Dead-time Correction for High-count-rate WDS Analysis in Electron Probe Microanalysis

High-count-rate electron probe WDS analysis demands improved dead-time correction, encompassing both the selection of appropriate models and the precise calibration of their parameters. To address this, we propose an algorithm that integrates the constant Kβ/Kα ratio method with least-squares optimization, enabling simultaneous calibration of dead time parameters and comparative evaluation of different correction models. Using this approach, we evaluated a series of single-parameter models situated between the limiting cases of ideal extendable and non-extendable dead time, alongside a dual-parameter model informed by the physics of proportional counter component interaction and dead time cascading. Experimental results demonstrate that the dual-parameter model consistently provides better correction. For a given detector under fixed operating conditions (identical bias/gain setting), the optimal correction expression varies with the characteristic radiation line to be measured.