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Numéro de publicationUS3911318 A
Type de publicationOctroi
Date de publication7 oct. 1975
Date de dépôt4 févr. 1974
Date de priorité29 mars 1972
Numéro de publicationUS 3911318 A, US 3911318A, US-A-3911318, US3911318 A, US3911318A
InventeursDonald M Spero, Bernard J Eastlund, Michael G Urv
Cessionnaire d'origineFusion Systems Corp
Exporter la citationBiBTeX, EndNote, RefMan
Liens externes: USPTO, Cession USPTO, Espacenet
Method and apparatus for generating electromagnetic radiation
US 3911318 A
There is disclosed a novel method and apparatus for generating high power electromagnetic radiation in the ultraviolet and visible regions of the electromagnetic spectrum wherein high energy electrons, produced by directing a lower frequency (radio to microwave) electromagnetic energy wave into a plasma producing medium (gas, vapor and mixtures thereof), are caused to collide with heavy particles of the medium to thereby cause same to be collisionally excited and subsequently emit electromagnetic radiation. Particular means are disclosed for coupling the lower frequency electromagnetic wave energy to the medium. In a preferred embodiment the medium is confined in a closed vessel or chamber at a selected pressure to which a magnetic field is applied to guide the high energy electrons to collision with said heavy particles.
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United States Patent Spero et al. Oct. 7, 1975 [5 METHOD AND APPARATUS FOR 3,541,372 11/1970 Omura et al. 315/111 GENERATING ELECTROMAGNETIC 5233 2; 313;} isq l rams RADIATION 3,641,389 2/1972 Leidigh..... 315/39 [75] Inventors: Donald M. Spero, Bethesda; 3,663,858 5/1972 Lisitano 315/39 Bernard J. Eastlund, Rockville; Michael G. Urv, Lanham, all of Md. Primary ExaminerSaxfield Chatmon, Jr. [73] Assignee: Fusion Systems Corporation, l il fi Flrm Browne Bevendge Rockville, Md.

[22] Filed: Feb. 4, 1974 57 ABSTRACT [21] Appl. No.: 439,173 There is disclosed a novel method and a aratus for PP Related U S A cation Data generating high power electromagnetic radiation in pp the ultraviolet and visible regions of the electromag- [62] Y of 239N191 March 1972 netic spectrum wherein high energy electrons, proabdndoned' duced by directing a lower frequency (radio to microwave) electromagnetic energy wave into a plasma pro- [52] US. Cl. 315/39, 225sOo/jl59ji235l0sl/5l0l4l, ducing medium (gas, vapor and mixtures thereof) are 2 caused to collide with heavy particles of the medium 2g ig ld g 3 to thereby cause same to be collisionally excited and 1 0 care g 5 6 subsequently emit electromagnetic radiation. Particular-means are disclosed for coupling the lower frequency electromagnetic wave energy to the medium. [56] References C'ted In a preferred embodiment the medium is confined in UNITED STATES PATENTS a closed vessel or chamber at a selected pressure to 3,313,979 4/1967 Landauer 315/39 which a magnetic field is applied to guide the high en- ,1 H1968 Grubcr et l ergy electrons to collision with said heavy particles. 3,374,393 3/1968 Bramlcy 315/39 3,378,723 4/1968 Napoli et a]. 315/39 5 Clams, 7 Drawmg Flgures XXI XXV FL. 5 i C, I J/ 1; 1| I H I 67" 281 MICROWAVE 1/2 I 1' :llzzgllnao acuanrron. l

l l x I US. Patent Oct. 7,1975 Sheet 1 of 3 3,911,318

U.S. Patent Oct. 7,1975 Sheet 2 of 3 3,911,318




US. Patent Oct. 7,1975 Sheet 3 of 3 3,911,318


Attention is directed to the disclosure of the following references for an exposition of background technology leading to a better understanding of the present invention:

l. K. S. Golovanivskii and V.D. Dugar-Zhabon, High Frequency Low Pressure Discharge at the Electron Cyclotron Resonance," Sov. Shys- .Tech. Phys. 16, 75 (July, 1971).

2. M.V. Krivosheev, Production of a High-Density Plasma by Microwaves in 21 Magnetic Field," Sov. Phys.Tech Phys. 15, 1805 (May, 1971).

3. V.E. Golant and M.V. Krivosheev, Anomalous Absorption of Microwave Power by a Plasma at Supercritical Electron Densities, Sov. Phys.Tech. Phys. 14, 719 (November, 1969).

4. V.E. Golant, M.V. Krivosheev, and V.I. Fedorov, Linear Wave Transformation and Absorption in a Plasma of Small Transverse Dimensions, Sov. Phys-Tech. Phys. 15, 282 (August, 1970).

5. A.l. Anisimov, NI. Vinogradov, V. Ye Golant, S.I. Nanobashvili, and L.P. Pakhomov, Super-High Frequency Generation of a Strongly Ionized Argon Plasma, AEC-tr-7056 of A.F. IOFFE Physico' Technical Institute Report No. 113, 1968.

6. V.N. Budnikov, N.1. Vinogradov, V.E. Golant, and A.A. Obukhov, Investigation of a Steady-State Microwave Discharge in a Magnetic Field, Sov. Phys-Tech. Phys. 13,19 (July, 1968).

7. A. 1. Anisimov, N.I. Vinogradov, V.E. Golant, S.I. Nanobashvili. and L.P. Pakhomov, Determination of Plasma Parameters Produced by Super High- Frequency Power in a Magnetic Field in a Steady- State Condition, AEC-tr-7052 of IOFFE Institute Report, 1968.

8. A. 1. Anisimov, N.1. Vinogradov, V.E. Golant, and LP. Pakhomov, Microwave Production of a Plasma in a Trap," Sov. Phys.-Tech. Phys. 12, 486 (October, 1967).

. V.N. Budnikov, NJ. Vinogradov, V.E. Golant, and A.A. Obukhov, Plasma Produced by Electron Cyclotron Resonance 1. Absorption of Microwave Power, Sov. Phys.Tech. Phys. 12, (November, 1967).

10. V.N. Budnikov, N.I. Vinogradov, V.E. Golant, Plasma Produced by Electron Cyclotron Resonance, 11 Charged Particle Balance, Sov. Phys .Tech. Phys. 12, (November, 1967).

l 1. V.N. Budnikov, V.E. Golant, and A.A. Obukhov, Absorption of Microwave Power by a Plasma at Magnetic Fields Above the Cyclotron Frequency, Sov. Phys-Tech. Phys. 15, 97 (July, 1970).

12. A. 1. Anisimov, V.N. Budnikov, N.I. Vinogradov, V.E. Golant, S.1. Nanobashvili, A.A. Obukhov, A.P. Pakhomov, A.D. Piliya, and V.I. Federov, Ultra-High Frequency Plasma Heating in a Magnetic Field, IAEA Conference on Plasma Physics and Controlled Fusion Research, Novosibirsk (August, 1968), paper CN-24/J-3.

