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A helicon wave plasma (HWP) discharge in an experimental advanced superconducting tokamak device with a toroidal magnetic field of 2 T is investigated. The HWP with an electron density of 10^12\ \cm^-3 was produced with two 4-turn flat spiral antennas in series that are perpendicular to the toroidal magnetic field and driven by a 13.56-MHz radio-frequency (RF) source at a power of 1500 W, a toroidal magnetic field of 2 T, and a pressure (helium) of 1 Pa. The increase of the toroidal magnetic field from 0.5 to 2 T, the increase of the RF power from 500 to 1500 W, and the decrease of the pressure (helium) from 1 to 0.01 Pa were found to improve the plasma uniformity from the CCD images. [ABSTRACT FROM AUTHOR]

Zn1-xCrxO(x = 0, 0.03, 0.09) films were prepared by the radio frequency (RF) magnetron sputtering technique on Si(111) and quartz glass substrates. The effects of Cr-doping on the structural and optical properties of ZnO films have been discussed. The structural properties were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM) while optical properties using UV-Visible spectrophotometer (UV-VIS). XRD measurement revealed that the films were single phase and wurtzite structure with c-axis orientation. With the increase of Cr concentration, the intensity of the (002) peak and the grain size of the Zn1-xCrxO(x = 0, 0.03, 0.09) films decreased, and the Full Width at Half Maximum (FWHM) of (002) peak, the crystal lattice parameter c of Zn1-xCrxO(x = 0, 0.03, 0.09) films and the width of optical band gap increased, respectively. In the transmittance spectra of the Zn1-x CrxO(x = 0, 0.03, 0.09) films, the movement of the absorption edge of the ultraviolet region is the Burstein–Moss shift with the increase of Cr concentration. [ABSTRACT FROM AUTHOR]