Exo-electron emission from platinum wires cooling in hydrocarbons and other gases as observed in a modified proportional counter

Abstract

A proportional counter has been modified to contain a platinum filament which could be electrically heated. The counter was characterised by field-plotting, voltage changes, gas flow etc. and its gas multiplication factor determined: it operated successfully over a temperature range between ≈ 800 and 298 K with a wide variety of gaseous fillings.

When platinum wires inside the counter were heated to red heat in various gases and the wire allowed to cool in those gases, electron emission curves with a high degree of structure were obtained. These cooling curves were characteristic of the gases examined: O₂, H₂, Ar, N₂, CH₄, C₂H₂, C₂H₄, C₂H₆ and C₄H₆. An important feature of the work was the observation that emission seemed strongly dependent on carbiding of the surface. The implications for catalysis are discussed.