Skip to main content
Disclaimer: This software is for radiation protection education, screening calculations, and professional support only. It does not replace qualified health physicist judgment, regulatory requirements, approved procedures, emergency response tools, or formal shielding design review. Exposure, absorbed dose, equivalent dose, and effective dose are distinct quantities; do not equate R and Sv without explicit context and assumptions.

Point-source dose-rate

Gamma constant auto-fills from the nuclide table when available; you may override it. Dose-rate magnitude depends on the selected output quantity (e.g. ambient dose equivalent rate vs exposure rate) — constants are illustrative screening values only.

Nuclide

The catalog supplies half-life and, when present, a screening gamma constant. Changing nuclide only auto-fills gamma when a tabulated constant exists; otherwise the numeric field keeps your prior value as a manual entry.

Selected: Cs-137

Cs-137γ · β

Brachytherapy (historical)

Catalog id: cs-137

Half-life (bundled row)
30.17 y
Decay modes
β⁻ (Ba-137m), γ
Photon energies (keV)
662
Gamma constant (µSv·m²/MBq·h)
0.08
Gamma constant confidence / provenance
IllustrativeScreening air-kerma-rate style constant (µSv·m²/MBq·h) bundled for training; verify against your approved reference table or measurement certificate.
MBq
m
Gamma: tabulated
µSv·m²/MBq·h

Screening constant; verify against your approved reference set.

Tabulated constant confidence (nuclide row):IllustrativeScreening air-kerma-rate style constant (µSv·m²/MBq·h) bundled for training; verify against your approved reference table or measurement certificate.

Estimated dose rate

8.00000 uSv/h

DoseRate = Gamma * Activity / Distance^2

Dose rate vs distance

No chart data for current inputs.