| 释义 |
undulator|ˈʌndjʊleɪtə(r)|
[f. undulate v. + -or.]
1. Telegr. A device for recording Morse signals in which a line is traced on a roll of paper by a pen that is deflected sideways during the transmission of a dot or dash.
1910Post Office Electr. Engineers' Jrnl. II. 312 The undulator is an instrument of considerable sensitiveness working with a current of ·5 milliampères, and is capable of recording 200, or slightly more, words per minute. 1921Wireless World IX. 479/2, I have in addition two picture slides which illustrate the undulator of Messrs. Creed & Co. 1959K. Henney Radio Engin. Handbk. (ed. 5) xxiv. 35 Reception..is effected by recording the incoming Morse signal on an ink recorder, or undulator.
2. Physics. A device in which a beam of particles is made to describe a sinusoidal path (and so emit radiation) by a series of transverse electric or magnetic fields of alternating polarity.
Orig. introduced as a means of generating microwaves of millimetre and submillimetre wavelength.
1951H. Motz in Jrnl. Appl. Physics XXII. 529/2 We want to calculate the energy radiated by an electron riding through a succession of electric or magnetic fields of alternating polarity. We shall call the arrangement an undulator. 1963A. F. Harvey Microwave Engin. xii. 559 The electrons can be given a transverse motion by passage through an undulator. 1981McGraw-Hill Yearbk. Sci. & Technol. 406/1 Multiperiod wigglers or undulators have also been used recently to make quasi⁓monochromatic photon beams. |