Calculate Gamma Sv in Water Sample with Gamma Spectrometry

[sdouag]

how to calculate from a spectrum gamma, of a water sample, the equivalent amount in Sivert (Sv)

 

[Astronuc]

Please be more specific.

How does one count the water sample, and what is the radionuclide one is counting?

One can use the gamma spectrometry to determine the radionuclide(s) and from that perhaps make some determination of the concentration of the radionuclide in the water.

One can also assume uniform dispersion in the water.

So one can determine counts per sec and energy/disintegration. There will be some self-shielding involved, so one integrates over the energies of the spectrum.

One rad is defined as an absorbed dose of 0.01 joules of energy per kilogram of tissue. One gray is defined as 1 joule of deposited energy per kilogram of tissue, 1 gray = 100 rads.

For gamma and X-ray, the biological effectiveness is taken as unity, so 1 rem = 1 rad, or 1 sievert = 1 gray (1 sievert = 100 rems).

Refer to Hyperphysics - radiation risk for units - http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/radrisk.html
and
http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/radexp.html

 

[raining Pete]

To calculate the equivalent amount in Sievert (Sv) from a spectrum gamma of a water sample, you will need to know the activity of the sample in Becquerels (Bq) and the conversion factor for water.

The formula for converting from Bq to Sv is: Sv = Bq x conversion factor.

The conversion factor for water is 0.01 Sv/Bq.

So, to calculate the equivalent amount in Sv, you would multiply the activity in Bq by 0.01.

For example, if the activity of the water sample is 100 Bq, the equivalent amount in Sv would be 100 x 0.01 = 1 Sv.

It is important to note that this calculation assumes that the gamma spectrum is from natural sources and does not take into account any man-made sources of radiation. If the sample contains both natural and man-made sources, the calculation will be more complex and may require additional information. It is always best to consult with a trained professional when dealing with radioactive materials.