ATOMIC DENSITIES MEASURED RADIALLY IN METAL HALIDE LAMPS UNDER MICROGRAVITY
CONDITIONS WITH EMISSION AND ABSORPTION SPECTROSCOPY (ARGES)
Research Area: Life Support Systems and Habitation
Expedition(s): 8 and 9
Principal Investigator(s): ● Gerrit Kroesen, Eindhoven University of Technology,
Eindhoven, Netherlands
RESEARCH OBJECTIVES
The Atomic Densities Measured Radially in Metal
Halide Lamps Under Microgravity Conditions with
Emission and Absorption Spectroscopy (ARGES)
experiment investigates the High-Intensity Discharge
(HID) lamps (which utilize plasma technology) in
weightlessness. The experiment’s goal is to
understand imperfections that existed in the
technology in a similar way to the instabilities from
the Plasma Crystal Research (PK) experiment series
of experiments. These cause uneven light emission
and instabilities that could cause cracks in the burner
wall leading to non-functionality.
RESULTS
The experiment in which electronics company Philips and Eindhoven Technical University were
participating, was a 100% success and yielded to very promising results. The instabilities in the
lamp were expected to be shaped as a rotating helix, and instead they appeared to be a singly
bent curve that was not rotating. This fact is
very important in improving the
performance of the lamps, especially since
the instabilities occurred mainly in the most
efficient lamps.
Analysis afterwards indicated that the
rotation in the metal was caused solely by
convection and the curving was caused by
self-generated magnetic fields. For one
condition, residual gravity caused a very
slow rotation. As expected, the axial de-
mixing did not occur during the in-orbit
mission experiments, so the radial demixing
could indeed be studied undisturbed. The first results from the experiment actually concluded
that one of the main problems/influences causing flickering in the lamps was gravity.
High Intensity Discharge lamps for the Atomic
Densities Measured Radially in Metal Halide
Lamps Under Microgravity Conditions with
Emission and Absorption Spectroscopy. Pim
Kemps image.ARGES experiment chamber. Dutch Space image.