Particle beam mass spectrometer and particle measurement method by means of same

Patent metadata

Field	Value
Publication number	US-10283339-B2
Application number	US-201515518408-A
Country	US
Kind code	B2
Filing date	Oct 7, 2015
Priority date	Oct 29, 2014
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

The present invention relates to a particle beam mass spectrometer and particle measurement method by means of same. More particularly, the present invention relates to a particle beam mass spectrometer including: a particle focusing unit focusing a particle beam induced by gas flow; an electron gun forming a charged particle beam by accelerating thermal electrons to ionize the particle beam focused by the particle focusing unit; a deflector deflecting the charged particle beam according to kinetic energy to charge ratio; and a sensing unit measuring a current induced by the deflected charged particle beam, wherein the deflector includes at least one particle beam separation electrode provided at each of opposite sides with respect to a progress axis of the charged particle beam before being deflected.

First claim

The invention claimed is:

1. A particle beam mass spectrometer comprising:
a particle focusing unit focusing a particle beam induced by gas flow;
an electron gun forming a charged particle beam including a positive ion or a negative ion by accelerating thermal electrons to ionize the particle beam focused by the particle focusing unit;
a deflector deflecting the charged particle beam according to kinetic energy to charge ratio; and
a sensing unit measuring a current induced by the deflected charged particle beam,
wherein the deflector includes at least one particle beam separation electrode provided at each of opposite sides with respect to a progress axis of the charged particle beam before being deflected, and
the sensing unit is configured to simultaneously collect the positive ion and the negative ion in different regions of the sensing unit, wherein the positive ion and the negative ion are separated from each other by a voltage applied to the at least one particle beam separation electrode.

2. The particle beam mass spectrometer of claim 1 , wherein each particle beam separation electrode has a shape selected from a plate shape, a cylindrical shape, a spherical shape, an elliptical shape, and a bar shape with a cross section having a half-circular shape or a quarter-circular shape.

3. The particle beam mass spectrometer of claim 1 , wherein each particle beam separation electrode includes at least two separation electrodes provided at each of opposite sides with respect to the progress axis of the charged particle beam before being deflected.

4. The particle beam mass spectrometer of claim 3 , wherein each particle beam separation electrode includes an upper separation electrode and a lower separation electrode, whereby a four-pole (quadrupole) shape is provided, and polarities of the separation electrodes respectively provided at positions diagonally facing each other are same.

5. The particle beam mass spectrometer of claim 4 , wherein each particle beam separation electrode has a quarter-circular shape when viewed from a cross section, and has a bar shape in a longitudinal direction.

6. The particle beam mass spectrometer of claim 1 , wherein a DC or a combined signal of the DC with RF is applied to a separation electrode of the particle beam separation electrode.

7. The particle beam mass spectrometer of claim 6 , wherein a voltage applied to the particle beam separation electrode is a DC voltage having a constant value over time, or a signal of one of patterns where a voltage increases or decreases, or the voltage decreases after increases, or the voltage increases after decreases within a particular range over time is applied to the particle beam separation electrode.

8. The particle beam mass spectrometer of claim 1 , wherein the sensing unit includes Faraday cups ranging in number from 1 to 10, and when there is a plurality of the Faraday cups, the sizes of the Faraday cups are equal to each other or are different from each other.

9. The particle beam mass spectrometer of claim 1 , wherein the particle focusing unit is provided with an opening positioned at a body of the unit so as to discharge gas to outside.

10. A method of obtaining information about a size or a density or both of a particle by using the particle beam mass spectrometer of claim 1 .

Assignees

• Korea Res Inst Standards & Sci

Inventors

• Park Chang Joon
• Ahn Sang Jung
• Han Cheolsu
• Lee Keu Chan
• Yoon Seok Rae

Classifications

• H01J49/26 Primary

  Mass spectrometers or separator tubes · CPC title

• H01J49/4225

  Multipole linear ion traps, e.g. quadrupoles, hexapoles · CPC title

• G01N27/623

  combined with mass spectrometry · CPC title

• G01N27/62

  by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode · CPC title

• H01J49/147 Primary

  with electrons, e.g. electron impact ionisation, electron attachment (H01J49/145 takes precedence) · CPC title