What is the role of the ion pump in the image intensifier?

What is the ion pump inside the image intensifier? What is its role? Today I will introduce the role of the ion pump inside the image intensifier.

Because the vacuum in the image-enhanced tube is high, if there is gas in the tube, the gas molecules will be told to move and ionize and become ionized, become positive and negative ions, and negative ions reach the input.
The screen breaks the image; the positive ions hit the photocathode, generating secondary electrons, and the “air point” is generated on the output screen, so that I.I cannot work normally.

The suction electrode is made of titanium, zirconium, hafnium or the like in the tube, and a certain potential is applied to absorb the gas molecules to ensure the degree of vacuum in I.I.

Author:Alina