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COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Modelling of spectral line shapes in electrodeless discharge lamps G. Revalde 1, N.

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Presentation on theme: "COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Modelling of spectral line shapes in electrodeless discharge lamps G. Revalde 1, N."— Presentation transcript:

1 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Modelling of spectral line shapes in electrodeless discharge lamps G. Revalde 1, N. Denisova 2, A.Skudra 1 1 High-resolution spectroscopy and light source technology laboratory, Institute of Atomic Physics and Spectroscopy, University of Latvia 2 Institute of Theoretical and Applied Mechanics, Novosibirsk, Russia Web:

2 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Electrodeless lamps: Bright radiators in the broad spectral range (VUV - IR); Filled with a gas or metal vapor+buffer gas; No electrodes – long working life Inductive coupled/ capacitatively coupled; Hf, Rf Electromagnetic field excitation; Different designs and types in dependence on application

3 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Our experience and technology : manufacturing of electrodeless lamps containing such elements as Sn, Cd, Hg, Zn, Pb, As, Sb, Bi, Fe, Tl, In, Se, Te, Rb, Cs, I 2, H 2, He, Ne, Ar, Kr, Xe as well as combined Hg-Cd, Hg-Zn, Hg- Cd-Zn, Se-Te etc (also isotope fillings, as example Hg202) etc. for different applications

4 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Examples

5 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Spectral line profile is important to control self-absorption or radiation trapping for design consideration of low pressure lamps for lighting application - resonance radiation of Hg at 185 nm and 254 nm in all cases when narrow spectral line is necessary – for atomic absorption, optical pumping, quantum standards, for spectral reference to get important plasma parameters (such as gas temperature, lower state density, collisional broadening)

6 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Example of atomic absorption spectrometry Narrow, not self-absorbed spectral line is neccessary -- > to get high differential cross section of atomic absorption --> low limits of detection

7 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia But with self-absorption dependent on – working regime – filling pressure, – filling content – lamp geometry – excitation geometry Possibilty to avoid the self-absorption – optimisation of all parameters

8 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Capillary Lamp Capillary Monochromator Power supply Fabry – Perrot interferometer PhotomultiplierComputer Lens Vacuum chamber Amplifier Line profile measurements High-resolution scanning Fabry-Perrot interferometer

9 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia High-resolution scanning Zeeman spectrometer for resonance lines

10 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Hg 253,7 nm Natural filling Hg 202 isotope In dependence on the Tcold spot On the working regime

11 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia

12 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia

13 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia

14 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia

15 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Zeeman spectrometerFabry-Perrot spectrometer Necessity to take into account the instrument function, also by a small FWHM value of instrument profile due to the influence on the self-reversal Examples of experimental and modeled profiles

16 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Hg 202 /Ar(2 Torr) experimental and modeled profiles of nm line, spherical discharge

17 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia 160 mA, Tc.spot.=72 o C 50 mA, Tc.spot.=72 o C Example, Hg 202 (99.8 %) 253,7 nm line Distribution of the intensitites other isotopic components (0.2 %) also fitted

18 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Hg 202 /Ar capillary Experiment Reff = 0,8% ( ninstr =0,071 cm -1 ).

19 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Hg 202 /Ar (10 Torr) capillary, nm line, T cold spot = 25 o C The estimated optical density in the line center The total experimental spectral line FWHM as a function of the HF generator current The estimated temperature of the emitting atoms

20 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Hg 202 /Ar (2 Torr) capillary, nm line, T cold spot = 65 o C

21 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Comparison- spherical and capillary 160 mA and T cold spot =25 o C, p Ar =10 Torr

22 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Hg visible triplett Experimental nm line shapes in dependence on the HF generator current for a HF isotope electrodeless lamp Example of the line shape fitting of Hg nm line, HF generator current i=100 mA. Fitted parameters wG=0,032 cm-1; wL=0,002 cm-1; R=0,72, kol=1,8, n=13, using the model of Cowan and Dieke

23 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Experimental radial distributions of Hg nm line intensity, emitted from HF electrodeless lamp by two different discharge power values. Example of the line shape fitting of nm Hg line, i=140 mA. Fitted parameters wG=0,033 cm-1; wL=0,002 cm-1; R=0,8; kol=35; with taking into account the measured distributions.

24 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Helium example Optical density in the line center in dependence on the HF generator current estimated for 501,6 nm and 567,8 nm lines in the helium electrodeless discharge using the model of uniformly excited source. Experimental radial distributions of He 587,6 nm line intensity, emitted from helium HF electrodeless lamp by two different discharge power values.

25 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia Thank you for your attention!

26 COST 529, April 12-16, Madeira, Portugal IAPS, University of Latvia


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