Semispherical electronic collecting device and measurement method for secondary electron yield measurement

The invention discloses a semispherical electronic collecting device and a measurement method for secondary electron yield measurement. The semispherical electronic collecting device comprises an electron gun arranged in a vacuum chamber and a collecting device; the collecting device sequentially comprises a semispherical collecting electrode, a first layer of metal screen and a second layer of metal screen from outward to inward; an electron beam channel cavity which is open in upper and lower ends runs through the collecting electrode, the first layer of metal screen and the second layer of metal screen; an upper opening of the electron beam channel cavity aligns at the electron gun, and a lower opening of the electron beam channel cavity aligns at a sample bed which moves and rotates horizontally; the sample bed is provided with samples; a Faraday cylinder is connected to one end of the sample bed. The electron beam channel cavity can shield the influence of an external bias electric field between the connecting electrode and the two layers of screens on the electron beam motion track; the second layer of metal screen plays roles of shielding the positive bias of the collecting electrode and the negative bias of the first layer of metal screen, and creates an electric-field-free region, so that electron is not affected by an external electric field when arriving at the samples via the region.