Characterizations of light sources with carbon fiber cathodes

In the present work a cathodo-luminescent lamp with a polyacrylonitrile carbon fiber bundle cathode is presented. Electrical and spectral-brightness characteristics of the designed prototype are analyzed. The optimal anode voltage is 10 kV and the anode current is 150 μA. For this electrical regime the brightness of this light source is up to 13,000 cd/m2 (for the green phosphor) at the light efficiency about 7 lm/W. The low light efficiency is explained by technological aspects of phosphor coating.