#quadrupole

Great Moments in Science History

There are many great moments in science history that a good science teacher would know about, like Galileo’s discovery of his Law of Falling Bodies, or Faraday’s discovery of Electromagnetic Induction.

But it’s another thing to be alive when something truly phenomenal is discovered.

I can think of three great moments that have…

principle of operation of nuclear quadrupole resonance

A number of core elements in the periodic table (N, Na, Cl, etc.) are instituted and absorb energy when exposed to external radiofrequency fields strictly determined frequency. When it reaches the equilibrium they emit stored energy in the same frequency. This phenomenon is called nuclear quadrupole resonance (NQR). NQR phenomenon unrelated to nuclear physics and not associated with ionizing and…

A quadrupole or quadrapole is one of a sequence of configurations of—for example—electric charge or current, or gravitational mass that can exist in ideal form, but it is usually just part of a multipole expansion of a more complex structure reflecting various orders of complexity.

Magnetic quadrupole

Coils producing a quadrupole field.

Schematic quadrupole magnet ("four-pole").

See also: Quadrupole magnet

All known magnetic sources give dipole fields. However, to make a magnetic quadrupole it is possible to place four identical bar magnets perpendicular to each other such that the north pole of one is next to the south of the other. Such a configuration cancels the dipole moment and gives a quadrupole moment, and its field will decrease at large distances faster than that of a dipole.

An example of a magnetic quadrupole, involving permanent magnets, is depicted on the right. Electromagnets of similar conceptual design (called quadrupole magnets) are commonly used to focus beams of charged particles in particle accelerators and beam transport lines, a method known as strong focusing. The quadrupole-dipole intersect can be found by multiplying the spin of the unpaired nucleon by its parent atom. There are four steel pole tips, two opposing magnetic north poles and two opposing magnetic south poles. The steel is magnetized by a large electric current that flows in the coils of tubing wrapped around the poles.

Changing magnetic quadrupole moments produces electromagnetic radiation.

Gravitational quadrupole