Quantum Illumination Density (qild): Wavelength-Projected Photomagnetic Activation in Laser-Plasma Coupling

This paper introduces Quantum Illumination Density ($qild$) as the wavelength-projected form of Quantum Photomagnetic Density ($qpmd$) within the Quantum Measurement Unit (QMU) framework of the Aether Physics Model (APM). The work investigates the physical quantity measured when volumetric luminous-charge activation is projected through a characteristic photonic length scale. Transported photon quanta are represented by phtn, while the local luminous state of the Aether is ligt=phtn\,freq. Quantum illumination density is defined as qild=λC\,qpmd, where λC is the electron Compton length. The resulting quantity is interpreted as the characteristic-length projection of luminous charge activation. Measured hot-electron energies define the QMU electron activation fraction Θₑ=Eₕ/mₑ c², which also serves as the QMU regime coordinate ηq=Θₑ. The practical wavelength-projected coordinate is qT⁼Θₑ λL, providing an empirical bridge between photomagnetic activation density and illumination-density behavior. The investigation analyzes an expanded database of 555 records derived from published electron measurements, x-ray measurements, simulations, and supplemental entries compiled in the recent hot-electron meta-analysis literature. A forward QMU model is constructed using wavelength-projected intensity, pulse duration measured in optical cycles, and pre-plasma scale length measured in laser wavelengths: ηq,pred=A(I₁₈λL²)ᵖ(cτL/λL)ˢ(Lₚ/λL)ʳ. Five-fold cross-validation yields Rlog²=0.829 for the full model, with similarly strong performance across electron measurements and simulations. The fitted intensity exponent, p=0.509 ± 0.014, lies close to square-root response in the wavelength-projected intensity coordinate. The results demonstrate that QMU-native coordinates reproduce substantial hot-electron structure directly from laser-plasma input parameters without using measured hot-electron temperature as an input. Quantum illumination density therefore emerges as a practical and falsifiable QMU research coordinate that bridges luminous-charge activation, characteristic photonic length scales, and experimentally measurable laser-plasma coupling phenomena.