An Integrated Data Analysis model to determine ion effective charge from beam attenuation and charge exchange emission measurements

We have created a forward model for charge-exchange impurity density measurements that incorporates neutral beam attenuation measurements self-consistently for determining the ion effective charge $Z_{\rm eff}$ in MST PPCD plasmas. Detailed knowledge of $Z_{\rm eff}$ is critical to determining the resistive dissipation of hot plasmas and requires knowledge of the impurity content and dynamics. Previously, $Z_{\rm eff}$ profiles were determined from soft-x-ray brightness measurements by using charge-exchange impurity density measurements as prior information using an Integrated Data Analysis (IDA) method. The model is extended to include a self-consistent calculation of the neutral beam attenuation and includes measurements of the beam Doppler-shift spectrum and shine-through particle flux. Methods of experimental design are employed to calculate the information gained from different diagnostic combinations. The analysis shows that while attenuation measurements alone do not provide a unique impurity density measurement in the case of a multi-species inhomogeneous plasmas, they do provide a valuable measurement of the $Z_{\rm eff}$ profile and constrain the range of contributing impurity densities.