Skip to content

Nuclear data explorer · reaction

16O(n,γ)17O

All 31 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.

31 datasets in 12 EXFOR entries, 1963–2020 · 4 without an energy range, not drawn

massive star, core helium burning, kT = 25.9 keV

Lowest energy in EXFOR
23.8 meV
McDonald et al., 1977; Firestone et al., 2016 · σ · 10668.004
Maxwellian averages measured
4 sets
kT from 30 keV to 30 keV
Rate from energies not in EXFOR
> 99.99%
at kT = 25.9 keV, smooth estimate
10 meV1 eV100 eV10 keV1 MeV100 MeVEnergy, or kT for a Maxwellian average (keV)kT = 25.9 keVσσ→Eₓdσ/dΩωγMACSother
  • Energies that matter at kT = 25.9 keV
  • 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 section723.8 meV – 531 keV
σ→Eₓpartial1223.8 meV – 531 keV
dσ/dΩangular distribution16.58 MeV – 13.2 MeV
ωγresonance strength1408 keV – 408 keV
MACSMaxwellian average430 keV – 30 keV
…other223.8 meV – 6.98 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 Not counted: extrapolated, calculated, evaluated or derived values; superseded, deleted or preliminary data; ratios; a single S-factor value, which in EXFOR is a fit result; and indirect methods (Trojan horse, Coulomb dissociation, ANC,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.

Loading the datasets…