On the prospects of using runaway electron beams generated in an open discharge for the pumping of metal-vapor lasers

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

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Generation of high-current electron beam in a wide-aperture open discharge

Бохан

Zakrevsky

Гугин

2011

Physics of Plasmas

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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 in a mixture of helium with nitrogen and water vapor. In the experiments, a discharge cell with coaxial electrode geometry, permitting radial injection of the electron beam into operating lasing medium, was used, with the cathode having radius 2.5 cm and length 12 cm. It was shown possible to achieve an efficient generation of a high-intensity electron beam (EB pulse power ∼250 MW and EB pulse energy up to 4 J) in the kiloampere range of discharge currents (up to 26 kA at ∼12 kV discharge voltage). The current-voltage characteristics of the discharge proved to be independent of the working-gas pressure. The existence of an unstable dynamic state of EB, conditioned by the presence of an uncompensated space charge accumulated in the discharge cell due to the exponential growth of the current in time during discharge initiation and the hyperbolic growth of current density in the direction towards the tube axis, was revealed. The obtained pulsed electron beam was used to excite the self-terminated laser on He 21P10-21S0 transition. The oscillations developing in the discharge cell at high discharge currents put limit to the pumping energy and emissive power of the laser excited with the radially converging electron beam.

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On the prospects of using runaway electron beams generated in an open discharge for the pumping of metal-vapor lasers

Cited by 14 publications

References 19 publications

Output Limiting Mechanisms and the Prospects for Metal Vapour Lasers with Average Output Power Above 1 kW/m

Output Limiting Mechanisms and the Prospects for Metal Vapour Lasers with Average Output Power Above 1 kW/m

Peculiarities of electron emission from the cathode in an abnormal glow discharge

Generation of high-current electron beam in a wide-aperture open discharge

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