13. V.N. Budnikov, V.P. Gorelik, V.V. Dyachenko, K.M. Novik, and A. A. Obukhov, Microwave Discharges at Harmonics of the Electron Cyclotron Frequency," Sov. Phys-Tech. Phys. 16, 404 (Sep tember, 1971 14. B. V. Calaktionov, V.V. Dyachenko, and O.N. Shcherbinin, High Frequency Plasma Heating Near the Lower Hybrid Frequency," Sov. Phys.- Tech. Phys. 15, 1809 (May, 1971).

15. B.V. Galaktionov, V.E. Golant, A.D. Piliya, and O.N. Shcherbinin, Plasma Absorption of RF Energy Near the Lower I-llybrid Frequency, Sov. Phys-Tech. Phys. 14, 721 (November, 1969).

16. A.D. Piliya and V.I. Fedorov, Linear Wave Conversion in an Inhomogeneous Magnetoactive Plasma, Soviet Physics JETP 30, 653 (April, 1970).

17. V.I. Arkhipenko, A.B. lBerezin, V.N. Budnikov, V. Ye Golant, K. M. Novik, A.A. Obukhov, A.D. Piliya, V.I. Fedorov, and K.G. Shakovets, Studies of the Transformation and Adsorption of High- Frequency Waves in a Plasma for the Purpose of Developing Plasma Heating Techniques, IAEA Conference on Plasma Physics and Controlled Nuclear Fusion Research, Madison, Wisconsin, June, 1971, paper CN-28/L-4.

18. A.]. Anisimov, N.1. Vinogradov, V.E. Golant, and L.P. Pakhomov, Absorption of Electromagnetic Waves in a Plasma at Frequencies Near Harmonics of the Electron Cyclotron Frequency, Sov. Phys.- Tech. Phys. 12, 141 (July, 1967).

19. V. N. Budnikov, V.E. Golant, and A.A. Obuchov, The Study of Microwave Absorption by a Plasma in a Magnetic Field," 31A, 76 (Jan. 26, 1970).

20. B.V. Galaktionov, V.E. Golant, V.V Dyachenko,

and O.N. Shcherbinin, Determination of the Limiting Frequency for Plasma Absortpion of High Frequency Waves at Frequencies between the Electron Cyctron Frequency and the Lower Hybrid Frequency, Sov. Phys-Tech. Phys. 15, 1813 (May, 1971).

21. V.E. Golant and A.D. Piliya, "Linear Transformation and Absorption of Waves in Plasma, Uspekhi Fiz. Nauk 74, No. 3 (1971).

22. G. Lisitano, M, Fontanesi, and E. Sindoni, Ap-

plied Physics Letters, 122, Feb. 1, 1970.

23. G. Lisitano, P. Caldirola, N, Barassi, M. Fontanesi, and E. Sindoni, IAEA Conference on Plasma Physics and Controlled Thermonuclear Re search, Novosibirsk, USSR, 1968.

24. Schlag, E.W. and Comes, F.J., Intense Light Sources for the Vacuum Ultraviolet II, J. Opt. Sci. Am., Vol. 50, No. 9, p. 866.

25. Wilkinson, P.G., New Krypton Light Source for the Vacuum Ultraviolet", J. Opt. Sci. Am., Vol. 45, No. 12, p. 1044.

26. Wilkinson, PG. and Tanaka, Y., New Xenon- Light Source for the Vacuum Ultraviolet J. Opt. Soc. Am., Vol 45, No. 5, p. 344.

27. Dieke G.H. and Cunningham, S.P., A New Type of Hydrogen Discharge Tube, J. Opt. Sci. Am., Vol. 42, No. 3, p. 187.

28. Okabe, I-1., Intense Resonance Line Sources for Photochemical Work in the Vacuum Ultraviolet Region, J. Opt. Sci. Am., Vol. 54, No. 4, p. 478.

29. Minnhagen, L., Review of Methods for the Excitation of Atomic and Ionic Spectra by Means of High-Frequency Discharges and Sliding Sparks, J Res. Natl. Bur. Std. (U.S.), Vol. 68C, No.4, p. 237.

30. Warneck, P., A Microwave-Powered Hydrogen Lamp for Vacuum Ultraviolet Photochemical Research, Appln. Opt., Vol. 1, No. 6, p. 721.

31 McCarroll, B., An Improved Microwave Discharge Cavity for 2450 MHZ, Rev. Sci. lnstr., 41, 279, 70 p 32. Worden, E.F., Gutmacher, R.G. and Conway, .I.G., Use of Electrodeless Discharge Lamps in the Analysis of Atomic Spectra, Appl. Opt., Vol. 2, No. 7, p. 707.

33. Fehsenfeld, F.C., Evenson, K.M. and Broida, I-I.P., Microwave Discharge Cavities Operating at 2450 MHZ Rev. Sci. lnstr., Vol. 36, No. 3, p. 294.

34. Tuma, D.T., A Quiet Uniform Microwave Gas Discharge for Lasers, Rev. Sci. lnstr., Vol. 41, No. 10, p. 1519.

35. Gleason, W.S. and Pertel, R., High Stability Electrodeless Discharge Lamps, Rev. Sci. lnstr., Vol. 42, No. 11, p. 1638.

36. Dodo, Taro, et al., Electron Cyclotron Resonance Heating Device, US. Pat. No. 3,431,461, Mar. 4, 1969.

37. Omura, Itiro, et. al., Microwave Plasma Light Source, US. Pat. No. 3,541,372, Nov. 17, 1970.

This invention relates to a novel method and apparatus for efficiently generating high power ultraviolet and visible radiation with a high degree of control over the range of frequencies produced.

Sources of ultraviolet and visible radiation, having wavelengths of less than 5,000 A, are extensively used in industry for curing paints and inks, in other coating and surface treatment processes, and in the industrial synthesis of certain chemicals by photochemical reactions. Present sources of such radiation are generally limited by their low efficiencies and unwanted radiation by-products, or by their limited output powers. Existing large industrial ultraviolet sources are based on plasmas produced by DC or low frequency electrical discharges. The plasmas generated are at relatively high gas pressures (about 1 mm of mercury to about 1 atmosphere), and low plasma temperatures (about 5,000 to 10,000I(). These sources may produce several hundred watts of ultraviolet radiation but large fractions of their radiation are in the visible and infrared portions of the spectrum. The considerable power which is radiated in the visible and infrared regions represents an inefficiency for the ultraviolet source and also is often deleterious to the materials whose treatment by ultraviolet radiation is desired. Moreover, in such cool dense plasmas the electromagnetic energy is converted into kinetic energy of the atoms and ions as well as the electrons, whereas it is principally the energetic electrons which are responsible for the production of ultraviolet radiation. Hence, the kinetic energy unavoidably invested in ion and neutral atom motion represents another limitation to the efficiency of such devices as ultraviolet sources. Finally, such devices provide limited control over the frequencies of radiation produced.

