Power Losses in RF Inductor of Ferrite-Free Closed-Loop Inductively-Coupled Low Pressure Mercury Lamps

2020 ◽  
pp. 89-94 ◽  
Author(s):  
Ekaterina V. Lovlya ◽  
Oleg A. Popov
Keyword(s):  
Closed Loop ◽  
Low Pressure ◽  
Mercury Vapour ◽  
Plasma Power ◽  
Power Losses ◽  
Inductive Discharge ◽  
Inductively Coupled ◽  
Radial Inhomogeneity ◽  
Transformer Model ◽  
Rf Inductor

RF inductor power losses of ferrite-free electrode-less low pressure mercury inductively-coupled discharges excited in closed-loop dielectric tube were studied. The modelling was made within the framework of low pressure inductive discharge transformer model for discharge lamps with tubes of 16, 25 and 38 mm inner diam. filled with the mixture of mercury vapour (7.5×10–3 mm Hg) and argon (0.1, 0.3 and 1.0 mm Hg) at RF frequencies of 1, 7; 3.4 and 5.1 MHz and plasma power of (25–500) W. Discharges were excited with the help of the induction coil of 3, 4 and 6 turns placed along the inner perimeter of the closed-loop tube. It was found that the dependence of coil power losses, Pcoil, on the discharge plasma power, Ppl, had the minimum while Pcoil decreased with RF frequency, tube diameter and coil number of turns. The modelling results were found in good qualitative agreement with the experimental data; quantitative discrepancies are believed to be due skin-effect and RF electric field radial inhomogeneity that were not included in discharge modelling.

ElectrodeLess FerriteFree ClosedLoop InductivelyCoupled Fluorescent Lamp

2018 ◽  
pp. 140-142 ◽  
Author(s):  
Oleg A. Popov ◽  
Pavel V. Starshinov ◽  
Victoriya N. Vasina
Keyword(s):  
Closed Loop ◽  
Copper Wire ◽  
Glass Tube ◽  
Luminous Flux ◽  
Induction Coil ◽  
Mercury Vapour ◽  
Plasma Power ◽  
Fluorescent Lamp ◽  
Power Losses ◽  
Pressure Discharge

Electrode-less ferrite-free inductivelycoupled low pressure discharge was excited in the mixture of mercury vapour (~10–2 Torr) and argon (0.1 Torr) at a frequency of 2.0 MHz and lamp RF powers of (150–202) W with the help of a 6turn induction coil. The discharge lamp of rectangular shape (50 cm in length and 7 cm in height) employed a closed-loop glass tube of 30 mm in diam. Tube walls inner surface was coated with three-color phosphor (Тcc = 3100 K, Ra = 80). The induction coil made from silver-coated copper wire (ρw = 2.2x10–3 Ohm/cm) was disposed on the atmospheric side of tube walls, along closed-loop lamp tube perimeter. As plasma power, Ppl, grew from 127W to 180 W, coil power losses practically were unchanged, Pcoil = (25–22) W. Lamp luminous flux, Фv, grew with plasma power from 10430 lm (Ppl =127 W) to 13500 lm (Ppl =180 W), while plasma efficacy, ηpl = Фv/Ppl, decreased from 82 to 75 lm/W, and lamp efficacy ηV = Фv/(Ppl + Pcoil) decreased from 70 to 67 lm/W.

The Characteristics of a Ferrite-free Closed-loop Inductively-coupled Low-pressure Mercury Discharge Lamp

Vestnik MEI ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 89-96 ◽  
Author(s):  
Oleg A. Popov ◽  
◽  
Pavel V. Starshinov ◽  
Viktoriya N. Vasina ◽  
◽  
...  
Keyword(s):  
Closed Loop ◽  
Low Pressure ◽  
Inductively Coupled ◽  
Discharge Lamp

High Efficiency Ferrite-Free Closed-Loop InductivelyCoupled Low Mercury Pressure Discharge UV Lamps

2020 ◽  
pp. 73-79
Author(s):  
Pavel V. Starshinov ◽  
Oleg A. Popov ◽  
Rimma A. Ilikeeva ◽  
Darya A. Bureeva ◽  
Igor V. Irkhin ◽  
...  
Keyword(s):  
Power Efficiency ◽  
Closed Loop ◽  
High Efficiency ◽  
Gas Pressure ◽  
Induction Coil ◽  
Mercury Vapour ◽  
Buffer Gas ◽  
Inductively Coupled ◽  
Linear Resistance ◽  
Uv Lamps

