re used to create a connection between equipment inside a vacuum chamber and the outside world. They are made from 1 or more conductors that pass through a vacuum flange and are insulated from the flange. The insulating material needs to be able to withstand a pressure of 1 bar from the air-side when the chamber has been evacuated; it is normally glass ceramic.
Allectra has developed a full range of sub-D feedthroughs and high vacuum and UHV connectors, together with their associated cables. The availability of a full range of sub-D cables and connectors has been very well received by the high vacuum industry. The greatly increased convenience of using an industry standard system has been responsible for the great success of this product. The Allectra range is true UHV standard without any glue or adhesives.
Thermocouple feedthroughs have pins made from the corresponding thermocouple pair materials. On the vacuum side the pins terminate with a screw connector. The (+) pole is 25 mm longer than the (-) pole.
Coaxial feedthoughs have a central conductor with an external conducting shield and are normally used to carry signals at high frequencies.
These feedthroughs are often available with an impedance of 50 Ω, for matching to the impedance of coaxial cables to minimise the reflected signal at the cable – feedthrough interface.
They can be supplied with a grounded or floating shield and single or double sided.