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RAD-17

Absorbed dose

D = E / m. One gray is one joule per kilogram.

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DosimetryAbsorbed dose

Governing equation

D=E/mD=E/m

E∈[1×10−6,10]E \in \left[1\times 10^{-6}, 10\right]

where

E
Energy imparted (J)
m
Mass (kg)
D
Absorbed dose (Gy)

The figure, part by part

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RAD-17 · dose
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①

Governing law — red

D=E/mD=E/m

E∈[1×10−6,10]E \in \left[1\times 10^{-6}, 10\right]

E=1×10−6E = 1\times 10^{-6}D=1×10−6D = 1\times 10^{-6}

②

Domain of the variable — blue

Emin⁡=1×10−6,Emax⁡=10E_{\min} = 1\times 10^{-6},\quad E_{\max} = 10

E∈[1×10−6,10]E \in \left[1\times 10^{-6}, 10\right]

E=1×10−6E = 1\times 10^{-6}E=1×10−6E = 1\times 10^{-6}

③

Response curve — green

D=E/mD=E/m

E∈[1×10−6,10]E \in \left[1\times 10^{-6}, 10\right]

E=1×10−6E = 1\times 10^{-6}D=1×10−6D = 1\times 10^{-6}

④

Rate of change — amber

dDdE\frac{\mathrm{d}D}{\mathrm{d}E}

E∈[1×10−6,10]E \in \left[1\times 10^{-6}, 10\right]

E=0.063E = 0.063D′=1D^{\prime} = 1

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-17 — Absorbed dose) is the form associated with Absorbed dose. Working symbols: EE, mm →\rightarrow DD. The fundamental stochastic-mean quantity of dosimetry. Everything else is a weighted D.

Purpose

Purpose: compute DD from EE, mm in Radiation physics via D=E/mD=E/m D = E / m. One gray is one joule per kilogram. 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 E=0.020 JE = 0.020\,\mathrm{J}, m=1.000 kgm = 1.000\,\mathrm{kg}, the governing relation D=E/mD=E/m yields D=0.0200 GyD = 0.0200\,\mathrm{Gy}. A mass, an energy dump, a D. Move a slider: the numbers are this situation, not a canned story.

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Outputs

  • Absorbed dose D0.0200 Gy
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RAD-17 · dose
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Narration of this film

A mass, an energy dump, a D.

The fundamental stochastic-mean quantity of dosimetry. Everything else is a weighted D.

Reading speed

Watch on YouTube