RPR-17

Number of tenth-value layers

n = log10(1/B). How many TVLs a barrier must provide.

Reading speed

ShieldingTenth-value count

Governing equation

n=\log_{10}(1/B)

where

B: Transmission B (—)
n: Tenth-value layers (—)

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-17 — Number of tenth-value layers) is the form associated with Tenth-value count. Working symbols: $B$ $\rightarrow$ $n$ . A transmission of 10^{−3} is three TVLs. Designers often add a first TVL plus (n−1) equilibrium TVLs.

Purpose

Purpose: compute

n

from

B

in Radiation protection via

n=\log_{10}(1/B)

n = log10(1/B). How many TVLs a barrier must provide. 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

B = 0.001\,\mathrm{—}

, the governing relation

n=\log_{10}(1/B)

yields

n = 3.000\,\mathrm{—}

. A tiny B and a count of decades of attenuation. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Transmission B B0.001 —

Outputs

Tenth-value layers n3.000 —

Reading speed

Watch on YouTube

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Narration of this film

A tiny B and a count of decades of attenuation.

A transmission of 10^{−3} is three TVLs. Designers often add a first TVL plus (n−1) equilibrium TVLs.

Reading speed

Watch on YouTube