1. TU/e Polydiagnostics on the COST lamp Aim: To calibrate various methods against each others find the truth & and nothing but the truth For validating models Joost van der Mullen Technische Universiteit Eindhoven Madeira Model Inventory Workshop April 12-16: 2005

2. TU/e The problems; the challenges Three methods to measure the temperature Usually give three (or even more) answers Even for so-called “LTE” plasma: differences up to 30% Difficult to answer the question: is LTE present? Or: are the method (in)correct? Impossible to validate the models

3. TU/e Final Goal To find Easy/Global observables To Characterise the plasma: n e, T e etc To determine the state of the lamp: Light technical properties Remaining Lifetime Candidate Easy/Global observables (Filtered) Emission Electronic behavior

4. TU/e Polydiagnostics on good defined plasma Different people Various techniques Limited amount of Lamps Cost Reference LampFamily

5. TU/e The COST reference LampFamily: Second generation: (in preparation) 1) Outer envelope is filled with N_2; Additional convection cooling 2) electrodes simplified (no spirals but rods) Request on last COST meeting: plasma-electrode interactions. First generation Shortcomings: burner wall too hot  limitation in life span & power. Invitation to work on 1ste generation: requests for the final design. The followings types 1 ste generation are available: a) Pure Hg; b) Hg with Na c) Hg with Dy.

6. TU/e Provided from: EINLighTRED Philips Licht ASMLDraka Tue/N Eindhoven INstitute for Lighting Technology Research and EDucation Philips NatLab COST Europa Philips Aachen

7. TU/e The plasmas: in MH lamps 10 bar Hg 10 mbar add Color non-uniformity Segregation

8. TU/e 2-D 3D Plasma: orientation dependent Gravitation

9. TU/e Main characteristics Main feature:Majority plasma properties Minority species Largely non-linear Example: Color: orientation dependent F e (ion) = 10 9 F g (ion) Chemistry:10 bar Hg : 20 mbar DyI 3

10. TU/e General exploration phenomena Demands: High Efficiency Radiation Long life span  T large High T central LowT wall High p Hg  large Buoyancy Continuity

11. TU/e Elemental: whats in that name ?? Species: H 2 O; OH; O; H; H + etc. [H] = atomic concentration: H atoms per volume {H} = elemental concentration: all H atoms per volume irrespective binding/state {H} = [H] + 2[H 2 O] + [H + ]

12. TU/e Radial segregation; Diffusion Centrum T high atoms small fast Wall T low Molecules Large slow N ele a v a = N ele m v m N ele a / N ele m = v m /v a << 1

13. TU/e Axial segregation Large N ele at wall pushed down Small N ele at centrpushed up Net effect: Emiting species Pushed-down Or differently Quick atoms can leave upstream easily Slow molecules stay streaming downwards

14. TU/e Competition Convection Diffusion Chemistry Radiation

15. TU/e Methods Grand Modeling Radiation Transport 3D Polydiagnostics X-ray Abs Tomo Emission Absorption: LaserD Thomson Sc Flow Patterns E-Field Chemistry Diffusion X-ray Flouresc Absorption Broadband Self-Absorption In Search for COST cooperation

16. TU/e Convergence Polydiagnostics X-ray Abs Tomo X-ray Flouresc Emission Laser Diode Abs Thomson Sc Normal Terrestial: 1 g Zero g The Truth

17. TU/e The Final Goal Can we by just looking to easy/global observables Characterise the plasma:n e ; T e, etc Assess the status of the lamp: Efficiency Remaining lifetime Examples Easy/Global observables: Emission/Filters V/I response

18. TU/e Settings Model – Diagnositcs validation for Several settings Buffer gas Radiation “gas” Fillings Power Quantity Waveform Gravitation Zero g Extreme g Vessel Geometry

19. TU/e Zero g: methods limited

20. TU/e Normal conditions many possibilities Guided by Atomic State Distribution Function (ASDF) Passive spectroscopy Emission Intensity: Line Continuum Integrated, Line Shape/Reversal Active Spectroscopy Fluorescence: LIF Xray F Absorption: Laser (line) broadband Scattering: Thomson

21. TU/e The ASDF TS Slope by TS ES E Saha Jump Ion. En. 0 by LIF and AS Ln (n/g) LiRe

22. TU/e Emission Spectroscopy Intensity as function of Wavelength Wavelength calibration big effort Calibrate Intensity of lines ALI Calculate Density of Dysprosium Atomic State Distribution Function (ASDF) Gives T; gives various n’s

23. TU/e Setup ES Czerny-Turner 1m-monochromator ST-6 CCD ST-2000 CCD lamplens dia Two CCD Global Precise

24. TU/e Spectral Impression: grass field Line identification: not trivial

25. TU/e Radial profile Dy1

26. TU/e Abel inversion  (r): emission as a function of radius r I(x): measured lateral emission-line intensity

27. TU/e ALI

28. TU/e ASDF for central position T=5524 K DyI DyII Note Steeper Slope

29. TU/e Future Plans Join forces with Plasimo Compare results with that of other techniques Still much work : Spectrum identification Measurements Important Part of the collection Easy/Global Observable ALI will be The reference frame: For other thechniques COST cooperation

30. TU/e Absorption Spectroscopy burner outer balloon lens Ilens IIlaser lens III interferenc e filter diode array Dy groundstate density Charlotte Groothuis

