Influence of self-reflected radiation on plasma characteristics gas-discharge lamp

The paper deals with the influence on the parameters of the discharge in cesium – mercury – xenon vapor-gas mixture returned back to the plasma of the self-radiation of a gas-discharge lamp. The transformation of the radiation spectrum and the formation of a plasma channel upon reaching the quasi-stationary stage have been studied. As a result of studying the self-reversal of the resonance line of cesium, the decisive role of the increase in the vapor pres-sure of the plasma-forming medium on the change in the characteristics of the plasma has been proved.

Innovative Method of Treating Sintered Metal Powders Surfaces with Optical Radiation Pulses, Using Gas-Discharge Lamp

The research conducted in the present paper is part of a comprehensive study to innovate a method of surface treatment for some metallic powder materials with alternative energy sources to lasers and electron beams (i.e. with gas-discharge lamp (GDL)), typically used as sources of optical pumping for the lasers, having a solid active element. The radiant energy sources used for study are composed of a GDL and the high voltage power supply consists of a block of high-capacity capacitors. The materials were selected from the Fe-Cu-C grade, with a carbon content between 0.5 to 0.72%, and the measurements were made on microscopes with electron beam scanning. Configurational modifications of a surface layer of approximatively 30-35 im, characteristic for Fe-C-Cu alloys, containing nearly 0.7% C (pearlite, ferrite and cementite) are highlighted by the microscopic examinations. At the surface level, the energy flux created by the lamp in the visible spectrum, generates pressure, determining elongation of the surface layer pores, under optical action, resulting an effect comparable to plastic deformation by induration or compaction through mechanical actions. The results obtained highlight the potential of this class of materials to surface treatments and the options for the energy sources used.

Distinctions of the Design of UHP Xenon Lamps with Sapphire Envelope

This article describes the major development results of the first Russian sample of a UHP xenon discharge lamp with sapphire envelope. The article proposes a method of monitoring of thermal fields of semi-transparent materials and studies the thermal distribution of quartz and sapphire envelopes of UHP discharge lamps. Mechanical strength of sapphire tubes depending on the temperature is studied, the thickness of the discharge envelope wall is calculated, and distinctions of the design of a UHP xenon lamp with the sapphire envelope are considered.