Production of a periodic plasma structure for basic experiments on plasma photonic crystals in microwave range

A 2-D periodic plasma structure is produced by a low-pressure direct-current argon discharge for basic experiments on plasma photonic crystals in the microwave range of a few gigahertz. A cathode consisting of 7 × 11 stainless steel rods located at 3-cm intervals, which are covered by an insulator, and a grounded anode are set in a vacuum chamber. An axial profile of a plasma density measured by a Langmuir probe shows the production of the periodic plasma structure with the same intervals as the electrode. The highest and lowest plasma densities are about 1.5 × 10⁹ and 0.9 × 10⁹ cm^-3, respectively. The image of the discharge suggests the production of a 2-D periodic structure composed of plasma columns.