[Local Link Removed for Guests] ha scritto: [Local Link Removed for Guests]14/11/2021, 11:32
So, as I understand it, the calibration for efficiency is done with a 3rd party software.
The device has pre-programmed energy to efficiency fuctions for a different types of geometries & crystal. The functions derived with Monte Carlo simulations.
To calibrate the efficiency of the acitivty calculator the device require only to select correct geometry in menu and set the factor. If you have a calibration source of Cs-137 with known activity it very easy to set the factor after several measurements of the source activity in situ. The main parameter is correct geometry has to be selected prior the test, proper positioning of the probe with the source and performing 3-5 meausrements to get the factor. Every probe due to difference in the enclosure material thickness and crystal dope% has some variance of the efficiency at 662keV. The factor that you can find experimentally helps to compensate it. Defualt value is 1.0, in practice the factor will differ a little bit.
After the factor set with Cs-137, you can test with a different isotope at same geometry to be sure that evryhting is fine. For example with Ba-133.
4.08 software can calculate activity for Cs-137, Ba-133, Ra-226. Am-241 still under test since I don't have the proper source with exactly know activity.