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.

For formal radiation safety advice, visit our Radiation Protection Adviser (RPA) services page. 

  • When \(1/d^2\) breaks down - part 1: line source

    Published: Mar 22, 2024

    Source: Dr Chris Robbins, Grallator

      Tags:
    • 1/d2 for a line source
    • Inverse square law
    • radiation
    • radioactive line source
    • Radiation protection mathematics
    • Maths for radiation safety

    When \( 1/d^2 \) breaks down - part 1: line source. Using some mathematics to explore how the inverse square law works with a radiation line source.

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  • What is an RPA (Radiation Protection Adviser)?

    Published: Mar 16, 2024

    Source: Ionactive Radiation Protection Resources

      Tags:
    • RPA
    • Radiation Protection Adviser (RPA)
    • Radiation Protection Advisor
    • RPA2000
    • IRR17
    • Ionising Radiations Regulations 2017
    • Notification
    • Registration
    • Consent
    • HSE
    • Health and Safety Executive (HSE)
    • Certain practices
    • Specified practices

    At Ionactive we are often asked 'What is a Radiation Protection Adviser (RPA), and do we need one?' This is an interesting question and concept, since the question is aimed directly at an RPA. We give objective advice and for most uses of ionising radiation a Radiation Protection Adviser is required, sometimes only for initial advice via consultation, but more often than not via an official appointment (in writing). Here is a quick summary of the role of the RPA and why a user of ionising radiation will probably need to appoint an RPA.

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  • Lead shielding thickness - what are the lead codes?

    Published: Mar 09, 2024

    Source: Ionactive Radiation Protection Resource

      Tags:
    • Lead shielding
    • Lead codes
    • Lead thickness
    • x-ray shielding
    • Gamma ray shielding
    • Lead sheeting
    • Lead bricks

    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.

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  • 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
    • Radioactivity
    • 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.

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  • 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
    • Radioactive source
    • 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?

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  • 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
    • Radioactive
    • Dose Rate
    • Inhalation
    • Ingestion
    • Shielding
    • skin contamination
    • Liquid scintillation counting

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

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Physics is, hopefully, simple. Physicists are not

– Edward Teller -