Another category of commonly used ultraviolet sources operates at lower gas pressures and may be based on low frequency MHz) or microwave (-1 GHz) discharges (Refs. 2437). They operate at relatively higher electron energies and may produce ultraviolet radiation fairly efficiently, either directly by emission or through the use of fluorescent materials. However, because of the nature of the discharge plasma employed, such devices are severely restricted as to their operating power densities (i.e., the average number of watts of input electromagnetic power which can be absorbed in a given volume of plasma). This limits the total power of ultraviolet radiation that can be obtained from a source of a given size. In addition, the size and hence the power of these devices may be rigidly limited by the methods, such as resonant cavity and waveguide structures. employed for coupling microwave energy into the plasma. Furthermore, the microwave coupling structures often constrain useful viewing geometries of such devices. Because of these limitations in ultraviolet power and geometry, this class'of devices is not used extensively in industrial applications, although they are employed in analytical chemistry.

The method and apparatus disclosed herein will permit the efficient production of selected ranges of ultraviolet radiation (for example, between 1800 and 2500 Angstroms in wavelength) at high power levels which are of great importance in industrial processes such as photon induced crosslinking of polymers, free radical formation, and chemical synthesis by photochemical reactions.

Accordingly, it is an object of this invention to provide an apparatus and method for producing ultraviolet and visible radiation using a microwave generated plasma.

Another object of this invention is to provide apparatus and method for efficiently producing ultraviolet radiation at very high power densities and extracting the radiation in suitable geometric configurations.

A further object of this invention is to provide an apparatus and method for producing ultraviolet radiation in selected wavelength regions without generating comparable powers of visible and infrared radiation.

The above and other objects, advantages and distinguishing features of the invention will become apparent from the following specification, when considered with the following drawings, wherein:

FIG. 1 is a schematic block diagram illustrating the method disclosed herein,

FIG. 2 is a diagramatic structural illustration of a preferred embodiment of the invention for generating ultraviolet radiation,

FIG. 3 illustrates the location and relative intensity of the magnetic fields with respect to the heated plasma,

FIG. 4 is a diagramatic illustration of a modification of the invention incorporating power coupled to the plasma tube or vessel from two ends and a UV reflector for treating a surface or material,

FIG. 5 is a diagramatic illustration in cross section of a further modification wherein microwave power is coupled to an annular plasma tube through the center of which flows the material to be irradiated by ultraviolet light,

FIG. 6a discloses an alternative structure for coupling microwave energy with the plasma tube, and

FIG. 6b discloses a structure wherein the microwave energy is coupled radially inward to the plasma tube and allows working access to both ends of said vessel.

The present invention produces ultraviolet radiation by efficiently generating a magnetized plasma, at relatively low gas densities but high input power densities, in which the electron temperature may be varied between I0,000 and 600,000K. These highly energetic electrons subsequently collide with cooler heavy particles of the medium: atoms, molecules or ions. It is these inelastic excitation collisions and the subsequent radiative de-excitations of the heavier particles of the plasma producing medium which produce the large amounts of ultraviolet radiation. These heavy particles of the plasma producing medium include one or more of the particle species of atoms, ions and molecules. By the proper choice of operating parameters, as will be discussed below. such plasma media continuously emit up to many hundreds of Watts of ultraviolet radiation without appreciable amounts of visible and infrared radiation. Moreover, by appropriately changing the operating conditions, such as the microwave power level and/or the composition and/or pressure of the gas or gases from which the plasma is formed, the radiation can be made to be emitted elsewhwere in the spectrum from the visible to, in principle, the x-ray region. However, in the preferred practice of this invention, operation in the UV region of the spectrum is particularly preferred.

In order to clarify the description of the present invention, it is of interest to note some definitions, particularly as here employed. By plasma" is meant a partially or highly ionized gas composed of atomic or molecular particles having one or more orbital electrons removed and thus constituting ions, together with a sufficient number of free electrons to balance the electrical charge of the ions, so that the resultant plasma is subsequently electrically neutral. The plasma utilized in the present invention is generated by a technique known as collisionless transformation of waves. This term refers to the process by which the energy in electromagnetic waves (which, in the present example, represents power flowing from the microwave generator), is efficiently transferred within some region of a magnetized plasma, into electrostatic 0r longitudinal plasma waves. The energy of such plasma waves, in turn, is rapidly transferred into the kinetic energy of the plasma electrons by collective loss mechanisms such as the well-known Landau damping or collisionless absorption process. Theoretical and experimental analysis of collisionless transformation of waves indicates that the process is efficient in local regions of the plasma in which the index of refraction becomes infinite for the incident electromagnetic waves. This determines ranges of frequency w for the incident electromiC and where -Continued 2 in which definitions (u is the electron plasma frequency, defined by and a is the angle between the magnetic field and the gradient in density (and it is assumed that In these expressions, n is the number density of electrons per cubic centimeter; me and mi the electron and ion masses, respectively; e the electron charge, C the speed of light, and B the magnetic field strength. The units are CGS Gaussian.

It should be noted that if the frequency w of incident electromagnetic energy is considered as fixed, the expressions l define a range of magnetic field strengths B for which electron heating will occur. The expressions predict that as B is reduced to zero, a finite frequency range O w wpe still exists for collisionless transformation of waves. The frequency ranges defined by 1 are calculated by a somewhat simplified, or linearized theory. It is expected that nonlinear effects, such as high electromagnetic power levels, may tend to broaden the frequency range in which efficient transformation of waves may occur.

If the conditions in some region or regions of the plasma are such that the incident electromagnetic wave frequency lies in either of the regions defined by (1) above, an efficient transformation of energy from the electromagnetic waves into electrostatic or plasma waves, can occur in that region. These plasma waves, in turn, will carry the energy out of the regions and be themselves converted by collective loss porcesses such as Landau damping and other collisionless effects into energetic electrons throughout the plasma. The energetic electrons then collide with cooler heavier particles (atoms, molecules and ions), and transfer energy to their internal excitation. Finally, this energy is released in the form of deexcitati on radiation. The distribution of this radiation among the ultraviolet, visible, and other parts of the spectrum is determined by the energies of the electrons in the plasma, as well as by the types of heavy particles (atoms, ions and molecules) present.

Several features of the processes described above will be mentioned. First, the plasma heating is a collisionless process in which collective plasma behavior is responsible for converting the incident electromagnetic (microwave) energy to random kinetic energy of the electrons. This is in distinction to conventional low frequency or DC discharge lamps in which collisional heating of the gas by an electric current produces the ultraviolet emission. It is also distinguishable from nonmagnetized electrodeless discharges in which the directed energy imparted to the electrons by the electromagnetic fields is converted to kinetic energy by collisions. Thus, the present process is relatively insensitive to initial gas density or temperature. Since the present technique is not collision dependent it can also be used in plasmas which are already highly ionized where collisional methods would be ineffective. Thus unusually high power densities of incident microwave radiation can be effectively absorbed.

