Particle Excited Luminescence in Diamond

The luminescent effects, excited in the diamond crystals under bombardment by monoenergetic α- and β-particles and by 50 kev monoenergetic electrons, have been investigated for some 50 natural diamonds and for several specimens which had suffered previous radiation damage. The wavelength spectrum in the luminescent emission has been measured and also the effect of crystal temperature on this spectrum. Emphasis has been placed on the difference between the wavelength spectra of the luminescence arising from the different types of excitation and, also, the relative dependence of the wavelength spectra on the condition of the crystal. A comparison has been made of the luminescence and conduction counting efficiencies of the crystals. The results indicate the importance, in diamond, of defects which trap the carriers but do not give rise to the emission of visible or near infra-red radiation.