论文标题
$^4 $ he $ _2 $二聚体的分裂，相对论高度充电的弹丸在与小动能释放的碰撞中
Fragmentation of the $^4$He$_2$ dimer by relativistic highly charged projectiles in collisions with small kinetic energy release
论文作者
论文摘要
从理论上讲，我们研究了氦二聚体的碎片，$^4 $ he $ _2 $，与相对论高的弹丸相撞的单一收费离子。我们讨论了推动这一过程的主要机制，重点是在与弹丸的一次碰撞中，由二聚体的两个原子位点直接电离引起的碎片化。这种直接机制主导着$ _2 $ $ \ to $^+$+$+he $^+$分解事件，并具有新兴的离子片段的动力，低于$ 4 $ - $ 5 $ 5 $ ev。我们探讨了$^+$离子在碰撞中产生的$ 1 $和7 $ gev/u u $ u $^{92+} $弹丸的能量和角度分布，并表明它们的形状受到相对论和高阶效应的显着影响，在弹丸和二聚体之间的相互作用中。我们还表明，能量谱的形状对He $ _2 $二聚体的结合能非常敏感，该二聚体的精确确定可以利用。直接机制对He $ _2 $片段的总横截面的贡献分别为$ 1 $和$ 7 $ GEV/U $ u $^{92+} $，分别为$ 3.65 $ MB和$ 2.4 $ MB，大约代表了该交叉部分的一半。
We study theoretically the fragmentation of the helium dimer, $^4$He$_2$, into singly charged ions in collisions with relativistic highly-charged projectiles. We discuss the main mechanisms driving this process with the focus on the fragmentation caused by direct ionization of both atomic sites of the dimer in a single collision with the projectile. This direct mechanism dominates the He$_2$ $\to $ He$^+$ + He$^+$ breakup events with the kinetic energies of the emerging ionic fragments below $4$--$5$ eV. We explore the energy and angular distributions of the He$^+$ ions produced in collisions with $1$ and $7$ GeV/u U$^{92+}$ projectiles and show that their shape is significantly affected by relativistic and higher-order effects in the interaction between the projectile and the dimer. We also show that the shape of the energy spectrum is quite sensitive to the binding energy of the He$_2$ dimer which can be exploited for its precise determination. The contribution of the direct mechanism to the total cross section for the He$_2$ fragmentation by $1$ and $7$ GeV/u U$^{92+}$ was calculated to be $3.65$ Mb and $2.4$ Mb, respectively, representing roughly half of this cross section.