Second, although this process commonly makes use of a magnetic field in the plasma region, it can easily be distinguished from the more conventional electron cyclotron resonance heated (ECRH) discharges. ln these latter plasmas, the magnetic field, B, and external electromagnetic power generator must be adjusted so that the frequency, to of the incident microwaves is equal to the electron cyclotron frequency, wce in the plasma, or to a harmonic of it. In the present process, no such restrictions on w or B exist, provided the more general conditions of 1) are met. Thus, for example, lower values of magnetic field than those required by the cyclotron resonance heating condition, w=wce are sufficient for the present process, down to and including B=0. Further, the desired value of magnetic field need only be achieved over the local regions of heating, which regions have dimensions much smaller than the wavelength of the incident electromagnetic radiation (Ref. 17). These facts result in a considerable simplification in the design of a practical plasma radiation source. A third feature to be noted about the process of the present invention is that it depends geometircally only on the angle a between the magnetic field and the density gradient, but not on the direction or polarization of the incident electromagnetic waves. All three of the preceeding features are in sharp contrast to the requirements of other plasma heating techniques such as microwave cavity resonance or ECRH. These features serve to differentiate the collisionless wave transformation process and also permit flexibility in the design of a radiation source.

The manner in which the plasma heating process described above is employed to produce a unique ultraviolet source will become more clear from a consideration of a flow or operational block diagram in FIG. 1. The input electromagnetic energy, in the form of microwave radiation, is generated by a conventional source 10 such as a magnetron, and is transmitted by conventional waveguides or coaxial transmission lines to the chamber in which the plasma is to be made. The coupling of the microwave power to the gas in the plasma chamber can be accomplished by a variety of techniques and configurations.

A particularly useful configuration is shown in FIG. 2, which is a schematic of a preferred embodiment. It uses a waveguide to circular transition section 11 fitted over a tapered section 21 of the plasma tube 22. The tapered section 21 provides a region of rapidly changing plasma density in which the angle between the density gradient (i.e., the direction of maximum rate of change of density) and magnetic field can be adjusted so as to satisfy equation (1) above. This then permits efficient transformation of the microwave energy to plasma wave energy in that region. The plasma waves propagate out of that region and rapidly convert their energy into electron kinetic energy. The heated electrons then flow throughout the plasma region causing After being produced, the ultraviolet radiation passes out of the discharge tube, and by means of reflectors or lenses is directed onto the region to be irradiated. In this configuration, the ultraviolet can be emitted from the length of the discharge vessel. The intensity and spectral quality of the radiation is relatively insensitive to the gas pressure in the vessel 22, the frequency of power of the microwave radiation, or the magnitude of the magnetic field over certain ranges of these parameters. However, particular adjustments of these parameters within the allowed ranges can be employed to optimize the intensity, efficiency and spectral distribution of emitted ultraviolet radiation. The broad operating range of the device is a decided advantage over conventional methods of producing microwave plasma light sources, and in the practical utilization of such devices.

The plasma vessel 22 or tube, is usually circularly V shaped and made out of quartz or fused silica to permit the ultraviolet radiation to escape. Straight section 12 of length designated B is permitted to protrude into the rectangular to circular microwave waveguide transition section 11 having inside diameter, D, and may be any size that will fit in waveguide transition section 1 1. Straight section 12 of plasma tube 22 is followed by a conically tapered section 21 of length designated A, protruding still further into waveguide transition section 11. Conically tapered section 21 is a convenient way of providing a region of density gradient in which collisionless transformation of waves can occur. While a conical section is disclosed herein specifically, any section providing a region of density gradient in which collisionless transformations can occur can be used, including rounded tips and other shapes. In typical operation quartz tubing of 1 inch OD and 1 mm wall thickness is used as the plasma tube, and the various lengths are A=3 inches, B=6 inches, C=30 inches and diameter D=3 inches. The plasma tube is filled with a preselected gas vapor, or mixture of gases constituting the plasma forming medium and sealed off. Typical fills are gases such as air, oxygen, and xenon, mixtures such as %CO plus lO%O metal vapors such as mercury, cadmium, zinc, and antimony, and other vapors such as phosphorus and iodine. The metals may be introduced by using their inherent vapor pressure (e.g., mercury) or their high vapor pressure compounds, by using heated filaments coated with the desired metal, or by placing a small quantity of the pure metal in the tube and allowing it to be heated by a background plasma of hydrogen, helium, neon, or some other gas. In the case where a pure gas is used, the gas pressure is sufficient to sustain the microwave plasma generation, and the radiation produced ischaracteristic of the atoms, ions, or molecules present in the plasma. A mixture of gas such as CO plus 0 may be used in order to create a chemical equilibrium in the plasma which prevents material from coating the walls of the tube during operation. Another modification is to use majority gas with either a second minority gas or a metal vapor which is present in much smaller quantity, in which the minority gas or vapor is the principal source of ultraviolet radiation, and the function of the majority gas is principally to create the proper plasma conditions for excitation of the minority atoms or ions.

Typical gas fill pressures range from I to 100 millitorr for optimum performance, with limited operation possible throughout the pressure range of 10 to 5 torr. The choice of gases and pressures is determined by the spectral output that is desired. The choice of plasma tube material is primarily governed by the requirement that as much ultraviolet radiation as possible be transmitted through the tube wall in the desired spectral region. A second requirement is that the wall material exhibits minimal dielectric loss for the incident microwave energy. The plasma tube 22 may have any diameter which fits inside the circular waveguide diameter D. Large tube diameters are used in cases where the maximum ultraviolet radiation intensity (in watts per inch of lamp length) is desired.

The plasma tube is surrounded by a concentric copper mesh screen 25 or any conducting surface which acts as an extension of the circular portion of the transition section 1 l. The copper mesh waveguide extension 25 serves to prevent microwave radiation leakage outside its cylindrical volume and to redistribute that fraction of the incident microwave power which is not absorbed in the vicinity of the tapered end 21 of the plasma tube 22. This redistribution causes further microwave energy absorption along the length of the plasma tube which improves the axial uniformity of the emitted radiation. The waveguide transition section 11 is separated from the concentric screen 25 by a waveguide flange plate 26 with a hole 27 to permit the plasma tube to fit through. The size of the hole 27 and the thickness of the flange plate 26 may be varied in order to vary the distribution of microwave power between the transition section region and the remainder of the extended concentric waveguide mesh or screen. A second waveguide flange plate 28 is used to terminate the concentric screen waveguide 25. To prevent microwave radiation from escaping at that end, the hole 29 in the plate 28 must be made only slightly larger than the tube diameter and a short metal tube 30 is inserted over the discharge tube 22 and through the flange plate hole 29. Typically, this metal tube may be 1 inch ID and 2 inches long for a plasma tube of 1 inch OD. Alternatively, this tube may have any larger ID which is convenient and its end may be terminated with a metallic cap to prevent microwave leakage.

In the single ended operation as in FIG. 2, plasma tube 22 is supported by a collar clamped to the tube by set screws (not shown) at the right end and cantilevered so as to pass through the center of hole 27 in flange 26. Hole 27 is preferably much larger than the outside diameter of plasma tube 22 to permit more of the microwave energy to flow from transition section 1] to the extended, screen mesh wave guide section 25, thereby improving the axial uniformity of the emitted ultraviolet energy. The edges of hole 27 are rounded as shown to minimize electric field enhancement and re sultant arcing. In cases where the screen mesh 25 is sufficiently opaque to the incident microwave radiation, flange 26 may be entirely dispensed with by increasing the diameter of hole 27 until it equals dimension D of the transition section 11.

