electric quadrupole lens

electric quadrupole lens

[i¦lek·trik ′kwä·drə‚pōl ‚lenz]
(electronics)
A device for focusing beams of charged particles which has four electrodes with alternately positive and negative polarity; used in electron microscopes and particle accelerators.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.