quadrupole, n. and a. Physics.
(ˈkwɒdruːpəʊl)
Also quadri-.
[ad. Du. quadrupool: see quadru-, quadri-, and pole n.2]
A. n. a. A multipole of order l = 2 (cf. multipole n.). Usu. attrib.
| 1922 Proc. Sect. Sci. K. Akad. Wetensch. Amsterdam XXIII. 939 Assuming the molecules to act on each other as electric quadrupoles with constant quadrupole moment..Burgers has calculated the quadrupole moment of the hydrogen molecule. 1927 Proc. Cambr. Philos. Soc. XXIII. 930 A method of calculating the probability of switches due to radiation by the quadripole moment seems to be supplied by Dirac's recent theory of the interaction between matter and radiation. 1932 Proc. R. Soc. A. CXXXVIII. 666 Assuming for the field of the nucleus the field of a quadripole, instead of that of a dipole. 1957 [see dipole 1]. 1957 Sci. News XLIII. 87 There is an electrical property of nuclei..called the quadrupole moment, which is a measure of the departure of the nucleus from a spherical to an ellipoidal shape. 1970 G. K. Woodgate Elem. Atomic Struct. iii. 50 Pure quadrupole radiation arises when two parts of the charge distribution are oscillating like dipoles out of phase so that the dipole contribution vanishes. |
b. An arrangement of four magnetic (or electric) poles, of alternate polarity, pointing at the same volume of space (used to focus beams of sub-atomic particles).
| 1954 Rev. Sci. Instruments XXV. 289/2 The introduction of the quadrupoles Q1 and Q2 introduces both vertical and horizontal focusing effects for a given energy. 1961 D. Luckey in D. M. Ritson Techniques High Energy Physics ix. 429 A single quadrupole can be used to obtain vertical focusing in a broad-range uniform-field spectrometer. 1969 IEEE Trans. Nucl. Sci. XVI. 728/2 Work on the dipole magnetic circuits as well as on cryogenic temperature iron core quadrupoles and sextupoles has continued. 1976 McGraw-Hill Yearbk. Sci. & Technol. 387/2 Even when dipoles or quadrupoles are to be operated at flux densities considerably above 2 T,..addition of iron shields around the windings has important advantages. |
B. adj. Having or pertaining to two pairs of magnetic (or electric) poles.
| 1955 Rev. Sci. Instruments XXVI. 220/1 A second possibility..is to use a succession of electric or magnetic quadrupole lenses. 1960 Ann. Rev. Nucl. Sci. X. 163 A single quadrupole magnet has a focusing action for motion in one plane (either horizontal or vertical) and a defocusing action in the other plane. However, two or more quadrupole magnets may be used to give a net focusing action in both planes. 1976 McGraw-Hill Yearbk. Sci. & Technol. 387/1 Usually, uniform or quadrupole fields are required over considerable distances along the beam path. 1979 Sci. Amer. May 64/3 The ZGS lacks the quadrupole and sextupole magnets that are employed for focusing in many other accelerators. |
Hence quadruˈpolar a.
| 1950 Physical Rev. LXXIX. 698/1 A situation in which any quadrupolar splitting of the nuclear resonance in a magnetic field is small compared to the magnetic resonance frequency itself. 1959 G. Troup Masers ii. 28 This statement can be generalized, because the dipole moment may be electric or magnetic; or the moment may be of higher order, quadrupolar, for example. 1972 Science 26 May 903/3 The author directly proceeds to describe the effects due to quadrupolar and hyperfine interactions between electrons and nuclei. |