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Nuclear data explorer · reaction

12C(12C,α)20Ne

All 15 EXFOR datasets of this reaction: who measured it, where and when, what they measured and over which energies.

Gamow window and the gap

Every dataset EXFOR holds for this reaction, drawn by the energies it covers, against the energies a star uses.

15 datasets in 12 EXFOR entries, 1973–2024

Temperature
Lowest energy in EXFOR
2.13 MeV
Spillane et al., 2007 · S · O1712.002
Distance from the Gamow peak
Inside the window
E₀ = 2130 keV, window 1680–2590 keV
Rate from energies not in EXFOR
45%
at T₉ = 0.83, smooth estimate · 45% of it lies below the lowest energy in EXFOR
1 MeV10 MeV100 MeVCentre-of-mass energy (keV)E₀ = 2130 keVσSσ→Eₓdσ/dΩotherlowest in EXFOR 2.13 MeV
  • Gamow window, hatched where no measurement reaches
  • Outlined bars are shown but not counted (the rule is under “How these numbers are made”).
  • A diamond is a dataset at a single energy. Bars running off the right edge continue to higher energies.
The datasets of the gap map, by quantity
The datasets of the gap map, by quantity
QuantityDatasetsE_cm range (keV)
σcross section14.42 MeV – 6.48 MeV
SS-factor22.11 MeV – 5.34 MeV
σ→Eₓpartial72.2 MeV – 6.01 MeV
dσ/dΩangular distribution42.9 MeV – 35.8 MeV
…other14.88 MeV – 7.5 MeV
How these numbers are made

Lowest measured energy, everywhere in the data explorer: the lowest centre-of-mass energy at which a dataset in EXFOR measures the reaction itself (cross section, S-factor, angular distribution, yield or resonance strength), judged point by point. A point counts when it is a value, not an upper or lower limit, when it lies at least one standard deviation above zero, and when its energy is physical: at least 1 keV for charged particles, and not below the threshold of an endothermic reaction. Not counted: extrapolated, calculated, evaluated or derived values; superseded, deleted or preliminary data; ratios; a single S-factor value, which in EXFOR is a fit result; and indirect methods (Trojan horse, Coulomb dissociation, ANC, surrogate reactions), recognized from EXFOR's method and analysis codes, their text and the title. Frame and unit errors of EXFOR are corrected first, and values the literature shows to be upper limits are read as limits, from a list that gives the evidence for each. Datasets that reach the same energy within 0.5% are all credited, earliest first. Rate from energies not in EXFOR: the share of the rate integrand at that temperature outside the energy ranges the counted datasets cover (from their lowest measured point to their highest), with a constant S-factor (σ ∝ S(E₀)/E · e^−2πη, so the integrand is e^(−E/kT − 2πη)); for a neutron capture, σ ∝ 1/v. Resonances make the real integrand lumpy, so read it as a smooth baseline.

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