Spatiotemporal characterization of different dielectric barrier discharges designed for soft ionization

Dielectric barrier discharges (DBDs) are versatile tools and can assume important roles in analytical applications. Due to their soft ionization capabilities they are ideal ion sources for atmospheric mass spectrometers or ion mobility spectrometers. Previous studies have shown that a further distinction of DBDs in full and half-dielectric variants is appropriate as both variants have different analytical performances. Spatiotemporal optical characterization of such discharges has proven to be a powerful diagnostic, as it allows for precise identification of relevant discharge mechanisms. Better understanding of these mechanisms has led to the "flexible micro tube plasma" (F mu TP) design which is a half-dielectric barrier discharge optimized for an efficient soft ionization of molecules under ambient air for MS and IMS detection. A comparison of the spatiotemporal characterization of four different soft ionization sources with comparable geometric dimensions will be presented, with attention turned to the development of the plasma in the F mu TP.