Differentially Pumped UHV Viewport

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Differentially Pumped UHV Viewport

Client – Berkeley Geochronology

Application requirements:

Laser quality viewport compatible with high temperature exposure, and extreme vacuum requirements of gas extraction-mass spectrometry systems. These systems are used for dating rocks and minerals, and require very fine gas analysis. Systems must be maintained to extremely low vacuum pressures and free from any detectable outgassing.

Critical Issues:

The ideal window material to match the laser transmission requirements is Zinc Sulfide (with AR coating for 8-12 microns). This assembly must be differentially pumped since the system requires 1×10-12 vacuum range.

Design Basis:

MPF is able to seal to Zinc Sulfide and other extended range materials using our proprietary seal technology. The assembly must also include integrated pumping of the housing, which reduces the pressure differential across the primary seal and thus potential in-leaks to the XHV system.

Results:

MPF was able to design and produce a suitable assembly, which performed well on the systems employed at the Geochronology lab. In order to provide practical costs and delivery to this niche user-base, MPF worked with various labs to determine a practical demand and launched a series of Differentially Pumped “Cleartran” viewports intended for such applications.

MPF has since done numerous iterations and custom versions of these now standard assemblies.

“MPF provides the best viewport option for our somewhat unique application. The differentially pumped Cleartran viewport has performed perfectly for us. I have recommended their product to many labs around the world.

MPF have developed products for us that have improved our analytic capability. For example, a large, non-standard sapphire viewport and custom modifications to catalog items to fit our application.

Production time and costs for custom items has always been very reasonable.

Technical support has always been prompt and productive. Several times, a team of MPF engineers has responded to questions and concerns. MPF have also contributed ideas to the design of some of our vacuum equipment.”

Tim Becker
Laboratory Manager
Berkeley Geochronology Center
Berkeley, CA