Measurements are reported of the populations copper atom 2D5/2 levels and frequency characteristics a laser utilizing self-terminating transitions, in tubes diameter 20, 27, 40 mm. It was shown that optimal repetition determined not by relaxation rate metastable level but plasma recombination rate. In pure Cu–Ne mixture took place as result ambipolar diffusion, so lowering from 1316 to 4–5 kHz observed on increasing coaxial 2 4 cm. The addition hydrogen led an increase efficiency three-body...

ABSTRACT The results of experimental studies an “open” discharge (type abnormal glow discharge) at helium pressures up to 756 Torr excited by high‐voltage pulses with amplitude 16 kV, duration 5 ns, rise rate ~5 kV·ns −1 , and repetition equal 100 kHz in the burst operation mode are presented. Under these initiation conditions, remains volumetric 1 atm. Pulse currents 200–250 A input powers 1.1–3.5 MW have been achieved. Studies pulse characteristics demonstrates its difference from...

The results of a study an abnormal glow discharge in helium initiated by direct current, half-cycle sinusoidal voltage, and millisecond pulses cells with cold SiC, Mo, Cu cathodes are presented. It is shown that under spectroscopically pure conditions, for all the experimental conditions studied, current–voltage characteristics change from monotonically increasing to S-shaped pressure operating gas. demonstrated known similarity relations U ∼ j/p2 not fulfilled. assessment accounting changes...

The lasing characteristics of a copper vapour laser are investigated in the regime pulse train excited internal-heating tube with diameter and length . Two power supply schemes compared: conventional scheme storage capacitor discharged through thyratron connected to peaking which is active element kivotron – fast switch based on 'open discharge' turn-on time less than It shown that considered range repetition rates first case we deal typical energy dependence frequency having maximum near In...

In the present study, it was examined generation of nanosecond-duration electron-beam (EB) pulses by a wide-aperture open discharge burning in helium or mixture with nitrogen and water vapor. experiments, cell coaxial electrode geometry, permitting radial injection electron beam into operating lasing medium, used, cathode having radius 2.5 cm length 12 cm. It shown possible to achieve an efficient high-intensity (EB pulse power ∼250 MW EB energy up 4 J) kiloampere range currents (up 26 kA at...

High-voltage open discharge experiments in helium [1, 2] showed a possibility to control the electron avalanche development on subnanosecond timescale. The controlled current growth rate was of 500 A (cmns) for an applied voltage 20 kV and gas pressure 6 Torr. Here, kinetic model breakdown is developed analyze mechanism growth, which takes into account kinetics electrons, ions, fast atoms photons with Doppler shift (DS). Using particle-in-cells simulations, we show critical role DS secondary...

Emissive properties of cold cathodes under the conditions abnormal glow discharges are considered. Unlike earlier made investigations, account is taken alloying surface layer by fast atoms generated in cathode fall region. Atom implantation into to a depth 10 nm changes electron emission gas discharge radically as compared with vacuum conditions. Potential reduced because an increase work function. Kinetic enhanced owing inelastic energy losses material. Also greatly amplified photoemission;...

In the present study, electron-beam generation by open discharges was examined. The study performed at gas pressures up to 20 Torr, and covered all inert gases. At voltages 8 kV, currents 1600 A with current density ∼130 A/cm2 a beam efficiency in excess of 93% were obtained. production electrons from cold cathode concluded be photoemissive nature, enabling high-intensity electron beams any noble or mixture molecular gases irrespective material.

Experimental investigation results for photoemission affected by vacuum ultraviolet radiation of xenon and krypton atoms from a solid in the target surface contact with plasma (gas) are presented. It is demonstrated that, adsorption (or implantation) gas into target, response considerably (to an order magnitude) increases. This caused change mechanism (gas), as compared to vacuum. phenomenon can be characterized term adsorption- (implantation-) induced resonant photoemission. The inclusion...

The investigation results for plasma switching devices of high-voltage pulses with pulse rise times less than 1 ns are presented. approach is based on using conditions suitable bringing a gas discharge chamber in state high conductivity due to generation an electron beam owing photoelectron emission from the device cathode. It shown that co-axial geometry pulses, time 0.45 active load RL = 50 Ω at voltage U 20 kV can be achieved. method doubled impulses such regenerate acceptable electric...

An investigation is made of the elementary processes and characteristics a pulsed nanosecond discharge plasma in copper vapor–buffer gas mixture their correlation with laser energy parameters. It shown that saturation stimulated emission power rising pressure must be associated drop effective electron temperature. The complex dependence on buffer (neon) identified explained. established at high operating pressures pulse repetition frequency governed by cooling rate recombination afterpulse...

Luminescence and superradiance characteristics of 0.5–1.2-μm thick AlxGa1−xN films grown by molecular-beam epitaxy on sapphire substrates were studied under excitation the with low-energy (<20 keV) high-energy (170 electron beams. In both cases, luminescence spectra looked quite similarly; they exhibited a band-edge x-dependent wavelength ranging from 365 nm to 310 broadband emission taking over whole visible spectral region. Superradiance within broad band was obtained pumping...

The mechanism of subnanosecond current front rise observed previously in the experiment high-voltage pulse open discharge helium is studied kinetic particle-in-cell simulations. Boltzmann equations for electrons, ions, and fast atoms are solved self-consistently with Poisson electrical potential. partial contributions to secondary electron emission from atoms, photons, bombarding electrode, calculated. In simulations, as experiment, glows between two symmetrical cathodes anode grid midplane...

An investigation was made of relaxation processes metastable states Ba, Ba+, Ca+, Cu, Eu, Eu+, Mn, Pb, Sn, and Sr+ atoms ions. It found that are deexcited in collisions with electrons, identical ground-state atoms, buffer gas the walls. These were distinguished measurements their constants. established under real conditions lasers utilizing self-terminating transitions, relax within 10−6–10−8 sec cannot be responsible for limiting repetition frequency lasing pulses. electron-beam-pumped Mn...