| 释义 |
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.
1922Proc. 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. 1927Proc. 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. 1932Proc. 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]. 1957Sci. 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. 1970G. 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).
1954Rev. Sci. Instruments XXV. 289/2 The introduction of the quadrupoles Q1 and Q2 introduces both vertical and horizontal focusing effects for a given energy. 1961D. 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. 1969IEEE 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. 1976McGraw-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.
1955Rev. Sci. Instruments XXVI. 220/1 A second possibility..is to use a succession of electric or magnetic quadrupole lenses. 1960Ann. 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. 1976McGraw-Hill Yearbk. Sci. & Technol. 387/1 Usually, uniform or quadrupole fields are required over considerable distances along the beam path. 1979Sci. Amer. May 64/3 The ZGS lacks the quadrupole and sextupole magnets that are employed for focusing in many other accelerators.
Hence quadruˈpolar a.
1950Physical 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. 1959G. 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. 1972Science 26 May 903/3 The author directly proceeds to describe the effects due to quadrupolar and hyperfine interactions between electrons and nuclei. |