The breakdown voltage (VKB) of a cold cathode glass discharge tube, driven by negative voltage pulses, is greatly increased by charges which the pulses deposit on the inside walls of the tube. It is shown that VKB can be almost halved by neutralizing these negative wall charges with positive pulses of amplitude V+, applied to the tube electrodes. Explanations are given of the dependence of VKB on V+ and the implications for gas discharge display systems are also considered.
This paper describes the method of measuring ion temperature (Ti) electron temperature (Te) and density n of the streaming plasma by inserting plane probes, each Of these faces to appropriate direction. Using this method, furthermore, reasonable values of Ti, Te and n of the plasma made with coaxial plasma e gun are obtained.
The field strength at a cathode is increased by the presence of a moving plasma due to the formation of a cathode sheath in which the ion mobility is reduced by the high neutral density in the cold boundary layer formed around the electrode. If further field intensification due to surface irregularities is included, the field at the cathode reaches and exceeds 3×107 V/cm, the field emission threshold. This field can be achieved at an applied voltage between electrodes of 40 V, which is well below the Paschen minimum. This effect was studied experimentally using the argon plasma generated in electromagnetically driven shock tube for wide ranges of plasma density (109−1016cm−3), degree of ionization, and initial pressure (0.1–10 Torr). The results should form the basis for prediction of the reignition characteristics in the all important period immediately (1–10 μsec) after the cessation of an arc.
A one-dimensional analytical model is presented for the compression of matter (e.g., thermonuclear fusion fuel to densities of more than 103 times the solid density) by an accelerating subsonic heat wave. The heat wave, driven possibly by the absorption of a temporally tailored laser pulse, launches a large number of successive weak shock waves which compress and heat the target quasiadiabatically in order to keep the energy expenditure at a minimum. The net power to drive this heat wave must have a stepwise increase in time approximated by W = 98ρ0c03K2/τ2, where K = Dfρf/D0ρ0 is the fraction of the initial target mass (of density ρ0 and thickness Df) which reaches the final state (of ρf and Df. The adiabaticondition sets the requirement that K should be much smaller than one. The time t is scaled as τ = 1 − t/t8, where t8 = D0/c0 and c0 is the initial sound speed. The sound speed in the compressed matter, from which pressure and density can be obtained using the adiabatic equations of state, will increase approximately as c0(K/τ)1/4. Half of the total driving energy is expended by the time tf[τf = (Df/D0) (ρ0/ρf)1/3], from which time the power has to be held constant at Wf = 98(ρf/ρ0)8/3ρ0c03 until time t8.
Although a contiguous-subfield, grouped address-while-display addressing provides high luminance without motional artifacts, the scheme suffers from low dark room contrast. The contrast is improved by adopting a hybrid write- and erase-addressing. A PDP was driven with 38 contiguous subfields, 39 gray levels with variable gamma (γ) characteristics. The dark room contrast ratio was 6,800:1 and peak luminance in white was 1,020cd/m2.
Abstract Data pulse voltage for the 3‐electrode, surface‐discharge AC‐PDP is reduced to less than 20V by using Address‐while‐Display scheme which is capable of attaining 96% light‐emission duty. Metastable atoms created in each sub‐field play the key role to the voltage reduction.
Abstract— A 5.2‐in.‐diagonal simple‐structured argon‐mercury cold‐cathode flat discharge fluorescent lamp has been developed for LCD backlighting. A pair of insulated electrodes is provided at the top and bottom ends of the inner surface of the front glass plate. Phosphor is deposited on both the front and rear glass plates. A luminance of 30,000 cd/m 2 and a luminous efficacy of 50 lm/W were obtained with a luminance uniformity of 92% without the use of a diffuser sheet. A mechanism for obtaining the high luminous efficacy is described. Luminance can be dimmed down to 4% of the peak value by extending the pulse interval and/or by reducing the pulse amplitude.
