Wilson霧函における針端放電のFigureについて

抄録

The could figure of the positive corona discharge in Wilson cloud chamber is a branching' figure, but sometimes a ring or a semi-sphere is seen in the center of the figure. The ring or the semi-sphere cloud figure depends on the sharpnessof the needle and the crest value of the impressed impulse voltage. When the needle is sharp and also the impressed voltage is high, such a cloud figure appears. When the expansion ratio is smaller than the value which is suitable for appearance of the branching figure, or the impulse voltage is sent to the needle sooner a little, the branching figure diffuses, while the ring or the semi-sphere cloud figure appears more clearly. As the reason for appearance of such a cloud figure, the corona wind from the needle is considered.
Experiments are carried out in air which contains some water and ethylalcohol vaper, , with a single needle electrode and a double needle electrode.