Abstract
An important consideration in the measurement of activation energies of surface processes observed with the field emission microscope is the production of a square temperature wave. That is, the initial temperature rise to the final operating temperature must be sufficiently rapid so that uncertainties in time measurements can be eliminated. The temperature-current characteristics of a typical field emission microscope tungsten filament operating in a low temperature bath such as liquid nitrogen or liquid helium are derived from the well known solution of the heat conduction equation. The steady state current-temperature curves are of the form i = F + (B/T) where B is negative for filament end temperatures above 50° K, zero at this temperature, and negative below. The steady state temperature-current curve for the filament of a tube operating at liquid helium temperature represents an unstable equilibrium. These predictions were confirmed experimentally with a 0.1 mm diameter, 2.5 cm long filament. A circuit capable of producing a filament temperature above 4.2° K to any desired temperature below 600° K in less than 0.3 sec will be described.
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© 1960 Springer-Verlag Berlin Heidelberg
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Klein, R. (1960). Production of square temperature waves in filaments of field emission microscopes operating at low temperatures. In: Möllenstedt, G., Niehrs, H., Ruska, E. (eds) Physikalisch-Technischer Teil. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-50195-1_8
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DOI: https://doi.org/10.1007/978-3-642-50195-1_8
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-50196-8
Online ISBN: 978-3-642-50195-1
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