Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7674762 | Spectrochimica Acta Part B: Atomic Spectroscopy | 2014 | 5 Pages |
Abstract
The reason for the significant advantage offered by long-pulse (150Â ns) irradiation in underwater laser-induced breakdown spectroscopy (LIBS) is investigated from the point of view of the behavior of nascent cavitation bubbles. Shadowgraphs of nascent bubbles generated by pulsed laser irradiation of Cu targets in water were observed for two different pulse widths, 20Â ns and 150Â ns. It is clearly seen that the nascent bubble is formed at the leading edge of the laser pulse profile, regardless of the pulse width. Bubbles generated by a 20-ns pulse are characterized by a flat-shape filled with dense matter with intense optical emission, which is in contrast to more hemispherical low-density bubbles observed under the irradiation by a 150-ns pulse. The behavior of the nascent bubbles is consistent with the behavior of the later plasma in the bubbles, which is crucial for observation of well-defined atomic spectral lines for underwater LIBS.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Tetsuo Sakka, Ayaka Tamura, Ayumu Matsumoto, Kazuhiro Fukami, Naoya Nishi, Blair Thornton,