DEVICE FOR CONVERTING ION CURRENT OF ION MOBILITY SPECTROMETER Russian patent published in 2017 - IPC H01J49/02 

FIELD: physics.

SUBSTANCE: invention relates to the ion mobility spectrometry, which allows to detect minute quantities of explosives, drugs, hazardous and toxic substances, to conduct medical researches, as well as to ensure the quality control of food products, construction and industrial materials. The device for converting the ion currrent of the ion mobility spectrometer with fast switching the polarity of the detected ions is based on the use of the integrating and differentiating stages converting the input ion current into voltage and providing an equivalent resistive characteristic of transimpedance converting the ion current, as well as, at least, of one controlled current generator at the integrating stage inlet to set the starting voltage at its output. The compensating pulse charge of the controlled generator current is determined by the integral charge of the previous ion cycle, by the induced capacitive charges from the electrical circuits, altering the potential when switching the high voltage polarity, and the required voltage at the integrating stage output.

EFFECT: reduction of the integrating stage storage capacitor, charge control on the storage capacitor by using a current source, minimized charge transfer through the current generator control circuit, that allows to increase the integrating stage sensitivity and to optimize the dynamic range of the transimpedance ion current conversion, when switching the detected ion polarity.

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