Coupled Magnetic and Electric Divergence Precursors in Tokamak Disruptions: Empirical Validation of Relativistic Frame Transformations and Force Density Equilibrium

Achieving stable magnetic confinement in thermonuclear fusion plasmas remains a major physics and engineering challenge. While classical Magnetohydrodynamic (MHD) models treat fluid motion and electrodynamics as decoupled systems enforcing strict solenoidality (divergence of B = 0), this paper presents an extended theoretical framework based on unified volumetric force density (N/m3) and classical Lorentz transformations (Electric Field = velocity cross Magnetic Field, and Magnetic Field = - velocity cross Electric Displacement). We demonstrate that rapid, localized plasma movement and electron acceleration during instability onset generate coupled spatial divergence signals: a macroscopic magnetic divergence (divergence of B not equal to 0) paired with a mirror-symmetric electric divergence (divergence of E not equal to 0). The anti-phase relationship (sign of divergence of B = - sign of divergence of E) provides an unequivocal relativistic signature that distinguishes genuine structural plasma collapse from non-disruptive field compression or single-sensor diagnostic noise. To empirically validate this dual-divergence precursor framework, a frozen double-blind testing protocol was executed across four radically different magnetic confinement topologies: TCABR (Brazil): Isolation of the coupled precursor signal yielded an average early warning lead time of 0.234 ms (max 1.502 ms). FAIR MAST (UK): Validation on a mega-ampere spherical tokamak (>700 kA) expanded the lead window to over 7.16 ms. NIFS LHD (Japan): In a highly asymmetric 3D superconducting stellarator, the algorithm successfully detected the precursor in 49.58% of disruptive shots (468 detections), delivering massive early warning lead times up to 199.9 ms (mean 124.5 ms). GOLEM (Czech Republic): Ultimate scale-invariance was proven on a mini-tokamak with 100% sensitivity and lead times up to 10.2 ms. By expanding high-resolution precursor profiles with dual magnetic and electric divergence plots, this study establishes a universal, physically explainable, and noise-resilient early warning metric for active disruption mitigation systems (such as SPI and MGI) in modern fusion reactors.