Cooling by flow through narrow pores
Publication Date
2006
Journal or Book Title
Low Temperature Physics, Pts A and B
Abstract
We consider the possibility of cooling 3He atoms in dilute solutions with liquid 4He by “filtering out” the hot atoms through a screen of small holes or channels. The proposed method is somewhat analogous to that employed to evaporatively cool trapped gases, and the specific heat of the 3He-4He mixture makes it feasible to use in a device to refrigerate other samples. Three methods are considered: 1) Effusion through holes having diameters larger than a mean free path allowing atoms to pass through easily; 2) Particle waveguide-like motion (also effusive) using very narrow channels that greatly restrict the quantum states of the atoms in them; and 3) Wall-limited diffusion through channels of various widths, in which the wall scattering is disordered so that local density equilibrium is established within a channel. The methods studied all require sufficiently low temperatures and holes or channels with sufficiently small dimensions that temperature equilibrium between the escaping gas and the original gas is avoided; that is, we assume that channel dimensions are smaller than the mean free path for atom-atom interactions. We find that the particle waveguide and the wall-limited diffusion methods using channels on the order of the de Broglie wavelength give cooling. Recent advances in nano-filters give these methods some hope of being practical.
Pages
1563-1564
Volume
850
Book Series Title
AIP CONFERENCE PROCEEDINGS
Recommended Citation
Mullin, WJ and Kalechofsky, N, "Cooling by flow through narrow pores" (2006). Low Temperature Physics, Pts A and B. 28.
Retrieved from https://scholarworks.umass.edu/physics_faculty_pubs/28
Comments
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