傳統的介電屏蔽放電是在兩個被介電質覆蓋的電極之間所產生的一種大氣壓電漿。目前已用於各種目的，例如晶片的蝕刻，疤痕的去除等。對於這些應用，DBD通常在大氣下操作。該研究主旨在以DBD開發用於磁化電漿實驗室(MPX)的新電漿源。我們開發了一種低氣壓磁化的DBD電漿源，使用逆變器電路與帶有噴射配置的玻璃管。外部磁場沿著玻璃管的軸向施加。實驗研究了DBD產生電漿的機制。從氬氣DBD實驗中，說明了以下內容:
1.使用低頻電壓源(800Hz,1.5Kv)在低氣壓下(~mtorr)下可觀察常規大氣壓DBD的特徵。
2.使用逆變器電路的高頻電壓源(48kHz,0.5kV)，確定了兩種不同的放電狀態: 一種是似DBD電漿，其特徵是電極電流有尖狀波形與高電子密度。電漿噴射區以及玻璃管內的高吸收功率。另一種是似CCP電漿，其特徵為電極電流的鋸齒狀波形，噴流區域的低電子密度和玻璃管內的低吸收功率。似DBD電漿狀態在高氣體流速(80~100sccm)下產生，且磁場強度低於閥值。似CCP電漿態在低氣體流速與高於閥值磁場下產生。
3.我們提出了一個簡單的模型來解釋似DBD與CCP店將之間的轉換。該模型通過虛擬的電容器電極之間的距離變化來解釋過度的現象。在弱磁場的情況下，正電極和相鄰的接地電極構成類似DBD電漿的電容。在強磁場下，正電極與遠端的接地網構成類似CCP電漿的電容。
4.在我們實驗室的裝置中，於磁場限制區域或的的DBD電漿密度約為1013 "m" ^(-3)。氬氣電漿噴流直徑與長度分別為4公分與150公分。

關鍵字: 大氣DBD，電漿源，電荷記憶效應，磁化電漿與朗缪爾探針理論。

Conventional dielectric barrier discharges (DBDs) are one type of atmospheric pressure plasmas produced between two ac-biased electrodes covered with dielectric material. DBDs have been used in various purposes such as a source of reactive fields, etching of wafer, removal of skin scars, and so on. For these applications, DBDs are typically operated at atmospheric pressure. This study aims at development of a new DBD-based plasma source for magnetized plasma experiment (MPX). We developed a low pressure-magnetized DBD plasma source using an inverter circuit and a glass tube with a jet configuration for MPX. The external magnetic field was applied in the axial direction of the glass tube. Mechanism of plasma production by the DBD source were experimentally investigated. From the argon DBD experiments, the followings are clarified:
1.Features of conventional atmospheric pressure DBDs were observed at low pressure (~ mTorr) with the use of low frequency voltage source (800 Hz, 1.5 kV).
2.With high frequency voltage source (48 kHz, 0.5 kV) using an inverter circuit, two distinct discharge states were identified: One is DBD-like plasma state, which is characterized by a spikey waveform of the electrode current, high electron density at the jet region, and high absorption of injected power inside the glass tube. The other is CCP-like plasma state characterized by a sawtooth waveform of the electrode current, low electron density at the jet region, and low absorption of injected power inside the glass tube. The DBD-like plasma states were realized at high gas flow rate (~ 80 – 100 sccm) and lower magnetic field strength than a threshold. The CCP-like plasma states were produced at low gas flow rate and higher magnetic field strength than the threshold.
3.A simple model is proposed for the explanation of the transition between DBD-like plasma and CCP-like plasma states. The model explains the transition phenomenon by change of distance between the virtual capacitor electrodes. In the case of the weak magnetic field, power electrode and the neighboring grounding electrode constitutes a capacitor like conventional DBD plasma jet. In the case of the strong magnetic field, the power electrode and the distant grounding grid (i.e. the vacuum chamber) constitutes a capacitor.
4.The achieved DBD plasma density at the confinement region of the MPX device was on the order of 1013 "m" ^(-3). The plasma diameter and length of the plasma jet were 4 cm and 150 cm, respectively. These parameters were obtained in the CCP-like plasma states.

