Mandrel for producing quartz glass and production method for optical fiber mother material, optical fiber and quartz glass body using the same

摘要

A mandrel for producing a large quartz glass body, comprising at least two columnar or cylindrical, carbon fiber-reinforced carbon composite members and joined in series by screw thread parts, wherein preferably the contact surface of the screw thread parts of the mandrel is impregnated and/or coated with carbon, and more preferably a reinforcing member made of a C/C composite is provided on the outer periphery of the screw thread parts.