geiger counter readings re: top soil
If one tests a soil sample containing 12.42 Bq/kg of Iodine-131 in a background of 10CPM with a geiger counter what reading would you expect to get? (in CPM? or mSv/h?)
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You need to tell us your
You need to tell us your sample weight in order to know how many Bq are present.
However, in a perfect state of efficiency, you would expect to read all disintegrations as CPM. The problems you will encounter have to do with sensor efficiency, sensor size, self attenuation and background readings from other nuclides.
A simple Geiger counter can not tell you the composition of a sample in terms of nuclides. You need a special type of meter called a scintillation counter, that measures energy levels as well as disintegrations.
If you got a soli sample and it registers 150 CPM, you wouldn't be able to tell how much of that was Iodine vs. Uranium, Radon progeny, Potassium, and countless other natural sources. You would only be able to tell how radioactive it is.
Thank you for your prompt
Thank you for your prompt reply.
My primary interest is the how radioactive the sample is.
What do you think would be the approximate reading (in CPM) for the following sample?
For a known 1.04kg soil sample registering at 12.42 Bq/kg of Iodine-131 in a background of 10CPM using a Digilert-100 hand held monitor.
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That's not something that
That's not something that can be predicted. See my post above. There are other natural nuclides in soiling varying amounts that will mask counts from I-131.
You simply can not tell what is I-131 with background interference unless you do a time-decay plot and look for curves that match I-131s halflife.
Even so, your data would be confounded by Radon progeny from natural uranium present in the soil.
To do this kind of detection you would need a scintillation counter.
Thank you
Thank you