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DEPARTMENT OF PLASMA PHYSICS
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LABORATORY OF EXPERIMENTAL PLASMA PHYSICS
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Dynamics of Experimental Research on Open Magnetic Traps
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See corresponding publications:
Department of Plasma Physics -
Experiment -
Plasma in Open Magnetic Trap -
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1969 -
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Definition of preliminary parameters of the experimental device which was intended for investigation of interaction of
electromagnetic waves with plasma in magnetic field (in particular, in open magnetic trap) started in Department of Plasma
Physics together with sketch designing of main component of the device – solenoid, selection process of ultra-high frequency
(UHF) source and waveguide scheme for plasma formation in electron-cyclotron resonance (ECR) regime, design and
manufacturing of corresponding elements, also selection and manufacturing of necessary diagnostics
(S. Nanobashvili).
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1971 - 1972
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Designing of multifunction solenoid (S. Nanobashvili),manufacturing in mechanical shop of our Institute
(N. Kakhniashvili) and assembly in the laboratory of plasma physics, precise adjustment and tuning (S. Nanobashvili,
T. Odzelashvili) Assembly and tuning of high vacuum system ad UHF waveguide tract (S. Nanobashvili,
G. Rostomashvili,
Sh. Maisuradze).
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1972 -
till now
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Entire complex described above functions under the name – Open Magnetic TrapOMT-1.
Main parameters of OMT-1 device: length – 77cm, inner diameter – 14 cm, stationary controllable magnetic field within
0 - 2000 Oe range. Possibility to create uniform, mirror and multimirror configuration magnetic field. Precision distant feeding of
the solenoid by DC current is performed by means of amlidynes (electromechanical amplifiers). Solenoid cooling is performed by
special water system, which guarantees its unproblematic operation in stationary regime.
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1973,
28th of May
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First plasma was obtained in OMT-1 experimental device. This was ultra-high frequency discharge in
electron-cyclotron resonance regime S. Nanobashvili, G.Rostomashvili, G. Amiranashvili, Sh. Maisuradze).
This Day - can be considered as date of foundation of the Independent Experimental Research Group which functions
up to now.
This Group always performed and continues to perform scintific investigations in the following main fields –investigation of
physical nature (picture) of electromagnetic wave interaction with magnetized plasma in open magnetic traps as well as in
tokamaks; Investigation of plasma turbulence under these experimental conditions conditions and development of methods for its
external control; Also development of plasma ultra-high frequency diagnostic methods, inparticular – interferometry,
reflectometry and radiometry.
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1973 – 1974
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Study of plasma characteristics parameters in uniform magnetic field on the device OMT-1. Definition of possibilities
of plasma formation and conditions of transition of electromagnetic wave absorption by plasma from linear to nonlinear regime
under the condition when magnetic field is higher than cyclotron one. Investigation of low frequency wave excitation in the
plasma accumulated inside the trap under the same conditions.(S. Nanobashvili, G. Rostomashvili)
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1975 -
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First publication about - OMT-1 plasma in journal ЖТФ(Journal of Technical Physics), 45,
445-447, 1975.
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1975 -
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For simultaneous heating of plasma ion and electron component it was proposed (S. Nanobashvili) to study interaction of modulated UHF waves with plasma, when
carrier frequency is of the order of plasma electron component own frequency and
modulation frequency is of the order of ion component own frequency. As experiments later showed, when modulation frequency approaches plasma ion-cyclotron frequency
(ion-cyclotron resonance), modulation frequency amplitude is sharply reduced, i.e. absorption of modulated wave energy by ion component of plasma takes place. In
the future, after detailed study and refinement this method can be considered as one of the possibility for plasma ion and electron component simultaneous heating.
(S. Nanobashvili, G. Rostomashvili).
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1976 -
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G. Gogiashvili, student of Plasma Physics speciality on Physics Faculty of Tbilisi State University, who systematically
participated in experimental investigation of electromagnetic wave interaction with plasma in open manetic trap OMT-1
made presentation about the results of these investigations on International Student Conference in Physics organized at
Lodz University in June 1976. He became one of the laureates of the conference and was avarded Silver Medal.
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1980 – 1982
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Study of the peculiarities of UHF wave absorption by plasma in regime of electron-cyclotron resonance (ECR) and its
harmonics. Definition of relativistic upper limitation for the energy absorbed by electrons in ECR regime by theoretical analysis
of experimental results. (S. Nanobashvili, G. Rostomashvili, G. Gogiashvili)
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1983 - 1985
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Calculation of new solenoid with higher parameters and physical possibilities for open magnetic trap, design of the
solenoid (S. Nanobashvili) and its manufacturing in mechanical shop of our Institute (N. Kakhniashvili). After this assembly
of the solenoid, its precise adjustment and tuning, also assembly, adjustment and launch of high vacuum device. Assembly of
plasma UHF source and waveguide scheme, their precise adjustment, tuning and start of test experiments.
(S. Nanobashvili, G. Rostomashvili, G. Gogiashvili).
On this device entirely new method (S. Nanobashvili) was realized in order to obtain plasma. In particular, independent UHF
plasma source is located on the axis of magnetic trap at some distance from it. This distance can be modified within the 30 ÷ 70 cm
range. Plasma is formed in independent UHF source in electron-cyclotron resonance regime and is injected along the
magnetic field into the open magnetic trap. This is very convenient, because magnetic field in the trap can be modified in wide
range 0 ÷ Hmax in relation with different scientific problems and this has no effect on plasma formation in independent plasma
source. Plasma parameters can be modified independently from magnetic field and its structure inside the trap. This very
important, for example, for the study of such fine (delicate) processes in the magnetic field as transition of electromagnetic wave
absorption by plasma from linear to nonlinear regime etc. (S. Nanobashvili, G. Rostomashvili, G. Gogiashvili).
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1985 -
till now
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Entire complex described above functions under the name – Open Magnetic Trap OMT-2.
Main parameters of OMT-2 device: length – 91 cm, inner diameter – 20 cm, stationary magnetic field can be modified
smoothly within 0 ÷5000 Oe range. Possibility to create uniform, mirror and multimirror (with controllable mirror ratio)
configuration magnetic field. Magnetic field in independent UHF source is generated by means of the coils (length 15 cm)
identical to the coils of the open magnetic trap solenoid. Precision distant feeding of the open magnetic trap solenoid and
independent UHF plasma source by DC current is performed by means of amlidynes (electromechanical amplifiers). Maximum
power of DC current source in 30 kW. Solenoid cooling is performed by special water system, which guarantees its
unproblematic operation in stationary regime.
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January
1985
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First plasma was obtained in open magnetic trap OMT-2 and entire system was tested intensively.
(S. Nanobashvili, G. Rostomashvili, G. Gogiashvili).
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1985 -
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First scientific work about OMT-2 Plasma on International Conference (17th ICPIG, Budapesht, 1985) and
publication in journal ЖТФ (Journal of Technical Physics), 57, 1746-1750, 1987.
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1985 -
till now
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Investigation of physical properties of plasma accumulated in open magnetic trap under wide range of
experimental conditions on OMT-1 and OMT-2 experimental devices. Definition of the ranges for controllable modification of
plasma parameters. Detailed investigation of interaction of UHF electromagnetic waves with plasma accumulated in the open
magnetic trap with different magnetic configurations. Investigation of plasma turbulence and development of methods for its
external control. (S. Nanobashvili, G. Rostomashvili, I. Nanobashvili, G. Gogiashvili, Z. Beria, G. Tavkhelidze, I. Tsevelidze)
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