lulu
Are you sure you need to do a downhole correction? You can have a look at the raw 206/208 in the stacked plot tool to assess whether or not the ratio varies downhole. I would have thought that Pb/Pb wouldn't vary much, but maybe your case is different.
To get an idea how to apply a downhole correction you can have a look at what was done in the U-Pb python example posted here. Essentially, it boils down to:
- Compiling reference material data to build your downhole model from (see 'compileDownhole' function in python API).
- Fitting a model to that data -- in the U-Pb example, we use 'curve_fit' from scipy.optimize to fit 'downholeFunc' (exp + linear) to the compiled data.
- Using that model to adjust all of the data according to the beam seconds.
I think it would be pretty difficult to squeeze all of that into the calculator tool. However, we could consider adding some helper functions for this task if there is demand for it in the calculator tool.
All the best,