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It is found that the emission intensity of the 2+ band system of the N2 molecule (C3Πu → B3Πg transition) under electron bombardment of pyrolytic aerogel SiO2 in air at atmospheric pressure is 40–70% higher than that in the case of bombardment of aluminum under the same conditions. The dependences of the emission intensity at 337 nm (0-0 vibrational transition in the 2+ band system of the N2 molecule) on the target temperature in the range of 30–60°C are different for the aluminum and SiO2 targets, which indicates different excitation mechanisms of the N2(C3Πu) state. It is suggested that when the SiO2 target is bombarded, the N2(C3Πu) state is excited not only by direct collisions with the electrons of the primary beam and secondary electrons, but also by the energy transfer from SiO2 excitons and conduction electrons to N2 molecules upon their contact with the SiO2 surface.

We study the effect of pressing at a pressure of 1.6 MPa on the photoluminescence (PL) and pulsed cathodoluminescence (PCL) spectra of high-purity fumed silica powder at room temperature and in ambient air. PL is excited by laser radiation at 193 nm, and PCL is excited by electron beam with particle energies of 100–300 keV. Luminescence spectra of fumed silica are changed substantially after pressing. The relative intensity with respect to the luminescence intensity at 300 nm of both PL and PCL in the range 300–450 nm increase after pressing, while the relative intensity of both PL and PCL in the range 260–290 nm decrease. The pressing-sensitive luminescence band in the range 300–450 nm may be related to the defect composed of two facing surface sylilenes. The band in the range 260–290 nm is related to the other surface-related emitting center.

The dynamics and emission characteristics of pulsed breakdown over a ferrite surface at a current amplitude of 270 kA and current rise time of 80 ns were studied experimentally. It is shown that the characteristic transverse size of the discharge region in visible radiation is ~3 mm, while that in vacuum UV (VUV) radiation is ~200 μm. The duration of the VUV pulse with an average power of ≈0.275 GW is about 80 ns.

To study processes in a high-current vacuum diode with a cathode in the form of a single pin made of a metallic wire 20–30 μm in diameter, the method of high-resolution projection X-ray radiography with an X-pinch as a source has been used. A strong inhomogeneity of the energy contribution to the wire has been revealed. The smallest energy release has been observed near the end of the pin, where the electric field strength is maximal. Hard X rays, as well as the ejection of matter from the anode, have been observed, indicating the generation of an electron beam with the parameters characteristic of explosive electron emission in the diode with this configuration. The data obtained indicate complex processes occurring in the diode. Possible scenarios of their development have been considered.

Effects caused by fast laser frequency sweeping across absorption lines are investigated. Oscillations in the time dependence of intensity of radiation generated by the medium, which are caused by beats between oscillations at variable excitation frequency and constant eigenfrequencies, are discovered. The time intervals between local maxima of the oscillations are inversely proportional to the difference between the eigenfrequency of the atomic oscillator and the instant frequency of the external radiation. The method of using fast frequency sweeping for determining indices of absorption at high optical densities (k 0 z ~ 100) is proposed.

The effect of the airflow on the negative corona discharge is studied. It is shown by use of telemicroscopy that the localization of the discharge torch on the cathode surface can be significantly affected by the aerodynamic action on the discharge gap region.

We consider the possibility of using spectroscopy for the diagnostics of optically dense media by recording the time-dependent intensity of transmitted light under the action of a laser field with fast-changing frequency. We compare advantages of this approach with the traditional technique based on the Beer–Bouguer–Lambert law. Reasonably accurate extinction measurements of the order of k(ω 0)l ≈ 102 and greater are realizable with the help of tunable diode lasers.

Presented are the results of experimental research of temperature and velocity fields for lead and lead-bismuth coolant flows in channels having circular and annular cross sections under varying oxygen content in the coolant and varying characteristics of insulating coatings. Tests are performed under the following operating conditions: (1) lead-bismuth eutectic—temperature T = 400−520°C, thermodynamic oxygen activity a = 10−5–100, average flow velocity of the coolant w = 0.12−1.84 m/s, value of magnetic induction B = 0−0.85 T, Reynolds number Re = (0.24–3.5) × 105, Hartmann number Ha = 0−500, and Peclet number Pe = 320−4600; (2) lead coolant-T = 400−550°C, a = 10−5−100, w = 0.1−1.5 m/s, Re = (2.36−2.99) × 105, and Pe = 500−7000.

It is shown that when estimating the positional accuracy of axial drives in automatically controlled machines, the accumulated and periodic components along a single axis can be estimated separately. Analysis of a circular path along two coordinates makes it possible to determine 17 of the most important machine parameters, including the clearances along each axis, lateral clearances, desynchronization of the drive speeds, off-perpendicular deviations of the axes, and off-parallelism along each axis.

The spectra of pulsed cathodoluminescence (PCL) of CsI:Tl, YAG:Ge3+,Tb3+, and LFS-3 crystals excited by high-power (∼10 MW) short-time (∼2 ns) action of an electron beam with an average particle energy of ∼150 keV have been compared to the spectra of steady-state luminescence of the same crystals under the action of γ-photons with an energy of 511 keV emitted from a radioactive 22Na sample. It is established that the two spectra are identical, which allows the PCL method to be used for rapid analysis of scintillation crystals.

For the first time, the regime of a micrometer-size hot spot formation is impemented for an X-pinch in a plasma, which is fed from a current generator based on low-inductance capacitors and rapid current switches. The configurations of X-pinches, which can be used effectively as point sources of soft X-rays with this type of current generator, are determined. A prototype of a small-size radiation source for high-resolution point projection X-ray radiography has been constructed. The main parameters of X-pinch as a radiation source are analyzed and compared with X-pinch parameters in high-voltage setups with shaping lines. An analysis of the data on the operation of X-pinches in generators with different parameters has led to simple relations that can be used to select optimal initial X-pinch parameters.

Experiments on electron-impact vibronic excitation of molecular hydrogen in gas discharge plasmas and by electron beams reveal significant angular-momentum transfer and change in the ortho/para ratio. The observed effects are due to excitation via formation of negative intermediate ions. A model of such processes is proposed that provides a quantitative description of experimental results. The results of chi-square significance tests suggest that the dominant process is H2(X1Σg|) + e(p) → H2−(2Πu) → H2(d3Πu, I1Πg) + e′(l). The relative probabilities of ion decay by autodetachment of s, p, and other electrons are determined.

Results of experimental studies on the local characteristics of heat transfer from a lead heat carrier to the surface of a cooled tube in an annular gap are shown at control and alteration of oxygen admixture content under the conditions of power circuits with heavy liquid-metal heat-transfer agent. This work is aimed at obtaining the grounded formulas for engineering calculations of heat transfer surfaces. Investigations were carried out at the lead temperature of 400–500 °C, the average velocity of heat-transfer agent of 0.1–1.5 m/s, the range of Prandtl number of 0.0123–0.0211 and Peclet numbers of 500–7000. The heat flux changed within 50–160 kW/m2. Controllable changing content of oxygen admixture changed from the value of thermodynamic activity of oxygen from 10−5-100 to saturation and higher with deposition of lead oxides near the heat-transferring surface.