surface of the window supplied a discharge gas forming a stream of neutral atoms that intersected perpendicularly the plasma flowing toward the window along the magnetic field. The gas stream caused the change of the luminous intensity distribution of the plasma around the microwave window indicating reduction of the local plasma heat load. The window did not show any damage for a continuous operation of plasma up to 2 kW microwave input power.