12 research outputs found

    Optically pumped spin-exchange polarized-electron source

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    We describe the operation of a prototype polarized-electron source. Rubidium vapor, contained in a cell, is optically pumped in the presence of a buffer gas. Unpolarized electrons from a tungsten filament are injected into the cell and extracted after undergoing spin exchange with the Rb atoms. We compare the performance of the source when different buffer gases are used. We measure a decrease in electron polarization as their injection energy increases, but find an unexpected regime at higher injection energies yielding increased electron polarization accompanied by a 40-fold increase in current, suggesting the production of slow secondary electrons in the target cell. With ethylene, we have measured electron currents of 4 μA simultaneously with electron polarizations of 24%. This work offers the promise of a simple, benchtop, “turnkey” source of polarized electrons

    Techniques and Rules of Ineffability in the Dionysian Corpus

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    Is the Dionysian God, or an experience of the Dionysian God, absolutely ineffable? Does the Dionysian corpus assert or perform such ineffability? This paper will argue that the answer to each of these questions is no. The Dionysian God is known hyper-nous as the hyper-ousia cause of all. And the Dionysian corpus unambiguously refers to, asserts of, and metaphorizes about this God just so. In arguing these points, this paper will call upon both the speech act theory of John Searle and the metaphor theory of George Lakoff and Mark Johnson. More particularly, it will look to Searle’s rules of reference and predication and conditions of illocutionary acts, as well as Lakoff and Johnson’s schematization of metaphor gestalt and entailment to show how Dionysian expressions of inexpressibility are rule-governed and the Dionysian God is thereby (relatively) effable

    Optically pumped spin-exchange polarized-electron source

    Get PDF
    We describe the operation of a prototype polarized-electron source. Rubidium vapor, contained in a cell, is optically pumped in the presence of a buffer gas. Unpolarized electrons from a tungsten filament are injected into the cell and extracted after undergoing spin exchange with the Rb atoms. We compare the performance of the source when different buffer gases are used. We measure a decrease in electron polarization as their injection energy increases, but find an unexpected regime at higher injection energies yielding increased electron polarization accompanied by a 40-fold increase in current, suggesting the production of slow secondary electrons in the target cell. With ethylene, we have measured electron currents of 4 μA simultaneously with electron polarizations of 24%. This work offers the promise of a simple, benchtop, “turnkey” source of polarized electrons
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