Dielectric barrier discharge ionization detector

A dielectric barrier discharge ionization detector, comprising:

• a) a dielectric tube containing one section of a gas passage through which a plasma generation gas is passed;
• b) a high-voltage electrode circumferentially formed on an outer wall of the dielectric tube;
• c) two ground electrodes electrically grounded and circumferentially formed on the outer wall of the dielectric tube at positions between which the high-voltage electrode is located;
• d) a voltage supplier connected to the high-voltage electrode, for applying an AC voltage between the high-voltage electrode and each of the two ground electrodes so as to generate an electric discharge within the dielectric tube and thereby generate plasma from the plasma generation gas;
• and
• e) a charge-collecting section forming a section of the gas passage located downstream of a generation area of the plasma, including a sample-gas introducer for introducing a sample gas into the downstream section and a collecting electrode for collecting ions generated from a sample component in the sample gas by light emitted from the plasma,
• wherein a distance between one ground electrode of the two ground electrodes and the high-voltage electrode is longer than a discharge initiation distance between these two electrodes, while a distance between the other ground electrode and the high-voltage electrode is shorter than a discharge initiation distance between these two electrodes.