Ceramic vacuum tight bushings are generaly employed for the transmission of electric signals into vacuum sealed cavities.
They are applied in various instuments and devices for example in following fields:
Vacuum Technics and Electronics
vacuum pumps, power tubes, vacuum gauges
Electron Optics
mass spectrograf, electron microscope
X-ray and Nuclear Technics
X-ray convertors, spectrum analysers, epitax molecular beam sources, hydrogen ion sources, neutron beam sources, vacuum welding cameras
Measurement Technics
thermocell probes, Langmuir diodes, plasma diagnostics
The bushings are composed of low-loss corundum ceramics, metal flanges and pins. The ceramic is connected to a flange made exclusively of special metal alloys, whose thickness is 0,3 to 0,5 mm as a rule. The pins of different size or shape can be also made of thermocell materials.
The bushing is vacuum tight at inner pressure down to 10-8 - 10-9 Pa and temperature up to 600 °C (or 900 °C when copper brazed).