Inhaltszusammenfassung

Penning traps confine ions of atoms and molecules as well as other charged particles by a combination of static electric and magnetic fields to the central region of the trap, where these objects can be studied. Most experiments employ pulses of dipolar radio-frequency radiation followed by pulses of quadrupolar radio-frequency radiation to manipulate the motional state of the trapped particles. Instead of a sequential procedure an excitation of the ion motion by the simultaneous applicat...Penning traps confine ions of atoms and molecules as well as other charged particles by a combination of static electric and magnetic fields to the central region of the trap, where these objects can be studied. Most experiments employ pulses of dipolar radio-frequency radiation followed by pulses of quadrupolar radio-frequency radiation to manipulate the motional state of the trapped particles. Instead of a sequential procedure an excitation of the ion motion by the simultaneous application of dipolar and quadrupolar rf-fields is also conceivable. This paper investigates the theory of simultaneous excitation under very general assumptions, with inclusion of possible damping terms. The equations of motion are formulated and their solution is worked out for the most general case. This work is motivated by recent experiments performed by the ISOLTRAP collaboration [1] aiming at the development of a new technique for the isobaric purification of ion samples that does not make use of buffer gas damping. The ISOLTRAP experiments apply instead simultaneous dipole excitation at the magnetron frequency and resonant interconversion of the radial modes at the cyclotron frequency (SIMCO excitation). Such a technique will be of great importance for experiments with highly charged ions because it can be utilized in ultrahigh vacuum and thus avoids unwanted charge exchange effects due to collisions with neutral atoms. This paper presents a detailed theoretical analysis of the new method. © 2012 Elsevier B.V. All rights reserved.» weiterlesen» einklappen

Autoren

Klassifikation

DFG Fachgebiet:
Teilchen, Kerne und Felder

DDC Sachgruppe:
Naturwissenschaften