Laser Ablation Atomic Beam Apparatus with Time-Sliced Velocity Map Imaging for Studying State-to-State Metal Reaction Dynamics

We report a newly constructed laser ablation crossed molecular beam apparatus, equipped with time-sliced velocity map imaging technique, to study state-to-state metal atom reaction dynamics. Supersonic metal atomic beam is generated by laser vaporization of metal rod, and free expansion design without gas flow channel has been employed to obtain a good quality of metal atomic beam. We have chosen the crossed-beam reaction Al+O₂ to test the performance of the new apparatus. Two-rotational-states selected AlO(X²∑⁺, v=0, N and N+14) products can be imaged via P(N) and R(N+14) branches of the Δv=1 band at the same wavelength, during (1+1) resonance-enhanced multi-photon ionization through the AlO(D²∑⁺) intermediate state. In our experiment at 244.145 nm for simultaneous transitions of P(15) and R(29) branch, two rings in slice image were clearly distinguishable, corresponding to the AlO(v=0, N=15) and AlO(v=0, N=29) states respectively. The energy difference between the two rotational levels is 403 cm^-1. The success of two states resolved in our apparatus suggests a better collisional energy resolution compared with the recent research study J. Chem. Phys. 140, 214304 (2014).