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A Caltech Library Repository Feedhttp://www.rssboard.org/rss-specificationpython-feedgenenWed, 06 Dec 2023 15:29:49 +0000Collision-induced spin flip of hydrogen atoms
https://resolver.caltech.edu/CaltechAUTHORS:ROOpr59
Authors: von Roos, Oldwig
Year: 1959
DOI: 10.1103/PhysRev.115.911
The cross section of a radiationless electronic spin-state transition (triplet-singlet transition) of two colliding, unexcited, hydrogen atoms has been calculated for low relative velocities. The low-velocity limit of this cross section exhibits a logarithmic divergence and decreases rapidly to a value of the order of πr0^2 (r0=classical electron-radius e^2/4πmc^2) with increasing energy of relative motion.https://authors.library.caltech.edu/records/3667w-fzy88Plasma theory of the many-electron atom
https://resolver.caltech.edu/CaltechAUTHORS:LEVpr62
Authors: Levine, Paul H.; von Roos, Oldwig
Year: 1962
DOI: 10.1103/PhysRev.125.207
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.https://authors.library.caltech.edu/records/jqvzh-w0b91