PURPOSE: To reduce the dispersion of sensitivity resulting from the incident position of light by bending a grid-like electrode body along a closed tube.
CONSTITUTION: A grid-like electrode body 9 arranged between a closed tube and a cathode electrode 6 in the closed tube is bent along the closed tube. Owing to this shape, the equipotential line 1 of an electric field produced by a voltage applied between electrodes 6, 9 is impregnated into an area formed between the electrodes 6, 9 so that photo-electrons are incident on a diode Dy1 along an orbit L even in an area A. Thereby, the dispersion of sensitivity resulting from the incident position of light is reduced so that a photomultiplier tube by which high sensitivity detection can be conducted is obtained.
KATO HISAYOSHI
IKUMA TOSHIO
Next Patent: SINGLE END TYPE DISCHARGE LAMP