Ion generation apparatus and ion mobility analysis apparatus

An ion mobility analysis apparatus comprising:

• an ion generation apparatus;
• an ion detector;
• and
• an electric field formation electrode, wherein:
• the ion generation apparatus comprises an electron emission device, an opposite electrode, and a controller,
• the electron emission device includes a lower electrode, a surface electrode, and an intermediate layer provided between the lower electrode and the surface electrode,
• the opposite electrode is provided to be opposite to the surface electrode,
• the controller is provided to apply a voltage to the surface electrode, the lower electrode, or the opposite electrode such that a potential of the surface electrode becomes higher than a potential of the lower electrode and a potential of the opposite electrode in a positive ion mode for generating positive ions,
• the ion detector and the controller are provided to measure a current generated when the ion detector receives a charge from an ion and to output an ion mobility spectrometry spectrum, and
• the controller is further provided to adjust a voltage applied between the lower electrode and the surface electrode such that a reference peak appearing in the ion mobility spectrometry spectrum has a predetermined height or a predetermined area.

An ion mobility analysis apparatus comprising:

• an ion generation apparatus;
• an ion detector;
• and
• an electric field formation electrode, wherein
• the ion generation apparatus comprises an electron emission device, an opposite electrode, and a controller,
• the electron emission device comprises a lower electrode, a surface electrode, and an intermediate layer provided between the lower electrode and the surface electrode,
• the opposite electrode is provided to be opposite to the surface electrode,
• the controller is provided to apply a voltage to the surface electrode, the lower electrode, or the opposite electrode such that a potential of the surface electrode becomes higher than a potential of the lower electrode and a potential of the opposite electrode in a positive ion mode for generating positive ions,
• the ion detector and the controller are provided to measure a current generated when the ion detector receives a charge from an ion and to output an ion mobility spectrometry spectrum, and
• the controller is further provided to:
• apply a voltage to the surface electrode, the lower electrode, or the opposite electrode such that the potential of the surface electrode becomes higher than the potential of the lower electrode and lower than the potential of the opposite electrode in the negative ion mode for generating negative ions;
• switch between the negative ion mode and the positive ion mode;
• and
• when switching between the negative ion mode and the positive ion mode, change the potential of the surface electrode to a potential having an opposite polarity and substantially an equal absolute value and change the potential of the lower electrode to a potential having an opposite polarity and a different absolute value.