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The MOT cloud is loaded from a background of thermal vapour, or from an atomic beam, usually slowed down to the capture velocity using a Zeeman slower. However, the trapping potential in a magneto-optical trap is small in comparison to thermal energies of atoms and most collisions between trapped atoms and the background gas supply enough ...
Gas flow can be grouped in four regimes: For Kn≤0.001, flow is continuous, and the Navier–Stokes equations are applicable, from 0.001<Kn<0.1, slip flow occurs, from 0.1≤Kn<10, transitional flow occurs and for Kn≥10, free molecular flow occurs. [6] In free molecular flow, the pressure of the remaining gas can be considered as effectively ...
Effusion from an equilibrated container into outside vacuum can be calculated based on kinetic theory. [2] The number of atomic or molecular collisions with a wall of a container per unit area per unit time (impingement rate) is given by: =. assuming mean free path is much greater than pinhole diameter and the gas can be treated as an ideal gas.
An optical molasses consists of 3 pairs of counter-propagating orthogonally polarized laser beams intersecting in the region where the atoms are present. The main difference between an optical molasses and a magneto-optical trap (MOT) is the absence of magnetic field in the former. Unlike a MOT, an OM provides only cooling and no trapping.
As a simple approximate equation, the physical value of is usually very close to 1/3 of the detonation velocity of the explosive material for standard explosives. [1] For a typical set of military explosives, the value of D 2 E {\displaystyle {\frac {D}{\sqrt {2E}}}} ranges from between 2.32 for Tritonal and 3.16 for PAX-29n.
The two particles of the same energy have spin 1 ⁄ 2 (spin up) or − 1 ⁄ 2 (spin down), leading to two states for each energy level. In the configuration for which the total energy is lowest (the ground state), all the energy levels up to n = N/2 are occupied and all the higher levels are empty.
The thickness of the shock wave is comparable to the mean free path of the gas molecules in the flow field. [1] In other words, shock is a thin region where large gradients in temperature, pressure and velocity occur, and where the transport phenomena of momentum and energy are important.
Boltzmann's equation = is the realization that the entropy is proportional to with the constant of proportionality being the Boltzmann constant. Using the ideal gas equation of state ( PV = NkT ), It follows immediately that β = 1 / k T {\displaystyle \beta =1/kT} and α = − μ / k T {\displaystyle \alpha =-\mu /kT} so that the ...