At microwave input power levels in excess of 200 watts certain precautions may be needed to cool the system. Water cooling coils (not shown) may be required on waveguide transition section 11, and the second waveguide flange plate 28. It is sometimes necessary to flow gas around the discharge tube 22 itself to prevent excessive heating of the quartz wall. A way of effecting this is to install a lucite, glass, or quartz shield 31, concentric with the main discharge tube 22. It may also be used to hold the mesh screen 25 in place (and in some cases the mesh may be formed or plated on the inner surface of shield 31). The shield material must be chosen to transmit the desired wavelength regions if the lamps radiation is to be used outside the shield. A gas such as nitrogen may then be flowed into the transition section 11 through the annular space between the shield 25 and the discharge tube 22 and out the second waveguide flange plate 28. The flow rate may be adjusted to provide adequate cooling. Proper choice of gas and shield material may also serve to control unwanted photochemical processes caused by the lamp. For example, nitrogen gas prevents ozone formation around the lamp. Other gases can be used to effect surface changes caused by the lamps radiation if the material to be irradiated is either placed within the shield or passed beneath an opening cut in the shield.

The electromagnetic power which excites the dis charge is produced by a conventional microwave generator 10 such as a commercial type 2450 MHz magnetron supply. Other microwave frequencies. such as 915 and l 19 MHz, and radio frequencies, such as 19 MHz (Ref. 21) may also be used. This applied electromagnetic power may be continuous or pulsed. The microwave power is transmitted to the transition section through suitable lengths of the waveguide 40 or high power coaxial waveguide. The microwave power transmitted to the discharge tube and reflected back toward the microwave generator may be monitored by power meters (not shown). For efficient coupling into the plasma, the reflected power must be minimized. For a particular set of operating conditions this is most easily accomplished by adjustment of the magnetic field. A microwave tuner (not shown) may also be used to minimize the reflected power and an isolator (not shown) may be used to limit the power reflected back toward the microwave generator.

The axial magnetic field is produced by a pair of water cooled Helmholtz coils 45 and 46 which are powered by a DC power supply (not shown). The variation of the axial magnetic field with axial position is shown in FIG. 3. The precise variation of the magnetic field is not important for the operation of the lamp, nor is the absolute magnitude of the peak magnetic field, provided only that the conditions of equation l are met in some volume. Operation at zero magnetic field is found in some cases to be possible, as predicted by equation (1). However, of the wide range of magnetic fields over which the lamp operates, the region of optimum power coupling (i.e. minimum reflected microwave power) usually occurs when, simultaneously with satisfying conditions (1), the microwave frequency is approximately equal to the electron cyclotron frequency somewhere in the lamp volume, and preferably inside the waveguide transition section. The design of the magnetic field, besides creating conditions for collisionless transformation of waves, acts to guide the heated electrons throughout the quartz plasma tube. For this reason, the peak in magnetic field, B should be in the near or to the left of the region of plasma heating R, as indicated in FIG. 3, so that the heated plasma, which tends to flow to regions of lower magnetic field, will move out into the tube 22. The magnetic field also acts to minimize the loss of electron kinetic energy to the walls of the plasma tube, thus contributing to the ability for low temperature wall operation. Other magnetic field configurations and means for producing same, such as a single turn high current helical conductor extending the length of the plasma tube may also be used. By changing the spatial structure of the magnetic field, or fields, the spatial distribution of emitted radiation from plasma tube 22 may be changed to obtain optimum radiation distribution.

In the operation of the microwave plasma ultraviolet light source, cooling water and gas flows are first turned on. The DC magnet power supply is then turned on and the magnet coils 45 and 46 are energized. The current from the power supply is adjusted to provide the desired value of axial magnetic field. Typically, the power supply will provide 350 amps (DC) at 20 volts (DC) to produce a peak magnetic field, B on axis of 1000 gauss and a minimum field of 500 gauss with two coils (45 and 46) of 24 inch separation and 19 inch mean diameter. To ionize or excite the gas in plasma tube 22, the microwave power source is activated to supply microwave radiation to the gas within the vessel by means of waveguide 40 and transition section 11. Typically, the microwave power source provides an average power output of 500 to 2000 watts at a frequency of 2450 MHz (which is a standard FCC allowed industrial frequency). In practice, the magnetic field strength may be adjusted in order to ignite the plasma tube, or a Tesla coil or other high voltage generator may be used to initiate the plasma. The microwave power levels into and reflected from the plasma tube may be measured by means of a dual directional coupler and microwave power meters (not shown). The efficiency of operation of the system can be adjusted by adjusting the position of the plasma tube in the transition section (as indicated by arrow X in FIG. 2), or by varying the magnetic field intensity or distribution, or other parameters in such a way as to minimize the reflected microwave power, measured on the power meter, and maximize the power transmitted to the plasma.

The magnetic field coils and plasma tube geometry are selected to produce the desired length and shape of ultraviolet emitting tube. Special materials may be required for the plasma tube, or for windows in it, in order to permit ultraviolet radiation to secape with minimal attenuation. Thus, for example, sapphire windows might be used to allow the emission of 1700 A radiation. The emitted radiation can be focused and directed with suitable optical equipment such as mirrors, lenses, or reflectors 60 and 65 (FIG. 4). The specific form of the auxiliary optical system would depend on the application as well as the desired wavelength. For example, a system which seeks to utilize 1800 A radiation would have to be evacuated or filled with a gas such as argon to prevent excessive absorption of the radiation by gas along the optical path, between the lamp and the material to be irradiated. Alternatively, the material could be placed within the plasma tube itself,

which thereby serves directly as a reaction vessel for ultraviolet radiation.

Although the invention has been described above with reference to a preferred embodiment, it will be apparent that other modifications may be made within the scope contemplated by the invention. For instance, the microwave generator output may be split by means of a power divider 61 (FIG. 4) and the power fed into the discharge tube from waveguide transition sections 62, 63 at both ends of the tube 22. This would tend to provide a more uniform ultraviolet emission from a long plasma tube. Such a modification is shown schematically in FIG. 4 where a UV reflector 60 is also shown to illustrate one way of concentrating the ultra-violet energy on a surface to be irradiated. The reflector may also be constructed by depositing a coating of high UV reflectivity on the inside of the screen waveguide 25 around roughly half of its circumference. Another way is to use a lens system 65.

A further modification utilizing microwave power coupled in from two ends 76, 77 of a microwave chamber 74 is shown in FIG. 5. It is applicable to a large annular plasma vessel which is useful for photochemical applications. the material to be irradiated would be caused to pass or flow along the axis of the inner annular vessel 72, typically of quartz, and thereby would be surrounded by ultraviolet emitting plasma. The outside or outer vessel 78 could have a coating of high UV reflectivity material on its outer surface, or the inner surface of the microwave chamber 74 could carry the reflective coating. In the embodiment shown in FIG. 5 the ends 70 and 71 of the plasma vessel are tapered to replace full conical sections. The embodiment of FIG. 5 includes metallic tubes 79 of length l and inside diameter d at both ends of the microwave chamber. The as pect ratio l/d must be sufficiently large and d sufficiently small compared to the microwave wavelength that no appreciable amounts of microwave energy leak out of the cavity.