Radiation and electrical characteristics of ferrite-free closed-loop inductively-coupled low mercury pressure UV lamps of 375 mm in length and 120 mm in width were experimentally studied. Discharges were excited at a frequency of 1.7 MHz and lamp RF power, Рlamp = (95–170) W. It was in quartz closed-loop tubes of 16.6 mm in inner diam. and of 815 mm in length, in the mixture of mercury vapour (7 х 10–3 mm Hg) with Ar (0.7 and 1.0 mm Hg) and with the mixture of 30 % Ne + 70 % Ar (0,7 and 1,0 mm Hg). The 3-turn induction coil made from litz wire with a low specific linear resistance (ρw = 1.4 x 10–4 Ohm/cm) was disposed on the lamp surface along the closed-loop tube perimeter. In lamps with buffer gas pressure of 1,0 mm Hg, the increase of lamp power from 95 to 150 W caused the decrease of induction coil power losses, Pcoil, from (6–7) W to (3–4) W. Also in these lamps increased induction coil power efficiency, ƞcoil = 1 – Pcoil/Plamp, from 92 % to 97 % and lamp UV radiation (λ = 254 nm) generation efficiency, ƞe, 254, from 57 % to 66 %. The decrease of buffer gas pressure from 1.0 to 0.7 mm Hg caused the decrease of ƞe, 254 by (10–20)%.

Numerical study of the effect of gas flow in low pressure inductively coupled Ar/N2 plasmas

Open Physics ◽  
2012 ◽  
Vol 10 (4) ◽  
Author(s):  
Lizhu Tong
Keyword(s):  
Gas Flow ◽  
Numerical Study ◽  
Low Pressure ◽  
Input Power ◽  
Gas Flows ◽  
Gas Temperature ◽  
Plasma Discharges ◽  
Power Losses ◽  
Inductively Coupled ◽  
Plasma Species

AbstractThe effect of gas flow in low pressure inductively coupled Ar/N2 plasmas operating at the rf frequency of 13.56 MHz and the total gas pressure of 20 mTorr is studied at the gas flows of 5–700 sccm by coupling the plasma simulation with the calculation of flow dynamics. The gas temperature is 300 K and input power is 300 W. The Ar fractions are varied from 0% to 95%. The species taken into account include electrons, Ar atoms and their excited levels, N2 molecules and their seven different excited levels, N atoms, and Ar+, N+, N2 +, N4 + ions. 51 chemical reactions are considered. It is found that the electron densities increase and electron temperatures decrease with a rise in gas flow rate for the different Ar fractions. The densities of all the plasma species for the different Ar fractions and gas flow rates are obtained. The collisional power losses in plasma discharges are presented and the effect of gas flow is investigated.

Electrical Characteristics of the High-frequency Induction Coil for Low Pressure Discharge in Ferrite-free Closed-loop Tubes

Vestnik MEI ◽  
2021 ◽  
pp. 95-104
Author(s):  
Ekaterina V. Lovlya ◽  
◽  
Oleg A. Popov ◽  
Ilya A. Oshurkov ◽  
◽  
...  
Keyword(s):  
High Frequency ◽  
Closed Loop ◽  
Tube Diameter ◽  
Induction Coil ◽  
Spatial Inhomogeneity ◽  
Design Parameters ◽  
Mercury Vapour ◽  
Driving Frequency ◽  
Plasma Power ◽  
Field Frequency

The effect the high-frequency field frequency and lamp design parameters have on the performance characteristics of the inductor of a ferrite-free inductively-coupled closed-loop tube is studied within the framework of a transformer model. The discharge was excided in tubes with diameters equal to 16, 25 and 38 mm in a mixture of mercury vapour (~ 0.01 mm Hg) and argon (0.6 mm Hg) at driving frequencies equal to 1.7, 3.4 and 8.5 MHz and plasma power equal to 25–200 W by means of an induction coil containing 1, 2 and 3 turns, and placed over the closed-loop tube inner perimeter. It has been found that the dependences of inductor high-frequency current and voltage, and power loss in the coil wire on the discharge plasma power have a minimum, which shifts toward lower power levels with increasing the driving frequency and discharge tube diameter. The minimal values of coil current, voltage, and power losses decrease with increasing the driving frequency, tube diameter and number of coil turns. The prediction results are in satisfactory qualitative agreement with the experimental data; the mismatches are supposedly due to the assumptions adopted in the model, according to which the skin effect and electric field spatial inhomogeneity were not taken into account.

Global model and diagnostic of a low-pressure SF6/Ar inductively coupled plasma

2009 ◽  
Vol 18 (2) ◽  
pp. 025001 ◽  
Author(s):  
L Lallement ◽  
A Rhallabi ◽  
C Cardinaud ◽  
M C Peignon-Fernandez ◽  
L L Alves
Keyword(s):  
Inductively Coupled Plasma ◽  
Low Pressure ◽  
Global Model ◽  
Inductively Coupled
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