Simple AGB Model v4

AGB Convective Boundary Mixing Laboratory — V4.1 Blogger

Interactive reduced-network CBM laboratory • implicit diffusion • common-axis comparison • MESA CSV import

Model

ScenarioGrid cellsSteps / phaseHₚ [cm] Approx. modeled layer mass [M☉]

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Thermodynamic structure

T boundary [MK]T deep [MK]ρ boundary [g cm⁻³]ρ deep [g cm⁻³]

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Phase I: TDU / mixing

Duration [yr]D₀ [cm²/s]Exponential fStep / penetration αIGW D₀IGW scaleShear D₀Magnetic D₀Magnetic scale

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Composition

Envelope X(H)Intershell X(He)Intershell X(12C)

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Phase II: radiative burning

Duration [yr]Residual D factor12C+p scale13C+p scale13C+α,n scale14N poison factor

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MESA profile import

CSV import recognizes common headings such as mass, radius, logT/logRho or temperature/density, h1, he4, c12. Imported arrays are interpolated onto this model grid.

Ready.

13C pocket width–

Pocket mass–

Peak X(13C)–

Peak nₙ estimate–

τ estimate–

Runtime–

∂Xᵢ/∂t = ∂/∂z(D∂Xᵢ/∂z)+Rᵢ;   nₙ = ρNₐYₙ (reduced-network estimate);   τ = ∫nₙvₜdt.

T and ρ

Dmix — common scale

Final abundances

13C / 14N / neutron estimate

Time evolution

Neutron exposure estimate vs depth

Model comparison

Press “Compare all 9 models”.

Overlay: Dmix for compared models

Convergence

Press “Convergence test”.

Scientific limitation: V4 improves diagnostics and comparison, but nuclear rates remain reduced parameterizations rather than a full JINA REACLIB network. The reported nₙ and τ are therefore physical-unit estimates from the reduced network, not publication-grade predictions. Imported MESA profiles improve the background structure but do not make the HTML a self-consistent stellar-evolution calculation.

Ammar Sakaji, IAC