Re-entrant Fused Silica Viewports

Specifications:
Materials
Window : Corning HPFS^® 7890 fused silica
Carrier : St.St.
Flanges : St.St.

Max. Bakeout Temperature* :
CF flanged viewports : 200°C
Max. Thermal Gradient : 25°C per minute

Optical properties
Surface finish UV grade : 40/20 scratch/dig
Surface finish DUV grade: 20/10 scratch/dig
UV transmission @ 250nm (external)  : > 90%
DUV transmission @ 248nm (internal)  : ≥99.8%
Parallelism UV grade : <30 arc minutes
Parallelism DUV grade :  <10 arc seconds
Homogeneity grade UV / DUV : F / A
Inclusion class UV / DUV : 2 / 0
___________________________________________
* – Assembly rating is reduced to that of the lowest rated component.