A Penning trap mass spectrometer for the study of cluster ions

Abstract

A Penning trap system has been set up for storing and investigating cluster ions over time ranges from microseconds up to minutes. This enables studies of cluster reactions with extremely low cross sections and the observation of their time dependence in a new regime. The ions are created externally by laser vaporization, cooled by adiabatic expansion of a supersonic beam, and injected into the Penning trap. Detection of reaction products is achieved by combining the advantages of two complementary approaches, viz. the high resolution of Fourier transform mass spectrometry and the high sensitivity of single-ion counting with a time-of-flight mass spectrometer. The performance of the apparatus is illustrated by results of recent cluster experiments. 0 1995 American Institzde oj-Physics.

Fission barriers of doubly charged silver clusters

“…Detailed descriptions of the Penning trap system have been published recently [11][12][13]. The experimental procedure is demonstrated in Fig.…”

Photo fragmentation of metal clusters stored in a penning trap

“…1) and previous experimental results have been published recently [11,22]. Therefore, only a short overview will be given here.…”

“…2b), because less ions are lost by diffusion out of the trap due to collisions with buffer gas atoms [25]. In order to prepare a well defined cluster size all unwanted ions are radially ejected [11] (Fig. 2c).…”

“…In addition, there is no restriction of the storage time and the reaction and observation durations may be extended as desired [9]. Furthermore, all charged reaction products remain stored in the trap, and allow to determine the reaction pathways by standard mass spectrometrical methods, as Fourier transform ICR [10] or time-of-flight measurements [11]. By use of these features, Freiser et al have performed photodissociation experiments on a number of heteronuclear metal dimers [12].…”

Simultaneous monitoring of the radial modes of the ion motion and their manipulation in Penning traps by FT-ICR mass spectrometry

“…The experiments have been performed at ClusterTrap [30,31] which has been constructed and further developed for the investigation of metal clusters [32][33][34]. For the present measurements the highly sensitive time-of-flight analysis, that is usually performed at this setup for single-ion detection, has been replaced by a broad-band FT-ICR detection.…”