Buffer gas

About: Buffer gas is a research topic. Over the lifetime, 3565 publications have been published within this topic receiving 47283 citations.

Production of improved polymeric materials using electrical gas discharges

Abstract: A METHOD OF INCREASING THE SOLVENT RESISTANCE OF THE SURFACE OF A POLYMERIC MATERIAL BY EXPOSING THE SAME TO THE ACTIVE SPECIES FORMED BY AN ELECTRIC DISCHARGE IN A GASEOUS MIXTURE AT A PRESSURE OF AT LEAST 100 MM. OF MERCURY WITH THE GASEOUS MIXTURE MADE UP MAINLY OF AN INERT GAS SUCH AS ARGON AND A MINOR PROPORTION OF ANOTHER GAS SUCH AS OXYGEN WHICH MODIFIES THE ACTIVE SPECIES IN THE DISCHARGE PLASMA.

A study of electrode temperature lowering in Dy-containing ceramic metal halide lamps: I. The effect of mixtures of Dy, Tl and Na compared with pure Dy

Abstract: The reduction in the electrode temperature by the gas phase emitter effect of dysprosium in ceramic metal halide lamps is investigated within special research lamps in dependence on the operating frequency of switched-dc lamp currents. The lamp tubes are made of transparent YAG material. They are filled with a fixed amount of Hg, which produces a buffer gas during lamp operation at a pressure of 2 MPa, with different amounts of DyI3 and in part with different amounts of NaI plus TlI. The Dy atomic ground state density is measured phase resolved both in the middle of the discharge and in front of the upper electrode by broad band absorption spectroscopy. The Dy ion density in front of the electrode is evaluated from line intensities being measured in absolute units by emission spectroscopy. The electrode tip temperature is determined by a 1λ - 2D pyrometric measuring method. It is found that a high Dy ion density in front of the electrode is correlated with a strong reduction in the electrode tip temperature relating to a pure mercury lamp. At low operating frequencies (f ⩽ 100 Hz) the Dy ion density and the temperature reduction is high within the cathodic phase and low within the anodic phase, at higher operating frequencies an increased Dy ion density and a reduction in the electrode tip temperature overlaps onto the anodic phase. The Dy ion density is reduced and with it the tip temperature drop by an addition of Na and Tl vapour to the lamp plasma. The effect of Tl and Na is investigated in more detail in a successive paper.

The column of a dc arc burning in a metal halide atmosphere

Abstract: Starting from energy and mass balance (diffusion equation), temperature distributions and plasma compositions are calculated for metal halide discharges in closed cylindrical vessels with and without mercury (buffer gas). Special interest is given to arcs in tin halide atmospheres. While for pure tin halide discharge radiation can be neglected, the energy transfer by radiation must be considered in discharges containing larger amounts of mercury. The results obtained for electrical data as well as for thermal data of Sn–I arcs are in reasonable agreement with the experiments.

Influence of flowing helium gas on plasma plume formation in atmospheric pressure plasma

Abstract: We have studied atmospheric pressure plasma generated using a quartz tube, helium gas, and a foil electrode by applying RF high voltage. The atmospheric pressure plasma in the form of a bullet is released as a plume into the atmosphere. The helium gas flowing out of quartz tube mixes with air, and the flow channel is composed of the regions of flowing helium gas and air. The plasma plume length is equivalent to the reachable distance of flowing helium gas. Although the amount of helium gas on the flow channel increases by increasing the inner diameter of quartz tube at the same gas flow velocity, the plasma plume length peaks at around 8 m/s of gas flow velocity, which is the result that a flow of helium gas is balanced with the amount of gas. The plasma plume is formed at the boundary region where the flow of helium gas is kept to the wall of the air.