Knowledge Bank

Neat H$2$ clusters as well as H$2$ clusters embedded in helium droplets have been obtained in a pulsed cryogenic nozzle beam expansion and studied via Coherent anti-Stokes Raman Scattering (CARS) technique. The motivation for these experiments is to spectroscopically observe superfluidity in molecular hydrogen clusters. Results on large hydrogen clusters of about 10$\mathrm{<mrow\; data-mjx-texclass="ORD">4</mrow>}$ molecules presented. We have studied the composition and structure of the clusters obtained from the H$2$ gas with different concentrations of $para$-H$2$ and $ortho$-H$2$ molecules. CARS spectra indicate the enrichment in $ortho$-H$2$ in the clusters.