As a final example, other techniques may be employed for coupling the microwave energy into the plasma vessel. One particular technique involves the use of a rectangular waveguide section 80 directly, as shown in FIG. 6a. In this approach a standard section of rectangular waveguide is terminated (capped) at one end and a circular hole is cut to accept the plasma tube. A limitation to this approach is that the tube diameter cannot exceed the minimum waveguide dimension, )1. A further advantageous microwave coupling technique uses an axially or helically slotted slow wave structure which fits directly over the plasma tube such as the one illustrated in FIG. 6b and described in detail in references 22 and 23. In this case, a shielded coaxial cable 86 is used to convey microwave energy to the slotted coil 85. Alternatively, a waveguide, properly terminated may be used to couple energy to slotted coil 85. For low frequency electromagnetic input radiation (2-200 MHz), a simple antenna such as a single turn copper strap (Ref. 21) can be used to couple to the plasma tube. For these elctromagnetic coupling schemes and others, such as that shown in FIG. 5, which do not requiretermination of the plasma vessel at its end, the plasma vessel may be bent around and joined one end upon the other to form a closed ring or toroid.

The invention herein described is to be construed to be limited only by the prior art when considered by the spirit and scope of the appended claims.

What is claimed is:

l. A microwave generated light source for both producing and emitting light in the visible to ultraviolet region along a substantial length of a longitudinally extending plasma forming medium containing envelope, comprising; a sealed, longitudinally extending plasma forming medium containing envelope, means for exciting said plasma forming medium in said envelope to generate a plasma and produce said light, said means for exciting including:

1. means for generating microwave energy, and

2. microwave chamber means for coupling said generated microwave energy to said plasma forming medium, a part of said chamber means extending in the longitudinal direction of said envelope and surrounding said envelope at least along a substantial portion of the length of the envelope, and at least part of said chamber means being made of a metallic mesh whereby said microwave energy is retained in said chamber means while said light produced along a length of said envelope is emitted out of said chamber means through said mesh.

2. The light source of claim 1 wherein said mesh is made of copper.

3. The light source of claim 1 wherein said mesh is surrounded by a shield of solid, ultraviolet and visible transmissive material to prevent cooling gas which may be circulated around said envelope in the vicinity of said mesh from escaping.

4. The light source of claim 1 wherein said medium is of the type which may be collisionlessly excited and said means for exciting comprises means for collisionlessly exciting said medium.

5. The light source of claim 4 wherein said envelope is tapered at each longitudinal end thereof, further including microwave energy dividing means for dividing said generated microwave energy into two parts, said chamber means coupling each part to a respective longitudinal end of said envelope.

