Davies J A, Continetti R E, Chandler D W, Hayden C C
Combustion Research Facility, Sandia National Laboratories, P.O. Box 969, Livermore, California 94551-0969, USA.
Phys Rev Lett. 2000 Jun 26;84(26 Pt 1):5983-6. doi: 10.1103/PhysRevLett.84.5983.
Femtosecond time-resolved photoelectron angular distributions (PADs) are measured for the first time in the molecular frame of a dissociating molecule. Various stages of the dissociation process, NO2-->NO(C Pi)+O(P), are probed using ionization of the NO(C Pi) fragment to NO+(X Sigma(+)). The PADs evolve from forward-backward asymmetric with respect to the dissociation axis at short time delays ( < or =500 fs) to symmetric at long time delays (> or = 1 ps). Changes in the PADs directly reflect the time-dependent separation and reorientation of the dissociating photofragments.
首次在解离分子的分子框架中测量了飞秒时间分辨光电子角分布（PADs）。利用NO（Cπ）碎片电离为NO⁺（XΣ⁺）来探测解离过程NO₂→NO（Cπ）+O（P）的各个阶段。PADs从短时间延迟（≤500飞秒）时相对于解离轴的前后不对称演变为长时间延迟（≥1皮秒）时的对称。PADs的变化直接反映了解离光碎片随时间的分离和重新取向。
