Reaction product imaging : the H + D2 reaction

• Published in: Science (American Association for the Advancement of Science) Vol. 260; no. 5114; pp. 1605 - 1610
• Main Authors: KITSOPOULOS, T. N, BUNTINE, M. A, BALDWIN, D. P, ZARE, R. N, CHANDLER, D. W
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 11.06.1993
• Subjects: Atomic and molecular collision processes and interactions; Atomic and molecular physics; Chemical reactions; Exact sciences and technology; Physics; Scattering of atoms, molecules and ions; Very low energy; Diatomic molecule; Reactive collision; Differential cross section; Crossed beams; Imaging; Reaction product; Hydrogen Atoms; Deuterium Molecules; Atom molecule collision; Experimental study; Inorganic compound
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.260.5114.1605

The differential cross section for the H + D(2) --> HD + D reaction has been measured using a technique called reaction product imaging. In this experiment, a photolytically produced beam of hydrogen (H) atoms crossed a beam of cold deuterium (D(2)) molecules. Product D atoms were ionized at the intersection of the two particle beams and accelerated toward a position-sensitive detector. The ion images appearing on the detector are two-dimensional projections of the three-dimensional velocity distribution of the D atom products. The reaction was studied at nominal center-of-mass collision energies of 0.54 and 1.29 electron volts. At the lower collision energy, the measured differential cross section for D atom production, summed over all final states of the HD(v,J) product, is in good agreement with recent quasi-classical trajectory calculations. At the higher collision energy, the agreement between the theoretical predictions and experimental results is less favorable.