Ralchenko Yuri
Quantum Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8422, USA.
Nucl Instrum Methods Phys Res B. 2017;408. doi: 10.1016/j.nimb.2017.04.025.
Application of visible or infrared (IR) lasers for spectroscopy of highly-charged ions (HCI) has not been particularly extensive so far due to a mismatch in typical energies. We show here that the energy difference between the two lowest levels within the first excited configuration 3 4 in Ni-like ions of heavy elements from = 60 to = 92 is within the range of visible or near-IR lasers. The wavelengths of these transitions are calculated within the relativistic model potential formalism and compared with other theoretical and limited experimental data. Detailed collisional-radiative simulations of non-Maxwellian and thermal plasmas are performed showing that photopumping between these levels using relatively moderate lasers is sufficient to provide a two-order of magnitude increase of the pumped level population. This accordingly results in a similar rise of the X-ray line intensity thereby allowing control of X-ray emission with visible/IR lasers.
由于典型能量不匹配，可见光或红外（IR）激光在高电荷离子（HCI）光谱学中的应用迄今为止并不特别广泛。我们在此表明，原子序数从60到92的类镍离子第一激发组态3 4内两个最低能级之间的能量差在可见光或近红外激光的范围内。这些跃迁的波长在相对论模型势形式体系内进行了计算，并与其他理论和有限的实验数据进行了比较。对非麦克斯韦等离子体和热等离子体进行了详细的碰撞辐射模拟，结果表明，使用相对中等强度的激光在这些能级之间进行光泵浦足以使被泵浦能级的粒子数增加两个数量级。这相应地导致X射线谱线强度有类似的增加，从而可以用可见光/红外激光控制X射线发射。
