Chen G X, Kirby K, Silver E, Brickhouse N S, Gillaspy J D, Tan J N, Pomeroy J M, Laming J M
ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA.
Phys Rev Lett. 2006 Oct 6;97(14):143201. doi: 10.1103/PhysRevLett.97.143201. Epub 2006 Oct 5.
We report a fully relativistic close-coupling calculation of the electron impact excitation of Ni xix to derive the 3C/3D line intensity ratio, with an uncertainty of 5%. Convergence of the calculation with respect to both channel coupling effects and the many interacting Rydberg series of resonances has been achieved. New measurements in an electron beam ion trap agree with our calculation. We show that the 3C/3D x-ray line ratio depends sensitively on both electron energy and beamwidth in an optically thin plasma. Accounting for this dependence improves the accuracy of the Ni abundance determination in astrophysical sources.
我们报告了对镍 XIX 离子电子碰撞激发进行的全相对论紧密耦合计算，以得出 3C/3D 谱线强度比，其不确定性为 5%。计算在通道耦合效应和众多相互作用的里德堡共振系列方面均已实现收敛。在电子束离子阱中进行的新测量结果与我们的计算相符。我们表明，在光学薄等离子体中，3C/3D X 射线谱线比敏感地依赖于电子能量和束宽。考虑这种依赖性可提高天体物理源中镍丰度测定的准确性。
