Multiple ionization and complete fragmentation of OCS by impact with highly charged ions Ar4+ and Ar8+ at 15 keV q−1
Multiple ionization and complete fragmentation of OCS by impact with highly charged ions Ar4+ and Ar8+ at 15 keV q−1
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DOI：
10.1088/0953-4075/45/4/045205
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发表时间：
2012-02
期刊：
影响因子：
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通讯作者：
B. Wales;T. Motojima;J. Matsumoto;Zijian Long;W. Liu;H. Shiromaru;J. Sanderson
中科院分区：
文献类型：
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作者：
B. Wales;T. Motojima;J. Matsumoto;Zijian Long;W. Liu;H. Shiromaru;J. Sanderson
我们已经使用时间和位置敏感的符合装置来研究OCS在与Ar 4+和Ar 8+在15 keV q−1的碰撞中的多重电离，随后分子OCS-Oa++ Cb+ + Sc+完全分裂。我们已经比较了我们的结果与理论值通过模拟分裂，从基态分布的键长和键角假设一个点样离子和纯库仑势。这种比较表明，一般来说，能量释放的实验分布更广泛，峰值在较低的能量比计算。然而，随着最终电荷状态的增加，测量和计算之间的一致性更好。此外，诱导弯曲的量是相当少的高电荷状态。然而，即使总能量释放接近库仑（6+），单个碎片离子能量分布也因弯曲程度而不同于预期值。使用牛顿和Dalitz图，我们能够确定协调和逐步过程的程度。我们的研究结果表明，在低电荷态（3+），少量（<7%）的逐步过程也是可测量的不对称键过程的程度较高。
We have used time- and position-sensitive detection in a coincidence arrangement to study the multiple ionization of OCS in collisions with Ar4+ and Ar8+ at 15 keV q−1 followed by complete breakup of the molecule OCS—Oa++ Cb+ + Sc+. We have compared our results with theoretical values derived by simulating the breakup, from ground state distributions of bond lengths and bond angle assuming a point-like ion and purely Coulombic potential. This comparison shows that in general the experimental distributions of energy release are broader and peak at lower energy than calculated. Better agreement between measurement and calculation is however found with increasing the final charge state. Furthermore, the amount of induced bending is considerably less for the high charge states. However, even where total energy release is close to Coulombic (6+) individual fragment ion energy distributions differ from the expected values because of the degree of bending. Using Newton and Dalitz plots, we are able to identify the extent of concerted and stepwise processes. Our results indicate a higher degree of asymmetric bond processes at a low charge state (3+) where small amounts (<7%) of the stepwise processes are also measurable.