Fragment Correlation in the Three-Body Breakup of Triatomic Hydrogen

Abstract

We investigate the fragmentation of the triatomic hydrogen molecule H 3 in a triple-coincidence experiment. A single rovibronic state of H 3 is laser prepared and its breakup into three hydrogen atoms H͑1s͒ is monitored by time-and position-sensitive multihit detectors. For each triple hit, the momentum vectors of the three H͑1s͒ fragments are determined. The sixfold differential cross section of the fragment momentum components in the center-of-mass frame is found to be highly structured and to depend sensitively on the H 3 initial electronic state.

Two- and three-body photodissociation of gas phase I3−

“…The interpretation of Dalitz plots for the case of three particles of equal mass has been discussed at length by Muller et al, 44 Babikov et al, 45 and others. 42,46,48 Each point within the inscribed circle represents a mapping of the center-of-mass momentum vectors for the three photofragments, subject to the constraint that the sum of the vectors is zero.…”

Storage Ring Experiments with Cold Molecular Ions: the H3+ Puzzle

“…For studies of H 3 + ions, a hollow cathode ion source, built according to the design used in earlier experiments [27] on H 3 + and cooled to ∼80 K, was used in recent TSR measurements to supply the injected beam. Using DR fragment imaging as described in Sec.…”

Stark Field Control of Nonadiabatic Dynamics in Triatomic Hydrogen

“…Fragments from predissociation with sufficient transverse momentum pass the flag and reach the multihit coincidence detector after a free flight of 239 cm. The arrival times and positions of the three hydrogen atoms are registered by the detector [9]. Our new detection electronics [26] achieve a spatial resolution of 80 m and a temporal resolution of 50 ps.…”

“…In polyatomic systems the larger number of degrees of freedom complicates the observation and description of dynamical properties [2]. During the last decade powerful experimental techniques have been brought to bear on nonadiabatic processes: Ultrafast lasers make it possible to follow the course of a chemical reaction [3][4][5], molecular beam technology allows the quantum state preparation of reactants as well as the state selective detection of products [6][7][8], and novel multidimensional coincidence measurements provide hitherto inaccessible information about vector correlations in molecular dynamics [9][10][11][12].…”