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Wereport the direct angle-resolved measurement of collision-inducedalignment of short-lived electronically excited molecules using crossedatomic and molecular beams. Utilizing velocity-mapped ion imaging,we measure the alignment of NO in its first electronically excitedstate (A2Σ) following single collisionswith Ne atoms. We prepare A2Σ(v= 0, N= 0, j= 0.5)and by comparing images obtained using orthogonal linear probe laserpolarizations, we experimentally determine the degree of alignmentinduced by collisional rotational excitation for the final rotationalstates N′ = 4, 5, 7, and 9. The experimentalresults are compared to theoretical predictions using both a simpleclassical hard-shell model and quantum scattering calculations onan ab initio potential energy surface (PES). The experimental resultsshow overall trends in the scattering-angle dependent polarizationsensitivity that are accounted for by the simple classical model,but structure in the scattering-angle dependence that is not. Thequantum scattering calculations qualitatively reproduce this structure,and we demonstrate that the experimental measurements have the sensitivityto critique the best available potential surfaces. This sensitivityto the PES is in contrast to that predicted for ground-state NO(X)alignment. [ABSTRACT FROM AUTHOR]

We report the first measured differential cross sections for rotationally inelastic collisions between ND3and Ne, obtained using velocity-mapped ion imaging. In these experiments, ND3molecules initially in the J= 0, K= 0 and J= 1, K= 1 quantum states collide with Ne atoms at a center-of-mass collision energy of 65 meV, leading to rotational excitation of ND3. Differential cross sections are then determined from images of the rotationally excited scattered molecules using an iterative extraction method. These measurements complement and compare well with previous measurements of differential cross sections for the ammonia−rare gas system (Meyer, H.J. Chem. Phys.1994, 101, 6697.; Meyer, H.J. Phys. Chem.1995, 99, 1101.) and are also relevant to the production of cold ND3molecules by crossed-beam scattering (Kay, J. J.; van de Meerakker, S. Y. T.; Strecker, K. E.; Chandler, D. W.Faraday Discuss.2009, DOI: 10.1039/B819256C). [ABSTRACT FROM AUTHOR]