Polychromator filter design with genetic algorithm

In Thomson scattering (TS) diagnostics, polychromators are equipped with several optical band-pass filters which cover the spectral region where the radiation from the incident laser beam is expected to be Doppler shifted. The spectral location of the transmission band of individual filters has a strong influence on the measured electron temperature (T_e) since the latter is derived from a previously computed lookup table including the spectral specifications of the filters. Here, we present the design of the set of polychromator filters through genetic algorithms (GAs). We examine the developed algorithm under two specific target conditions, and optimized filter sets covering the wavelength region longer than the wavelength of the incident laser seem to be more effective in improving the accuracy of the T_e calculations provided by the diagnostic. (paper)