The theoretical formulation given in this article allows the vacuum ultraviolet (VUV) production efficiency to be calculated from the electron temperature of the plasma and the gas parameters including gas mixing ratio, excitation energies, and excitation cross sections using the separately determined conversion efficiency of the plasma input power into the electron heating power. The VUV production efficiencies calculated for (Ne+Xe) mixture (neon (Ne) and xenon (Xe) mixture) discharge gases using the formulation show that the efficiency can be increased by decreasing the electron temperature and by increasing the amount of Xe in the gas mixture. A method for determining the electron temperature of the plasma display panel (PDP) plasma from emission intensity measurements was also given, and was used to show that the electron temperature in the ordinary PDP plasma is 3 eV.
Time-domain spectroscopy of the classical accreting T Tauri star, TW Hya, covering a decade and spanning the far UV to the near-infrared spectral regions can identify the radiation sources, the atmospheric structure produced by accretion, and properties of the stellar wind. On timescales from days to years, substantial changes occur in emission line profiles and line strengths. Our extensive time-domain spectroscopy suggests that the broad near-IR, optical, and far-uv emission lines, centered on the star, originate in a turbulent post-shock region and can undergo scattering by the overlying stellar wind as well as some absorption from infalling material. Stable absorption features appear in Hα, apparently caused by an accreting column silhouetted in the stellar wind. Inflow of material onto the star is revealed by the near-IR He i 10830 Å line, and its free-fall velocity correlates inversely with the strength of the post-shock emission, consistent with a dipole accretion model. However, the predictions of hydrogen line profiles based on accretion stream models are not well-matched by these observations. Evidence of an accelerating warm to hot stellar wind is shown by the near-IR He i line, and emission profiles of C ii, C iii, C iv, N v, and O vi. The outflow of material changes substantially in both speed and opacity in the yearly sampling of the near-IR He i line over a decade. Terminal outflow velocities that range from 200 km s −1 to almost 400 km s −1 in He i appear to be directly related to the amount of post-shock emission, giving evidence for an accretion-driven stellar wind. Calculations of the emission from realistic post-shock regions are needed.
The time lag of address discharges is discussed in terms of its relation with discharge gas composition. We measured the discharge time lag in ACPDPs with Ne‐Xe‐He mixed gases. As the concentration of helium increases, the address discharge time lag becomes shortened because helium atoms reduce mostly the formative time lag of the discharge. The formative time lag depends on the ion drift velocity at the initial stage of discharge formation. This ion drift velocity becomes lager with higher helium atom concentration.
A theory of the surface acoustic soliton in a semiconductor is presented based on the coherentstate representation of the equation of motion for the surface phonons interacting with the conduction electrons. It is shown that the two-dimensional displacement field satisfies the nonlinear integro-differential equation with a damping term. With the aid of the reductive perturbation method, the equation can be reduced to the nonlinear Schrodinger equation with a damping term whose coefficient is the attenuation rate of the surface phonon. The approximate solution is derived to reveal excellent agreement with the numerical result.
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