Citations de brevets
Brevet cité Date de dépôt Date de publication Déposant Titre
US3313979 *29 juin 196211 avr. 1967Max Planck GesellschaftDevice for producing electro-magnetic oscillations of very high frequency
US3363138 *4 nov. 19649 janv. 1968Sperry Rand CorpElectron beam-plasma device operating at multiple harmonics of beam cyclotron frequency
US3374393 *12 févr. 196519 mars 1968Melpar IncIntense incoherent light source obtained by quenching the higher excited states and concentrating the energy on the lower states
US3378723 *2 janv. 196416 avr. 1968Rca CorpFast wave transmission line coupled to a plasma
US3541372 *21 déc. 196717 nov. 1970Hitachi LtdMicrowave plasma light source
US3577207 *7 mai 19694 mai 1971Vladimir Pavlovich KirjushinMicrowave plasmatron
US3609448 *14 janv. 197028 sept. 1971Varian AssociatesHigh-power plasma generator employed as a source of light flux at atmospheric pressure
US3641389 *5 nov. 19698 févr. 1972Varian AssociatesHigh-power microwave excited plasma discharge lamp
US3663858 *6 nov. 197016 mai 1972Giuseppe LisitanoRadio-frequency plasma generator
Référencé par
Brevet citant Date de dépôt Date de publication Déposant Titre
US4266162 *16 mars 19795 mai 1981Gte Laboratories IncorporatedElectromagnetic discharge apparatus with double-ended power coupling
US4359668 *15 juil. 198116 nov. 1982Fusion Systems CorporationMethod and apparatus for igniting electrodeless discharge lamp
US4414488 *26 juin 19808 nov. 1983Deutsche Forschungs- Und Versuchsanstalt Fur Luft-Und Raumfahrt E.V.Apparatus for producing a discharge in a supersonic gas flow
US4498029 *2 juil. 19845 févr. 1985Mitsubishi Denki Kabushiki KaishaMicrowave generated plasma light source apparatus
US4507587 *24 mai 198226 mars 1985Fusion Systems CorporationMicrowave generated electrodeless lamp for producing bright output
US4521717 *29 nov. 19824 juin 1985Leybold-Heraeus GmbhApparatus for producing a microwave plasma for the treatment of substrates, in particular for the plasma-polymerization of monomers thereon
US4575636 *30 avr. 198411 mars 1986Rca CorporationDeep ultraviolet (DUV) flood exposure system
US4586115 *6 avr. 198429 avr. 1986Zimmerman S MortElectromagnetic radio frequency excited explosion proof lighting method and system
US4625120 *30 avr. 198425 nov. 1986Rca CorporationDeep ultraviolet (DUV) flood exposure system
US4645973 *2 oct. 198424 févr. 1987L'Air Liquide, Societe Anomyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeHyperfrequency energy plasma torch
US4673846 *26 févr. 198516 juin 1987Mitsubishi Denki Kabushiki KaishaMicrowave discharge light source apparatus
US4728863 *4 déc. 19851 mars 1988Wertheimer Michael RApparatus and method for plasma treatment of substrates
US4749916 *18 juin 19857 juin 1988Mitsubishi Denki Kabushiki KaishaIlluminator for cultivating plant
US4792725 *10 déc. 198520 déc. 1988The United States Of America As Represented By The Department Of EnergyInstantaneous and efficient surface wave excitation of a low pressure gas or gases
US4812957 *23 juil. 198514 mars 1989Fusion Systems CorporationOptical system for uniform illumination of a plane surface
US4937532 *14 sept. 198826 juin 1990The Regents Of The University Of CaliforniaMethod of accelerating photons by a relativistic plasma wave
US4939424 *23 mai 19893 juil. 1990Leybold AktiengesellschaftApparatus for producing a plasma and for the treatment of substrates
US4984534 *9 févr. 198915 janv. 1991Idemitsu Petrochemical Co., Ltd.Method for synthesis of diamond
US4989542 *24 mai 19885 févr. 1991National Institute For Research In Inorganic MaterialsApparatus for synthesizing diamond
US4990789 *3 oct. 19895 févr. 1991Osamu UesakiUltra violet rays generator by means of microwave excitation
US5039918 *6 avr. 199013 août 1991New Japan Radio Co., Ltd.Electrodeless microwave-generated radiation apparatus
US5059400 *5 mars 199022 oct. 1991Societe Anonyme : Societe ProlaboApparatus for chemical reaction by wet process comprising a stack equipped with a barrier against the propagation of microwaves
US5070277 *15 mai 19903 déc. 1991Gte Laboratories IncorporatedElectrodless hid lamp with microwave power coupler
US5113121 *15 mai 199012 mai 1992Gte Laboratories IncorporatedElectrodeless HID lamp with lamp capsule
US5133825 *7 avr. 198828 juil. 1992Hi Tachi, Ltd.Plasma generating apparatus
US5144146 *11 avr. 19911 sept. 1992Ultraviolet Energy Generators, Inc.Method for destruction of toxic substances with ultraviolet radiation
US5166528 *4 oct. 199124 nov. 1992Le Vay Thurston CMicrowave-actuated ultraviolet sterilizer
US5298837 *22 sept. 199229 mars 1994Online Energy, Inc.Ultraviolet flash dryer
US5344433 *12 nov. 19926 sept. 1994Dimotech Ltd.Apparatus for the treatment of skin wounds
US5361274 *12 mars 19921 nov. 1994Fusion Systems Corp.Microwave discharge device with TMNMO cavity
US5470541 *28 déc. 199328 nov. 1995E. I. Du Pont De Nemours And CompanyApparatus and process for the preparation of hydrogen cyanide
US5504391 *27 janv. 19932 avr. 1996Fusion Systems CorporationExcimer lamp with high pressure fill
US5579332 *24 oct. 199426 nov. 1996United Kingdom Atomic Energy AuthorityPlasma light source
US5614151 *7 juin 199525 mars 1997R Squared Holding, Inc.Electrodeless sterilizer using ultraviolet and/or ozone
US5666640 *2 avr. 19969 sept. 1997Daniylchev; Vladimir A.Microwave powered ozone producing system
US5686793 *25 mars 199611 nov. 1997Fusion Uv Systems, Inc.Excimer lamp with high pressure fill
US5804922 *7 juin 19958 sept. 1998Fusion Lighting, Inc.Lamp with controllable spectral output
US5818167 *1 févr. 19966 oct. 1998Osram Sylvania Inc.Electrodeless high intensity discharge lamp having a phosphorus fill
US5825132 *7 avr. 199520 oct. 1998Gabor; GeorgeRF driven sulfur lamp having driving electrodes arranged to cool the lamp
US5914564 *7 avr. 199422 juin 1999The Regents Of The University Of CaliforniaRF driven sulfur lamp having driving electrodes which face each other
US5931557 *3 sept. 19973 août 1999Danilychev; Vladimir A.Energy efficient ultraviolet visible light source
US5977712 *23 janv. 19972 nov. 1999Fusion Lighting, Inc.Inductive tuners for microwave driven discharge lamps
US5981955 *23 mai 19979 nov. 1999The Regents Of The University Of CaliforniaIsotope separation using a high field source and improved collectors
US6110542 *5 mars 199929 août 2000Semiconductor Energy Laboratory Co., Ltd.Method for forming a film
US620723730 sept. 199827 mars 2001Kimberly-Clark CorporationElastic nonwoven webs and films
US621766120 nov. 199817 avr. 2001Semiconductor Energy Laboratory Co., Ltd.Plasma processing apparatus and method
US636244912 août 199826 mars 2002Massachusetts Institute Of TechnologyVery high power microwave-induced plasma
US642338320 nov. 199823 juil. 2002Semiconductor Energy Laboratory Co., Ltd.Plasma processing apparatus and method
US652843930 sept. 19984 mars 2003Kimberly-Clark Worldwide, Inc.Crimped polymeric fibers and nonwoven webs made therefrom with improved resiliency
US661099026 juil. 200026 août 2003Quay Technologies Ltd.UV light source
US6633130 *12 avr. 200214 oct. 2003Lg Electronics Inc.Cooling system of lighting apparatus using microwave energy
US666034210 août 20009 déc. 2003Semiconductor Energy Laboratory Co., Ltd.Pulsed electromagnetic energy method for forming a film
US6677001 *6 juin 199513 janv. 2004Semiconductor Energy Laboratory Co., Ltd.Microwave enhanced CVD method and apparatus
US6770896 *3 févr. 20033 août 2004Xtreme Technologies GmbhMethod for generating extreme ultraviolet radiation based on a radiation-emitting plasma
US68381268 juil. 20024 janv. 2005Semiconductor Energy Laboratory Co., Ltd.Method for forming I-carbon film
US6841790 *7 oct. 200311 janv. 2005Miltec CorporationSnap-in radio frequency screen for ultraviolet lamp system
US7060931 *16 avr. 200413 juin 2006Sungkyunkwan UniversityNeutral beam source having electromagnet used for etching semiconductor device
US708163620 août 200225 juil. 2006Quay Technologies LimitedPulsed UV light source
US71255888 déc. 200324 oct. 2006Semiconductor Energy Laboratory Co., Ltd.Pulsed plasma CVD method for forming a film
