Vogels Sjoerd N, Onvlee Jolijn, von Zastrow Alexander, Groenenboom Gerrit C, van der Avoird Ad, van de Meerakker Sebastiaan Y T
Radboud University Nijmegen, Institute for Molecules and Materials, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
Phys Rev Lett. 2014 Dec 31;113(26):263202. doi: 10.1103/PhysRevLett.113.263202. Epub 2014 Dec 30.
We present ultrahigh-resolution measurements of state-to-state inelastic differential cross sections for NO-Ne and NO-Ar collisions, obtained by combining the Stark deceleration and velocity map imaging techniques. We show that for counterpropagating crossed beam geometries, the effect of the velocity spreads of the reagent beams on the angular resolution of the images is minimized. Furthermore, the counterpropagating geometry results in images that are symmetric with respect to the relative velocity vector. This allows for the use of inverse Abel transformation methods that enhance the resolution further. State-resolved diffraction oscillations in the differential cross sections are measured with an angular resolution approaching 0.3°. Distinct structures observed in the cross sections gauge the quality of recent ab initio potential energy surfaces for NO-rare-gas atom collisions with unprecedented precision.
我们展示了通过结合斯塔克减速和速度映射成像技术获得的NO-Ne和NO-Ar碰撞中态-态非弹性微分截面的超高分辨率测量结果。我们表明，对于反向传播的交叉束几何结构，试剂束速度展宽对图像角分辨率的影响最小化。此外，反向传播几何结构产生的图像相对于相对速度矢量是对称的。这允许使用进一步提高分辨率的逆阿贝尔变换方法。以接近0.3°的角分辨率测量了微分截面中的态分辨衍射振荡。在截面中观察到的独特结构以前所未有的精度衡量了最近用于NO-稀有气体原子碰撞的从头算势能面的质量。
