TY - JOUR
T1 - Effects of Plume Hydrodynamics and Oxidation on the Composition of a Condensing Laser-Induced Plasma
AU - Weisz, David G.
AU - Crowhurst, Jonathan C.
AU - Finko, Mikhail S.
AU - Rose, Timothy P.
AU - Koroglu, Batikan
AU - Trappitsch, Reto
AU - Radousky, Harry B.
AU - Siekhaus, Wigbert J.
AU - Armstrong, Michael R.
AU - Isselhardt, Brett H.
AU - Azer, Magdi
AU - Curreli, Davide
N1 - We thank J. Zaug and M. Savina for their constructive discussion during the preparation of this manuscript. We thank R. Ryerson for providing 18O2, which was critical for this experiment. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Funding was provided by a DTRA Basic Science Grant (HDTRA1-16-1-0020) and by DNDO’s National Nuclear Forensics Expertise Development Program. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security. LLNL-JRNL-741043.
PY - 2018/2/15
Y1 - 2018/2/15
N2 - High-temperature chemistry in laser ablation plumes leads to vapor-phase speciation, which can induce chemical fractionation during condensation. Using emission spectroscopy acquired after ablation of a SrZrO3 target, we have experimentally observed the formation of multiple molecular species (ZrO and SrO) as a function of time as the laser ablation plume evolves. Although the stable oxides SrO and ZrO2 are both refractory, we observed emission from the ZrO intermediate at earlier times than SrO. We deduced the time-scale of oxygen entrainment into the laser ablation plume using an 18O2 environment by observing the in-growth of Zr18O in the emission spectra relative to Zr16O, which was formed by reaction of Zr with 16O from the target itself. Using temporally resolved plume-imaging, we determined that ZrO formed more readily at early times, volumetrically in the plume, while SrO formed later in time, around the periphery. Using a simple temperature-dependent reaction model, we have illustrated that the formation sequence of these oxides subsequent to ablation is predictable to first order.
AB - High-temperature chemistry in laser ablation plumes leads to vapor-phase speciation, which can induce chemical fractionation during condensation. Using emission spectroscopy acquired after ablation of a SrZrO3 target, we have experimentally observed the formation of multiple molecular species (ZrO and SrO) as a function of time as the laser ablation plume evolves. Although the stable oxides SrO and ZrO2 are both refractory, we observed emission from the ZrO intermediate at earlier times than SrO. We deduced the time-scale of oxygen entrainment into the laser ablation plume using an 18O2 environment by observing the in-growth of Zr18O in the emission spectra relative to Zr16O, which was formed by reaction of Zr with 16O from the target itself. Using temporally resolved plume-imaging, we determined that ZrO formed more readily at early times, volumetrically in the plume, while SrO formed later in time, around the periphery. Using a simple temperature-dependent reaction model, we have illustrated that the formation sequence of these oxides subsequent to ablation is predictable to first order.
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U2 - 10.1021/acs.jpca.7b11994
DO - 10.1021/acs.jpca.7b11994
M3 - Article
C2 - 29388772
AN - SCOPUS:85042167452
SN - 1089-5639
VL - 122
SP - 1584
EP - 1591
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 6
ER -