A new type of electrostatic ion trap for storage of fast ion beams

Abstract

A new technique for trapping of fast (keV) ion beams is presented. The trap, which is electrostatic, works on a principle similar to that of optical resonators. The main advantages of the trap are the possibility to trap fast beams without need of deceleration, the well-defined beam direction, the easy access to the trapped beam by various probes, and the simple requirement in terms of external beam injection. Results of preliminary experiments related to the radiative cooling of molecular ions are also reported.

Internal state thermometry of cold trapped molecular anions

“…In order to distinguish different ionic species the ions enter a multicycle reflectron time-of-flight mass spectrometer. This device consists of two coaxial reflectron mirrors that are placed 460 mm apart, similar to a resonator ion trap 23,24 . While the rear mirror is held on a repulsive potential the front mirror is grounded as the ion packet enters the device.…”

The aerosol impact spectrometer: a versatile platform for studying the velocity dependence of nanoparticle-surface impact phenomena

“…The QD selectively turns particles 90°based on their kinetic energy per charge into the next chamber that contains the NET. The NET is a linear electrostatic trap configured as an image charge mass spectrometer, as first described by Zajfman and co-workers on ion ensembles [31,32] and in a single-particle application by Benner [1]. Briefly, the NET is gated to trap one particle at a time, before measuring the mass-to-charge ratio and the absolute charge of the particle.…”

Synchronization effect in an ion trap resonator

“…Before the ion bunch returns to the entrance mirror, the potentials of its electrodes are rapidly (-100-200 ns) raised, thus confining the ions between the mirrors. At a residual pressure of 3x10'-1 Torr, a typical lifetime of the ions in the trap is -5 s. The trap stability criterion has been demonstrated [2,3,10] to be equivalent to the stability criterion of an optical resonator, namely S f < 00, (1) where L is the effective distance between the mirrors and f is their focal lengths, assuming that the mirrors are symmetric.…”

“…1. The mechanical design of the ion trap and its operation have been described previously [2,3]. Briefly, the ion trap consists of two coaxial electrostatic mirrors each composed of a stack of eigth cylindrical electrodes.…”

“…During the last four years, our group (at the Weizmann Institute of Science) has developed and studied a new type of ion trap [2,3], in which fast (keV) ions are stored between two electrostatic mirrors, much like photons in an optical resonator. This ion trap has been used for the study of metastable negative ions [4,5], metastable states in atomic and molecular ions [6,7], and collision induced dissociation, using a beam extraction scheme [8].…”