Lanthanum Hexaboride Cathode with Guard Ring

Lanthanum Hexaboride Cathode with Guard Ring


Please see Description Tab below.

1 in stock

Part #: 58-001860 Categories: ,
Model #: ES-423E-GR025 SG AEI


The Kimball Physics ES-423GR Guard Ring Lanthanum Hexaboride (LaB6) Cathode is a high performance, resistively heated, thermionic electron source. It is currently employed in many brightness-limited electron optical systems: SEM’s, TEM’s, probes, electron lithography systems, and more.

The design of the crystal geometry is similar to the conical shape with a microflat tip found in the LaB6 ES-423E design. However, this advanced design optimizes emission from the microflat region and suppresses emission from the inclined conical surface by utilizing the additional guard ring structure without requiring elevated electric fields from the Wehnelt/grid.

The exposed emitter surface can range from 10 µm to 250 µm diameter, with a standard diameter of 25 µm. The single crystal LaB6 <100> orientation, is mounted on the end of a single-piece, stress-free carbon heater rod, and is held in place by a carbon ferrule. The additional guard ring aperture structure controls the exposure of the LaB6 surface.

The model ES-423GR is available in custom configurations with the LaB6 crystal cut at a cone angle of 60º or 90º and with a microflat size range from 10 µm to 250 µm. The LaB6 cathode is available mounted on a standard AEI base, a Kimball Physics CB-104 ceramic base or on a variety of custom bases for particular systems.


  • Scanning Electron Microscopes
  • Transmission Electron Microscopes
  • Electron Lithography Systems
  • Electron Accelerators
  • X-ray Sources
  • Custom Applications

Features / Options:

  • Guard Ring Design with optimized emission from the microflat surface
  • Extended Lifetime
    • Thousands of functional hours in
      clean vacuum
    • Guaranteed Against Structural
      Mounting Failure
  • Exceptional Stability
    • Precision machined carbon mounting
    • High over-temperature tolerance
  • High Brightness / Low Energy Spread
    • <100> Oriented Single Crystal
    • Best Quality / High Purity Material
    • Emission current densities up to 30 A/cm2
    • Operating pressure < 10-7 torr
  • Accurate Microflats
    • Superior Optics
    • Controlled Source Size
    • Standard Diameters Available
    • Range of emission surface sizes
    • Custom sizes available
  • On AEI base, compact CB-104 base or request custom mounting

For More Information, please refer to the Resources Tab (above) on this page to access additional detailed content.

Additional information

Weight 1 lbs
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