Inverse Square Law — Radiation

Inverse Square Law — Radiation

RI-01
ASPCSPFoundational

Formula
I₁/I₂ = d₂²/d₁²
When to Use

Calculate how radiation intensity decreases with distance from the source. Doubling distance reduces intensity to one-quarter.

Symbol Legend
SymbolMeaningUnitNote
I₁Radiation intensity at distance d₁mR/hr or mSv/hr
I₂Radiation intensity at distance d₂mR/hr or mSv/hr
d₁Original distance from sourceft or m
d₂New distance from sourceft or m

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