HIGH-PRESSURE DISCHARGE TUBE Russian patent published in 1997 - IPC

FIELD: electric engineering, in particular, manufacturing of sodium gas-discharge tubes. SUBSTANCE: device has discharge bulb with electrodes in external envelope. Bulb is filled with noble gas and alkali metal or with amalgam of alkali metal. In addition discharge bulb has metal which covers inner ends of discharge tube and heats them. Vapor pressure and melting point of cover conform to condition P₁≅1,33×10³ Pa; P₂≥1,33×10^-2 Pa; T_melt>T_b.r, where P₁ is pressure of metal vapors under operating temperature in behind-electrode regions of discharge bulb; P₂ is pressure of metal vapors under operating temperature in central regions of discharge bulb; T_melt is melting point of metal; T_b.r is operating temperature in behind-electrode regions of discharge bulb. Amount of used metal is in range of 1.5-40.0 mg per cubic centimeter in inner surface of behind-electrode regions of discharge bulb. Metal is located on electrode unit and is added as alloy. EFFECT: increased functional capabilities. 4 cl, 2 dwg