Laboratorio de desintegración y enlace nuclear

Two nuclear-physics tools that go beyond a single half-life. The existing Half Life calculator answers “how much of one isotope is left?”; this lab answers “what does the whole chain look like?” and “why is Fe-56 near the top of the binding curve?”

Decay chains. Press Run chain to integrate the Bateman equations for a pure parent at t = 0. Amounts are fractions of the initial parent atoms; activities are λN in the same relative units. Secular equilibrium appears when a long-lived parent feeds a short-lived daughter: the daughter’s activity tracks the parent’s. Transient equilibrium (parent still longer-lived, but not vastly) shows the classic daughter peak then parallel decay. The Ra-226 excerpt of the uranium series is long enough to show both radon build-up and the slow drain into Pb-210.

Custom chains. One nuclide per line: Name, half-life unit, or Name, stable. Units: s, min, h, d, y. Equal half-lives are not supported (Bateman’s closed form divides by λ_k − λ_j).

Binding energy. The curve is the liquid-drop (Weizsäcker) semi-empirical mass formula, B(A,Z)/A, with Z chosen near the valley of β-stability. Click Calculate binding to mark a nuclide (A, Z) on that curve. Real AME masses wiggle around the SEMF; the shape — rise through light nuclei, peak near A ≈ 56–62, slow fall through the actinides — is what the formula is for.

Q-values. Example reactions use AME2020 mass excesses (MeV). Positive Q is exothermic. D–T fusion releases about 17.6 MeV; a typical U-235 fission channel around 200 MeV; splitting Fe-56 into two lighter equal pieces is endothermic, which is why the binding curve peaks there.

Limits. Chains are linear (no branching, no α/β type labels). Binding uses SEMF, not tabulated masses, except in the Q-value table. No dose, shielding or decay heat models.