M3 Threaded Ceramic Insulators for Ion Repellers & High-Voltage Vacuum Systems

ion source insulator tube

Electron gun and ion source assemblies work in harsh conditions—high voltage, high temperatures, and ultra-high vacuum alike. This is especially true for ion repeller insulators, a key interface component where reliable electrical isolation and airtight vacuum sealing are both must-haves.

Our glazed alumina ceramic tubes with precision internal threading—engineered as Ion Repeller Ceramic Tubes—are made specifically for these tough applications. As the core insulating part of repeller insulator assemblies, they pair perfectly with alumina bolts, delivering steady performance while ensuring firm mechanical fastening and reliable electrical isolation.

High-Vacuum Design: A Core Engineering Challenge
Keeping long-term vacuum integrity in high-voltage setups is a classic engineering hurdle. Insulators have to do three jobs at once: act as mechanical support, block electrical current, and seal the vacuum—all while staying stable when hit with thermal and electrical stress.

Common alternatives all come with risks. Metal inserts can weaken insulation; unprocessed ceramic surfaces have tiny microscopic pores that cause slow outgassing and vacuum loss. Even poorly machined threads can create leak paths, leading to gradual performance drops: higher internal pressure, unstable beam currents, and inconsistent ion repeller output.

How Our M3 Threaded Ceramic Tubes Fix These Issues
We’ve built this component from the ground up to tackle these pain points, combining tailored material selection with precise machining for high-vacuum, high-voltage needs.

95% Alumina Substrate
Our high-purity alumina is a tried-and-true choice, balancing all the key properties these applications demand:
– Dielectric strength over 15 kV/mm
– Stable performance even at high temperatures
– Ultra-low outgassing—critical for keeping vacuum purity intact

Precision M3 Internal Thread
Every M3 internal thread is machined to 6H tolerance, ensuring a tight, consistent fit with standard M3 alumina bolts and electrodes. This precision cuts down on misalignment, distributes clamping force evenly across the surface, and lowers the chance of ceramic cracking during installation and use.

Proprietary Vitreous Glaze Coating
We fuse a vitreous glaze to the ceramic surface, which eliminates all microscopic pores outright. This boosts vacuum retention and tracking resistance dramatically, and also creates a chemically inert, easy-to-clean surface that resists contamination and holds up over time.