Scale-Selective Propagation of Time-Rate Waves Through Fine Structure in the Enchan Field

This work studies how small perturbations of the Enchan local time-rate field propagate through fine spatial structure in the same field. The problem is motivated by the hard-wall boundary used in a previous Enchan two-route interference study: rather than imposing a primitive material opacity or an S=0 wall, the present work asks whether finite structure in the Enchan field itself can generate scale-selective transmission and reflection. Starting from the reduced finite-tension branch S_tt = div[mu(D) grad S] - S with mu(D) = 1/(1 + D^(3/2)), the field is decomposed as a structured background plus a small propagating perturbation. Stage A uses a predeclared one-dimensional frozen structured background and compares it with a matched smooth/homogenized control. The response is banded rather than a monotonic low-pass: long-scale perturbations remain comparatively transmissive while strong reflection bands appear when the perturbation resolves the fine structure. At ka = 2 the mean Stage-A structured transmission is approximately 6.25e-4 while the smooth control remains approximately 0.989; at ka = 4 the structured transmission is approximately 1.07e-14 while the smooth control remains approximately 0.962. Stage B replaces the hand-constructed surrogate with three previously frozen source-free Enchan final states from the published localized-field study. The source files are SHA-256 checked against the original run manifest before analysis. All three source profiles remain within the declared positive longitudinal branch and reproduce a scale-dependent structured-versus-smooth transmission difference. The largest Stage-B mean differences occur near ka = 1.0 and 1.5, where structured transmission is approximately 0.330 and 0.358 while the smooth controls remain approximately 0.994 and 0.988. The maximum Stage-B conservation residual is approximately 1.89e-15. The result supports a model-level statement: fine S-field structure can act as a wavelength-selective barrier for small time-rate perturbations within the declared linearized Enchan branch. It does not identify ordinary matter with the tested surrogate or source-free structures, does not claim monotonic high-frequency blocking, and does not yet replace the two-dimensional hard slit wall. The next experiment is a finite structured-S two-aperture wall using the established interference benchmark. The Zenodo deposit contains the Version 1.0 manuscript PDF, a reproducibility archive with the frozen Stage-A and Stage-B code and data, README, LICENSE and integrity manifest. The manuscript PDF is generated directly from the final Version 1.0 TeX source and is set as the default Zenodo preview. License: Enchan Research & Verification License v1.0. Copyright (c) 2026 Mitsuhiro Kobayashi.