waveguide
Copper cavity structure that accelerates electrons through cavity-by-cavity RF coupling driven by the klystron or magnetron. Vacuum-sealed; high-vacuum integrity is non-negotiable for stable operation. The accelerator structure that distinguishes a linac from any other megavoltage radiation source.
Why it matters to buyers: Vacuum leak = catastrophic. Repair is a major factory event — typically rebuilt or replaced rather than field-repaired. Waveguide vacuum history and pressure logs are part of refurb due-diligence on any linac purchase. A clean vacuum log is a meaningful asset; a marginal one is a leading indicator of expensive future events.
Why it matters to engineers: Interlocks shut down the system before vacuum damage spreads. Never bypass. Late-stage klystron arcing can take collateral damage to the waveguide, circulator, and bend magnet — a single failed klystron can become a multi-component event if vacuum integrity is lost.