Quadrupole Magnetic Filed

Purpose

To visualize the magnetic field of a quadrupole magnet.◙
 

Equipment

Two horseshoe magnets with plastic box for iron filings, overhead projector.◙

 

Images

j5-31

Description

Two large horseshoe magnets are arranged with their poles N to S and S to N, forming a "quadrupole." Quadrupole magnets are used in focusing of charged particle beams, where the beam moves through the field perpendicular to the pla ne of the magnets. A single quadrupole focuses in one direction and defocuses in the other direction, so quadrupole magnets are generally used in pairs as beam focusing magnets.
 

References

Richard L. Taylor, Focusing Electron Beams at SLAC, TPT 31, 18-26 (1993).