Spectroscopic studies of impurity-helium condensates containing stabilized N and O atoms

Abstract

We present optical spectra of impurity-helium condensates during the process of their formation by injection of gas mixtures N2-Rg-He (Rg=Ne, Kr) into bulk superfluid helium after passing through a RF discharge. Atomic lines of He, Ne, Kr, N, O atoms as well as bands (1+ and 2+ systems of N2) are present in the spectral range 320–1100 nm studied in these experiments. We also detected spectra emitted by the samples during their destruction, stimulated by warming through the temperature range 1.5–15 K The luminescence spectra of the N-N2-He and N-N2-Ne-He samples contain only intense N(2D-4S) (α-group) and O(1D-1S) (β-group) lines. For the N-N2-Ne-He sample we observed the transformation of spectra of the α-group. In thermo-stimulated luminescence spectra of the N-N2-Kr-He samples, the intense β-group of O atoms and M-bands of NO molecules were found. Differences in the spectra obtained during destruction of N-N2-Ne-He and N-N2-Kr-He samples may be explained by a different shell structure of the nanoclusters formed during sample preparation.