An ionization gauge to measure pressure, while controlling the location of deposits resulting from sputtering when operating at high pressure, includes at least one electron source that emits electrons, and an anode that defines an ionization volume. The ionization gauge also includes a collector electrode that collects ions formed by collisions between the electrons and gas molecules and atoms in the ionization volume, to provide a gas pressure output. The electron source can be positioned at an end of the ionization volume, such that the exposure of the electron source to atom flux sputtered off the collector electrode and envelope surface is minimized. Alternatively, the ionization gauge can include a first shade outside of the ionization volume, the first shade being located between the electron source and the collector electrode, and, optionally, a second shade between the envelope and the electron source, such that atoms sputtered off the envelope are inhibited from depositing on the electron source.

An ionization gauge to measure pressure, while controlling the location of deposits resulting from sputtering when operating at high pressure, includes at least one electron source that emits electrons, and an anode that defines an ionization volume. The ionization gauge also includes a collector electrode that collects ions formed by collisions between the electrons and gas molecules and atoms in the ionization volume, to provide a gas pressure output. The electron source can be positioned at an end of the ionization volume, such that the exposure of the electron source to atom flux sputtered off the collector electrode and envelope surface is minimized. Alternatively, the ionization gauge can include a first shade outside of the ionization volume, the first shade being located between the electron source and the collector electrode, and, optionally, a second shade between the envelope and the electron source, such that atoms sputtered off the envelope are inhibited from depositing on the electron source.

An ionization gauge to measure pressure, while controlling the location of deposits resulting from sputtering when operating at high pressure, includes at least one electron source that emits electrons, and an anode that defines an ionization volume. The ionization gauge also includes a collector electrode that collects ions formed by collisions between the electrons and gas molecules and atoms in the ionization volume, to provide a gas pressure output. The electron source can be positioned at an end of the ionization volume, such that the exposure of the electron source to atom flux sputtered off the collector electrode and envelope surface is minimized. Alternatively, the ionization gauge can include a first shade outside of the ionization volume, the first shade being located between the electron source and the collector electrode, and, optionally, a second shade between the envelope and the electron source, such that atoms sputtered off the envelope are inhibited from depositing on the electron source.

An ionization gauge to measure pressure, while controlling the location of deposits resulting from sputtering when operating at high pressure, includes at least one electron source that emits electrons, and an anode that defines an ionization volume. The ionization gauge also includes a collector electrode that collects ions formed by collisions between the electrons and gas molecules and atoms in the ionization volume, to provide a gas pressure output. The electron source can be positioned at an end of the ionization volume, such that the exposure of the electron source to atom flux sputtered off the collector electrode and envelope surface is minimized. Alternatively, the ionization gauge can include a first shade outside of the ionization volume, the first shade being located between the electron source and the collector electrode, and, optionally, a second shade between the envelope and the electron source, such that atoms sputtered off the envelope are inhibited from depositing on the electron source.

An ionization gauge to measure pressure, while controlling the location of deposits resulting from sputtering when operating at high pressure, includes at least one electron source that emits electrons, and an anode that defines an ionization volume. The ionization gauge also includes a collector electrode that collects ions formed by collisions between the electrons and gas molecules and atoms in the ionization volume, to provide a gas pressure output. The electron source can be positioned at an end of the ionization volume, such that the exposure of the electron source to atom flux sputtered off the collector electrode and envelope surface is minimized. Alternatively, the ionization gauge can include a first shade outside of the ionization volume, the first shade being located between the electron source and the collector electrode, and, optionally, a second shade between the envelope and the electron source, such that atoms sputtered off the envelope are inhibited from depositing on the electron source.

Various systems are provided for a cathode of an X-ray imaging system. In one example, a shield assembly for a cathode comprises a first shield part and a second shield part, the first shield part and the second shield part spaced apart such that the first shield part and the second shield part are not in direct physical contact.