120KV Tri-pole Heat-Exchanger Assembly

Client – MIT Research Lab

Application requirements:

• Customer required an assembly which incorporated 3 ceramic breaks into a water-cooled base mount for a High-Power Electron Gun.
• The E-gun mount must operate at 120KV and remain electrically isolated from the base flange.
• The entire assembly requires liquid coolant to circulate thru the base flange to the E-gun mount. Three ceramic-to-metal breaks were used to form a tri-pole assembly which isolated the base flange from the high voltage, and maintained a full hermetic barrier for the ultra-high-vacuum environment.
• Several dimensional tolerances regarding parallelism of sample flange to base flange, and locational tolerances for tapped holes and such on either.

Critical Issues:

• The sub-assemblies required highly toleranced ceramic tubes, and careful fixturing to keep ends parallel.
• Post-braze machining of the weld adapters was required to fit the flanges into the assembly and maintain parallelism of the plates.

Design Basis:

MPF considered ceramic break design for sub-assemblies which would withstand 130KV and provide structural support for the sample flange. These sub-assemblies would be brazed with weld cuffs, such that the 3 subs would then be assembled into the overall assembly using TIG welding.

Results:

The assembly was completed to exact specifications, and MPF was able to provide additional spare sub-assemblies (breaks with weld adapters). MIT installed the Heat-Exchanger in their system and proceeded with expected operations.