petrozavodsk state university

PETROZAVODSK STATE UNIVERSITYResearch and Educational Center "Plasma"

Research and Educational Center "Plasma"Research and Educational Center "Plasma"

Alexander V. ELETSKY.Supervisor of the Project’s Research Constituent.

Scientific research in Research and Educational Research and Educational

Center "Plasma"Center "Plasma"


Plasma fullerene production from powderedPlasma fullerene production from powdered carbon blackcarbon black

Experimental setup.1 – cathode; 2 – anode; 3, 4, 5, 6 – inlet channels; 7 – power supply; 8 – water-cooled chamber; 9 – movable soot collector; 10 – carbon black feeder; 11,12 – gas flow controllers; 13,14 – pressure gauges; 15 – gas cylinder; 16 – plasma jet

Carbon black powder (99.9% acetylene carbon black, specific surface area of 80 m2/g, “Alfa Aesar”). The inter-electrode gap is kept in the interval 1-3 mm. The plasmatron is powered by 12kW DC power supply. The total buffer gas (usually Ar) flow rate is kept at 18-

20 l/min.

Plasmatron AP-3

(“A-Flame Corporation”)

has been used


Plasma fullerene production from powdered Plasma fullerene production from powdered carbon blackcarbon black

Fullerene yield vs carbon black rate analyzed by HPLC method

An lowering in fullerenes yield at enhanced level (> 200 mg/min) of the CB feeding rate is caused by the breakdown of a stable discharge operation.

Besides, it increases sharply the metal erosion of the anode surface. The fullerene yield and all the operative characteristics of the setup depend

strongly on the way for inserting the CB into plasma.


Plasma fullerene production from powderedPlasma fullerene production from powdered carbon blackcarbon black

Theoretical analysis of mechanism of carbon particle vaporization of in plasma leads to conclusions:

1. Vaporization time depends critically on both parameters: the size of particle Ro and the plasma temperature Tp.

2. Vaporization is impossible if the plasma temperature Tp< Tl. For example, for a carbon particle of radius Ro = 5 m ( = 2.2 g/cm3; W = 30 kJ/g) in hot He (Ar) or mixture of these gases the vaporization time depends on the gas carrier ranging from 10-3 s (in the case of He) to 10-2 s (in the case of Ar).

3.Vaporization rate is inversely proportional to the radius of particle, so that the slowest stage of the vaporization relates to the initial period, when the radius of particle is close to the initial one.


X-ray diffraction investigation of fullerite structureX-ray diffraction investigation of fullerite structure

The powered fullerite C60 polycrystal sample was studied by X-ray diffraction using Cu K radiation

X-ray diffraction picture of simple cubic phase of fullerite C60 obtained using Cu K radiation

Solid line: X-ray diffraction picture for fullerite C60; broken line: result of the full

profile analysis


Investigation of plasma ordered dusty structuresInvestigation of plasma ordered dusty structures

The processes of creation of ordered plasma dust structures in glow discharge were studied, in particular, in dependencies on form, size, condition (phase) of such structures as function from electro kinetic and vacuum conditions in plasma generating medium were

investigated. The special experimental set up was developed controlled by personal computer with corresponding instrument interfaces based on LabView graphical environment, providing the simultaneous control of optical and electrical parameters of the plasma, synchronized with the moment of particles injection or registration of structure image.


Investigation of plasma ordered dusty structuresInvestigation of plasma ordered dusty structures

There have been found new earlier unknown regularities in conditions of mutual influence of plasma medium characteristics on parameters of "plasma crystal" and vice versa.

The dependence of structure image area (S), neon spectral line (I665.2 nm ) intensity and H intensity on discharge burning time in relative units. Total relative change is : for H intensity 14%, for neon line- 34%; S 3.5 times increases; discharge power does not change. Particle injected five times every 2 minutes. “a”-first injection, “b”-25 injections,”c”-50 injections.


Diagnostics of spatially inhomogeneous plasmaDiagnostics of spatially inhomogeneous plasma

Some innovations were introduced into the automated installation for spectroscopic diagnostics of plasma, based on high resolution spectrometer, spatial scanning block and controlled by PC and

LabView graphical environment.

Panel of VI “Data load and

processing”.Hg spectral line

profiles for different spatial

positions


Diagnostics of spatially inhomogeneous plasmaDiagnostics of spatially inhomogeneous plasma

The received experimental data array is processed by rational joint algorithm, which allows to decrease the processing time as well as the noise influence to results.

