Deep Dive: The Diagnostic Constellation

A dense array of sensors measures the plasma thousands of times a second — magnetics, interferometry, spectroscopy, and structural gauges — feeding the real-time control stack.

Purpose

Measure plasma state in real time

Sensors

Magnetics, interferometry, spectroscopy, FBG strain

Rate

Thousands of measurements per second

Feeds

The digital twin and control stack

Nothing can be controlled that isn't measured, so a fusion plant carries a whole constellation of diagnostics — sensors watching the plasma from every angle, thousands of times a second, without touching it.

The array spans magnetic sensors (tracking current, position, and instabilities), interferometry (density), spectroscopy (temperature and impurities), and structural gauges such as fiber-Bragg strain sensors on the magnet. Together they reconstruct the plasma's full state in real time.

In Kronos MetroVolt these signals are ingested through deterministic hardware, scored against the digital twin, and used by the AI-native control stack to hold the plasma within its safety envelope — a dropped channel votes to a redundant set in under 100 μs. The design is candid that this sensing-and- control system must ultimately be validated on real machine data, first at the G1 testbed.