A new approach to the many-electron atom, based on the formal equivalence between the Hartree-Fock equations and a quantum-mechanical generalization of the collisionless Boltzmann (Vlasov) equation, is presented. This equivalence casts the problem into the framework of conventional plasma theory, the Vlasov equation being merely replaced by its quantum-mechanical analog. The quantum Vlasov equation permits a straightforward expansion of the quantum-mechanical phase space distribution function in powers of h. The first step of this expansion, corresponding physically to a classical correlationless plasma obeying Fermi statistics, leads to the Thomas-Fermi model. Successive steps generate quantum and exchange corrections. The method is applied to the case of the "statistical" correlationless atom (or ion), generalized for the first time to arbitrary temperature and nonzero total orbital angular momentum, with quantum and exchange effects being included to order h 2 .1 The most recent comprehensive review articles dealing with the Thomas-Fermi model are those of P. Gombas in Handbuch der Physik, edited by S.
The equilibrium temperature distribution in an ideal metal rod, one end of which is subjected to an intense electric field, is studied. Particular attention is focused on the case where the emitting end cools down, and the necessary conditions for this effect are derived. Viewed as a ``heat pump,'' the maximum rate of heat flow as a function of emitter temperature is derived, and it is found that rates in excess of 0.1 cal/sec/cm2 are possible at room temperature if the emitter work function is less than an electron volt.
An experimental-theoretical program aimed at characterizing over-the-horizon (OTH) propagation via marine atmospheric aerosols is described. Pathloss measurements as a function of transmitter-receiver azimuth-elevation angles for 1.06 microm and 0.53 microm over two OTH links are reported. The first link involves an overwater range of 63 km with 19-km and 40-km horizons; the second involves an overwater range of 128 km with a 19-km horizon. Two theoretical models, one based on particulate single scatter and the other based on particulate multiple scatter, are presented and compared with the pathloss measurements obtained over the 63-km link. Good agreement between both models and experiments is shown. No quantitative comparison between the models and the 128-km experiment is made because of the lack of accurate meteorological data over this extended path.
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