Low Temperature Physics http://scitation.aip.org/ Low Temperature Physics A completely self-contained cryogen-free dilution refrigerator, the TritonDR[sup TM] http://link.aip.org/link/?LTP/34/404/1&agg=rss V. A. Mikheev, P. G. Noonan, A. J. Adams, R. W. Bateman, and T. J. Foster<br/> Oxford Instruments have developed a new dilution refrigerator for ultralow temperatures down to below 35 mK. The TritonDR system is a continuous cryogenic cycle dilution refrigerator. The refrigerator is driven by a closed cycle cryocooler and hence requires no liquid cryogens. The system has a ded ... [Low Temp. Phys. 34, 404 (2008)] published Wed May 14, 2008. Electron attachment to atomic hydrogen on the surface of liquid [sup 4]He http://link.aip.org/link/?LTP/34/397/1&agg=rss T. Arai, H. Yayama, and K. Kono<br/> We demonstrate a possibility that helium surface electrons at cryogenic temperatures can be used as a new source of very low energy electrons. Since both electrons (e) and hydrogen atoms (H) are bound on liquid helium surface, two-dimensional mixture gas of these two species is available on the surf ... [Low Temp. Phys. 34, 397 (2008)] published Wed May 14, 2008. Dip-effect in the conductivity of 2D electrons on a helium film with a rough substrate http://link.aip.org/link/?LTP/34/392/1&agg=rss P. Leiderer, S. Nazin, and V. Shikin<br/> The phenomenon generally referred to as the dip-effect in the conductivity of 2D electrons on a helium film with a rough substrate is discussed. The particular case where this effect arises with the motion of 2D electrons along a helium film on a periodically corrugated substrate is examined. Argume ... [Low Temp. Phys. 34, 392 (2008)] published Wed May 14, 2008. Dynamical structure factor of two-dimensional electrons over a helium film http://link.aip.org/link/?LTP/34/388/1&agg=rss P. C. Venturini, N. Studart, and J. P. Rino<br/> The dynamical structure factor of a two-dimensional electrons trapped to a helium film deposited on a solid substrate is determined through molecular dynamics simulations for different film thicknesses and two substrates. The phases of the system varying from the classical Wigner crystal to strong a ... [Low Temp. Phys. 34, 388 (2008)] published Wed May 14, 2008. Confinement effects on decay rate of surface electron states over liquid helium http://link.aip.org/link/?LTP/34/385/1&agg=rss S. S. Sokolov, Yu. P. Monarkha, J. M. Villas-Boas, and Nelson Studart<br/> The decay rate of excited states of surface electrons in liquid helium, trapped in a quantum dot system, is evaluated, taking into account the process of spontaneous radiation of two ripplons with short wavelength. It is found that the values of the decay rate in later process are rather higher than ... [Low Temp. Phys. 34, 385 (2008)] published Wed May 14, 2008. Photoresonance and conductivity of surface electrons on liquid [sup 3]He http://link.aip.org/link/?LTP/34/377/1&agg=rss D. Konstantinov, K. Kono, and Y. Monarkha<br/> Resonance variations of the in-plane conductivity of surface electrons (SEs) over liquid He induced by microwave (MW) radiation of a fixed frequency are experimentally and theoretically studied for low temperature scattering regimes (T<0.5 K). The system was tuned to resonance by varying the amplit ... [Low Temp. Phys. 34, 377 (2008)] published Wed May 14, 2008. Diatomic model of a quantum crystal http://link.aip.org/link/?LTP/34/368/1&agg=rss Yu. M. Poluektov<br/> The anharmonic zero-point vibrations of a crystal are studied using a two-atom model. It is shown that the amplitude of such vibrations cannot exceed a certain limiting value, which is a fraction of the interatomic distance. Compressing the crystal decreases and stretching increases the amplitude of ... [Low Temp. Phys. 34, 368 (2008)] published Wed May 14, 2008. Growth of [sup 3]He crystals at different magnetic fields http://link.aip.org/link/?LTP/34/357/1&agg=rss J. Bueno, R. Blaauwgeers, A. Y. Parshin, and R. Jochemsen<br/> Experiments on He crystal growth are carried out in magnetic field up 9 T. The data are analyzed and compared with the results found at zero magnetic field. It is found that the interface and the crystal lattice couple weakly in the presence of an external magnetic field, and we can set an upper li ... [Low Temp. Phys. 34, 357 (2008)] published Wed May 14, 2008. Bose--Einstein condensation in a decorated lattice: an application to the