2-D Images of the Metal-Halide Lamp Obtained by Experiment and Model

Flikweert, A.J.; Beks, M.L.; Nimalasuriya, T Tanya; Kroesen, G.M.W.; Mullen, J.J.A.M. van der; Stoffels, WW Winfred

doi:10.1109/tps.2008.917784

Cited by 6 publications

(9 citation statements)

References 9 publications

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“…Furthermore parabolic flights were carried out (0-2g, for periods of about 20 s) [17]. More recently a centrifuge was built, which can achieve gravity conditions from 1 to 10g [2,18,19]. The additive distribution in the lamp, in our case the two-dimensional column density of ground state dysprosium atoms in a COST lamp [20], is measured by means of imaging laser absorption spectroscopy (ILAS) [2,18].…”

Section: Introductionmentioning

confidence: 99%

Imaging laser absorption spectroscopy of the metal-halide lamp under hyper-gravity conditions ranging from 1 to 10g

Flikweert¹,

Meunier²,

Nimalasuriya³

et al. 2008

J. Phys. D: Appl. Phys.

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The metal-halide (MH) lamp shows an unwanted non-uniform distribution of the metal additive (Dy in our case), caused by convection and diffusion phenomena. MH lamps with various Hg pressures and burner lengths have been investigated by imaging laser absorption spectroscopy under varying gravity conditions in a centrifuge (1-10g). 2D ground state Dy density profiles have been determined. From these images, the density inhomogeneity and corrected axial segregation parameters are obtained. The profiles and parameters are affected by the axial temperature gradient, which is more pronounced for higher Hg pressures and shorter burner lengths.

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Section: Introductionmentioning

confidence: 99%

Imaging laser absorption spectroscopy of the metal-halide lamp under hyper-gravity conditions ranging from 1 to 10g

Flikweert¹,

Meunier²,

Nimalasuriya³

et al. 2008

J. Phys. D: Appl. Phys.

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show abstract

“…The amount of convection in the lamps depends on gravity [1,5,[20][21][22][23][24][25]. A centrifuge was built to investigate the lamp under varying gravitational accelerations.…”

Section: Centrifugementioning

confidence: 99%

“…The MH lamp is a high intensity discharge lamp with a good colour rendering index of ∼80 and a high luminous efficacy of about 100 lm W −1 [4][5][6][7][8][9][10][11][12][13][14]. The lamp is used in street lighting, stadium lighting, city beautification and shop lighting.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore parabolic flights were carried out (0-2g, for periods of about 20 s) [21,22]. More recently a centrifuge was built, in which we can achieve gravity conditions from 1-10g [1,5,23]. The additive distribution in the lamp has been measured by means of ALI measurements [2,12,20,23] and ILAS [1,5,22,24,25].…”

Section: Introductionmentioning

confidence: 99%

“…More recently a centrifuge was built, in which we can achieve gravity conditions from 1-10g [1,5,23]. The additive distribution in the lamp has been measured by means of ALI measurements [2,12,20,23] and ILAS [1,5,22,24,25]. By using ALI absolute number densities of Dy and Hg, and temperature profiles were obtained.…”

Section: Introductionmentioning

confidence: 99%

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Emission spectroscopy for characterizing metal-halide lamps

Flikweert

Nimalasuriya

Kroesen

et al. 2008

J. Phys. D: Appl. Phys.

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The metal-halide (MH) lamp shows an unwanted axial non-uniform distribution of the metal additives when burning in vertical position, which is caused by the interplay between convection and diffusion. Various MH lamps are investigated by means of emission spectroscopy under varying gravity conditions (1–10g) in a centrifuge. The method yields spectra, axial inhomogeneity parameters and axially integrated intensities. The method is easier than methods used before on the same type of lamp. Measurements on lamps with DyI3 as salt filling are used as a calibration of the setup. After comparison with the earlier measurements, we conclude that the new emission spectroscopy is valid for characterization of MH lamps. Next, we apply the method on commercial lamps (Philips MASTER CosmoWhite). For these lamps, in addition NaI densities at the wall and axial temperature profiles are obtained by using self-reversed lines of Na and Hg, respectively.

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The Metal-Halide Lamp Under Varying Gravity Conditions Measured by Emission and Laser Absorption Spectroscopy

Flikweert

Nimalasuriya

Kroesen

et al. 2009

Microgravity Sci. Technol.

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Diffusive and convective processes in the metal-halide lamp cause an unwanted axial colour segregation. Convection is induced by gravity. To understand the flow phenomena in the arc discharge lamp it has been investigated under normal laboratory conditions, micro-gravity (ISS and parabolic flights) and hyper-gravity (parabolic flights 2g, centrifuge 1g-10g). The measurement techniques are webcam imaging, and emission and laser absorption spectroscopy. This paper aims to give an overview of the effect of different artificial gravity conditions on the lamp and compares the results from the three measurement techniques.

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2-D Images of the Metal-Halide Lamp Obtained by Experiment and Model

Cited by 6 publications

References 9 publications

Imaging laser absorption spectroscopy of the metal-halide lamp under hyper-gravity conditions ranging from 1 to 10g

Imaging laser absorption spectroscopy of the metal-halide lamp under hyper-gravity conditions ranging from 1 to 10g

Emission spectroscopy for characterizing metal-halide lamps

The Metal-Halide Lamp Under Varying Gravity Conditions Measured by Emission and Laser Absorption Spectroscopy

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