| 摘要 |
<p>A discharge lamp comprising a discharge enclosure which is made of quartz glass and having an operating pressure higher than the atmospheric pressure is characterized in that the high-temperature viscosity (VA) in the outer surface region of the discharge enclosure is lower than that (VB) at a depth of 100 νm from the outer surface of the discharge enclosure. Thermal strain at and near the outer surface is little produced, and even after long operation the discharge enclosure does not break nor explode.</p> |
