In this study the charging efficiency of a radioactive and a non-radioactive plasma bipolar diffusion charger (Gilbert Mark I plasma charger) for sub-12 nm particles has been investigated at various aerosol flow rates. The results were compared to classic theoretical approaches. In addition, the chemical composition and electrical mobilities of the charger ions have been examined using an atmospheric pressure interface time-of-flight mass spectrometer (APi-TOF MS). A comparison of the different neutralization methods revealed an increased charging efficiency for negatively charged particles using the non-radioactive plasma charger with nitrogen as the working gas compared to a radioactive americium bipolar diffusion charger. The mobility and mass spectrometric measurements show that the generated bipolar diffusion charger ions are of the same mobilities and composition independent of the examined bipolar diffusion charger. It was the first time that the Gilbert Mark I plasma charger was characterized in comparison to a commercial TSI X-Ray (TSI Inc, Model 3088) and a radioactive americium bipolar diffusion charger. We observed that the plasma charger with nitrogen as the working gas can enhance the charging probability for sub-10 nm particles compared to a radioactive americium bipolar diffusion charger. As a result, the widely used classical charging theory disagrees for the plasma charger and for the radioactive chargers with increased aerosol flow rates. Consequently, in-depth measurements of the charging distribution are necessary for accurate measurements with differential or scanning particle sizers for laboratory and field applications.

中文翻译：

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非热等离子体源的特性，用作质谱校准工具和非放射性气溶胶充电器

在这项研究中，已经研究了在各种气溶胶流速下，放射性和非放射性等离子体双极扩散充电器（Gilbert Mark I等离子体充电器）对12纳米以下颗粒的充电效率。将结果与经典理论方法进行了比较。此外，已经使用大气压界面飞行时间质谱仪（APi-TOF MS）检查了带电离子的化学组成和电迁移率。对不同中和方法的比较表明，与放射性a双极扩散充电器相比，使用非放射性等离子体充电器和氮气作为工作气体时，带负电粒子的充电效率有所提高。迁移率和质谱测量结果表明，生成的双极扩散带电离子具有相同的迁移率和组成，而与所检查的双极扩散带电无关。与商用TSI X射线（TSI Inc，型号3088）和放射性a双极扩散充电器相比，这是Gilbert Mark I等离子充电器的首次表征。我们观察到，与放射性a双极扩散充电器相比，以氮气为工作气体的等离子体充电器可以提高10纳米以下颗粒的充电可能性。结果，广泛使用的经典充电理论不适用于等离子充电器和气溶胶流速增加的放射性充电器。所以，