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.

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.

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.

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)%.

Inductor and Plasma Characteristics of Ferrite-Free Inductively-сoupled Amalgam Ultraviolet Lamps with Closed-loop Small Diameter Discharge Tubes

Vestnik MEI ◽  
2020 ◽  
Vol 5 (5) ◽  
pp. 98-111
Author(s):  
Oleg A. Popov ◽  
◽  
Pavel V. Starshinov ◽  
Rimma A. Ilikeeva ◽  
Darya A. Bureeva ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Closed Loop ◽  
Unit Length ◽  
Small Diameter ◽  
Mercury Vapor ◽  
Induction Coil ◽  
Buffer Gas ◽  
Plasma Power ◽  
High Efficient ◽  
Radiation Generation

The electrical and radiation characteristics of innovative high-efficient 254-nm wavelength ultraviolet (UV) radiation sources employing ferrite-free inductively-coupled low-pressure discharges excited in closed-loop quartz tubes are experimentally studied. The discharge was excited using a 3-turn induction coil at a frequency of 1.7 MHz and lamp power equal to 90-160 W in a mixture of mercury vapor at a pressure of around 0.01 mmHg and buffer gas (Ar, a mixture of 30%Ne+70%Ar) at pressures of 0.7 and 1.0 mmHg in a closed tube 16.6 mm in diameter and 815 mm long. The coil turns made of multiconductor wire (Litz wire) with a low per unit length resistivity of 0.00014 Ωm/cm and 1.5 mm in diameter were arranged over the discharge tube perimeter. It was found that, as the lamp power was increased, the power loss in the induction coil wire decreased from 7-9 to 3-4 W, and the coil efficiency increased from 92 to 98%. In lamps filled with buffer gas at a pressure of 1.0 mmHg, the maximal plasma UV radiation generation efficiencies equal to 68% and 66%, respectively, were achieved at plasma power levels of 105-155 W. The decrease of buffer gas pressure to 0.7 mmHg entails a drop of lamp UV radiation generation efficiency by 10-20% and a shift of its maximum values to the zone of lower plasma power values.

Understanding thermo-fluidic characteristics of a glass tube closed loop pulsating heat pipe: flow patterns and fluid oscillations

2015 ◽  
Vol 51 (12) ◽  
pp. 1669-1680 ◽  
Author(s):  
V. K. Karthikeyan ◽  
K. Ramachandran ◽  
B. C. Pillai ◽  
A. Brusly Solomon
Keyword(s):  
Heat Pipe ◽  
Pipe Flow ◽  
Closed Loop ◽  
Glass Tube ◽  
Flow Patterns ◽  
Pulsating Heat Pipe

scholarly journals IV. On the development of electric currents by magnetism and heat

1869 ◽  
Vol 17 ◽  
pp. 265-267
Keyword(s):  
Copper Wire ◽  
Glass Tube ◽  
Rubber Band ◽  
The Other ◽  
Internal Diameter ◽  
External Diameter ◽  
Thin Glass ◽  
Iron Wire ◽  
It Flexibility ◽  
Electric Current Passing

I have devised the following apparatus for demonstrating a relation of current electricity to magnetism and heat. A A, fig. 3, is a wooden base, upon which is supported, by four brass clamps, two, B, B, on each side, a coil of wire, C; the coil is 6 inches long, 1½ inch external diameter, and ⅜ of an inch internal diameter, lined with a thin glass tube; it consists of 18 layers, or about 3000 turns of insulated copper wire of 0·415 millim. diameter (or size No. 26 of ordinary wire-gauge); D is a permanent bar-magnet held in its place by the screws E, E, and having upon its poles two flat armatures of soft iron, F, F, placed edgewise. Within the axis of the coil is a straight wire of soft iron, G, one end of which is held fast by the pillar-screw H, and the other by the cylindrical binding-screw I; the latter screw has a hook, to which is attached a vulcanized india-rubber band, J, which is stretched and held secure by the hooked brass rod K and the pillar-screw L. The screw H is surmounted by a small mercury cup for making connexions with one pole of a voltaic battery, the other pole of the battery being secured to the pillar-screw M, which is also surmounted by a small mercury cup, and is connected with the cylindrical binding-screw I by a copper wire with a middle flattened portion O to impart to it flexibility. The two ends of the fine wire coil are soldered to two small binding-screws at the back; those screws are but partly shown in the sketch, and are for the purpose of connexion with a suitable galvanometer. The armatures F, F are grooved on their upper edges, and the iron wire lies in these grooves in contact with them; and to prevent the electric current passing through the magnet, a small piece of paper or other thin non-conductor is inserted between the magnet and one of the armatures. The battery employed consisted of six Grove’s elements (arranged in one series), with the immersed portion of platinum plates about 5 inches by 3 inches; it was sufficiently strong to heat an iron wire 1·03 millim. diameter and 20·5 centims. long to a low red heat.

Time-resolved derivation of heat fluxes from quantitative infrared thermography and its relationship to photoacoustics

1986 ◽  
Vol 64 (9) ◽  
pp. 1190-1194 ◽  
Author(s):  
B. K. Bein
Keyword(s):  
Heat Conduction Equation ◽  
Magnetic Confinement ◽  
Heat Fluxes ◽  
Quantitative Interpretation ◽  
Plasma Power ◽  
Power Losses ◽  
Ir Thermography ◽  
Target Plate ◽  
Time Resolved ◽  
Complementary Techniques

Part of the plasma power losses in magnetic-confinement-based nuclear-fusion devices is deposited on limiters or divertor targets. This part can be deduced quantitatively from time- and space-resolved infrared (IR) surface-temperature measurements at the limiter or divertor targets by solving the heat-conduction equation of the target plate with the help of inversion solutions for the incident heat flux. This quantitative application of IR thermography and photoacoustic or photothermal frequency-dependent measurements are related, complementary techniques. Photoacoustics provides the means to measure the relevant thermal properties, i.e., the value of the effusivity (kρc)1/2 of the target plate, necessary for the quantitative interpretation of the thermographical measurements.

