Ion trap
From Wikipedia, the free encyclopedia
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 (quadrupole ion trap).
An ion trap mass spectrometer may incorporate a Penning trap (Fourier transform ion cyclotron resonance), Paul trap or the Kingdon trap.[1] The Orbitrap, introduced in 2005, is based on the Kindgon trap. Other types of mass spectrometers may also use a linear quadrupole ion trap as a selective mass filter.
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.
[edit] See also
[edit] References
- ^ Kingdon KH. "A Method for the Neutralization of Electron Space Charge by Positive Ionization at Very Low Gas Pressures". Physical Review 21: 408 year=1923.
[edit] External links
- VIAS Science Cartoons A cranky view of an ion trap...
|