Answers are grounded in this paper and cite their sources.
Time-resolved measurements of specular reflectivity of polished pure aluminum surfaces subjected to intense 10.6-μm pulsed-laser radiation in vacuum are reported. A sharp decrease in reflectivity to an anomalously low value (35%) was observed midway in the pulse followed by nearly complete recovery of full reflectivity near the end of the pulse. The peak-power-density threshold for this phenomenon was found to agree with the intrinsic surface melt threshold as determined from numerical heat-transfer calculations and microscopic examination of the samples.
No takes yet. Share an insight, caveat, or question.
Walters et al. (1978) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: