For a hybrid model of the low-current discharge considering, along with direct ionization of the mixture components by electrons, the Penning ionization of mercury atoms by metastable argon atoms, the ionization coefficient in the argon–mercury mixture used in illuminating lamps is calculated. The analytical approximation formula describing the dependence of the ionization coefficient of the mixture on the reduced electric field strength and temperature is obtained for sufficiently wide ranges of their variations, and its accuracy is estimated. It is demonstrated that the discharge ignition voltage calculated using this formula is in agreement with the results of simulation and the available experimental data.
The behavior of р1–п1–р2–п2-structure with contacts to п1- and п2-regions was studied. It is shown that at such double electrode closing, four-layer structures do not have stationary state in a certain voltage range, i.e. they develop instability accompanied by the generation of relaxation current pulses. A physical model is proposed for the observed instability. Key words: current instabi
A contribution of the electron-phonon scattering to the conductivity of a quantum cylinder in a magnetic field is calculated. It is demonstrated that the nanotube conductivity undergoes the Aharonov–Bohm oscillations with changes of the magnetic flux through the nanotube cross section.
Photoconductivity has been thoroughly studied for a long time. However, most researchers have examined
photoconductivity of semiconductors while illuminating the entire surface of samples. The present paper
examines the effect of local exposure that ensures a high level of injection of free charge carriers upon the
conductivity of high-ohmic cadmium telluride and semi-insulating gallium arsenide samples and upon the
properties of ohmic contacts to samples. The authors found that regardless of the exposure area the value of
transition resistance of ohmic contacts decreases and the concentration of the main charge carriers increases
in the sample in proportion to radiation intensity. This research uncovered a number of previously unknown
effects that are interesting from the physical point of view. This paper focuses on discussing these effects.
A theoretical model of the cathode sheath of a normal glow discharge for the cathode with a thin insulating film is developed. In addition to the ion-electron emission, the field emission of electrons from the metal cathode substrate into the film under the action of the strong electric field generated in the insulator is taken into account in the model. It is established that the influence of the field electron emission on the glow discharge characteristics is determined by the emission efficiency of the film, equal to the fraction of electrons going out of it into the discharge volume. It is demonstrated that the calculated normal cathode voltage drop in the discharge in argon for the cathode with a barium oxide film coincides with its measured value for the emission efficiency of the film of the order of 0.1, which is in agreement with its experimental estimations.
Special features of sputtering of the cathode with a thin dielectric film of variable thickness in a glow discharge are studied. It is shown that the flux density of atoms sputtered from the cathode is maximal on its sections with minimal film thickness due to focusing of ion flux caused by the violation of the electric field uniformity near the cathode surface. As a result, the non-uniformity of the film thickness increases with time, thereby leading to the formation of pores in the film.
A model of the thermo-field electron emission from the metal cathode with a thin insulating surface film at temperatures of 200–400 K is developed. An expression for the film emission efficiency in the gas discharge is obtained. The efficiency is equal to the fraction of electrons emitted into the film from the metal substrate, which enter the discharge volume and increase the effective secondary-electron emission yield of the cathode. It is shown that the thermo-field mechanism of electron emission influences noticeably the ignition voltage of the low-current discharge with such cathode at rather low temperatures exceeding the room temperature by less than 100 K.
А method for automated generating test programs for functional testing of single-core microprocessor memory subsystems is proposed. The proposed method is based on formal specifications of the caching and address translation mechanisms. The method variants have been successfully applied to testing of industrial microprocessors.
The temperature characteristics of magnetostatic waves ((MSW) in monocrystalline ferrite films are investigated. The special attention is given to finding-out of the features connected with influence of a magnetic anisotropy field of ferrite on temperature drift of frequencies of MSW. The way of improvement of the temperature characteristics, based on a choice of optimum crystallographic orientation of a film, is offered.