Clusters (N = 4, 6, 12) from condensed atomic hydrogen and deuterium indicating close-packed structures in the desorbed phase at an active catalyst surface

Condensed atomic hydrogen of the Rydberg matter H(RM) type at its lowest energy level nB = 1 is described in a few recent publications where neutral fragments released by laser pulses from the desorbed phase are studied. It is now possible to instead study ionized H N + cluster fragments from the desorbed phase outside the active catalyst surface, in contact with the boundary layer of the catalyst. Ions are observed as small (N = 2–12) clusters by time-of-flight mass spectrometry. The initial kinetic energy release (KER) of 9.4 eV, corresponding to an interatomic distance of 150 pm at nB = 1, is measured by varying the acceleration voltage. Supporting results are found with deuterium, forming small D N + clusters. Cluster ions are formed at the laser focus and give sharp time-of-flight peaks. Clusters with N values 4, 6 and 12 indicate close-packed tetrahedron, octahedron and icosahedron (with missing center atom) forms. Odd N values like 3 and 7, indicating planar structures, can also be detected. No large planar RM clusters are observed for nB = 1. Thus, a close-packed structure with a low filling factor at the gas–catalyst interface is observed.