SYNTHETIC SILICA GLASS, METHOD FOR PRODUCING THE SAME, AND DEVICE PROVIDED WITH LAMP FOR ELECTRIC-DISCHARGE LAMP OR SYNTHETIC SILICA SOOT FIRING FURNACE CORE TUBE USING THE SYNTHETIC SILICA GLASS

摘要

PROBLEM TO BE SOLVED: To provide a synthetic silica glass having excellent white devitrification resistance and black devitrification resistance and also having high heat resistance, to provide a method for producing the same, and to provide a device provided with a member generated by the synthetic silica glass.;SOLUTION: There is a synthetic silica glass in which OH group concentration is ≤5 ppm, the total of meal impurity concentrations is ≤1 ppm, the amount of oxygen-depleted type defects at 250 nm is 0.01 to 6/cm by an absorption coefficient, an absorption coefficient at 215 mm is lower than an absorption coefficient at 250 nm, and also, viscosity at 1,100°C is 10¹⁴ to 10¹⁶ poise. Particularly, in the synthetic silica glass, the internal transmittance of light with a wavelength of ≤250 nm is controlled to ≤50 %/cm for an arc tube for a lamp. Also there are a method for producing the same and a device provided with a member generated by the synthetic silica glass.;COPYRIGHT: (C)2010,JPO&INPIT