US712963919 janv. 200531 oct. 2006Lg Electronics Inc.Middle output electrodeless lighting system
US7180082 *22 févr. 200520 févr. 2007The United States Of America As Represented By The United States Department Of EnergyMethod for plasma formation for extreme ultraviolet lithography-theta pinch
US746297815 sept. 20009 déc. 2008Nordson CorporationApparatus and method for generating ultraviolet radiation
US7566890 *19 oct. 200428 juil. 2009Jenact LimitedUV light source
US775961916 sept. 200520 juil. 2010Jenact LimitedSterilisation of duct flows
US7794673 *24 sept. 200714 sept. 2010Severn Trent Water Purification, Inc.Sterilizer
US7921804 *8 déc. 200812 avr. 2011Amarante Technologies, Inc.Plasma generating nozzle having impedance control mechanism
US7923706 *3 oct. 200812 avr. 2011Nordson CorporationUltraviolet curing apparatus for continuous material
US797667213 févr. 200712 juil. 2011Saian CorporationPlasma generation apparatus and work processing apparatus
US802649713 nov. 200827 sept. 2011Jenact LimitedMethods and apparatus for generating ultraviolet light
US80350577 juil. 200511 oct. 2011Amarante Technologies, Inc.Microwave plasma nozzle with enhanced plume stability and heating efficiency
US821606117 mars 200610 juil. 2012Wms Gaming Inc.Wagering games with unlockable bonus rounds
US826919010 sept. 201018 sept. 2012Severn Trent Water Purification, Inc.Method and system for achieving optimal UV water disinfection
US84268009 sept. 201123 avr. 2013Vela Technologies, Inc.Integrating optical systems and methods
US885473416 déc. 20097 oct. 2014Vela Technologies, Inc.Integrating optical system and methods
US925165511 févr. 20152 févr. 2016IgtGaming device having a selectively accessible bonus scheme
US954281126 janv. 201610 janv. 2017IgtGaming device having a selectively accessible bonus scheme
US960973228 sept. 201528 mars 2017Energetiq Technology, Inc.Laser-driven light source for generating light from a plasma in an pressurized chamber
US20020176796 *4 févr. 200228 nov. 2002Purepulse Technologies, Inc.Inactivation of microbes in biological fluids
US20030021910 *8 juil. 200230 janv. 2003Semiconductor Energy Laboratory Co., Ltd.Plasma processing apparatus and method
US20030146398 *3 févr. 20037 août 2003Xtreme Technologies GmbhMethod for generating extreme ultraviolet radiation based on a radiation-emitting plasma
US20040115365 *8 déc. 200317 juin 2004Semiconductor Energy Laboratory Co., Ltd.Method for forming a film
US20040232358 *20 août 200225 nov. 2004Moruzzi James LodovicoPulsed uv light source
US20050194361 *16 avr. 20048 sept. 2005Sungkyunkwan UniversityNeutral beam source having electromagnet used for etching semiconductor device
US20050196549 *11 avr. 20058 sept. 2005Semiconductor Energy Laboratory Co., Ltd.Microwave enhanced CVD method and apparatus
US20050264215 *19 oct. 20041 déc. 2005Jenact LimitedUV light source
US20060076902 *19 janv. 200513 avr. 2006Lg Electronics Inc.Middle output electrodeless lighting system
US20070193517 *13 févr. 200723 août 2007Noritsu Koki Co., Ltd.Plasma generation apparatus and work processing apparatus
US20070273262 *28 avr. 200529 nov. 2007Pascal SortaisLight Source with Electron Cyclotron Resonance
US20070294037 *2 août 200520 déc. 2007Lee Sang HSystem and Method for Optimizing Data Acquisition of Plasma Using a Feedback Control Module
US20080017616 *7 juil. 200524 janv. 2008Amarante Technologies, Inc.Microwave Plasma Nozzle With Enhanced Plume Stability And Heating Efficiency
US20080131337 *24 sept. 20075 juin 2008James LucasSterilizer
US20090127480 *13 nov. 200821 mai 2009Jenact LimitedMethods and apparatus for generating ultraviolet light
US20100074810 *12 nov. 200825 mars 2010Sang Hun LeePlasma generating system having tunable plasma nozzle
US20100084574 *3 oct. 20088 avr. 2010Nordson CorporationUltraviolet curing apparatus for continuous material
US20100140509 *8 déc. 200810 juin 2010Sang Hun LeePlasma generating nozzle having impedance control mechanism
US20100201272 *9 févr. 200912 août 2010Sang Hun LeePlasma generating system having nozzle with electrical biasing
US20100254853 *21 avr. 20097 oct. 2010Sang Hun LeeMethod of sterilization using plasma generated sterilant gas
US20110108741 *16 déc. 200912 mai 2011Vela Technologies, Inc.Integrating Optical System and Methods
US20110253542 *13 nov. 200920 oct. 2011Achille Zanzucchi Editore Di Achille ZanzucchiStatic electromagnetic apparatus for accelerating electrically neutral molecules utilizing their dipolar electric moment
US20140231669 *18 févr. 201421 août 2014Sumitomo Heavy Industries, Ltd.Microwave ion source and method for starting same
USRE32626 *20 nov. 198622 mars 1988Mitsubishi Denki Kabushiki KaishaMicrowave generated plasma light source apparatus
CN100550282C4 mars 200514 oct. 2009Lg电子株式会社Middle output electrodeless lighting system
DE3323637A1 *30 juin 19835 janv. 1984Fusion Systems CorpElektrodenlose lampe und dafuer vorgesehenes lampengehaeuse
DE19708148A1 *28 févr. 19973 sept. 1998Umex Ges Fuer Umweltberatung UElectrodeless ultraviolet gas discharge lamp excited by high frequency oscillator
DE102007031628A1 *6 juil. 200715 janv. 2009Eastman Kodak Co.Radiation source for fixing UV-crosslinkable toners on a printing material comprises a low-pressure gas discharge lamp containing a gas emitting in the UV spectrum and a microwave application unit with two separate microwave applicators
DE102007031628B4 *6 juil. 200721 juin 2012Eastman Kodak Co.UV-Strahlungsquelle
DE102007031629B3 *6 juil. 200719 mars 2009Eastman Kodak Co.Microwave stimulated-radiation source for use in printing medium fixing device, has segments positioned on different areas of lamp body, where microwave power output of one segment is adjusted independent of other segment
EP0279895A2 *17 août 198731 août 1988Leybold AktiengesellschaftDevice for producing a plasma and for treating substrates in said plasma
EP0279895B1 *17 août 19875 mai 1993Leybold AktiengesellschaftDevice for producing a plasma and for treating substrates in said plasma
EP0457242A1 *13 mai 199121 nov. 1991Osram Sylvania Inc.Electrodeless HID lamp with microwave power coupler
EP0517929A1 *1 juin 199116 déc. 1992Heraeus Noblelight GmbHIrradiation device with a high power radiator
EP1262091A1 *22 déc. 20004 déc. 2002Fusion Uv Systems, Inc.Lamp with self-constricting plasma light source
EP1262091A4 *22 déc. 200010 sept. 2003Fusion Uv Sys IncLamp with self-constricting plasma light source
EP1684330A1 *5 janv. 200526 juil. 2006Lg Electronics Inc.Middle output electrodeless lighting system
WO1994021096A1 *4 mars 199415 sept. 1994Universite Des Sciences Et Technologies De LillePlasma production device
WO1996040298A1 *7 juin 199619 déc. 1996R Squared Holding, Inc.Electrodeless sterilizer using ultraviolet and/or ozone
WO2000032244A1 *23 nov. 19998 juin 2000Quay Technologies LtdSteriliser
WO2001009924A1 *26 juil. 20008 févr. 2001Quay Technologies LimitedUv light source
WO2005117069A1 *28 avr. 20058 déc. 2005Pascal SortaisLight source with electron cyclotron resonance
WO2006103287A3 *31 mars 200614 déc. 2006Xavier PelletMicrowave device for treating a flux with visible radiation
WO2007037980A2 *12 sept. 20065 avr. 2007Robert Chrysler Brennan, Trustee For Sdi Technology TrustSystem, apparatus, and method for increasing particle density and energy by creating a controlled plasma environment into a gaseous media
WO2007037980A3 *12 sept. 200611 oct. 2007Robert Chrysler BrennanSystem, apparatus, and method for increasing particle density and energy by creating a controlled plasma environment into a gaseous media
WO2014141184A114 mars 201418 sept. 2014Consiglio Nazionale Delle RicerchePacked microwave powered lamp
Classification aux États-Unis315/39, 422/186.3, 422/186.29, 422/906, 376/123, 422/186.5, 250/504.00R, 250/493.1, 376/140
Classification internationaleH05H1/46, B01J19/12, H01J65/04
Classification coopérativeB01J19/124, H01J65/046, H01J65/044, Y10S422/906, B01J2219/0894, H05H1/46, B01J19/122, B01J19/129, B01J19/126, B01J2219/1227
Classification européenneB01J19/12D2B, H01J65/04A1, H01J65/04A2, B01J19/12D, H05H1/46, B01J19/12D6, B01J19/12D12