Radio-frequency Plasma Jet Research Articles

Radio-frequency plasma jet generator of singlet delta oxygen with high yield

O 2 (a 1 Δ g ) was generated in a flowing discharge of a radio-frequency (rf) hollow electrode. The radio frequency was 99.9 MHz and the rf power was 200 W. The discharge was done in the gas mixture O2:N2:NO=200:20:10 sccm and then it was chilled reactively by the mixture Ar:NO2=200:10 sccm. The O2(a 1Δg) relative yield of 32% was achieved at the pressure of 0.43 Torr. Usage of the mixtures O2:NO=200:100 sccm and Ar:NO2=100:100 sccm resulted in the O2(a 1Δg) yield of 25% at the pressure of 0.6–0.9 Torr. The effluent was mixed with molecular iodine in a far afterglow region and it was tested in an oxygen–iodine laser. The iodine flow rate was 0.3 mmol/min. A strong enhancement of atomic iodine spontaneous emission at the wavelength of 1315 nm was observed in the optical resonator.

On‐line studies of plasma surface interactions between a radio frequency plasma jet and 3 w/o boron doped graphite samples

The aim of this study was to provide insights into the mechanisms governing the plasma–surface interactions (PSIs) between a doped graphite with 3 w/o boron and an oxidizing plasma jet (Ar/O2 and Ar/H2O) or a reducing (Ar/H2) plasma jet. The PSI was studied on line by optical emission spectroscopy and quadrupole mass spectrometry. A mechanism for the PSI is proposed and related to the PSI at TEXTOR (the fusion reactor at Jülich FZ).

Abnormal High Rate Deposition of TiN films by the Radio Frequency Plasma Jet System

Radio frequency Ar and plasma jets generated in a hollow electrode terminated by a small size Ti nozzle were used for deposition of Ti and films. The regime with low content of reactive gas resulted in an extreme enhancement of deposition rate, more than one order higher than that of Ti. Abrupt increase of the nozzle temperature to >1350°C in this regime is caused by additional thermal energy imparted to the nozzle. Abrupt decrease of the cathode dc self‐bias and simultaneous steep increase of the optical emission from Ti and from ions Ti+, , and Ar+ indicate the transition of the discharge into the RPJ‐arc. This reflects in an enhanced production of Ti and Ti+ which leads to a high rate (≈μm/min) growth of films. The microhardness of films at low nitrogen content is and the film resistivity is 80 μΩ cm. Geometry of the particle transport and the distribution of the, film thickness on substrates confirm a hollow profile of the particle density distribution in the plasma jet.

Deposition of Carbonaceous Films onto Internal Walls of Tubes

Deposition of carbonaceous films onto inner walls of small diameter tubes has been studied. A small size radio frequency plasma jet system with nozzles made from tungsten or graphite has been installed coaxially inside the tube. Changes in gas compositions affected strongly the coating conditions on inner walls of the tube. The growth rate distributions of the microcrystalline primarily sp3 bonded film along the substrate area indicate an important role of the afterglow and peripheral regions of the plasma jet. Films were deposited onto Si, Mo, W, Cu, and Fe surfaces. At particular conditions incorporation of the substrate material into the growing films was observed. Contamination of films from the W nozzle was detectable only when oxygen was admixed in the working gas.

Radio frequency plasma jet applied to coating of internal walls of narrow tubes

A novel method for deposition of thin films onto internal walls of narrow tubes is described. The method is based on sputtering and/or evaporation of the end of a nozzle in a radio frequency plasma jet system (RPJ). A Ti nozzle of 5 mm outer and 2 mm inner diameter, respectively, was used for TiNx film deposition onto Si substrate inserts fixed on the internal wall of a steel tube of 8 mm bore. The axial distribution of the film thickness along 20–50 mm of deposited area was measured. An effect of separation of macroparticles was found in the RPJ. This enabled the growth of high quality films on the tube walls at rf power levels exceeding 100 W.

Use of a radio frequency plasma jet in chemical synthesis

Use of a radio frequency plasma jet in chemical synthesis