Tritium Application: Self-Luminous Glass Tube (SLGT)

2005 ◽  
Vol 277-279 ◽  
pp. 698-702 ◽  
Author(s):  
Kyeong Sook Kim ◽  
Sook Kyung Lee ◽  
Eun Su Chung ◽  
Kwang Sin Kim ◽  
Wi Soo Kim ◽  
...  
Keyword(s):  
New Technology ◽  
Glass Tube ◽  
Main Process ◽  
Fluorescent Lamp ◽  
Coating Technology ◽  
Design Basis ◽  
Recovery System ◽  
Glass Tubes ◽  
Pulse Type ◽  
Injection Technology

To manufacture SLGTs (Self-Luminous Glass Tubes), 4 core technologies are needed: coating technology, tritium injection technology, laser sealing/cutting technology and tritium handling technology. The inside of the glass tubes is coated with greenish ZnS phosphor particles with sizes varying from 4~5 [µm], and Cu, and Al as an activator and a co-dopant, respectively. We also found that it would be possible to produce a phosphor coated glass tube for the SLGT using the well established cold cathode fluorescent lamp (CCFL) bulb manufacturing technology. The conceptual design of the main process loop (PL) is almost done. A delicate technique will be needed for the sealing/cutting of the glass tubes. Instead of the existing torch technology, a new technology using a pulse-type laser is under investigation. The design basis of the tritium handling facilities is to minimize the operator's exposure to tritium uptake and the emission of tritium to the environment. To fulfill the requirements, major tritium handling components are located in the secondary containment such as the glove boxes (GBs) and/or the fume hoods. The tritium recovery system (TRS) is connected to a GB and PL to minimize the release of tritium as well as to remove the moisture and oxygen in the GB.

scholarly journals The theory of the katharometer

1920 ◽  
Vol 97 (685) ◽  
pp. 273-286 ◽  
Keyword(s):  
Copper Wire ◽  
Outer Part ◽  
Glass Tube ◽  
Wheatstone Bridge ◽  
The Other ◽  
Lead Wire ◽  
Thin Glass ◽  
Small Frame ◽  
Outer Atmosphere ◽  
Lower Temperature

[ Historical Note by G. A. Shakespear, M. A., D. Sc. —In September, 1915, at the request of a member of the Board of Invention and Research of the Admiralty, I undertook to devise an instrument capable of giving automatic indication of the presence of hydrogen in small quantities ( e. g ., 1 or 2 per cent.) in air. The well-known surface-action of palladium and platinum wires suggested itself as a phenomenon obviously adapted to the purpose. The wire was used as two arms of a Wheatstone bridge, one of these arms being protected from the gas by a thin glass tube, the other being exposed. When a sufficiently great current of electricity was passed through the bridge, the exposed arm rapidly increased in temperature owing to surface combustion. The temperature, however, was liable to rise dangerously high if the hydrogen were present in suitable quantity, and, as safety from explosion was indispensable, this method was abandoned. The same apparatus was then applied with a much lower current, and with the wires consequently at a much lower temperature, to make use of the increase in thermal conductivity of the gas due to the admixture of hydrogen. This arrangement was found to be unexpectedly sensitive, and the method was adopted for the desired purpose. As the instrument was primarily intended to measure the purity of the air, the name “katharometer” was given to it. In its final form, the katharometer consisted of two small helices of thin platinum wire (about 0·001 inch diameter), enclosed each in one of two cells in a copper block. The arrangement will be readily understood from a reference to the accompanying figure (fig. 1). Each helix was mounted in a small frame, consisting of a loop of copper wire soldered to a ring of copper. This ring was fitted with an insulating plug, through which the lead wire, also of copper, was introduced. One extremity of the helix was soldered to the lead and the other to the distal end of the loop. The outer part of the lead passed through a plug of rubber fitting into the cell, and over this rubber an ebonite plug was pressed down by a screw collar or nipple. Thus the rubber filled tightly the upper part of the cell, and access of air or gas could only take place by diffusion through the rubber. This diffusion is a slow process, and, for the purpose for which the katharometer was originally intended, such a joint was sufficiently nearly gas-tight. Minor improvements in detail were afterwards introduced. Both cells were similarly fitted, but whereas one was thus hermetically sealed, the other communicated with the outer atmosphere through three small holes. The resistance of each helix was about 8 ohms when cold, and the main working current in the bridge was usually 0·100 ampère; this was sufficient for most purposes, and gave the wires a temperature about 15°C. above that of the block. The remaining arms of the bridge were of manganin wire.

scholarly journals Discharge tube for high luminous flux self-ballasted fluorescent lamp

1996 ◽  
Vol 80 (Appendix) ◽  
pp. 72-72
Author(s):  
Kenji Nakano ◽  
Shiro Iida ◽  
Kenji Itaya ◽  
Masaru Saito
Keyword(s):  
Discharge Tube ◽  
Luminous Flux ◽  
Fluorescent Lamp
Sign in / Sign up

Export Citation Format

Share Document