problem of supersolid He http://link.aip.org/link/?LTP/34/351/1&agg=rss D. V. Fil and S. I. Shevchenko<br/> The BoseEinstein condensation of vacancies in a three-dimensional decorated lattice is considered. The model describes possible scenario of superfluidity of solid helium, caused by the presence of zero-point vacancies in a dislocation network. It is shown that the temperature of BoseEinstein condens ... [Low Temp. Phys. 34, 351 (2008)] published Wed May 14, 2008. Formation of a glass phase in solid [sup 4]He. Contribution to the pressure in the supersolid region http://link.aip.org/link/?LTP/34/344/1&agg=rss V. N. Grigor'ev, V. A. Maidanov, V. Yu. Rubanskii, S. P. Rubets, E. Ya. Rudavskii et al.<br/> High-precision barometry is used to perform measurements of the temperature dependence of the pressure of helium crystals, located in a constant volume, in the temperature range 50800 mK on crystals of different quality ranging from freshly prepared to carefully annealed. It is found that an additi ... [Low Temp. Phys. 34, 344 (2008)] published Wed May 14, 2008. Defects and supersolidity: effects of annealing and stress on elastic behavior of solid [sup 4]He http://link.aip.org/link/?LTP/34/340/1&agg=rss A. Syshchenko, J. Day, and J. Beamish<br/> Recent measurements have shown that solid He can decouple from a torsional oscillator below 200 mK, and defects appear to be crucial to this behavior. Helium's shear modulus increases in the same range, which can be understood in terms of dislocations pinned by He impurities at the lowest temperatu ... [Low Temp. Phys. 34, 340 (2008)] published Wed May 14, 2008. Search for fourth sound propagation in supersolid [sup 4]He http://link.aip.org/link/?LTP/34/329/1&agg=rss Y. Aoki, H. Kojima, and X. Lin<br/> A systematic study is carried out to search for fourth sound propagation solid He samples below 500 mK down to 40 mK between 25 and 56 bar using the techniques of heat pulse generator and titanium superconducting transition edge bolometer. If solid He is endowed with superfluidity below 200 mK, ... [Low Temp. Phys. 34, 329 (2008)] published Wed May 14, 2008. ``Infrared'' singularities in the field theory of superfluidity and temperature corrections to the first and second sound velocities in helium II http://link.aip.org/link/?LTP/34/320/1&agg=rss E. A. Pashitskii, S. I. Vilchinskii, and A. V. Chumachenko<br/> Higher-order corrections to the self-energy parts of the field theory of superfluidity are obtained using V. N. Popov's perturbation theory modified for a strongly interacting Bose system and free of infrared divergences. It is shown that the calculation of these corrections reduces to solving kinet ... [Low Temp. Phys. 34, 320 (2008)] published Wed May 14, 2008. Neutron reflection from a liquid helium surface http://link.aip.org/link/?LTP/34/316/1&agg=rss T. R. Charlton, R. M. Dalgliesh, O. Kirichek, S. Langridge, A. Ganshin et al.<br/> The reflection of neutrons from a helium surface is observed for the first time. The He surface is smoother in the superfluid state at 1.54 K than in the case of the normal liquid at 2.3 K. In the superfluid state we also observe a surface layer ~200 A thick which has a subtly different neutron s ... [Low Temp. Phys. 34, 316 (2008)] published Wed May 14, 2008. Konstantinov effect in helium II http://link.aip.org/link/?LTP/34/312/1&agg=rss L. A. Melnikovsky<br/> The reflection of first and second sound waves by a rigid flat wall in helium II is considered. A nontrivial dependence of the reflection coefficients on the angle of incidence is obtained. Sound conversion is predicted at oblique incidence. ... [Low Temp. Phys. 34, 312 (2008)] published Wed May 14, 2008. Bubble nucleation in a superfluid [sup 3]He--[sup 4]He mixture induced by acoustic wave http://link.aip.org/link/?LTP/34/308/1&agg=rss H. Abe, Y. Saitoh, T. Ueda, R. Nomura, Y. Okuda et al.