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Title: Molecular formation in the stagnation region of colliding laser-produced plasmas

Abstract

The laser-produced colliding plasmas have numerous attractive applications and stagnation layer formed during collisions between plasmas is a useful system for understanding particle collisions and molecular formation in a controlled way. In this article, we explore carbon dimer formation and its evolutionary paths in a stagnation layer formed during the interaction of two laser-produced plasmas. Colliding laser produced plasmas are generated by splitting a laser beam into two sub-beams and then focus them into either a single flat (laterally colliding plasmas) or a V-shaped graphite targets (orthogonally colliding plasmas). The C2 formation in the stagnation region of both colliding plasma schemes is investigated using optical spectroscopic means and compared with emission features from single seed plasma. Our results show that the collisions among the plasmas followed by the stagnation layer formation lead to rapid cooling causing enhanced carbon dimer formation. In addition, plasma electron temperature, density and C2 molecular temperature were measured for the stagnation zone and compared with seed plasma.

Authors:
; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1344052
Report Number(s):
PNNL-SA-116897
Journal ID: ISSN 1361-6595
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plasma Sources Science and Technology; Journal Volume: 25; Journal Issue: 6
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; laser ablation (LA); Laser-produced plasma; plasma diagnostics; Colliding plasmas

Citation Formats

Al-Shboul, K. F., Hassan, S. M., and Harilal, S. S.. Molecular formation in the stagnation region of colliding laser-produced plasmas. United States: N. p., 2016. Web. doi:10.1088/0963-0252/25/6/065017.
Al-Shboul, K. F., Hassan, S. M., & Harilal, S. S.. Molecular formation in the stagnation region of colliding laser-produced plasmas. United States. doi:10.1088/0963-0252/25/6/065017.
Al-Shboul, K. F., Hassan, S. M., and Harilal, S. S.. Thu . "Molecular formation in the stagnation region of colliding laser-produced plasmas". United States. doi:10.1088/0963-0252/25/6/065017.
@article{osti_1344052,
title = {Molecular formation in the stagnation region of colliding laser-produced plasmas},
author = {Al-Shboul, K. F. and Hassan, S. M. and Harilal, S. S.},
abstractNote = {The laser-produced colliding plasmas have numerous attractive applications and stagnation layer formed during collisions between plasmas is a useful system for understanding particle collisions and molecular formation in a controlled way. In this article, we explore carbon dimer formation and its evolutionary paths in a stagnation layer formed during the interaction of two laser-produced plasmas. Colliding laser produced plasmas are generated by splitting a laser beam into two sub-beams and then focus them into either a single flat (laterally colliding plasmas) or a V-shaped graphite targets (orthogonally colliding plasmas). The C2 formation in the stagnation region of both colliding plasma schemes is investigated using optical spectroscopic means and compared with emission features from single seed plasma. Our results show that the collisions among the plasmas followed by the stagnation layer formation lead to rapid cooling causing enhanced carbon dimer formation. In addition, plasma electron temperature, density and C2 molecular temperature were measured for the stagnation zone and compared with seed plasma.},
doi = {10.1088/0963-0252/25/6/065017},
journal = {Plasma Sources Science and Technology},
number = 6,
volume = 25,
place = {United States},
year = {Thu Oct 27 00:00:00 EDT 2016},
month = {Thu Oct 27 00:00:00 EDT 2016}
}
  • The expansion dynamics of ion and neutral species in laterally colliding laser produced aluminum plasmas have been investigated using time and space resolved optical emission spectroscopies and spectrally and angularly resolved fast imaging. The emission results highlight a difference in neutral atom and ion distributions in the stagnation layer where, at a time delay of 80 ns, the neutral atoms are localized in the vicinity of the target surface (<1 mm from the target surface) while singly and doubly charged ions lie predominantly at larger distances, <1.5 and <2 mm, respectively. The imaging results show that the ions were foundmore » to form a well defined, but compressed, stagnation layer at the collision front between the two seed plasmas at early times ({Delta}t<80 ns). On the other hand, the excited neutrals were observed to form a V-shaped emission feature at the outer regions of the collision front with enhanced neutral emission in the less dense, cooler regions of the stagnation layer.« less
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