METHOD OF SOLID VOLUMERIC IMPULSE PLASMA GENERATION Russian patent published in 2017 - IPC H05H1/24 H01J37/77 

FIELD: electricity.

SUBSTANCE: method of solid volumetric impulse plasma generation is based on the discharge excitation with the self-inductive hollow cathode in the gas-discharge system of the electron source with the plasma emitter and the formation of the wide electron beam, that ionizes and excites the gas in the volume. The discharge with the self-exciting hollow cathode is ignited in the impulse-periodic mode. The combination of the mode parameters (amplitude, duration and impulses repetition frequency) is selected in such a way, that the emitting surface temperature increment of the hollow cathode during the impulse time (T_max-T_min), provided the required value of the cathode thermal emission impulse current, and the heat removal into the hollow cathode volume and radiation from its outer surface during the break time did not lead to the hollow cathode emitting surface temperature decrease below the minimum level T_min, which provides the minimum starting thermal emission current for the discharge development, when the voltage impulse is applied. The temperature values are determined from the Richardson-Dashman ratio I_max=AT²_maxexp(-eϕ/k_oT_max)S₁ and I_min=AT²_minexp(-eϕ/k_oT_min)S₁, the impulse duration t and the impulse repetition frequency f are determined from the ratios (T_max-T_min)=(2q/λ)(αt/π)^1/2, q=k₁U_II_max/S₁, k₁I_maxU⋅f⋅t~k₂σT⁴_minS₂, where I_max, I_min - the required current amplitude and the minimum starting current of the cathode thermionic emission, S₁, S₂ - the area of the emitting and external surface of the hollow cathode, A is the thermionic constant, T_max, T_min - maximum impulse and minimum starting temperature of the hollow cathode, eϕ - electronic work function from the hollow cathode material, e - electron charge, k_o - the Boltzmann constant, q - the power impulse density, released at the emitting surface of the hollow cathode, λ and α - coefficients of thermal conductivity and thermal diffusivity of the hollow cathode material, respectively, π=3.14; k₁ - the ion current fraction in the general current to the hollow cathode, U - the burning voltage of the impulsed discharge; k₂ - the emissivity coefficient (the blackness degree) of the hollow cathode outer surface, σ - the Stefan-Boltzmann constant. For the coatings deposition in the electron beam plasma, the spraying system, forming the stream of atoms in the direction of the processed articles can be used together with the electron source, as well as the plasma-chemical reactions, involving the components of gas mixture, activated by the low-energy electron beam.

EFFECT: increase of the excitation and gas ionization efficiency and providing the possibility to change the structural-phase state and functional characteristics of the products.

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