Rydberg Matter of K and N 2: angular dependence of the time-of-flight for neutral and ionized clusters formed in Coulomb explosions

Abstract

Laser fragmentation via Coulomb explosions in a cloud of Rydberg Matter (RM) is shown to give an angular dependence of the time-of-flight (TOF) observations for neutral RM clusters. The RM cloud is formed by emission from a K doped FeO catalyst sample at 700–900 K and is formed of K ∗ atoms, or N 2 ∗ molecules after nitrogen gas adsorption in the emitter. Close to the surface normal of the emitter, relatively large clusters from high excitation states in the RM dominate, while at large angles (40–50°) smaller clusters and monomers with high kinetic energy release from lower excitation states are observed more frequently. N 2 RM usually gives smaller clusters and more monomers than K RM. The extension of the RM cloud in the apparatus is easily observed by the different TOFs for the various particles at different angular settings of the detector, and by direct shifting of the laser focus point. The TOF results show well defined Rydberg states and RM clusters with very low translational temperature, below 100 K even for the monomers.