SPI Supplies^® Brand UHV View Ports

Introduction:
Many users of UHV systems, which could include MALDI TOF mass spectrometers, XPS, electron microscopes, or other surface analysis systems, frequently make use of viewing ports in order to observe the sample while in the chamber being analyzed (or moved around). For example, watching how the sample is being manipulated is one of the main reasons for the use of viewing ports. It is important however that the customer consider whether what is needed is a view port product with x-ray protection (e.g. with lead glass backing). If the application does not involve x-ray generation, such as in a vacuum evaporator or a sputtering system, one does not need protection from x-rays. But the just cited other examples, all involve the generation of x-rays and therefore any windows installed must have x-ray protection.

Just what is the product?
The product contains the "window" material which could be glass, quartz, sapphire or even ZnSe, either uncoated or coated with one of our standard or non-standard coatings. The choice of window material depends on the part of the electromagnetic spectrum that is of interest to our customer. We have view poarts that could be furnished that are optimized for use in the UV, or others that are designed for use even in the far infra-red. The actual choice then is dependent on the customer's needs and requirements.

The choice of the coating depends on what wavelength one is working with, since it would increase the tranmittance only within a window of the spectrum. Roughly half of our customers are perfectly happy with uncoated view ports. The next step "up" in coating performance is the 1QWOT, or 1 Quarter Wavelength of Thickness, and is based on a MgF2 coating system that is optimized for the visible part of the spectrum. The BBAR (BoardBand AntiReflective) is yet another step "up" both in performance and also cost. And our VAR ("V" shaped AntiReflective) coating is the highest performance and also, the highest in selling price. These are unusually high performance coatings. Pricing available upon request.

Further description of the product:
The window is supplied mounted on a Kovar^® ring that is welded into a standard Conflact CF flange manufactured from stainless steel