Study on Lichtenberg's Figures by Means of Special Dry Plates

The Lichtenberg's figures were researched on various conditions of the photographic dry plates, and these figures were obtained by applying a constant crest voltage of impulse. Special dry plates were adopted and researched as follows ; -It was observed that the change of the degree of emulsion ageing (or ripening) affected almost no variation on the positive and negative figures respectively. For the plates which added a desensitizer (including the nuclear track plates, the autoradiographic plates and the plates for electron beam), the existence of the desensitizer was dominant. There was observed great reductions of the size on both figures respectively. But the records of positive figures' streamers were fairly observed on the plates for electron beam, and clear records of coronets were obtained. For the plates of various electro-conductivity (K), gained by adding KNO_3 to the emulsion, there was observed small variation on the positive figures, and in the case of increased value of K, fine branched dendritic streamers appeared on the same figures. But, on the negative figures, remarkable enlargements of the figures were observed for the large value of K. At last, for the variations of silver halide (AgBr) content, there were observed enlargements of the size of the figures for the reduction of AgBr concentration on both figures, and vice versa