L. V. Deputatova

Coulomb stable structures of charged dust particles in a dynamical trap at atmospheric pressure in air

A mathematical simulation of a dust particles behavior in the electrodynamic linear quadrupole trap with closing end electrodes allowed us to reveal several features of the phenomena. Regions of stable confinement of a single particle, in dependence of frequency and charge-to-mass ratio, were determined. With an increase of the mediums dynamical viscosity, the region for confining charged particles by the trap becomes wider. We obtained values of the maximum quantities of charged particles confined by the trap at atmospheric pressure in air. Firstly, we presented observations of ordered Coulomb structures of charged dust particles obtained in the quadrupole trap in air at atmospheric pressure. The structures consisted of positively charged oxide aluminum particles 10?15??m in size and hollow glass microspheres 30?50??m in diameter. The ordered structure could contain particles of different sizes and charges. The trap could confine a limited number of charged particles. The ordered structures of charged micro-particles obtained in the experiments can be used to study Coulomb systems without neutralizing the plasma background and action of ion and electron flows, which are always present in non-homogeneous plasma.

Confinement of the charged microparticles by alternating electric fields in a gas flow

This paper presents the simulation and experimental results of charged microparticles dynamics in electrodynamic traps in a gas flow at atmospheric pressure. For the first time the capture and confinement of charged microparticles in a linear Paul trap has been experimentally confirmed at atmospheric pressure in gas flows. The regions of the microparticle, linear Paul trap and gas flow parameters needed for microparticle confinement have been obtained and experimentally tested.

Capture and retention of charged dust particles in electrodynamic traps

The conditions of capture and retention of charged dust particles in linear Paul traps in air at atmospheric pressure in a wide range of parameters characterizing both dynamic traps and confined particles have been found by means of Brownian dynamics. It is shown that the viscosity of a gaseous medium strongly affects capture and retention of dust particles. The simulation results are in agreement with the experimental data on the creation and retention of a stable Coulomb cluster of charged dust particles in a quadrupole trap.

Multipole electrodynamic ion trap geometries for microparticle confinement under standard ambient temperature and pressure conditions

Trapping of microparticles and aerosols is of great interest for physics and chemistry. We report microparticle trapping in multipole linear Paul trap geometries, operating under Standard Ambient Temperature and Pressure (SATP) conditions. An 8-electrode and a 12-electrode linear trap geometries have been designed and tested with an aim to achieve trapping for larger number of particles and to study microparticle dynamical stability in electrodynamic fields. We report emergence of planar and volume ordered structures of the microparticles, depending on the a.c. trapping frequency and particle specific charge ratio. The electric potential within the trap was mapped using the electrolytic tank method. Particle dynamics was simulated using a stochastic Langevin equation. We emphasize extended regions of stable trapping with respect to quadrupole traps, as well as good agreement between experiment and numerical simulations.

Measurement of the charge of a single dust particle

In this work the method of a single particle charge and mass measurement in electrodynamic Paul trap is proposed. In the experiments polydisperse Al2O3 particles were used. The measured masses were in the range from 1 × 10-8 to 9 × 10-8 g. The measured charges were in the range from 2 × 105 to 1.3 × 106 e.

Charging of Macroparticles in a Corona Discharge in an Air Flow

The charging of Al2O3 macroparticles with dimensions ranging from 20 to 40 μm in a gas flow passing through a multielectrode corona discharge is investigated. The corona discharge is produced by a system of wire electrodes arranged across the gas flow. The particle charge and mass are measured using a linear electrodynamic trap. For a corona voltage of 18 kV, the average charge-to-mass ratio is found to be 1.69 × 1013e/g for particles charged in the positive corona and 1.35 × 1013e/g for particles charged in the negative corona.

Charged particle capturing in air flow by linear Paul trap

The paper presents the simulation results of micro- and nanoparticle capturing in an air flows by linear Paul traps in assumption that particles gain their charges in corona discharge, its electric field strength is restricted by Paschen equation and spherical shape of particles.

Compression and stretching of Coulomb structures in a linear electrodynamic trap by an electric field

A method of the controlled effect by the electric fields on Coulomb structures in the linear electrodynamic trap for the controlled compression and stretching of these structures was proposed. The obtained images of the Coulomb structures at various frequencies of effect by rectangular pulses of the electric field are presented. Such effects can be used to obtain the thermodynamic properties of the Coulomb structures by the statistical method.

Nanoparticle confinement by the linear Paul trap

In this article, the possibility of nanoparticle confinement by electrodynamic Paul trap is shown. The areas of nanoparticle confinement as the dependencies of particle charge density on voltage frequency and geometry of the trap are found. The nanoparticle charge density for its confinement should be of order (1013-1014)e/m2.

Charged particles confinement condition in a microparticle electrodynamic ion trap

Conditions of the charged particles confinement in a vertically oriented microparticle electrodynamic ion trap have been determined experimentally. The experiment included two stages. At the first stage, charge-to-mass ratio of the trapped particle was measured by its position in a non-uniform electric field while at the second stage the ac voltage frequency was varied until the particle fell out of the trap. This frequency was taken as the boundary of particle confinement.