RAD-14

Equivalent dose

H = D w_R. Radiation weighting turns gray into sievert.

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DosimetryICRP equivalent dose

Governing equation

H=D\,w_R

$D \in \left[0.01, 100\right]$

where

D: Absorbed dose (mGy)
w_R: Radiation weight (—)
H: Equivalent dose (mSv)

The figure, part by part

Each numbered marker wears the color of its card. Hover a card to light the marker. Tap a marker to jump to that card. The slider walks a red point along the curve; Animate drawing traces it like a pen.

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①

Governing law — red

H=D\,w_R

$D \in \left[0.01, 100\right]$

$D = 0.01$ $H = 0.01$

Along the curve

②

Domain of the variable — blue

D_{\min} = 0.01,\quad D_{\max} = 100

$D \in \left[0.01, 100\right]$

$D = 0.01$ $D = 0.01$

Along the curve

③

Response curve — green

H=D\,w_R

$D \in \left[0.01, 100\right]$

$D = 0.01$ $H = 0.01$

Along the curve

④

Rate of change — amber

\frac{\mathrm{d}H}{\mathrm{d}D}

$D \in \left[0.01, 100\right]$

$D = 0.639$ $H^{\prime} = 1$

Along the curve

Lecture brief

Historical brief

Beer attenuation, Compton (1923), Klein–Nishina, Bragg–Gray cavity and KERMA are the transport of photons and charged particles in matter. The sheets compute fluence, kerma and stopping. This sheet (RAD-14 — Equivalent dose) is the form associated with ICRP equivalent dose. Working symbols: $D$ , $w_R$ $\rightarrow$ $H$ . w_R = 1 for photons and electrons, 20 for α, a function of energy for neutrons.

Purpose

Purpose: compute

H

from

D

w_R

in Radiation physics via

H=D\,w_R

H = D w_R. Radiation weighting turns gray into sievert. Use it when a real radiation physics question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given

D = 2.000\,\mathrm{mGy}

w_R = 1.000\,\mathrm{—}

, the governing relation

H=D\,w_R

yields

H = 2.00\,\mathrm{mSv}

. A dose, a weight, an H. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Absorbed dose D2 mGyRadiation weight w_R1 —

Outputs

Equivalent dose H2.00 mSv

Reading speed

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Narration of this film

A dose, a weight, an H.

w_R = 1 for photons and electrons, 20 for α, a function of energy for neutrons.

Reading speed

Watch on YouTube