An ion trap is a combination of electric or magnetic fields that captures ions in a region of a vacuum system or tube. The two most common types of ion traps are the Penning trap and the Paul trap.

For example, in an electron gun (a device emitting high-speed electrons, such as those in CRTs) an ion trap may be implemented above the cathode (using an extra, positively-charged electrode between the cathode and the extraction electrode) to prevent its degradation by positive ions accelerated backward by the fields intended to pull electrons away from the cathode.

Ion traps were also used in early television receivers, prior to the introduction of aluminized CRT faces in approximately 1958. The ion trap must be delicately adjusted for maximum brightness.

The term ion trap is also used to refer to a Quadrupole ion trap mass spectrometer.

See also

• Quadrupole ion trap
• Penning trap
• Cylindrical ion trap
• Trapped ion quantum computers

External links

• VIAS Science Cartoons A cranky view of an ion trap...