Momentum transfer gauge

The momentum transfer gauge (MTG) was first developed as a lab curiosity in 1962. It uses the principle of gas viscosity to slow a spinning ball bearing that is... 

In the case of heavy atoms improved experimental accuracy will pay oil in all elements, particularly in Cs and to a somewhat lesser extent in 71 because of the accuracy of the atomic theory and the degree of understanding of the levels involved in these two atoms. Because the transition of interest involves a / = 0 state, Pb also offers some advantages for advanced atomic calculations. Improved measurements of Qw will yield more refined comparisons of the type shown in Eqs. (43)-(45) above. It remains to be seen whether improved experimental accuracy will allow resolution of the C2 terms of Eqs. (8) and (11), which should show up as small fractional differences in PNC between hyperfine components of a transition. The ongoing experiments in atomic hydrogen offer the hope of determining C and C2 with no uncertainties in atomic theory, and furthermore are sensitive to radiative corrections that test the essence of gauge theories at 100 Gev/c momentum transfer. ... 

Pair transfer interaction between the states of an electron system components can cause the gauge symmetry breaking realized in superconductivity. This circumstance forms the basis of the two-band model of superconductivity known already during a considerable time [1,2], The basic advantage of such approaches consists in the possibility to reach pairing by a repulsive interband interaction which operates in a considerable volume of the momentum space. An electronic energy scale is... 

All previously mentioned gauges require a certain level of particle density for operation. Once the level of particle density has dropped below a certain level (approximately 1018 particles/m3), it is not possible to detect transfer of momentum forces either from gas to solid wall or from gas to gas. On the other hand, it is possible to ionize gas particles and then count the ionized molecules. 

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