Abstract: The invention is directed to a high-voltage lead-through arrangement for introducing a high voltage into an enclosure wherein a vacuum is maintained such as for particle-beam apparatus. The arrangement includes: a high-voltage electrode for carrying a high potential; an insulator enclosing the high-voltage electrode and having a surface defining a boundary with the vacuum; and, an outer low-voltage electrode surrounding the insulator for carrying a low potential. The electrodes are spaced from each other by an electrode spacing measured along the surface of the insulator. The high-voltage electrode and the insulator conjointly define a first region wherein the high potential is present to a good approximation; and the first region is bounded by the insulator surface for a first distance of up to approximately 1/10 of the electrode spacing.

Abstract: A cooling chamber has an interspace between the structure defining the work chamber and coolant vessel on the one hand, and the outer insulating vessel on the other hand to provide better thermal insulation. The work chamber is disposed above the coolant vessel and has apertures formed in the base wall thereof so that the vaporized coolant flows directly into the work chamber. The consumption of coolant is minimal and the cooling chamber is of simple configuration is that it can be manufactured economically.

Abstract: The invention contemplates lead-through structure for the high-voltage electrode of an electron microscope or the like, in conjunction with shaping of the high-voltage electrode and of the body of insulating material via which the lead-through is supported, in reference to metal envelope structure. The high-voltage electrode has a step-wise enlargement, and the surface of the insulating material which is exposed to the vacuum commences at the start of the step-wise enlargement. As a result, the field strength along the vacuum-exposed insulator surface is so influenced that a minimum electric field strength is produced at the boundary line between the vacuum and the high-voltage electrode. The further result is to prevent occurrence of microdischarges.