Helium is a finite global resource, which becoming vitally important to recover and reuse as it continually diminishes. The helium recovery process uses plant machinery that can consume significant amounts of power generate large carbon footprint. Many organizations around the world are actively trying reduce their footprint and, therefore, lessen impact operations on climate. Here we have asse...

In classical systems, the atomic momentum distribution (AMD) is always the renowned Maxwell–Boltzmann distribution.1,2 Essentially, the atomic momentum p = k and atomic position r are independent, canonical variables and the momentum distribution n(k) is always a Gaussian independent of the interatomic or any external potential. Neutron scattering measurements3–10 have shown that n(k) for atoms...

We have been using molecular-beam techniques to study superfluid liquid helium and other systems at low temperature. The following helium beam experiments are in progress. 1. Measurement of the cross section of 4helium atoms for collision with both 4helium and 3helium at low temperatures (D. E. Oates). 2. Measurement of the velocity distribution of atoms evaporating from helium II at low temper...

The angular distribution after reflection at a cleaved NaF-liquid He interface of a collimated phonon beam incident from the helium at a grazing angle of incidence of ̂ 10° has been measured. The results suggest the existence of interface states which interact with only a part of the incident phonon spectrum. In the light of experiments which have been aarried out on the problem of phonon transm...

This paper introduces a nonlinear Schrr odinger model for superruid that captures the process of mutual friction between the superruid and normal uid components of helium II. Superruid vortices are identiied as topological defects in the solution of this equation. A matched asymptotic analysis of Neu 7] is adapted to derive an asymptotic dynamics for the vortices in the case they are widely sep...

One of the most appropriate methods for elimination of trace impurities in helium is cryogenic adsorption process. So, in this study design and construction of cryogenic adsorption helium purification system (3 Nm3.hr-1, 80 bar) carried out using activated carbon as adsorbent at 77K. To evaluation of adsorption dynamics and effect of pressure on elimination of trace impurities, helium purificat...

The significant structure theory of quantum liquids such as hydrogen, deuterium, and helium has been applied to the physical adsorption occurring in the submonolayer region. The partition function for the two-dimensional adsorbed fluid has been derived. The properties of isothermal and isosteric heat show good agreement with the available data from the literature.

For the thickness 0 5 a liquid or solid quantum f i lm, like liquid helium or solid hydrogen, there exist still open questions about how the film thickness develops in certain limits. One of these is the thick film limit, i.e., the crossover from the thick film to bulk. We have performed rneasurements in this range using the surface plasmon resonance technique and an evaporated h g film deposit...

Electron mobilities in supercritical and liquid helium were investigated as a function of the density. The mobilities were derived from I(V) curves measured in a high-pressure cryogenic cell using a corona discharge in point-plane electrode geometry for charge generation. The presented data spans a wide pressure and temperature range due to the versatility of our experimental set-up. Where data...