Thermoluminescence in solid methane

Abstract

Thermoluminescence from both CH₄ and CD₄ doped with benzene or toluene (⩽0.5 mol %) has been measured in the temperature region 10 < T/K < 40. The methane was deposited from the vapour on a rotatable copper target usually held at T≈ 10 K, and irradiated with ultraviolet light (predominantly of wavelength 2537 Å). Before the glow curves (emitted light intensity as a function of temperature) were recorded, phosphorescence and recombination luminescence from the specimens were allowed to decay isothermally. Certain sharp peaks in the thermoluminescence spectrum can be correlated with the known phase transitions in CH₄ and CD₄.