Ion generation apparatus and ion mobility analysis apparatus

Patent metadata

Field	Value
Publication number	US-2022178876-A1
Application number	US-202117536863-A
Country	US
Kind code	A1
Filing date	Nov 29, 2021
Priority date	Dec 9, 2020
Publication date	Jun 9, 2022
Grant date	—

Abstract

An ion generation apparatus according to the present invention includes 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, and 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.

First claim

What is claimed is:

1 . An ion generation apparatus comprising:
an electron emission device; an opposite electrode; and a controller, wherein 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, and 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.

2 . The ion generation apparatus according to claim 1 , wherein the controller is provided to apply a voltage between the lower electrode and the surface electrode such that the electron emission device emits electrons having an energy higher than an ionization energy of a gas component between the surface electrode and the opposite electrode in the positive ion mode.

3 . The ion generation apparatus according to claim 1 , wherein the controller is provided to apply a voltage of 16 V or more and 60 V or less between the lower electrode and the surface electrode in the positive ion mode.

4 . The ion generation apparatus according to claim 1 , wherein the controller is 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 a negative ion mode for generating negative ions and is provided to switch between the negative ion mode and the positive ion mode.

5 . The ion generation apparatus according to claim 4 , wherein the controller is provided to apply a voltage of 6 V or more and 60 V or less between the lower electrode and the surface electrode in the negative ion mode.

6 . The ion generation apparatus according to claim 4 , wherein the controller is provided to switch between the negative ion mode and the positive ion mode such that a potential difference between the surface electrode and the lower electrode in the positive ion mode becomes larger than a potential difference between the surface electrode and the lower electrode in the negative ion mode.

7 . An ion mobility analysis apparatus comprising:
the ion generation apparatus according to claim 1 ; an ion detector; and an electric field formation electrode, wherein 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.

8 . The ion mobility analysis apparatus according to claim 7 , wherein the controller is 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.

9 . The ion mobility analysis apparatus according to claim 7 , wherein the controller is provided to fix the potential of the surface electrode and change the potential of the lower electrode to adjust a voltage applied between the lower electrode and the surface electrode.

10 . The ion mobility analysis apparatus according to claim 7 , wherein
the controller is 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 and is provided to switch between the negative ion mode and the positive ion mode, and the controller is provided to adjust a voltage applied between the lower electrode and the surface electrode such that a height or area of a first reference peak appearing in the ion mobility spectrometry spectrum in the positive ion mode is substantially identical to a height or area of a second reference peak appearing in the ion mobility spectrometry spectrum in the negative ion mode.

11 . The ion mobility analysis apparatus according to claim 7 , wherein
the controller is 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 and is provided to switch between the negative ion mode and the positive ion mode, and the controller is provided to, 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.

12 . The ion mobility analysis apparatus according to claim 7 , wherein
the controller is 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 and is provided to switch between the negative ion mode and the positive ion mode, and the controller is provided to integrate and average the plurality of ion mobility spectrometry spectra obtained by repeating a measurement to calculate an average ion mobility spectrometry spectrum and is provided to switch between the negative ion mode and the positive ion mode each time calculation of the average ion mobility spectrometry spectrum ends.

Assignees

• Sharp Kk

Inventors

• Komaru Shohei
• Kyuhken Katsuhiko
• Shinkawa Kohji
• Iwamatsu Tadashi

Classifications

• G01N27/68

  using electric discharge to ionise a gas · CPC title

• G01N27/622 Primary

  Ion mobility spectrometry · CPC title

• G01N27/624

  Differential mobility spectrometry [DMS]; Field asymmetric-waveform ion mobility spectrometry [FAIMS] · CPC title

• H01J27/205 Primary

  with electrons, e.g. electron impact ionisation, electron attachment · CPC title

• H01J49/102

  using reflex discharge, e.g. Penning ion sources · CPC title