An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A system of three charges +q, -2q, and +q, arranged along a line to form an axial quadrupole. The → electric potential  V due to a linear quadrupole varies as 1/r³, whereas the → electric intensity  E varies as 1/r⁴.

→ linear; → electric; → quadrupole.

A set of either two → electric dipoles or two → magnetic dipoles in close proximity to each other arranged with alternating polarities and acting as a single unit. Quadrupole interactions are much smaller than dipole interactions, but can allow transitions forbidden in dipole moment transitions.

From L. quadru-, variant of quadri- "four" + → pole, on the model of → dipole.

Cahâr, → four, + qotb, → pole + noun/nuance suffix -é.

The → anisotropy which is at the origin of the → cosmic microwave background polarization. The quadrupole anisotropy could arise from three types of perturbations: → scalar perturbation, → vector perturbation, and → tensor perturbation

→ quadrupole; → anisotropy.

A device, consisting of four → electrodes or → magnetic poles arranged in alternating → polarity, that focuses a beam of → charged particles.

→ quadrupole; → lens.

A quantity characterizing an electric charge distribution, determined by the product of the charge density, the second power of the distance from the origin, and a spherical harmonic over the charge distribution.

→ quadrupole; → moment.