A Power-Efficient Plasma Jet Line Enabled by Dielectric Anapole Resonator Technology

In this paper, we have introduced an anapole-based high-Q resonator in which radiation was suppressed due to destructive interference between the induced electric dipoles over the dielectric and metallic parts. The operation of the anapole resembles that of cavities in which energy leakage is minimized with metallic walls, except that the anapole doesn't require any metallic walls. The anapole device was later optimized to realize a uniform E field over a rectangular cross-section of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.3 ~\text{mm} \times 20 ~\text{mm}$</tex>. The E-field intensity goes as high as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$10^{6} ~\mathrm{V}/\mathrm{m}$</tex> with 1 W of input microwave power, surpassing that of the cavity resonator. The high electric field facilitates plasma formation when an inert gas is pumped at a controlled flow rate. Realizing plasma lines with minimal microwave power is challenging and hasn't been explored. The proposed approach not only realizes plasma over a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2-\text{cm}$</tex> line with a low power of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$5-10 ~\mathrm{W}$</tex> but also demonstrates enhanced electron density around room temperature from a compact and PCB-compatible device, enabling the plasma sources to be more accessible for several applications in material processing, electron accelerator, medicine, and agriculture.