<br/> The nucleation dynamics of bubbles induced by an acoustic wave pulse in HeHe liquid mixtures is reported. The experiment is performed mixtures with fixed He concentrations of about 4% and 25% and for pure superfluid He. When a pulse of 1 ms duration is applied to the mixture at the saturated vapor ... [Low Temp. Phys. 34, 308 (2008)] published Wed May 14, 2008. On cavitation in liquid helium in a flow due to a vibrating quartz fork http://link.aip.org/link/?LTP/34/298/1&agg=rss M. Blazkova, D. Schmoranzer, and L. Skrbek<br/> Cavitation in normal and superfluid liquid He at saturated vapor pressure and slightly elevated pressures has been experimentally studied in a flow due to quartz forks vibrating at high amplitudes. Above the temperature- and pressure-dependent critical velocity, heterogeneous cavitation is observed ... [Low Temp. Phys. 34, 298 (2008)] published Wed May 14, 2008. Energy spectrum of the velocity field induced by a fractal vortex line in superfluid helium http://link.aip.org/link/?LTP/34/293/1&agg=rss S. K. Nemirovskii and V. A. Andryushchenko<br/> A Gaussian model of a vortex tangle is used to calculate the energy spectrum E(k) of a three-dimensional random velocity field induced by chaotic vortex lines. It is proposed that the lines have a random-walk structure (Brownian line) with different Hausdorff dimension H. It is shown that for a frac ... [Low Temp. Phys. 34, 293 (2008)] published Wed May 14, 2008. Observation of acoustic turbulence in a system of nonlinear second sound waves in superfluid [sup 4]He http://link.aip.org/link/?LTP/34/288/1&agg=rss A. N. Ganshin, P. V. E. McClintock, V. B. Efimov, G. V. Kolmakov, and L. P. Mezhov-Deglin<br/> The results of recent studies of acoustic turbulence in a system of nonlinear second sound waves in a high-quality resonator filled with superfluid He are discussed. It is found that when the driving amplitude is increased sufficiently, a steady-state direct wave cascade, involving a flux of energy ... [Low Temp. Phys. 34, 288 (2008)] published Wed May 14, 2008. Collective modes in superfluid helium when there is a relative velocity between the normal and superfluid components http://link.aip.org/link/?LTP/34/279/1&agg=rss I. N. Adamenko, K. E. Nemchenko, V. A. Slipko, and A. F. G. Wyatt<br/> Collective modes are studied in superfluid helium when the normal and superfluid components have a relative velocity w. In this paper the general dispersion relation for first and second sound modes is obtained for arbitrary values of w, and we have found the relationship between the amplitudes of t ... [Low Temp. Phys. 34, 279 (2008)] published Wed May 14, 2008. Superfluidity of [sup 4]He confined in nanoporous media http://link.aip.org/link/?LTP/34/273/1&agg=rss K. Shirahama, K. Yamamoto, and Y. Shibayama<br/> We have examined superfluid properties of He confined to a nanoporous Gelsil glass that has nanopores 2.5 nm in diameter. The pressure-temperature phase diagram was determined by torsional oscillator, heat capacity, and pressure studies. The superfluid transition temperature T approaches zero at 3. ... [Low Temp. Phys. 34, 273 (2008)] published Wed May 14, 2008. On the possible nature of the electric activity of He II http://link.aip.org/link/?LTP/34/262/1&agg=rss V. M. Loktev and M. D. Tomchenko<br/> An attempt is made to explain the nature of the electric signals observed in helium II in a second-sound standing wave. It is shown on the basis of the general principles of quantum mechanics that as a result of interatomic interactions each helium atom acquires a small induced dipole moment d, whic ... [Low Temp. Phys. 34, 262 (2008)] published Wed May 14, 2008. Interaction of microwaves with superfluid flow in He II http://link.aip.org/link/?LTP/34/254/1&agg=rss A. S. Rybalko, S. P. Rubets, E. Ya. Rudavskii, V. A. Tikhii, R. Golovashchenko et al.<br/> The absorption of 40200 GHz electromagnetic waves in liquid helium at temperatures 1.42.8 K is investigated experimentally. The spectrum of oscillations of the whispering gallery modes of a dielectric disk-shaped resonator immersed in liquid helium is recorded. Superfluid flows in He II is produc ... [Low Temp. Phys. 34, 254 (2008)] published Wed May 14, 2008. Quantum-limited mass flow of liquid [sup 3]He http://link.aip.org/link/?LTP/34/249/1&agg=rss G. Lambert, G. Gervais, and W. J. Mullin<br/> We consider theoretically the possibility of observing unusual quantum fluid behavior in liquid He and solutions of He in He systems confined to nanochannels. In the case of pure ballistic flow at very low temperature the conductance will be quantized in units of 2m/h. We show that these steps shoul ... [Low Temp. Phys. 34, 249 (2008)] published Wed May 14, 2008. In celebration of the 100[sup th] anniversary of the liquefaction of helium http://link.aip.org/link/?LTP/34/247/1&agg=rss E. Ya. Rudavskii<br/> ... [Low Temp. Phys. 34, 247 (2008)] published Wed May 14, 2008.