LASER DOUBLE STAGE EXCITATION EMISSION ANALYSIS METHOD AND APPARATUS

摘要

PURPOSE:To enable implementation of a quantitative analysis quickly with a high accuracy by irradiating a vapor cloud formed by a first laser pulse with a second laser pulse at a time interval of 10ns-10mus between the two laser pulses. CONSTITUTION:A trigger for a laser light emission is applied to a switching circuit 3' at a time of 10ns-10mus from an electric delay circuit 2. Laser pulses 5 and 5' emitted from first and second laser devices 4 and 4' by way of switching circuits 3 and 3' are condensed to an analysis sample 8 through reflecting mirrors 6 and 6' and condenser lenses 7 and 7'. Then, a high excitation plasma is formed at a position slightly biased to a plasma receiving side of a vapor cloud formed by a laser right 5. Light released from the plasma forms an image on a photoelectric surface of an image intensifier 16 through a lens 9 and a spectroscope 10 and a light intensity ratio of an atomic spectral line is determine by a photodiode array 17 and a signal processing section 18 and the concentration of an element to be analyzed is determined by a calibration curve and the results are displayed 20.