Implement the simplest but crudest method for obtaining an estimate of the ion saturation current from the probe characteristic.

Parameters:probe_characteristic (Characteristic) – The probe characteristic that is being analyzed.
Returns:I_is – Estimate of the ion saturation current in units convertible to A.
Return type:Quantity


The method implemented in this function assumes the ion saturation current to be the smallest probe current in the characteristic. This assumes the bias range in the ion region is sufficiently negative for the ion current to saturate.