[Mesa-users] Custom weak rate

[Guo Li]

Hi all


I am writing to seek clarification regarding anomalous results in my AGB star s-process nucleosynthesis simulations using MESA-r12778. I encountered unexpected behavior with the decay of Dy-163 that contradicts theoretical expectations, and I would appreciate your expertise in diagnosing the issue.

Simulation Setup
Model: 2M☉ star with metallicity Z = 0.01
Physics Focus: s-process nucleosynthesis during thermally pulsing AGB phase
Custom Weak Rate: Implemented the dy163_wk-minus_ho163 rate from literature via an HDF5 table (attached).
MESA confirmed successful loading: reading user weak rate file: /home/liguo/MESA/.../weak_rates_dy163_ho163_right_length.h5
Observed Anomaly

He-flash Convective Zone (TP-AGB phase)

Temperature: ~3×10⁸ K
log(ρYₑ) (lYeRho): ≲ 3.5
Result: Minimal Dy-163 decay (negligible Ho-163 production)

Convective Envelope

Temperature: < 10⁶ K
log(ρYₑ): < -5
Result: Excessive Dy-163 decay → Abnormally high Ho-163 abundance

This contradicts literature , where Dy-163 is expected to decay efficiently in high-temperature He-burning zones (T ≳ 2×10⁸ K).

Could the issue be caused by insufficient coverage of T9s and lYeRho ranges in my HDF5 weak-rate table? I extended the ranges to both lower temperatures and broader/extremes of lYeRho (larger and smaller values), yet the results remain unchanged.

Attachments
HDF5 weak-rate table
profile.data during a thermal pulse (illustrating T, lYₑRho, and abundances)

I would be grateful for any insights into resolving this discrepancy. Thank you for your time and expertise.




Best regards,  

Guo Li  
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