Vacuum Technology: Keys and Applications. Before You Select a Vacuum Pump.

Vacuum Gauge to Vacuum Pump Valve

Rarefied gas dynamics and its applications to vacuum technology

Basic concepts of rarefied gas dynamics are given in a concise form. Some problems of rarefied gas flows are considered, namely, calculations of velocity slip and temperature jump coefficients, gas flow through a tube due to pressure and temperature gradients, and gas flow through a thin orifice. Results on the two last problems are given over the whole range of gas rarefaction. A methodology f...

Vacuum defects without a vacuum

Topological defects can arise in symmetry breaking models where the scalar field potential V (φ) has no minima and is a monotonically decreasing function of |φ|. The properties of such vacuumless defects are quite different from those of the “usual” strings and monopoles. In some models such defects can serve as seeds for structure formation, or produce an appreciable density of miniblack holes...

Vacuum Energy and Θ–vacuum

The highly non-trivial structure of the θ–vacuum encodes many of the fundamental properties of gauge theories. In particular, the response of the vacuum to the θ–term perturbation is sensitive to the existence of confinement, chiral symmetry breaking, etc. We analyze the dependence of the vacuum energy density on θ around two special values, θ = 0 and θ = π. The existence or not of singular beh...

A THEORY OF VACUUM TUNNELING MICROSCOPY1

A theory for tunneling between a real surface and a model probe tip, applicable to the "scanning tunneling microscope" is presented. The tunneling current is found to be proportional to the local density of states of the surface, at the position of the tip. It can be shown that the tunneling conductance has exponential dependence on the distance of the nearest approach to the surface