Electrostatic Quadrupole Lens, without vacuum housing
We design electrostatic quadrupole lenses for low energy and low power ion beams. They are typically used on injectors and in the accelerator.
NEC has designed and built many electrostatic quadrupole lenses to meet specific optics requirements, including doublet, triplets, and quadruplet lenses. Steering and offset versions are also available.
We have designed many electrostatic quadrupole lenses, but if they do not meet all required specifications, we can provide custom designs. We can work with you to determine the optimal lens design based on your current or proposed setup.
Since a quadrupole singlet acts as a converging lens in one plane and as a diverging lens in the other, the focusing properties of the triplet are specified in terms of these two planes:
Because the lens strength is different in each of these planes, quadrupole lenses are in general astigmatic. However, the excitation of each of the quadrupole singlets can adjust such that stigmatic operation is obtained.
Most of our models operate as a symmetric triplet, though we also offer an offset triplet that allows independent adjustment of the axis of its three elements with respect to the housing axis. This particular design selects charge states in the terminal of tandem accelerators.
Magnetic vs. Electrostatic Quadrupole Lenses
Magnetic Quadrupoles Electrostatic Quadrupoles
- Stronger – Can focus heavier ion beams
- Mass dependent (ME/q2)
- Not as strong: generally used to focus low energy ion beams
- Mass independent (E/q)
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