Drawing of a schematic Paul Trap (some kind of ion-cage) for the storage of charged particles by the use of an oscillating electric field (blue), generated by a quadrupole (a:end caps) and (b:ring electrode). A particle, indicated in red (here positive) is stored in between caps of the same polarity. The particle is trapped inside a vacuum chamber. The particle is surrounded by a cloud of similarly charged particles in red. For detailed description see at <a href="https://en.wikipedia.org/wiki/Quadrupole_ion_trap" class="extiw" title="en:Quadrupole ion trap">en:Quadrupole ion trap</a>
Arian Kriesch <a href="//commons.wikimedia.org/wiki/User:Akriesch" title="User:Akriesch">Akriesch</a> 15:58, 14 April 2006 (UTC) (also <a href="https://de.wikipedia.org/wiki/Benutzer:Akriesch" class="extiw" title="de:Benutzer:Akriesch">de:Benutzer:Akriesch</a>)
CC BY 2.5
<span class="int-own-work" lang="en">Own work</span>