Atomizing method for producing synthetic quartz glass

A method for producing synthetic quartz glass, said method comprising:

• (A) providing a liquid SiO2 feedstock material, which comprises more than 70% by wt. of octamethylcyclotetrasiloxane (D4) and an additional component hexamethylcyclotrisiloxane (D3) and/or an additional component decamethylcyclopentasiloxane (D5), whereby the sum of the weight fractions of D3 and D5 is in the range between 0.5% by wt. and 3% by wt. of a total weight of the liquid SiO2 feedstock material,
• (B) vaporizing the liquid SiO2 feedstock material into a gaseous SiO2 feedstock vapor,
• (C) converting the gaseous SiO2 feedstock vapor into SiO2 particles,
• (D) depositing the SiO2 particles on a deposition surface so as to form SiO2 soot body with an outer diameter of more than 300 mm, and
• (E) vitrifying the SiO2 soot body so as to form the synthetic quartz glass, wherein said vaporizing of the liquid SiO2 feedstock material comprises:
• heating the SiO2 feedstock material, and
• an injection phase during which said heated SiO2 feedstock material is injected into an expansion chamber in which the heated SiO2 feedstock material is atomized into droplets, the droplets having a mean diameter of less than 5 μm, said heated SiO2 feedstock material being introduced into the expansion chamber so that at least a first part of the heated SiO2 feedstock material vaporizes due to a pressure drop in a range between 1.8 and 5 bar.