foam - fuel
- foam polystyrene
- foamed plastics
- foamed rubber
- focal distance
- focal length
- focal spot
- focousing field
- foctor of merit
- focus
- focus rays
- focused beam laser
- focused ion beam lithography
- focusing
- focusing anode
- focusing by accelerating field
- focusing coil
- focusing electrode
- focusing field
- focusing magnet
- focusing system
- focusing unit
- fog
- fog type insulator
- folded dipole
- follow current
- follow up control
- follow up control system
- follow up system
- foot push
- footing
- footwarmer
- forbidden band
- forbidden bandwidth
- forbidden gap
- forbidden increment
- forbidden line
- forbidden transition
- force
- forced air cooling
- forced betatron oscillation
