Basic 1D Fitting: Scientific inconsistency needs fixing

[smk78]

User AdrianR has pointed out that in the SDS example in:

https://www.sasview.org/downloads/basic_1d_fitting_in_sasview_v3x_4x.pdf

it recommends setting the salt concentration to zero. He comments:

The suggested parameters include a salt concentration of zero for the Hayter-Penfold RMSA model with a charge on the micelles of 20.77 electrons. This presents an inconsistency as if there is dissociation the must be some dissolved ions. I would normally expect micelles to be in equilibrium with dissolved surfactant that is not micellised at the critical micelle concentration that would give a minimum ionic concentration of 8 or 9 mmol L-1. This concentration would be increased by dissociation of a fraction of the surfactant in the micelles. Fitting would then give a higher charge.

The tutorial should be updated.