31. TU/e Linking absorption with density

32. TU/e Lateral

33. TU/e

34. Lateral

35. TU/e Segregation parameter λ ≡ ∂p /∂z

36. TU/e X-ray absorption Xiaoyan Zhu & Evert Ridderhof

37. TU/e Procedure Hg is dominant  p /p <<1 (n T) any pos = (n T) wall Pyrometer T g on any position Xray

38. TU/e XRA on Helios lamp Exposure time: 200s. on off 258 464 788 852 1012

39. TU/e

40. The Wall temperature as a function axial position z

41. TU/e The Radial T profile as a F(z) New

42. TU/e The Shape as a F(z)

43. TU/e The shape as a F(power)

44. TU/e The Radial T profile as a F(z) T of 5000 K In Hg part Are low Blame Abel Inv ?

45. TU/e X-ray Induced Fluorescence measurement of segregation in MH lamps Tanya Nimalasuriya (TU/e) Evert Ridderhof (TU/e) John J. Curry (NIST) Craig J. Sansonetti (NIST) Sharvjit Shastri (APS)

46. TU/e Introduction

47. TU/e Advanced Photon Source

48. TU/e Experiment station E.J. Ridderhof

49. TU/e XRF sketch 4 cm X-ray Beam Ge Detector 7 cm Ion Chamber Pb shield W slits W slits burner jacket The x-ray beam is produced by the Sector 1 Insertion Device beam line at the Advanced Photon Source at the Argonne National Laboratory J.J.Curry NIST

50. TU/e XRF basic principle An electron in the K shell is ejected from the atom by an external primary excitation x- ray, creating a vacancy. An electron from the L or M shell "jumps in" to fill the vacancy. In the process, it emits a characteristic x-ray unique to this element and in turn, produces a vacancy in the L or M shell.

51. TU/e XRF spectral lines Principal fluorescence lines produced by K-shell excitation in Dy. The excited levels correspond to a singly ionized atom X-ray induced fluorescence spectrum excited by 70 keV photons at x/R = 0.56. x is displacement from the arc axis in the direction of the detector and R=4.5 mm is the arc tube radius J.J.Curry NIST

52. TU/e XRF advantages X-ray induced fluorescence: - determines elemental densities of Dy,Hg - is effective anywhere in the burner No inversion technique is needed T profile with Hg densities

53. TU/e XRF-Spectra 1mm above bottom electrode x, z: center 1mm above bottom electrode z: center, x: at wall I Ce Dy I Ce Dy W

54. TU/e Wall influence Dy density profile Density (cm -3 ) normalised radial position 6.7% 21 % 36 % 50 % Dissociation Ionisation

55. TU/e Ratio elemental densities Dy/ Hg Relative concentration T. Nimalasuriya, J.J. Curry, C.J. Sansonetti, E.J. Ridderhof Wall influence Dissociation Ionisation

56. TU/e Diffusion versus (radial) convection

57. TU/e Temperature profile from Hg density XRF 140 W XRA 142 W, X.Y. Zhu T XRF < T XRA !!

58. TU/e XRF Conclusions In future: compare results with Absolute Line Intensity measurements and Laser Absorption Spectroscopy Polydiagnostics Axial and radial segregation clearly observed T profile XRF shows similarities with XRA; T XRF lower !!

59. TU/e Conclusions TS (versus XRA) TS for the first time applied on real lamp Indications that the LTE assumption is not valid – Thermal: T e - T gas  2000 K XRA compared – Chemical: T exc  Te, b 1 >10. – Plasma always ionizing even at I-zero-crossing!!

60. TU/e Zero g

61. TU/e Parabolic flights  20 seconds 1.8 G  25 seconds 0 G  20 seconds 1.8 G

62. TU/e

64. Setup in zero g plane

65. TU/e Setup PFC

66. TU/e Parabolic Flights

67. TU/e

68. Fisher model Competition between Diffusion and Convection. Gravitation

69. TU/e Prediction for increased convection Left hand side: Decrease diffusion Increase convection More demixing Right hand side: Decrease diffusion Increase convection Better mixing

70. TU/e The Convection/Diffusion competition 0g: Diffusion solely 1g:Optimal competition 2g: Convection dominant

71. TU/e Results for absorption

72. TU/e Sphere of Ullbricht: integrated intensity Job Beckers/Winfred Stoffels  Highly reflective diffusive coating  Integrates all light  Homogenious light the whole sphere

73. TU/e ARGES burner, DyI 3 -salt, 5 mg Hg 1.Output increases cause of axial de-segregation 2.(right on the “Fischer curve”) 3.Output increases cause of disappearence of axial segregation (totally left on the “Fischer curve”) and new equilibrium. 4.Equilibrium comes back

74. TU/e Conclusions The total Light output varies with gravity. Difference of the light output can be explained by the theory of axial- radial segregation of lamps at the right side “Fischer curve”. Lamps do not reach equilibrium at the end of a zero-g phase. The results inegrated emission agree with absorption

75. TU/e International Space Station

76. TU/e ISS data analysis Dy 642 and Hg 579 lateral profile abel inversion T profile using absolute measurement of Hg density profile of Dy 642

77. TU/e Analysis Dy 642

78. TU/e Concluding Remarks Polydiagnostics is an enormous field Preliminary work on active and passive spectr has been done Strong indications: LTE not present under high pressure conditions There is need for much more COST projects ALI the best platform for mutual calibration Line identification: not trivial & A-values needed