Abstract: 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.

Abstract: 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° of twist.

Abstract: 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° of twist.

Abstract: 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.

Abstract: The invention relates to an improved O-ring seal for use as a high vacuum seal. A limitation of standard O-rig 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.