Molten Salt Reactor: Precursor Drift — Space-Time Strip (2D)

This 2D companion to the 3D racetrack-loop simulator unrolls the closed fuel loop into a single position axis and integrates the precursor advection–decay equation live, in real time, from a cold start — instead of solving directly to a pre-baked steady state. Watch the concentration profile along the loop build up frame by frame, and see how flow speed, external loop length, precursor group choice, and pausing the flow (a genuine physics change, not a cosmetic one) reshape both the profile and the effective delayed-neutron fraction retained inside the core.