GE Measurement & Control Solutions

Glossary of terms used on this site

F

Filament

Source of electrons in the X-ray tube. A thin tungsten wire (0.1- 0.5 mm) emitting electrons due to thermionic emission when in a vacuum and energized with electric current.

Filter

Thin plates made of materials such as iron, copper and aluminium that filter out lower energy (soft) X-rays, for instance to prevent overexposure.

Fine focus X-ray tube

An X-ray tube with a focal spot* smaller than 0.5 millimeters.

Focal spot

The spot on the target which is struck by the electron beam.