论文标题
keV离子在绝缘纳米毛细管时的图像充电力有什么问题
What is wrong with the image charge force of keV ions in insulating nano-capillaries
论文作者
论文摘要
在较大纵横比的纳米毛细管中，有吸引力的图像电荷力足够强，可以影响穿过毛细血管的离子的轨迹，从而减少了透射束离子的比例。我们使用静态离子和无限的圆柱介电界面的图像电荷力的接近但对CPU友好的表达进行了理论传输的分数。当将理论传播的分数与内径小于200 nm的纳米毛细管的可用实验数据进行比较时，我们发现出人意料的大分子分歧，即，理论传播的分数很容易比实验性的分数低。指出图像电荷力取决于离子通过频率依赖性相对介电常数的速度，我们研究了是否可以使用速度取决于图像电荷力来解除分歧。我们给出了平面和圆柱电介质界面的动力图像电荷力的精确表达，这是离子速度的函数。然后，在SIO $ _2 $和PET介电接口的情况下，我们重新评估了理论传输的分数。根据可用的实验数据，讨论了我们的发现。
In nano-capillaries of large aspect ratio, the attractive image charge force is strong enough to affect the trajectory of ions passing through capillaries and consequently to diminish the fraction of transmitted beam ions. We calculated the theoretically transmitted fraction, using an approached but CPU-friendly expression of the image charge force valid in the case of a static ion and an infinite cylindrical dielectric interface. When comparing the theoretically transmitted fraction to available experimental data for nano-capillaries with an inner diameter of less than 200 nm, we found a surprisingly large disagreement, i.e., the theoretically transmitted fractions were easily an order of magnitude lower than the experimental ones. Noting that the image charge force depends on the velocity of the ion via the frequency dependent relative permittivity of the insulator, we investigated whether the disagreement could be lifted using a velocity depend image charge force. We give the exact expressions of the dynamical image charge force for a plane and cylindrical dielectric interface as a function of the ion velocity. We then re-evaluated the theoretically transmitted fractions in the case of SiO$_2$ and PET dielectric interfaces. Our findings are discussed in the light of the available experimental data.
