RPR-41

HVL from μ

Narrow-beam half-value layer.

Reading speed

GoverningHVL from μ

Governing equation

HVL=\\ln 2/\\mu

$mu \in \left[0.01, 2\right]$

where

mu: mu (1/cm)
hvl: HVL from μ (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.

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①

Governing law — red

HVL=\\ln 2/\\mu

$mu \in \left[0.01, 2\right]$

$mu = 0.01$ $hvl = 69.31$

Along the curve

②

Domain of the variable — blue

mu_{\min} = 0.01,\quad mu_{\max} = 2

$mu \in \left[0.01, 2\right]$

$mu = 0.01$ $mu = 0.01$

Along the curve

③

Response curve — green

HVL=\\ln 2/\\mu

$mu \in \left[0.01, 2\right]$

$mu = 0.01$ $hvl = 69.31$

Along the curve

④

Rate of change — amber

\frac{\mathrm{d}hvl}{\mathrm{d}mu}

$mu \in \left[0.01, 2\right]$

$mu = 0.023$ $hvl^{\prime} = -1978.6$

Along the curve

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-41 — HVL from μ) is the form associated with HVL from μ. Working symbols: $mu$ $\rightarrow$ $hvl$ . Narrow-beam half-value layer. Pedagogical SI sheet with a live model and a swept parameter.

Purpose

Purpose: compute

hvl

from

mu

in Radiation protection via

HVL=\\ln 2/\\mu

Narrow-beam half-value layer. 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

mu = 0.150\,\mathrm{1/cm}

, the governing relation

HVL=\\ln 2/\\mu

yields

hvl = 4.621\,\mathrm{cm}

. One governing identity, SI units, a single sweep on the sheet. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

mu mu0.15 1/cm

Outputs

HVL from μ hvl4.621 cm

Reading speed

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Narration of this film

One governing identity, SI units, a single sweep on the sheet.

Narrow-beam half-value layer. Pedagogical SI sheet with a live model and a swept parameter.

Reading speed

Watch on YouTube