Weld-on (W) Viewport, UV Grade Fused Silica, 1.37 Inch Clear Aperture, 1.5 Inch Diameter, Stainless Steel Flange.
Weld on (W) viewports are used for light transmission in ultra-high vacuum applications. The window is brazed or fused to a thin, bent metal tube. The brazed connection is compatible with ultra-high vacuum and the bent metal tube introduces enough flexibility that the windows do not crack during dissimilar thermal expansion between the window and flange. The brazed connection between window and metal allows these viewports to handle higher bakeout temperatures than viewports that contain O-rings. The outer stainless steel flange must be welded onto the final article for a permanent, non-alterable ultra-high vacuum compatible seal.
Fused silica is a high quality optics material used by default in a wide range of optical applications. It is highly transparent in the ultraviolet (UV), visible, and near infrared (NIR) regions, has high strength and scratch resistance, and resists most chemicals.
Specifications:
- Window Material: Corning HPFS 7980 Fused Silica or Equivalent
- Flange Material: Stainless Steel
- Thermal Range: -100°C to 200°C
- Leak Rate: < 1 x 10-9 atm cc sec-1 of helium
- Common Dimensions:
- A. Weld Flange OD: 1.500"
- B. Clear Aperture: 1.37"
- C. Max OD: 1.81"
- D. Internal Distance to Window: 0.64"
- E. Total Length: 0.85"
- F. Window Thickness: 0.125"
- Optical Specs:
- Transmitted Wavefront Distortion: <10λ at 632nm (peak to valley)
- Parallelism: <30 arcmin
- Surface Finish: 40/20 Scratch-Dig
- Homogeneity Grade: F
- Inclusion Class: 2
