Abstract
In order to measure mobility distribution of nanometer-sized clusters and ions, the Cluster-Differential Mobility Analyzer with the integrated electrometer (CDMA-IE) has been manufactured following the design by Rosell-Llompart et al. (J. Aerosol Sci., 27, 695-719 (1996)). To evaluate the flow pattern of aerosol and sheath air in cylindrical annulus of this CDMA-IE, we employed the flow visualization technique developed by Otani et al. (J. Chem. Eng. Jpn., 31, 1065-1069 (1997)). The visualization results were compared with the calculation results using a fully developed laminar flow and mobility measurement results by means of the Tandem DMA method, and the necessary conditions under which the aerosol and sheath air flow ideally inside the DMA without any turbulence and mixing were clarified. After changing the width of aerosol inlet and properties of the upper filter respectively, we finally determined the detail of the CDMA-IE. Using the well confirmed CDMA-IE, we measured the size and concentration of water cluster ions generated by various methods, α -ray radiolysis, corona discharge, UV/photoelectron method and the Lennard's effect.
