Glass composition and method for producing glass article

摘要

The glass composition of the present invention is an inorganic glass composition in which the volume ratio of helium with a mass number of 3 to helium with a mass number of 4, namely ³He/⁴He in the glass (0° C., 1 atm) is smaller than the volume ratio ³He/⁴He in the atmosphere. The method of producing a glass article of the present invention includes the steps of: melting a glass raw material by heating; homogenizing molten glass; forming the molten glass into a desired shape; and cooling the shaped glass to room temperature, in which helium with a certain mass ratio is dissolved in the glass material so that the glass article of the present invention is obtained.