Abstract
ZnS: CuAl powder molded in insulating substance was subjected to high frequency electric field from 120 cycles to 50 megacycles, whereby the E. L. brightness was measured aguinst frequency. The experimental results within this frequency range follow the relation B=exp (-b/i./V), where B and V are respectively the brightness and applied voltage; b is a constant dependent on the frequency, which may be expressed as b=b0fn.
The wave-forms of brightness under excitation of sinusoidal voltage were observed in the frequency range from 30 cycles to 200 kilocycles. Two peaks in the brightness wave-form where recognized. The ratio of the first peak to the second increases proportionally with the n'th power of frevqency.
