RAD-15

Particle fluence

Φ = N / A, Ψ = Φ E. Number and energy fluence through an area.

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DosimetryFluence

Governing equation

\Phi=N/A,\quad\Psi=\Phi E

$N \in \left[1\times 10^{6}, 1\times 10^{16}\right]$

where

N: Particles (—)
A: Area (cm²)
E: Energy (MeV)
\Phi: Fluence (1/cm²)
\Psi: Energy fluence (µJ/cm²)

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

\Phi=N/A,\quad\Psi=\Phi E

$N \in \left[1\times 10^{6}, 1\times 10^{16}\right]$

$N = 1\times 10^{6}$ $\Phi = 1\times 10^{5}$

Along the curve

②

Domain of the variable — blue

N_{\min} = 1\times 10^{6},\quad N_{\max} = 1\times 10^{16}

$N \in \left[1\times 10^{6}, 1\times 10^{16}\right]$

$N = 1\times 10^{6}$ $N = 1\times 10^{6}$

Along the curve

③

Response curve — green

\Phi=N/A,\quad\Psi=\Phi E

$N \in \left[1\times 10^{6}, 1\times 10^{16}\right]$

$N = 1\times 10^{6}$ $\Phi = 1\times 10^{5}$

Along the curve

④

Rate of change — amber

\frac{\mathrm{d}\Phi}{\mathrm{d}N}

$N \in \left[1\times 10^{6}, 1\times 10^{16}\right]$

$N = 6.29\times 10^{13}$ $\Phi^{\prime} = 0.1$

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-15 — Particle fluence) is the form associated with Fluence. Working symbols: $N$ , $A$ , $E$ $\rightarrow$ $\Phi$ , $\Psi$ . Planar fluence counts tracks crossing a plane. Kerma and dose are built from Ψ.

Purpose

Purpose: compute

\Phi

\Psi

from

N

A

E

in Radiation physics via

\Phi=N/A,\quad\Psi=\Phi E

Φ = N / A, Ψ = Φ E. Number and energy fluence through an area. 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

N = 1.000e+12\,\mathrm{—}

A = 10.000\,\mathrm{cm^{2}}

E = 1.000\,\mathrm{MeV}

, the governing relation

\Phi=N/A,\quad\Psi=\Phi E

yields

\Phi = 1.000e+11\,\mathrm{1/cm^{2}}

\Psi = 16021.7663\,\mathrm{\mu J/cm^{2}}

. A plane, a rain of tracks. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Particles N1000000000000 —Area A10 cm²Energy E1 MeV

Outputs

Fluence \Phi100000000000.000 1/cm²
Energy fluence \Psi16021.7663 µJ/cm²

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Narration of this film

A plane, a rain of tracks.

Planar fluence counts tracks crossing a plane. Kerma and dose are built from Ψ.

Reading speed

Watch on YouTube