Results 1 to 10 of about 492,230 (223)

Helium Emissions Observed in Ground-Based Spectra of Solar Prominences [PDF]

, 2012
The only prominent line of singly ionized helium in the visible spectral range, helium-II 4686 A, is observed together with the helium-I 5015 A singlet and the helium-I 4471 A triplet line in solar prominences.
Bianda, Michele, Ramelli, Renzo, Stellmacher, Goetz, Wiehr, Eberhard   +3 more
core   +2 more sources

Rb*He_n exciplexes in solid 4_He [PDF]

, 2006
We report the observation of emission spectra from Rb*He_n exciplexes in solid 4He. Two different excitation channels were experimentally identified, viz., exciplex formation via laser excitation to the atomic 5P3/2 and to the 5P1/2 levels.
Hofer, A., Moroshkin, P., Nettels, D., Ulzega, S., Weis, A.   +4 more
core   +2 more sources

Cavitation pressure in liquid helium [PDF]

, 2001
Recent experiments have suggested that, at low enough temperature, the homogeneous nucleation of bubbles occurs in liquid helium near the calculated spinodal limit. This was done in pure superfluid helium 4 and in pure normal liquid helium 3. However, in
B. M. Abraham, B. M. Abraham, C. E. Campbell, D. M. Jezek, F. Caupin, F. Caupin, F. Caupin, F. Dalfovo, G. H. Bauer, G. W. Waters, H. J. Maris, H. J. Maris, H. Lambaré, J. A. Nissen, J. Boronat, J. C. Wheatley, J. Casulleras, J. Wilks, K. Dransfeld, Lord Rayleigh, M. A. Solis, M. Guilleumas, M. Guilleumas, M. Kollar, M. P. Bertinat, P. Roche, S. Balibar, S. Balibar, S. Balibar, S. N. Burmistrov, W. H. Press, X. Chavanne   +31 more
core   +3 more sources

Free-energy model for fluid helium at high density [PDF]

, 2004
We present a semi-analytical free-energy model aimed at characterizing the thermodynamic properties of dense fluid helium, from the low-density atomic phase to the high-density fully ionized regime. The model is based on a free-energy minimization method
Christophe Winisdoerffer, G. Chabrier, Gilles Chabrier, L. Landau   +3 more
core   +2 more sources

Electric-field-induced helium-helium resonances

Physical Review A, 2019
The tunability of the helium-helium interaction through an external electric field is investigated. For a static external field, electric-field induced resonances and associated electric-field induced bound states are calculated for the $^4$He-$^4$He, $^3$He-$^4$He, and $^3$He-$^3$He systems. Qualitative agreement is found with the literature for the $^
Guan, Qingze, Blume, Doerte
openaire   +3 more sources

Coupling a single electron on superfluid helium to a superconducting resonator. [PDF]

, 2019
Electrons on helium form a unique two-dimensional system on the interface of liquid helium and vacuum. A small number of trapped electrons on helium exhibits strong interactions in the absence of disorder, and can be used as a qubit.
Koolstra, Gerwin, Schuster, David I, Yang, Ge   +2 more
core   +3 more sources

Black-Body Radiation Correction to the Polarizability of Helium [PDF]

, 2011
The correction to the polarizability of helium due to black-body radiation is calculated near room temperature. A precise theoretical determination of the black-body radiation correction to the polarizability of helium is essential for dielectric gas ...
D. A. Varshalovich, J. J. Sakurai, M. Puchalski, P. J. Mohr, U. D. Jentschura   +4 more
core   +3 more sources

The helium trimer with soft-core potentials [PDF]

, 2011
The helium trimer is studied using two- and three-body soft-core potentials. Realistic helium-helium potentials present an extremely strong short-range repulsion and support a single, very shallow, bound state.
A. Kievsky, A. Kievsky, A.K. Motovilov, A.R. Holt, A.R. Janzen, B.D. Esry, C. Romero-Redondo, C. Romero-Redondo, E. Garrido, E. Nielsen, E. Nielsen, E.A. Kolganova, E.A. Kolganova, F. Luo, F.E. Harris, H. Suno, J. Stecher von, K.T. Tang, M. Jeziorska, M. Lewerenz, M.V. Zhukov, P. Barletta, P. Barletta, P. Barletta, P. Barletta, R. Grisenti, R.A. Aziz, R.A. Aziz, T. Korona, V. Efimov, V. Efimov, V. Roudnev, W. Cencek, W. Schoellkopf, W. Schollkopf   +34 more
core   +3 more sources

Arc pressure and weld metal fluid flow whilst using alternating shielding gases Part 2 : arc force determination [PDF]

, 2013
The transient variation of the shielding gas present in the alternating shielding gas process produces a dynamic action within the liquid weld metal. Flow vectors opposite in direction have been reported due to the various forces acting on the weld metal
Campbell, Stuart, Galloway, Alexander, McPherson, Norman   +2 more
core   +1 more source

Microscopic two-fluid theory of rotational constants of the OCS-H$_2$ complex in $^4$He droplets

, 2003
We present a microscopic quantum analysis for rotational constants of the OCS-H$_2$ complex in helium droplets using the local two-fluid theory in conjunction with path integral Monte Carlo simulations.
K. Birgitta Whaley, Patel M., Yongkyung Kwon   +2 more
core   +1 more source