High-Bandwidth State-Vector Ingress

L1 assembles a coherent plasma or plug state vector every control cycle from dozens of diagnostics, validated and time-aligned in fabric.

The state vector

A controller acts on a state estimate x: for the breeder, quantities like plasma current, vertical and radial position, shape moments, and stored energy; for the burner, plug density, ambipolar potential, and mirror-cell conditions. L1's ingress path builds this vector every cycle from the diagnostics constellation and hands a validated, time-coherent x to the control loops.

Feeding the estimate

Inputs arrive from Thomson scattering, interferometry, Mirnov coils, flux loops, ECE, fast-ion trackers, neutron flux, and magnet strain, through cryo-rated vacuum feedthroughs. Each channel is sampled on the shared clock so the assembled vector is a single-instant snapshot. Fabric performs range checks, spatial normalization, and unit conversion before any value enters x.

Validation before use

• Range and rate checks reject impossible readings.
• Cross-checks compare redundant or physically related channels.
• Dropped channels are flagged; L3's GNN imputer can fill them.
• A validity mask travels with x so downstream logic knows what to trust.

Validation is not optional decoration; a controller acting on a corrupted position estimate can drive the plasma the wrong way. By validating at ingress, L1 ensures the fast loops act only on trustworthy state, and the failsafe never depends on a diagnostic it cannot verify.

Bandwidth and determinism

Ingress is high-bandwidth — many channels at sub-microsecond sampling — yet it must stay deterministic. Kronos handles this with parallel fabric front ends, one region per channel group, so aggregate bandwidth scales spatially without lengthening any single channel's WCET. The coherent x is then published to the control loops and, in parallel, streamed to the L2 archive.