Excimers in the Lowest Rotational Quantum State in Liquid Helium.
Evidence for helium excimers (He2*) in the lowest allowed rotational quantum state in liquid helium is presented. He2*was generated by a corona discharge in the gas and normal liquid phases. Fluorescence spectra recorded in the visible region between 3.8 and 5.0 K and 0.2 and 5.6 bar showed the rotationally resolved d3Σu+→ b3Πgtransition of He2*. Analysis of the pressure and temperature dependence of lineshifts and line intensities showed features of solvated He2*superimposed on its gas-phase spectrum and, in the liquid phase only, pressure-induced rotational cooling. These findings suggest that He2*can be used to investigate bulk helium in different phases at the nanoscale.
Department of Physics and Astronomy, University of Leicester , University Road, Leicester LE1 7RH, United Kingdom.
Luis Guillermo
LG
Mendoza-Luna
Department of Physics and Astronomy, University of Leicester , University Road, Leicester LE1 7RH, United Kingdom.|Department of Physics, College of Science, University of Kerbala , Karbala, Iraq.
Nagham M K
NM
Shiltagh
Department of Physics and Astronomy, University of Leicester , University Road, Leicester LE1 7RH, United Kingdom.
Mark J
MJ
Watkins
G2ELab-CNRS Equipe MDE, 25 Av. des Martyrs BP 166, 38042 Grenoble Cedex 9, France.
Nelly
N
Bonifaci
G2ELab-CNRS Equipe MDE, 25 Av. des Martyrs BP 166, 38042 Grenoble Cedex 9, France.
Frédéric
F
Aitken
Department of Physics and Astronomy, University of Leicester , University Road, Leicester LE1 7RH, United Kingdom.
Klaus
K
von Haeften