ACOUSTOOPTIC SIGNAL MODULATION FOR ATOMIC-EMISSION SPECTROMETRY BACKGROUND CORRECTION

An acousto-optic diffraction device is mounted within a polychromator to perform spectral shifting for the purpose of background correction for atomic spectrometry. Controlling the applied frequency to the acou sto-optic allows ''on-line'' and ''off-line'' spectral observations. P reliminary investigations included characterization of the behavior of the photomultiplier tube (PMT) signal output at various acoustic freq uencies and applied powers to verify the applicability of the system. Low-rate (0.1 Hz) frequency modulation was performed to successfully t est the applicability of the background-correction system.