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Journal de Physique IV (Proceedings)

Compression experiments with 2D atomic hydrogen gas on liquid He

Sergey A. Vasilyev, S. Jaakkola

Published Oct 1, 2004• 3 citations
Publisher

Abstract

\nWe review experiments in which atomic hydrogen has been\ncompressed magnetically or thermally to become a degenerate two-dimensional\nBose gas on the surface of liquid helium.\n
DOI
10.1051/jp4:2004116011

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Doubly polarized hydrogen has been produced up to densities of 2\ifmmode\times\else\texttimes\fi{}1018{10}^{18}1018 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$ with the use of a compression technique. Samples were compressed up to five orders of magnitude into small bubblelike volumes under a column of liquid helium. This technique enabled us to study the volume decay of a bubble at almost constant gas density for minutes. The analysis of the volume decay of such a bubble is discussed. A bulk three-body recombination process was observed with rate constant C3{C}_{3}C3​=[7(2)]\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}39}$ cm6{\mathrm{cm}}^{6}cm6 ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$, as well as bulk electronic b\ensuremath{\rightarrow}c relaxation with rate constant Gbcv{G}_{\mathrm{bc}}^{v}Gbcv​\ensuremath{\downarrow}=[12(4)]\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}16}$ cm3{\mathrm{cm}}^{3}cm3 ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. The nature of the three-body process is analyzed with a set of extended rate equations. The samples were very delicate and rapid compressions could result in explosions.