RPR-19

Ambient dose equivalent H*(10)

H*(10) = h*_K K_air. Survey-meter operational quantity at 10 mm depth.

Reading speed

OperationalICRU 51 H*(10)

Governing equation

H^*(10)=h_K^* K_{\mathrm{air}}

where

K_{air}: Air kerma (µGy)
h_K^*: Conversion h*K (Sv/Gy)
H^*(10): Ambient dose equivalent (µSv)

Lecture brief

Historical brief

Inverse-square, half-value layer, ICRP weighting and ALARA are the protection craft since the 1920s commissions. The lab computes transmission, equivalent dose and a shielding snapshot. This sheet (RPR-19 — Ambient dose equivalent H*(10)) is the form associated with ICRU 51 H*(10). Working symbols: $K_{air}$ , $h_K^*$ $\rightarrow$ $H^*(10)$ . h*_K is about 1.0–1.2 Sv/Gy for photons above 100 keV. Ambient equivalent is conservative and isotropic.

Purpose

Purpose: compute

H^*(10)

from

K_{air}

h_K^*

in Radiation protection via

H^*(10)=h_K^* K_{\mathrm{air}}

H*(10) = h*_K K_air. Survey-meter operational quantity at 10 mm depth. Use it when a real radiation protection question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given

K_{air} = 10.000\,\mathrm{\mu Gy}

h_K^* = 1.160\,\mathrm{Sv/Gy}

, the governing relation

H^*(10)=h_K^* K_{\mathrm{air}}

yields

H^*(10) = 11.60\,\mathrm{\mu Sv}

. A sphere, a 10 mm depth, an isotropic fluence. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Air kerma K_{air}10 µGyConversion h*K h_K^*1.16 Sv/Gy

Outputs

Ambient dose equivalent H^*(10)11.60 µSv

Reading speed

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Narration of this film

A sphere, a 10 mm depth, an isotropic fluence.

h*_K is about 1.0–1.2 Sv/Gy for photons above 100 keV. Ambient equivalent is conservative and isotropic.

Reading speed

Watch on YouTube