# Technical Guidance

Here you will find data and articles on radiation shielding, frequently asked questions (FAQ), monitor performance, specific gamma ray constants, mathematical derivations, radiation protection widgets  - everything we have personally found useful from our own tool kit. New resources will be uploaded here from time to time.

• ## Lead shielding thickness - what are the lead codes?

Published: Mar 09, 2024

Source: Ionactive Radiation Protection Resource

Tags:
• x-ray shielding
• Gamma ray shielding

What do lead codes mean and how do they relate to thickness? Often you might calculate a certain level of lead radiation shielding required (e.g. for an x-ray inspection enclosure) and need to supply this information to an architect who is helping you design the facility. They will ask you -"what code lead do we need to use? Find out what you need to know in this article.

• ## Formula for calculating dose rates from gamma emitting radioactive materials

Published: Mar 01, 2024

Source: Ionactive Radiation Protection Resource (Mark Ramsay, RPA)

Tags:
• Gamma emitter
• Dose Rate
• Formula
• D=ME/6r2
• Gamma rays
• Gray (Gy)
• Sieverts (Sv)
• MeV
• Mass energy attenuation coefficient
• Linear attenuation Coefficient
• Air absorption factor
• Tissue absorption factor
• Cobalt 60
• Co-60
• Caesium-137
• Cs-137
• Iridium-192
• Ir-192
• Low energy photons

A rule of thumb updated for 2024! This article considers the following expression D=ME/6r2 which has turned up in text books and training courses, but there appears to be no direct reference to when it was created and by whom. We start by using the expression with Cs-137 and see how the results compare with other resources available for calculating dose rates for chosen radionuclides with given activity and distance. We then hand over to Dr Chris Robbins of Grallator who is a maths, physics and nuclear physics whizz who derives this expression from first principles, outlining the good, the not so good and how it can be improved.

• ## The accumulated radiation dose when moving up to a source

Published: Nov 27, 2023

Source: Dr Chris Robbins, Grallator

Tags:
• Dr Chris Robbins
• Grallator
• Accumulated dose
• Maths in radiation protection
• accumulated radiation exposure moving towards a source
• Inverse square law
• Point source

Consider the situation where you move up to a radioactive source, perform some operations for a period of time, and then move away. What total dose will be received?

• ## H-3 (Tritium) Radiation Safety Data

Published: Aug 21, 2023

Source: Ionactive Radiation Protection Resource

Tags:
• H-3
• Tritium
• Low energy beta emitter
• Radiation safety data
• Dose Rate
• Inhalation
• Ingestion
• Shielding
• skin contamination
• Liquid scintillation counting

H-3 (Tritium) radiation safety data from Ionactive.

• ## C-14 (Carbon-14) Radiation Safety Data

Published: Aug 21, 2023

Source: Ionactive Radiation Protection Resource

Tags:
• Radiation safety data
• C-14
• Carbon-14
• Low energy beta emitter
• Dose Rate
• Inhalation
• Ingestion
• skin contamination
• Shielding
• Liquid scintillation counting

C-14 (Carbon-14) radiation safety data from Ionactive.

• ## F-18 (Fluorine-18) Radiation Safety Data

Published: Aug 21, 2023

Source: Ionactive Radiation Protection Resource

Tags:
• F-18
• Fluorine-18
• Positron emitter
• Shielding
• Radiation safety data