Vacuum ultraviolet photodissociation dynamics of $N2O+hv→N2(X1Σg+)+O(1S)$ in the short wavelength tail of D¹Σ⁺ band

Vacuum ultraviolet photodissociation dynamics of $N2O+hv→N2(X1Σg+)+O(1S0)$ in the short wavelength tail of D¹Σ⁺ band has been investigated using the time-sliced velocity-mapped ion imaging technique by probing the images of the O(¹S₀) photoproducts at a set of photolysis wavelengths including 121.47 nm, 122.17 nm, 123.25 nm and 123.95 nm. The product total kinetic energy release distributions, vibrational state distributions of the $N2(X1Σg+)$ photofragments and angular anisotropy parameters have been obtained by analyzing the raw O(¹S₀) images. It is noted that additional vibrationally excited photoproducts (3≤v≤8) with a Boltzmann-like feature start to appear except the non-statistical component as the photolysis wavelength decreases to 123.25 nm, and the corresponding populations become more pronounced with decreasing of the photolysis wave-length. Furthermore, the vibrational state specific anisotropy parameter β at each photolysis wavelength exhibits a drastic fluctuation near β=1.75 at v<8, and decreases to a minimum as the vibrational quantum number further increases. While the overall anisotropy parameter β for the $N2(X1Σg+)+O(1S0)$ channel presents a roughly monotonical increase from 1.63 at 121.47 nm to 1.95 at 123.95 nm. The experimental observations suggest that there is at least one fast nonadiabatic pathway from initially prepared D¹Σ⁺ state to the dissociative state with bent geometry dominating to generate the additional vibrational structures at high photoexcitation energies.