METHOD FOR MANUFACTURING SYNTHETIC QUARTZ GLASS SOOT BODY, AND METHOD FOR MANUFACTURING TRANSPARENT SYNTHETIC QUARTZ GLASS INGOT

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a synthetic quartz glass soot body having a uniform refraction factor and no inflection point in OH group concentration distribution, without practicing calcination or the like.SOLUTION: A method for manufacturing a synthetic quartz glass soot body by radiating grown flame to a seed rod to deposit glass particles thereon includes an initial stage where the diameter of the synthetic quartz glass soot body is increased by depositing the glass particles on the seed rod, and a steady stage where the diameter of the synthetic quartz glass soot body is not changed even by depositing the glass particles on the seed rod. Temperature difference is 50°C or less in a flame-exposed surface area of the synthetic quartz glass soot body within a radius of 80% from a rotation axis of the synthetic quartz glass soot body in the steady stage. The flame-exposed surface area is a part of a whole flame-exposed surface area exposed to the grown flame radiated from a concentric multiple tube burner.