Quadrupolaire

Quadrupolaire is a term that can refer to several concepts, primarily in physics and chemistry. In electromagnetism, a quadrupole is a distribution of electric charge or magnetic poles. An electric quadrupole consists of four point charges arranged in a specific pattern, such as two positive charges and two negative charges positioned at the corners of a square or along a line. Similarly, a magnetic quadrupole is formed by four magnetic poles. These configurations produce electric or magnetic fields that decrease more rapidly with distance than those of a dipole. Quadrupole moments are used to describe the deviation of a charge or current distribution from spherical symmetry.

In the context of nuclear physics, a nuclear quadrupole moment describes the deviation of the shape of an atomic nucleus from perfect sphericity. A positive quadrupole moment indicates a prolate (cigar-like) shape, while a negative quadrupole moment indicates an oblate (pancake-like) shape. This property is important for understanding nuclear structure and interactions.

The term quadrupolar can also be used as an adjective to describe something having the characteristics of a quadrupole. For example, a quadrupolar electric field is a field generated by a quadrupole charge distribution.