On the formation mechanism of impurity–helium solids: evidence for extensive clustering
On the formation mechanism of impurity–helium solids: evidence for extensive clustering
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杂质氦固体的形成机制：广泛聚类的证据
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
H. Kunttu
中科院分区：
文献类型：
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作者：
E. Popov;J. Eloranta;J. Ahokas;H. Kunttu
描述了在 1.5 K 附近注入超流氦中的放电氮氦气的光学发射研究。对原子（α 基团）和分子 Vegard-Kaplan 跃迁的分析清楚地表明发射物质嵌入氮簇内。团簇形成在液体表面形成的凹坑中是最有效的。基于经典气泡模型和密度泛函理论的模型计算表明，在实验条件下，只有超过1000个分子组成的团簇才有足够的动能在液氦内部形成稳定的空腔。获得的结果表明，杂质氦固体的形成是气体射流中广泛聚集的结果。
Optical emission studies of a discharged nitrogen–helium gas injected into superfluid helium near 1.5 K are described. Analysis of atomic (α group) and molecular Vegard–Kaplan transitions clearly indicates that the emitting species are embedded inside nitrogen clusters. Cluster formation is most efficient in the crater formed on the liquid surface. Model calculations based on the classical bubble model and density functional theory suggest that under the experimental conditions only clusters consisting of more than 1000 molecules have sufficient kinetic energy for stable cavity formation to occur inside liquid helium. The results obtained suggest that impurity–helium solids formation is a consequence of extensive clustering in the gas jet.