Abstract
A breathing sphere model is presented for molecular dynamics simulations of laser ablation of organic solids. An approximate representation of the internal molecular motion permits a significant expansion of the time- and length-scales of the model and still allows one to reproduce a realistic rate of the vibrational relaxation of excited molecules. The model provides a realistic description of the ablation of molecular films and matrix-assisted laser desorption (MALDI). A well-defined threshold fluence has been found to separate two mechanisms for the ejection of molecules - surface vaporization for low laser fluences and collective ejection or ablation for high fluences. Above the threshold the laser induced high pressure and the explosive homogeneous phase transition leads to the strongly forwarded emission of ablated material and high, from 500 up to 1500 m/s, maximum velocities of the ejected plume expansion. Large analyte molecules in MALDI get axial acceleration from an expanding plume and move along with the matrix molecules at nearly the same velocities. Big molecular clusters are found to constitute a significant part of the ejected plume at fluences right above the ablation threshold. The processes in the plume are found to have a strong influence on the final velocities and angle distributions of ejected molecules and molecular clusters.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 239 |
| Number of pages | 1 |
| Journal | Polymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering |
| Volume | 76 |
| State | Published - 1997 |
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All Science Journal Classification (ASJC) codes
- Chemical Engineering (miscellaneous)
- Polymers and Plastics
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Molecular dynamics model for laser ablation of organic solids. / Zhigilei, L. V.; Kodali, P. B S; Garrison, Barbara Jane.
In: Polymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering, Vol. 76, 1997, p. 239.Research output: Contribution to journal › Article
TY - JOUR
T1 - Molecular dynamics model for laser ablation of organic solids
AU - Zhigilei, L. V.
AU - Kodali, P. B S
AU - Garrison, Barbara Jane
PY - 1997
Y1 - 1997
N2 - A breathing sphere model is presented for molecular dynamics simulations of laser ablation of organic solids. An approximate representation of the internal molecular motion permits a significant expansion of the time- and length-scales of the model and still allows one to reproduce a realistic rate of the vibrational relaxation of excited molecules. The model provides a realistic description of the ablation of molecular films and matrix-assisted laser desorption (MALDI). A well-defined threshold fluence has been found to separate two mechanisms for the ejection of molecules - surface vaporization for low laser fluences and collective ejection or ablation for high fluences. Above the threshold the laser induced high pressure and the explosive homogeneous phase transition leads to the strongly forwarded emission of ablated material and high, from 500 up to 1500 m/s, maximum velocities of the ejected plume expansion. Large analyte molecules in MALDI get axial acceleration from an expanding plume and move along with the matrix molecules at nearly the same velocities. Big molecular clusters are found to constitute a significant part of the ejected plume at fluences right above the ablation threshold. The processes in the plume are found to have a strong influence on the final velocities and angle distributions of ejected molecules and molecular clusters.
AB - A breathing sphere model is presented for molecular dynamics simulations of laser ablation of organic solids. An approximate representation of the internal molecular motion permits a significant expansion of the time- and length-scales of the model and still allows one to reproduce a realistic rate of the vibrational relaxation of excited molecules. The model provides a realistic description of the ablation of molecular films and matrix-assisted laser desorption (MALDI). A well-defined threshold fluence has been found to separate two mechanisms for the ejection of molecules - surface vaporization for low laser fluences and collective ejection or ablation for high fluences. Above the threshold the laser induced high pressure and the explosive homogeneous phase transition leads to the strongly forwarded emission of ablated material and high, from 500 up to 1500 m/s, maximum velocities of the ejected plume expansion. Large analyte molecules in MALDI get axial acceleration from an expanding plume and move along with the matrix molecules at nearly the same velocities. Big molecular clusters are found to constitute a significant part of the ejected plume at fluences right above the ablation threshold. The processes in the plume are found to have a strong influence on the final velocities and angle distributions of ejected molecules and molecular clusters.
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M3 - Article
AN - SCOPUS:0030671627
VL - 76
SP - 239
JO - Polymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering
JF - Polymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering
SN - 0743-0515
ER -