Abstract The measurement of aerosol growth kinetics at ever smaller sizes toward the transition and free molecular regime is of interest to provide for validation of theoretical predictions. Such measurements remain challenging to accomplish, particularly those occurring in the kinetic regime. Toward this goal, an instrument based on the ultraviolet constant angle Mie scattering (UV-CAMS) method was developed. The instrument utilizes adiabatic expansion to cause supersaturation and drive aerosol growth. Aerosol particles growing by water condensation are illuminated with a pulsed UV laser at 337 nm wavelength and a reference laser with red light (wavelength of 632 nm). The scattered light fluxes at 30° are measured simultaneously and are then compared with size resolved Mie scattering calculations providing aerosol growth measurements. The growth curves obtained from UV match those from the red laser. These measurements allow us to see the first Mie peak for UV scattering for particles in the 500 nm range. This is an almost two-fold resolution increase compared to the smallest particles that can be seen via red laser scattering in similar conditions (first Mie peak above 900 nm).

中文翻译：

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紫外等角米氏散射检测器的研制，用于测定过渡态和自由分子态中的气溶胶生长动力学

摘要 在越来越小的尺寸下，向过渡和自由分子状态的气溶胶生长动力学的测量对于提供理论预测的验证是有意义的。这种测量仍然具有挑战性，尤其是那些发生在动力学状态下的测量。为实现这一目标，开发了一种基于紫外线恒定角米氏散射 (UV-CAMS) 方法的仪器。该仪器利用绝热膨胀引起过饱和并驱动气溶胶生长。通过水凝结生长的气溶胶颗粒用 337 nm 波长的脉冲紫外激光和红光（波长为 632 nm）的参考激光照射。同时测量 30° 处的散射光通量，然后与提供气溶胶生长测量的尺寸分辨米氏散射计算进行比较。从紫外线获得的生长曲线与从红色激光获得的曲线相匹配。这些测量使我们能够看到 500 nm 范围内粒子的 UV 散射的第一个 Mie 峰。与在类似条件下通过红色激光散射可以看到的最小颗粒（第一个 Mie 峰高于 900 nm）相比，分辨率几乎提高了两倍。