Ryan Kathleen E, Garrison Barbara J
Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Anal Chem. 2008 Sep 1;80(17):6666-70. doi: 10.1021/ac800995w. Epub 2008 Aug 8.
Cluster bombardment of a molecular solid, benzene, is modeled using molecular dynamics simulations in order to investigate the effect of projectile cluster size and incident energy on the resulting yield. Using the mesoscale energy deposition footprint (MEDF) model, we are able to model large projectiles with incident energies from 5 to 140 keV and predict trends in ejection yield. The highest ejection yield at 5 keV was observed at C 20 and C 60, but shifts toward larger clusters for higher energies. These trends are explained in terms of the MEDF model. For these projectiles, all of the incident energy is deposited in the near-surface region, which is optimal for the projectile energy to contribute to the ejection yield. Because the energy is deposited in the optimal position for contributing to the ejection process, the yields increase linearly with incident energy with a slope that is nearly independent of the cluster size.
为了研究抛射体团簇尺寸和入射能量对产率的影响，利用分子动力学模拟对分子固体苯的团簇轰击进行了建模。使用中尺度能量沉积足迹（MEDF）模型，我们能够对入射能量为5至140 keV的大型抛射体进行建模，并预测喷射产率的趋势。在5 keV时，在C20和C60处观察到最高的喷射产率，但对于更高的能量，产率向更大的团簇转移。这些趋势根据MEDF模型进行了解释。对于这些抛射体，所有入射能量都沉积在近表面区域，这对于抛射体能量对喷射产率的贡献是最佳的。由于能量沉积在有助于喷射过程的最佳位置，产率随入射能量线性增加，其斜率几乎与团簇尺寸无关。
