ppm by volume this can be achieved for example by purging the reactor 10 with a dry and inert gas and using a desiccant such as zeolite to absorb moisture the glass 48 can be used as photomask material for microlithography applications or other applications requiring chlorine free glass in alternate embodiments the silica glass may be doped with small amounts of other elements such as f b al ge sn ti p se er na k ca and s in fig1 a dopant feed 46 is inserted through the wall of the reactor 10 the dopant feed 46 can be used to supply the dopant materials toward or through the center of the plasma 40 at the same time that the injector 14 projects the powder 20 into the plasma 40 examples of dopant materials include but are not limited to fluorinated gases and compounds capable of being converted to an oxide of b al ge sn ti p se er or s examples of fluorinated gases include but are not limited to cf 4 cf 6 chlorofluorocarbons e g cf x cl 4 u2212 x where x ranges from 1 to 3 nf 3 sf 6 sif 4 c 2 f 6 and f 2 in an alternate embodiment a fluorine doped silica.