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High voltage applications utilize insulator materials that can handle mechanical stresses as well as high intermittent heat loads. Combining materials, segmenting them in a device, can take advantage of differing material properties for higher tolerances and an overall better performance.


The approach is to build a high voltage insulator consisting of two materials:  Poly-Ether-Ether-Ketone (“PEEK”) and Machinable Ceramic (“MACOR”).  PEEK has a high stress tolerance but cannot withstand high temperatures, while MACOR has high heat tolerance but is difficult to machine and can be brittle.  MACOR is used for the plasma-facing surface, while PEEK will handle the stresses and high voltages.  This approach also uses a precision-machined threaded insulator design with gaskets and grease to seal the parts.

  • Allows mating two unlike materials to take advantage of differing physical properties
  • Does not require epoxy that can trap gas in the parts, require curing, and may need additional pieces to align the parts
  • The thread and gasket designs make the track length across the material long enough for the failure modes to arc through the material
Potential Applications
  • High-voltage insulators with plasma facing components (e.g., Dense Plasma Focus, Z-machine)
  • Plasma rail-gun construction
Development Status

Current stage of technology development:  TRL 3 (Analytical and experimental critical function and characteristic proof of concept)

LLNL has filed for patent protection on this invention.

U.S. Patent Application Publication No. 2021/0327615 HIGH-VOLTAGE INSULATORS HAVING MULTIPLE MATERIALS, published 10/21/2021 (

U.S. Patent No. 10,978,225 High-Voltage Insulator Having Multiple Materials, issued 04/13/2021 (

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