PURPOSE: To equalize the energy distribution in a breakdown generation area and to improve the particle size resolution by dividing an irradiated light into many beamlets by many condensing elements placed in front of a sample cell.
CONSTITUTION: As for light 2 emitted from a laser 1 controlled by a controller 16, a part thereof is reflected by a half mirror 3, etc., and monitored by a photodiode 4. A laser beam 7 which transmits through the half mirror 3 passes through a uniform beam forming member 8 and a cell 9 and is absorbed by a beam stopper 10. A sample is led into the cell 9 from a leading-in port 11, and discharged from a discharge port 12. When the electric field intensity made by light in the sample is set so that is becomes larger than a breakdown thresh old of the particle and becomes smaller than a breakdown threshold of the medium, only the particle is broken down and converted to plasma, and an acoustic wave and light emission are generated. This acoustic wave and the light emission are converted to electric signals by a piezoelectric element, an AE sensor or a photodetector 13, sent to a computer 16, and particle number density in the sample and a particle size distribution are calculated.
NISHITARUMI TAKESHI
KOGA TADATAKA