Restored profile of Tl and Hg spectral lines for different spatial points,which allows to find spatial distribution of atom and electron densities


Gas discharge plasma kinetic researchGas discharge plasma kinetic research

The research is targeting onto:1. Study of plasma discharge conditions favorite for the formation of diamond like films 2. Determination of radial dependencies of low pressure glow discharge

parameters in absence and presence of magnetic field

Setup for studying the electron kinetics in glow discharge

Results:1.Two setups for diamond like film deposition have been

built and tested.

2. Staying striations in Ne discharge have been discovered


Gas discharge plasma kinetic researchGas discharge plasma kinetic research

3. Electron energy distribution function (EEDF) of glow discharge in Ne at the current of 5 - 15 mA and the pressure of 1 Torr has been measured and calculated in the case of presence and absence of a high magnitude magnetic field. It was stated that the applied magnetic

field changes the EEDF from non-local to the local form.

Setup for studying the discharge in crossing fields

4. The experimental setup for investigation of the cathod region of glow discharge has been built. Preliminary measurements of the EEDF and the profile of the potential in glow discharge in Ne at the current of 3 - 20 mA and pressure of 1 Torr have been performed


Investigation of tools for plasma controlInvestigation of tools for plasma control

The aim: Development of problem-oriented generators of low temperature plasmaResults:1. Development of probe diagnostics of multi-component plasma using dynamic probe characteristics (frequency of 110 MHz).

Experimental setup for probe diagnostics

2. The method of plasma retention by magnetic field of specific configuration was developed and tested.

3. The set up for plasma fullerene production was developed


Laser formation of an ion beam for nanotechnologiesLaser formation of an ion beam for nanotechnologies

Our purpose is to improve the resolution of the ion beam lithography. We propose:1)To make the initial beam as atomic, but not ionic one. .2)To collimate the atomic beam through the laser transversal cooling. 3)To ionize the atomic beam formed by the same laser .

Schematic representation of the formation method proposed. An atomic beam from oven is subjected to the preliminary collimation by diaphragm facility. Then the beam is collimated by the transverse laser irradiation and cooling. The highly collimated atomic beam is ionized by the focussed radiation of the samelaser. The ion beam produced,having

almost no chromatic aberration, is focussed by a standard ion optical device.


Emission characteristics Emission characteristics of carbon nanotube-based cathodsof carbon nanotube-based cathods

Current - voltage characteristics for nano-tube cathodes deviate from famous Fowler – Nordheim law.

Good emission properties of CNT-based cathodes are caused by their favorite geometry.

We study the influence of spread in geometry on the

emission characteristics.

Deviation on Fowler – Nordheim Dependence


Plasma production and modification of films Plasma production and modification of films of transition metals oxidesof transition metals oxides

Technologies for generation of nanostructures (carbon nanotubes and amorphous-like films) in controlled conditions were experimental tested.The first experiments gave the first samples of structures, their analysis is carried out and the modification of technological methods of generation of nanostructures are developing; the realization of these technologies is scheduled on the following stages of work.

2 25 4 25 625 82 5

0

20

40

6 0R , %

1

2

,nm

3

4Influence of thermal treatment on absorption coefficient of VO2 film1-without treatment,

2- 70оС, 3 - 200 оС, 4 - 500 оС


Low temperature plasmaLow temperature plasma for ecology and biomedical applicationsfor ecology and biomedical applications

The aim of the project is development of a source of microplasma spherical formation less than 1 mm in diameter. It is reached by

use of a sharpened cathode with a small curvature radius.

Results:

1. Three types of experimental devices have been built; the preliminary test investigations have shown their applicability. 2. Microplasma source of coherent radiation has been manufactured

and tested


Low temperature plasmaLow temperature plasma for ecology and biomedical applicationsfor ecology and biomedical applications

3. A source of a microplasma stream on the basis of the

sharpened anode plasmatron have

been developed and studied


Plasma processing of organic wastes ofPlasma processing of organic wastes of timber industry and treating mineral raw materialstimber industry and treating mineral raw materials

The aim of the project is twofold: development of technology for utilization of timber industry wastes and treatment of mineral raw material resulting in metal production.

The results:1. The specific energy cost for extraction of magnetite concentrate

by wet timber at various mass ratio of concentrate has been determined.

Specific energy cost (by 1 kg iron) for extraction of magnetite concentrate (67%Fe) by wet timber vs mass ratio of concentrate to wood with air presence. The degree of reduction is shown at the relevant points


Plasma processing of organic wastes ofPlasma processing of organic wastes of timber industry and treating mineral raw materialstimber industry and treating mineral raw materials

2. The pilot experimental setup for investigation of reduction of

iron concentrate has been built and tested

The results obtained will be used for designing the

industrial facility with productivity up to

1000 kg iron per hour for introduction at the

Kostomuksha industrial plant.


Research and Educational Center "Plasma"Research and Educational Center "Plasma"

petrozavodsk state university

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