An ionization gauge includes an electron generator array that includes a microchannel plate that includes an electron generating portion of the microchannel plate comprising a source for generating seed electrons and an electron multiplier portion of the microchannel plate, responsive to the seed electrons generated by the electron generating portion, that multiplies the electrons. The ionization gauge includes an ionization volume in which the electrons impact a gaseous species, and a collector electrode for collecting ions formed by the impact between the electrons and gas species. The collector electrode can be surrounded by the anode, or the ionization gauge can be formed with multiple collector electrodes. The source of electrons can provide for a spontaneous emission of electrons, where the electrons are multiplied in a cascade.