Fei Comapny

Rients Jan De Groot

Casper Maria Smit

Pleun Dona

Stephanus Hubertus Leonardus Van Den Boom

Henricus Fransiscus Maria Van Den Boom

Pieter Hendrik Trudo Johannes Uland

Roland Wilhelmus Pieter Jonkers

Methods and apparatus are disclosed for providing an X-ray shield within an ultra-high vacuum enclosure. A shell is fabricated, leak-tested, filled with an X-ray shielding material, and sealed. An elongated twisted X-ray shield can be deployed within a pump-out channel of an electron microscope or similar equipment. The shield can incorporate lead within a stainless steel shell, with optional low-Z cladding outside the shell. Further variations are disclosed.

Vacuum compatible X-ray shield

An x-ray shield for improved vacuum conductivity is disclosed herein. An example x-ray shield includes at least one elongate member formed from high atomic weight material shaped into a twist with at least 180&#xb0; of twist.

X-ray and particle shield for improved vacuum conductivity

The invention relates to an improved O-ring seal for use as a high vacuum seal. A limitation of standard O-ring seals is the permeation of water through the O-ring. Especially for instruments in which parts are kept at a cryogenic temperature, such as a cryogenic electron microscope, the presence of water in the vacuum is a problem, as this results in ice growth on the cryogenic parts. As a solution often a double O-ring seal is used, or a metal seal. Both of these solutions have severe draw-backs. The invention proposes to place the O-ring in a channel in which dry gas, such as dry nitrogen, is blown. In this way no water can permeate through the O-ring, resulting in a reduced base pressure and highly reduced ice growth.

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Heeze, Netherlands

Rients Jan De Groot