Spektroskopische und massenspektrometrische Untersuchungen zur Natriumverstärkung in Halogen-Metalldampfentladungen

Hilpert, K.; Seehawer, J.

doi:10.1007/978-3-642-52255-0_3

Cited by 9 publications

(15 citation statements)

References 30 publications

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“…Various spectroscopic methods have been developed to derive plasma temperatures from absolute or relative intensities of spectral lines or from their broadening. We have used a relative method developed by Seehawer [15][16][17] to determine axial profiles of plasma core temperature based on the well-known Bartels theory. This technique is relatively simple avoiding e.g.…”

Section: Spectroscopic Determination Of Axial Plasma Temperature Prof...mentioning

confidence: 99%

Investigation of the connection between plasma temperature and electrode temperature in metal-halide lamps

Fromm

Lieder

Gleixner

2002

J. Phys. D: Appl. Phys.

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Spatial profiles of electrode temperatures and plasma temperatures have been measured on `real' HID lamps filled with a commercial metal-halide compound. The absolute accuracy of pyrometric determination of electrode tip temperatures was ±30 K, while the determination of plasma core temperatures, using a modified Bartels method, has an accuracy of ±100 K. We could deduce a close correlation between the plasma temperature in front of an electrode Tp and its tip temperature Tt due to the influence of the cataphoresis. If Tp is reduced at the cathode the Tt value has also lowered, whereas Tp at the anode is raised together with its Tt data. This correlation disappears at ballast frequencies above 100 Hz, whereas the cataphoresis influence on Tp continues up to 500 Hz. Based on the latter limit, a rough estimation of the cataphoresis velocity delivers 700 cm s-1. As a tentative interpretation, we suggest that the connection between Tp and Tt is caused by an increase of the ion part of the total current at the cathode due to Na accumulation before it. Thus, the cathode has to emit fewer electrons and works at a lower temperature. Further results are the temporal behaviour of Tt depends on the ballast type. For vertical operation the strong influence of convection on Tt has also to be taken into account. Above 100 Hz, where only convection plays a role, the upper electrode Tt exceeds the Tt value of the lower electrode by nearly 400 K. This discrepancy one may explain, tentatively, by convection heating of the upper electrode and convection cooling of the lower one.

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Section: Spectroscopic Determination Of Axial Plasma Temperature Prof...mentioning

confidence: 99%

Investigation of the connection between plasma temperature and electrode temperature in metal-halide lamps

Fromm

Lieder

Gleixner

2002

J. Phys. D: Appl. Phys.

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“…The chemical activities of NaI in Table 3 and the NaI partial pressures for pure NaI [16] yield the NaI partial pressures in Fig. 4.…”

Section: Partial Pressures Sities Inmentioning

confidence: 99%

Thermodynamic Properties of the Melt of the NaI — DyI₃ System

Hilpert¹,

Miller

Gerads³

et al. 1990

Ber Bunsenges Phys Chem

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The vaporization of the phases of the NaI — DyI3 system present at a temperature of 1000 K, DyI3(s) + melt for 0 < xNaI < 0.53 and melt for 0.53 ≤ xNaI ≤ 1, has been investigated by Knudsen effusion mass spectrometry. The species NaI(g), (NaI)2(g), DyI3(g), NaDyI4(g), and Na2DyI5(g) were identified in the vapour and their partial pressures determined over the entire concentration range of the system. Chemical activities of NaI and DyI3 and excess chemical potentials of NaI were evaluated. The integral excess Gibbs energies of the melt were determined as negative and showed a minimum near the composition xNaI = 0.75 which may indicate the presence of short‐range ordering states of the composition 3NaI:DyI3 caused by the ionic complex [DyI6]3−. The partial pressures are discussed with respect to their significance for chemical vapour transport in metal halide lamps.

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“…According to the preceding section, the reversal maximum can be identified with the p-dependent maximum Y max (p) of the unique function (22) has an accuracy of <0.4% over the whole p range. The final result of Bartels' approach for the emissivity at the reversal maxima becomes…”

Section: Bartels Approachmentioning

confidence: 99%

“…The iteration cycle begins with the choice of an appropriate initial temperature distribution. Then, with the functions η i and η k , equation (20), all integrals in equations ( 20) and ( 21) can be numerically solved for different side-on positions u, and p ∞ (u) as well as M ∞ (u) followK s (u), cf (23), results with Y max according to equation (22). With these K s values equation ( 5) yields a new approximation for T (u) at all positions u with measured radiance maxima L s (u).…”

Section: Bartels Approachmentioning

confidence: 99%

“…However, the main limitations of both methods are retained. In [22] as well as in [23,24] further relative spectroscopic methods were suggested for temperature determination from optically thin and optically thick lines, recently applied in [25] to HID lamps. In [26,27] the axis temperature of high-pressure sodium lamps was related to the reversal maxima of the Na D lines by radiation transport calculations.…”

Section: Introductionmentioning

confidence: 99%

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Basic concepts of temperature determination from self-reversed spectral lines

Schneidenbach¹,

Franke²

2008

J. Phys. D: Appl. Phys.

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Complex high-pressure plasmas have become increasingly important in technical applications such as high-intensity discharge lamps. The knowledge of temperature distributions is of basic interest for the understanding of the physical mechanisms in these plasmas and for a selective manipulation of their properties. It is shown that self-reversed spectral lines provide a powerful diagnostic tool for temperature determination. The two most important approaches for the corresponding data analysis are reviewed and their limitations are discussed. On the basis of these approaches a new method is proposed which avoids the main limitations especially in the application to resonance lines. The temperature has been determined in a Hg/Ar and a Hg/Ar/TlI high-pressure discharge. Measured spectral radiances of the Hg 546.1 and 253.7 nm as well as Tl 377.6 nm lines are analysed and the potentials of the different methods are demonstrated.

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Spektroskopische und massenspektrometrische Untersuchungen zur Natriumverstärkung in Halogen-Metalldampfentladungen

Cited by 9 publications

References 30 publications

Investigation of the connection between plasma temperature and electrode temperature in metal-halide lamps

Investigation of the connection between plasma temperature and electrode temperature in metal-halide lamps

Thermodynamic Properties of the Melt of the NaI — DyI₃ System

Basic concepts of temperature determination from self-reversed spectral lines

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Spektroskopische und massenspektrometrische Untersuchungen zur Natriumverstärkung in Halogen-Metalldampfentladungen

Cited by 9 publications

References 30 publications

Investigation of the connection between plasma temperature and electrode temperature in metal-halide lamps

Investigation of the connection between plasma temperature and electrode temperature in metal-halide lamps

Thermodynamic Properties of the Melt of the NaI — DyI3 System

Basic concepts of temperature determination from self-reversed spectral lines

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Thermodynamic Properties of the Melt of the NaI — DyI₃ System