Theoretical model for transient cataphoretic segregation in a discharge tube with large cylindrical end volumes

Ongena, J.; Sanctorum, C.; Wieme, Willem

doi:10.1016/0378-4363(84)90050-0

Cited by 2 publications

(1 citation statement)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Later on, the development of the models became based on solving the particle conservation equation/the macroscopic diffusion equation like those by Shair [34,35], Oskam [36], Gaur [13,37], Metze [18], Sanctorum [38] and Ongena [39]. These models with all their respective assumptions again revealed the same dependencies as obtained above; in the respective cases only exponential dependencies were found, if the densities of the segregated species were low.…”

Section: Existing Models and Their Applicabilitymentioning

confidence: 64%

Axial mercury segregation in direct current operated low-pressure argon–mercury gas discharge: Part II. Model

Gielen¹,

Groot²,

Dijk³

et al. 2004

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

In a previous paper we had presented experimental results on mercury segregation due to cataphoresis in direct current operated low-pressure argon–mercury gas discharges. In this paper, we present our model to describe cataphoretic segregation in argon (or another noble gas)–mercury discharges. The model is based on the balance equations for mass and momentum and includes electrophoresis effects of electrons on mercury. Good agreement is found between the experimental results and model calculations. The model confirms our experimental observation that the mercury vapour pressure gradient depends on the local mercury vapour pressure. Furthermore, the model predicts the reversal of the direction of the transport of mercury under certain conditions (the phenomenon known as retrograde cataphoresis).

show abstract

Section: Existing Models and Their Applicabilitymentioning

confidence: 64%

Axial mercury segregation in direct current operated low-pressure argon–mercury gas discharge: Part II. Model

Gielen¹,

Groot²,

Dijk³

et al. 2004

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

Axial mercury segregation in direct current operated low-pressure argon–mercury gas discharges: Part I. Experimental

Gielen

Groot

Dijk

et al. 2004

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Due to cataphoresis, axial segregation of mercury will occur when the gas discharge of a fluorescent lamp is operated by means of a direct current. A consequence of this is a non-uniform axial luminance distribution along the lamp. To determine the degree of axial mercury segregation experimentally, axial luminance distributions have been measured which are converted into axial mercury vapour pressure distributions by an appropriate calibration method. The mercury segregation has been investigated for variations in lamp tube radius (3.6–4.8 mm), argon buffer gas pressure (200–600 Pa) and lamp current (100–250 mA) at mercury vapour pressures set at the anode in the range from 0.2 to 9.0 Pa. From the experiments it has been concluded that the mercury vapour pressure gradient at any axial position for a certain lamp tube diameter, argon pressure and lamp current depends on the local mercury vapour pressure. This observation is in contrast to assumptions made in earlier modelling publications in which one mercury vapour pressure gradient is used for all axial positions. By applying a full factorial design, an empirical relation of the mercury segregation is found for any set of parameters inside the investigated parameter ranges.

show abstract

Theoretical model for transient cataphoretic segregation in a discharge tube with large cylindrical end volumes

Cited by 2 publications

References 3 publications

Axial mercury segregation in direct current operated low-pressure argon–mercury gas discharge: Part II. Model

Axial mercury segregation in direct current operated low-pressure argon–mercury gas discharge: Part II. Model

Axial mercury segregation in direct current operated low-pressure argon–mercury gas discharges: Part I. Experimental

Contact Info

Product

Resources

About