Gamma Dose Rate & Shielding
Point-kernel dose rates for 1,252 radionuclides — ICRP 107 emissions, NIST XCOM attenuation, ANS-6.4.3 buildup, H*(10) via ICRP 74.
Results
Per-line detail
| E (keV) | Yield /decay | Shield mfp | e−mfp | Buildup | H*(10) | Share |
|---|
Method & data
Dose rates are computed line by line from the evaluated photon emissions (γ, X rays, annihilation quanta) of ICRP Publication 107, using the point-kernel method: inverse-square fluence, exponential attenuation through each shield layer (NIST XCOM mass attenuation coefficients, combined by the mixture rule for compounds and alloys), a scatter buildup factor (ANSI/ANS-6.4.3-1991 exposure buildup, applied for the outermost layer's material at the whole stack's optical depth), and conversion to air kerma (NIST μen/ρ), exposure (33.97 J/C), and ambient dose equivalent H*(10) (ICRP 74 conversion coefficients). Line sources integrate the kernel along the line; spheres integrate over the volume with optional self-absorption. A "+ daughters" toggle folds in short-lived progeny in secular equilibrium (Ba-137m with Cs-137, Tc-99m with Mo-99, the Ra-226 chain through Po-214, …).
Known limits: photons below 15 keV are excluded (below the buildup data); buildup is clamped beyond 40 mean free paths; in-source scatter of a self-absorbing sphere is only approximated; air attenuation is neglected unless an explicit air layer is added. Computed dose-rate constants reproduce IAEA and published values for the common nuclides to a few percent — but this is a planning estimate, not a substitute for a survey meter.