A multilayer antireflection coating based on titanium oxide and silicon oxide has been developed. The dispersions of the refractive index and absorption coefficient of these materials are obtained in a wide spectral region of 500-8000 nm. Taking into account these dispersions, a calculation was made of a four-layer interference coating with ZGP substrate antireflection in the range of 2097 nm and 3500-5000 nm, with residual reflection R≤0.2% and R≤2.1%, respectively. The modes of coating deposition by the method of ion-beam sputtering on the substrate are selected.
Using an electrode with a ceramic coating, a new method for the formation of an apokampic discharge in the pressure range of 30-150 Torr has been obtained. It was found that the average plasma bullets velocity propagated from such an electrode can reach 520 km/s. The results obtained are in good agreement with the simulation results obtained earlier in the framework of the streamer model.
Using emission spectra, the electronic, vibrational, rotational, gas temperatures and the reduced electric field strength at different distances along the propagation of the apokamp from the discharge channel at an air pressure of 150 Torr, a voltage of 7.6 kV, and a frequency of 37.5 kHz were determined. To determine the above values of plasma parameters, the methods of optical emission spectroscopy were used, after which the experimentally obtained values were compared with the values obtained in the course of modeling the emission spectra of the discharge plasma using a code based on the radiation-collisional plasma model. It is shown that the values of the electron temperature and reduced field strength increase abruptly at a height of ~ 12 mm above the discharge channel, marking the transition from the offshoot zone to the positive streamer zone. The gas temperature along the distribution of the apokamp decreases exponentially and at a distance of 75 mm reaches about 530° C (which is about 3 times less than at the base of the apokamp). The data obtained are in agreement with the streamer model of the plasma plume of the apokamp and allow us to hope for the creation of a plasma source based on an apokampic discharge with a moderate gas temperature at the end of the plasma plume.
The paper demonstrates the possibility of studying blue jets in laboratory apokamp discharges as a source of blue streamers that move upward from the discharge channel. Research data are presented on the formation of such streamers in low-pressure air at a voltage of tens of kilovolts, showing for the first time that they do arise at low (∼8 Hz) pulse repetition frequencies under pressures at which gigantic blue jets develop 10–20 km above the Earth. At a voltage of positive polarity with an amplitude of 33 kV, the streamer velocity in a pulsed apokamp discharge reaches 560 km/s. When applying microsecond voltage pulses of amplitude 15 kV with a repetition frequency of 50 kHz, the length of streamers ranges to more than 120 cm.
The energy dissipation processes in dielectric barrier discharge KrCl- and XeCl-excilamps at various voltage, frequencies and pulse duration are revealed by a pressure jump method. It is offered and tested a way of radiation power calculation in conditions of non-uniform filling of device bulb by discharge plasma. The previous data (Pikulev A.A., Sosnin E.A., 2010-2013) are confirmed. The regularity was formulated: conditions of maximal ultraviolet radiation power corresponds to conditions of maximal heat release in plasma.
The paper proposes a new atmospheric pressure plasma jet (APPJ) source for operation in air and nitrogen. The conditions for the formation of stable plasma jets 4 cm long are determined. Energy and spectral measurement data are presented.
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