Radiation protection widgets

Radium 226 (Ra-226) is a well known alpha emitter. It does emitter gamma rays, the most prominent being 186 keV with about a 3.5% emission probability. So compared to other well known historic radioisotopes (such as Cs-137 or Co-60), its external radiation properties (dose rate) should be negligible? Well - yes and no, it depends on whether the source of Ra-226 is closed (sealed) or open (unsealed). It so happens that the external dose rate from 1 GBq of Cs-137 (as a point source) at 1m is about 78 μSv/h. The same dose rate for a closed source of Ra-226 is about 181 μSv/h for the same activity at the same distance. From an alpha emitter!? But the same measurement from an open source of Ra-226 will reveal gamma dose rates not much higher than background? So what is going on? It is all about the radium progeny which is the subject of this resource article.  Our long term friend and professional "physics & maths head",  Dr Chris Robbins of Grallator, has produced for Ionactive some excellent interactive resource investigating this subject. Ra-226 has been historically used in radium dials and other artefacts - so read on and investigate.  

Ionactive is pleased to introduce the latest radiation protection widget resource produced for us by Dr Chris Robbins of Grallator. It is a companion to the Counting statistics (Radioactivity) Widget released late 2025. This widget asks the question 'Is the mean activity of an area of land above a given threshold?' This widget is highly interactive with many variables to alter and can demonstrate how you might answer questions such as : How big a survey sample size is required to be reasonably sure the mean site activity is below a desired threshold? Where should the measurements that make up the sample be taken? The widget is accompanied by a detailed paper written by Chris which explains the statistics and how they can be demonstrated by using the widget. 

Ionactive has the pleasure of introducing the latest radiation protection widget resource produced for us by Dr Chris Robbins of Grallator. Take a journey into the concept of the Poisson distribution and how statistics (e.g. standard deviation etc) can be used when considering monitoring of radioactivity. The Counting statistics (Radioactivity) Widget (a simulator) can be used to investigate many counting attributes including false positive or false negative situations. For this widget we especially encourage our visitors to read the included paper by Chris and follow through with the examples given. A great learning resource, freely available to all.  

This widget is used to run Monte Carlo calculations to demonstrate the inverse-square law of radiation intensity at 1m and 2m from a point source of radiation. The widget is accompanied by a set of notes by Dr Chris Robbins from Grallator (who designed the widget),  explaining the basics of how the calculations are performed, and includes a summary of the mathematics of the Monte Carlo method.

Imagine an uncollimated radioactive source (e.g. Se-75 or similar) in the middle of a concrete shielded enclosure which is open topped.  The shielding is designed to mitigate all direct radiation from the source down to background levels on the outside of the enclosure. Any remaining exposure potential is from skyshine. This latest widget explores skyshine in terms of dose rate where the horizontal and vertical measurement position can be explored, and where the vertical height of the source can be adjusted. Some of the results provided may surprise you. Developed for Ionactive by Dr Chris Robbins from Grallator.

You are performing a critical examination on an x-ray cabinet where you find a small radiation "leak" measuring slightly >1 micro Sv/h on the surface. What is the potential whole body radiation exposure from this situation? How does it vary with the position of the source (x-ray collimator) to the inner surface of the x-ray cabinet covers? And how does it vary with the diameter of the shielding deficiency or the distance of the monitoring prob to the x-ray cabinet covers? Explore these radiation protection questions with this widget.  Developed for Ionactive by Dr Chris Robbins from Grallator.