탄소나노튜브 기반 전자충격 이온화원을 이용한 초소형 비행시간차 질량분석기에 대한 연구
A Study on the Micro Time of Flight Mass Spectrometer with Electron Impact Ionizer using Carbon Nanotube
- 주제(키워드) Micro electromechanical system(MEMS) , Time-of-flight(TOF) , Electron impact(EI) , Carbon nanotube(CNT)
- 발행기관 아주대학교
- 지도교수 양상식
- 발행년도 2016
- 학위수여년월 2016. 2
- 학위명 박사
- 학과 및 전공 일반대학원 전자공학과
- 실제URI http://www.dcollection.net/handler/ajou/000000022054
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
A mass spectrometer is a powerful analytical techniques used for both qualitative and quantitative analysis of substances, on the other hand, it is still bulky, expensive, high vacuum demanding, and high power consuming. Owing to such natures, it is not suitable for in situ analysis or monitoring. Recently, progress has been achieved on miniaturized or micro-machined MSs with various mass-filtering methods which considerably reduces disadvantages of conventional MS systems. Generally, a miniature or micro-machined MS systems consist of small and precise micro-machined components of conventional MS system such as ion sources, mass analyzers or ion detectors. In the thesis, it is demonstrated the triode-type field emitter using CNTs and the μ-TOFMS. The μ-TOFMS consists of two components: a triode-type field emitter for ionization and an ion separator with the repeller, the acceleration electrodes, and the flight tube, and they are fabricated with MEMS technologies individually and assembled. As a cold-cathode, a field emitter with CNT is the promising electron sources with advantages of compact size, low power consumption due to the absence of heating elements, excellent durability and high electron emission density, compared to conventional thermionic electron sources. It is successful to detect ions of argon and methyl iodine signals with the μ-TOFMS. It is practically proved with preliminary experiments of ionization and mass spectrum tests with argon and methyl iodide, theoretical analysis and FE modeling in this thesis.
more목차
Chapter 1. Introduction 1
1.1 Overview 2
1.2 Mass spectrometer system 3
1.2.1 Sector analyzer ８
1.2.2 Linear quadrupoles ８
1.2.3 Ion cyclotron resonance and ion traps ９
1.2.4 Time-of-flight ９
1.3 Objectives １３
Chapter 2. Triode Field Emitter with Carbon Nanotube as an ion source １４
2.1 Introduction １５
2.2 Triode field emitter with a low-threshold voltage １６
2.2.1 Structure １７
2.2.2 Fabrication １９
2.2.3 Field emission test ２３
2.2.4 Discussions ２８
2.3 Triode field emitter with a high electron transparency ２８
2.3.1 Structure ２８
2.3.2 Fabrication ３２
2.3.3 Experimental results and discussion ３６
2.3.4 Discussion ５０
2.4 Conclusions ５０
Chapter 3. Micro-machined Time-of-flight Micro Mass Spectrometer ５２
3.1 Introduction ５３
3.2 Principle ５４
3.3 Theoretical analysis ５５
3.4 μ-TOFMS with enhancement of electrical insulation and connection. ５８
3.4.1 Structure ５８
3.4.2 Design and simulation ６０
3.4.3 Fabrication ６５
3.4.4 FEM analysis ７０
3.4.5 Experimental setup ７５
3.4.6 Ionization test ７５
3.4.7 Mass spectrum test ８１
3.4.8 Discussions ９４
Chapter 4. Conclusions ９５
