Effect of vacuum heating on the corrosion resistance of Al-4.5Zn-2Mg

Conclusion Preliminary heat treatment in vacuum of Al-Zn-Mg alloys improves the stress corrosion resistance. One of the probable reasons for this effect is the impoverishment of the surface layer in magnesium and zinc.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 10–13, July, 1978.     

The Concentration Quenching of Photoluminescence and the Quantum Yield in (Y1–xPrx)2O2Se Solid Solutions

Inorganic Materials - (Y1–xPrx)2O2Se solid solutions with х = 0.004, 0.008, 0.010, 0.012, and 0.020 have been prepared from oxides by ampule synthesis. We have measured their excitation...     

Generation of subnanosecond electron beams in air at atmospheric pressure

Optimum conditions for the generation of runaway electron beams with maximum current amplitudes and densities in nanosecond pulsed discharges in air at atmospheric pressure are determined. A supershort avalanche electron beam (SAEB) with a current amplitude of ∼30 A, a current density of ∼20 A/cm², and a pulse full width at half maximum (FWHM) of ∼100 ps has been observed behind the output foil of an air-filled diode. It is shown that the position of the SAEB current maximum relative to the voltage pulse front exhibits a time shift that varies when the small-size collector is moved over the foil surface.     

KrCl and XeCl exciplex glow discharge lamps with an output power of ∼1.5 kW

A high-power multisection cylindrical exciplex lamp pumped by a glow discharge is created. The energy, temporal, and spectral characteristics of the emission from KrCl* (λ～-222 nm) and XeCl* (λ～308 nm) molecules are studied. The average output UV radiation power is 1.6 kW (for 222 nm) and 1.1 kW (for 308 nm) at a power pumping efficiency of up to 14%.     

Electron beam formation in helium at elevated pressures

The formation of a beam of runaway electrons in a diode filled with helium at a pressure from 0.1 to 760 Torr was studied under conditions of a pulsed ≈4 ns) high ≈200 kV) voltage applied to the discharge gap. Both theoretical results and experimental data indicate that the electron beam is generated both at a large strength of the electric field, when the fraction of runaway electrons is large, and in a field of low strength, where intensive electron multiplication takes place. In the latter case, a high current can be obtained despite a small fraction of runaway electrons relative to their total number. The electron beams obtained in the helium-filled diode had a current amplitude of up to 140 A (corresponding to a current density above 10 A/cm²) at an electron energy of ～150 keV.

     

Subnanosecond electron beams formed in a gas-filled diode

We have studied the conditions for the formation of a pulsed beam of runaway electrons in a diode filled with air at atmospheric pressure, whereby the current and voltage pulses in the system were measured with a subnanosecond time resolution. It is experimentally demonstrated for the first time that the electron beam appears on the leading front of the voltage pulse at a relatively small voltage on the discharge gap. At atmospheric pressure, a full width at half maximum of the current pulse does not exceed 0.3 ns.     

Method of measuring the spectral absorptance

To determine the spectral absorptance of a material the authors use a method that modulates the monochromatic radiation incident on the specimen and directly compares the absorbed power with electrical power released in the specimen.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 53, No. 1, pp. 59–64, July, 1987.