INGENIA
Index/Radiation physics/RAD-31

RAD-31

Exposure X

Legacy, air ionisation.

Reading speed
Radiationexposure

Governing equation

X=Q/mairX=Q/m_{\mathrm{air}}

Q∈[1×10−10,0.001]Q \in \left[1\times 10^{-10}, 0.001\right]

where

Q
Charge (C)
m
Air mass (kg)
X
Exposure (C/kg)

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.

RAD-31 · dose
00:0 / 00:08
①

Governing law — red

X=Q/mairX=Q/m_{\mathrm{air}}

Q∈[1×10−10,0.001]Q \in \left[1\times 10^{-10}, 0.001\right]

Q=1×10−10Q = 1\times 10^{-10}X=1×10−7X = 1\times 10^{-7}

②

Domain of the variable — blue

Qmin⁡=1×10−10,Qmax⁡=0.001Q_{\min} = 1\times 10^{-10},\quad Q_{\max} = 0.001

Q∈[1×10−10,0.001]Q \in \left[1\times 10^{-10}, 0.001\right]

Q=1×10−10Q = 1\times 10^{-10}Q=1×10−10Q = 1\times 10^{-10}

③

Response curve — green

X=Q/mairX=Q/m_{\mathrm{air}}

Q∈[1×10−10,0.001]Q \in \left[1\times 10^{-10}, 0.001\right]

Q=1×10−10Q = 1\times 10^{-10}X=1×10−7X = 1\times 10^{-7}

④

Rate of change — amber

dXdQ\frac{\mathrm{d}X}{\mathrm{d}Q}

Q∈[1×10−10,0.001]Q \in \left[1\times 10^{-10}, 0.001\right]

Q=6.29×10−6Q = 6.29\times 10^{-6}X′=1000X^{\prime} = 1000

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-31 — Exposure X) is the form associated with exposure. Working symbols: QQ, mm →\rightarrow XX. Legacy, air ionisation.

Purpose

Purpose: compute XX from QQ, mm in Radiation physics via X=Q/mairX=Q/m_{\mathrm{air}} Legacy, air ionisation. 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 Q=1.000e−6 CQ = 1.000e-6\,\mathrm{C}, m=0.001 kgm = 0.001\,\mathrm{kg}, the governing relation X=Q/mairX=Q/m_{\mathrm{air}} yields X=0.001000 C/kgX = 0.001000\,\mathrm{C/kg}. Legacy, air ionisation. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Outputs

  • Exposure X0.001000 C/kg
Reading speed

Watch on YouTube

Free library

Full library

Free PDF / open book

YouTube channels

RAD-31 · dose
00:0 / 00:08

Narration of this film

Legacy, air ionisation.

Legacy, air ionisation.

Reading speed

Watch on YouTube