RAD-32

CSDA range

Straight-ahead slowing down.

Reading speed

RadiationCSDA

Governing equation

R=E/(-dE/dx)

$E \in \left[0.1, 200\right]$

where

E: Energy (MeV)
-dE/dx: Stopping (MeV/cm)
R: Range (cm)

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.

00:0 / 00:08

①

Governing law — red

R=E/(-dE/dx)

$E \in \left[0.1, 200\right]$

$E = 0.1$ $R = 0.02$

Along the curve

②

Domain of the variable — blue

E_{\min} = 0.1,\quad E_{\max} = 200

$E \in \left[0.1, 200\right]$

$E = 0.1$ $E = 0.1$

Along the curve

③

Response curve — green

R=E/(-dE/dx)

$E \in \left[0.1, 200\right]$

$E = 0.1$ $R = 0.02$

Along the curve

④

Rate of change — amber

\frac{\mathrm{d}R}{\mathrm{d}E}

$E \in \left[0.1, 200\right]$

$E = 1.357$ $R^{\prime} = 0.2$

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-32 — CSDA range) is the form associated with CSDA. Working symbols: $E$ , $-dE/dx$ $\rightarrow$ $R$ . Straight-ahead slowing down.

Purpose

Purpose: compute

R

from

E

-dE/dx

in Radiation physics via

R=E/(-dE/dx)

Straight-ahead slowing down. 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 = 10.000\,\mathrm{MeV}

-dE/dx = 5.000\,\mathrm{MeV/cm}

, the governing relation

R=E/(-dE/dx)

yields

R = 2.000\,\mathrm{cm}

. Straight-ahead slowing down. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Energy E10 MeVStopping -dE/dx5 MeV/cm

Outputs

Range R2.000 cm

Reading speed

Watch on YouTube

Free library

Full library

Free PDF / open book

YouTube channels

00:0 / 00:08

Narration of this film

Straight-ahead slowing down.

Reading speed

Watch on YouTube