Skip to main content

NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

X-Ray Induced Fluorescence Measurement of Segregation in a DyI3 Metal-Halide Lamp

Published

Author(s)

T Nimalisuriya, John J. Curry, Craig J. Sansonetti, E J. Ridderhof, S Shastri, A J. Flikweert, W W. Stoffels, M Haverlag, J J. van der Mullen

Abstract

X-ray induced fluorescence measurements, using high energy synchrotron radiation generated on the Sector 1 Insertion Device beamline at the Advanced Photon Source, were performed on a metal-halide lamp containing Hg and DyI$_3}$. Density distributions of Dy show significant axial and radial segregation. Density distributions of I show little axial and radial segregation, a surplus of I is formed in the discharge as Dy forms Dy silicates at the wall of the lamp burner. Axial segregation is quantified using the Fischer axial segregation parameter $\lambda$. For Dy $\lambda = 0.215 \pm 0.002$ mm$^-1}$, this is in agreement with $\lambda$ found with a laser absorptionmethod \citeFlikweert05}. The $\lambda$ value for Iodine was found to be four times smaller. From the Hg density distribution a temperature profile was constructed, using a wall temperature measurement for calibration.
Citation
Journal of Physics D-Applied Physics
Volume
40

Keywords

dysprosium, lighting, plasma, spectroscopy, x-ray

Citation

Nimalisuriya, T. , Curry, J. , Sansonetti, C. , Ridderhof, E. , Shastri, S. , Flikweert, A. , Stoffels, W. , Haverlag, M. and van der Mullen, J. (2007), X-Ray Induced Fluorescence Measurement of Segregation in a DyI3 Metal-Halide Lamp, Journal of Physics D-Applied Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=840863 (Accessed October 11, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created April 18, 2007, Updated October 12, 2021
Was this page helpful?