Research & Teaching Faculty

Doped helium crystals growth and study

TitleDoped helium crystals growth and study
Publication TypeJournal Article
Year of Publication2005
AuthorsGordon, EB, Kumada, T, Ishiguro, M, Aratono, Y, Momose, T, Nakashima, N
Date PublishedFEB

The new technique for embedding microimpurities into solid helium has been developed. A He crystal was grown in a vertical cylindrical cell placed in the bath of pumped LHe cryostat. The He solid was continuously moved downward by exhaust of helium from the cell bottom and was simultaneously restored from its upper edge by sedimentation of a jet of gas helium mixed with impurity. A guest particle density of 3. 10(19) per cc and stable during an hour doped crystal growth with the rate of 1 m per 20 s were achieved The solid Deuterium clusters isolated in solid Helium have been investigated at T = 13K and P = 3 MPa by CARS technique. The strong effect of Raman scattering sensitivity to the molecular environment nuclear spin has been found in CARS - the ratio of probabilities for the scattering hy para (J=1) andortho (J=0) deuterium being equal to 1 in a gas is as high as 10,000 in nearly pure o-D-2, whereas it is 50 in common Raman scattering. This effect has been shown to give rise starting from cluster size corresponding to the phonon band onset.