Further investigation of the plasma production mechanisms including associated atomic process, helium discharge etc. are needed.

Key words: Atmospheric pressure DBDs, plasma sources, charge memory effect, magnetized plasma, Langmuir probe theory

Chapter 1
[1] Jon Tomas Gudmundsson, and Ante Hecimovic, “Foundations of DC plasma sources”. Plasma Sources Sci. Technol. 26 123001
[2] H Conrads and M Schmidt, “Plasma generation and plasma sources”. Plasma Sources Sci. Technol. 9 (2000) 441–454.
[3] Tashiro Ona, Hiroshi Nishimura, Masaru Shimada, and Seitaro Matsuo, “Electron cyclotron resonance plasma source for conductive film deposition”, Journal of Vacuum Science & Technology A 12, 1281 (1994).
[4] K. Saeki, S. lizuka, N. Sato, and Y. Hatta, “A new plasma source, the plasma emitter”, Appl. Phys. Lett. 37, 37 (1980).
[5] Weiman Jiang, Jie Tang, Yishan Wang, Wei Zhao, and Yixiang Duan, “A low-power magnetic-field-assisted plasma jet generated by dielectric-barrier discharge enhanced direct-current glow discharge at atmospheric pressure”, Applied Physics Letters 104, 013505 (2014)
[6] Yidi Liu, Haicheng Qi, Zhihui Fan, Huijie Yan, and ChunSheng Ren, “The impacts of magnetic field on repetitive nanosecond pulsed dielectric barrier discharge in air”, Phys. Plasmas 23, 113508 (2016).
[7] Eiichirou Kawamori, Jyun-Yi Lee, Yi-Jue Huang, Wun-Jheng Syugu, Sung-Xuang Song, Tung-Yuan Hsieh, and C. Z. Cheng, “Lithium plasma emitter for collisionless magnetized plasma experiment”, Rev. Sci. Instrum. 82, 093502 (2011).

Chapter 2
[1] Ronny Brandenburg, “Dielectric barrier discharges: progress on plasma sources and on the understanding of regimes and single filaments”, 2017 Plasma Sources Sci. Technol. 26 053001.
[2] E Wagenaars, R Brandenburg, W J M Brok, M D Bowden and H-E Wagner, “Experimental and modelling investigations of a dielectric barrier discharge in low-pressure argon”, Phys. D: Appl. Phys. 39 700
[3] Keiichiro Urabe, Yosuke Ito, Osamu Sakai, and Kunihide Tachibana,” Interaction between Dielectric Barrier Discharge and Positive Streamer in Helium Plasma Jet at Atmospheric Pressure”, Japanese Journal of Applied Physics 49 (2010) 106001

Chapter 4
[1] Xian-Jun Shao, Nan Jiang, Guan-Jun Zhang, and Ze-xian Cao, “Comparative study on the atmospheric pressure plasma jets of helium and argon”, Appl. Phys. Lett. 101, 253509 (2012)
[2] E Wagenaars, R Brandenburg, W J M Brok, M D Bowden and H-E Wagner, “Experimental and modelling investigations of a dielectric barrier discharge in low-pressure argon”, J. Phys. D: Appl. Phys. 39 (2006) 700–711
[3] M. Asgar Ali, P.M. Stone, “Electron impact ionization of metastable rare gases: He, Ne and Ar”, International Journal of Mass Spectrometry 271 (2008) 51–57
[4] Jozef Rahel’ and Daniel M Sherman, “The transition from a filamentary dielectric barrier discharge to a diffuse barrier discharge in air at atmospheric pressure”, J. Phys. D: Appl. Phys. 38 (2005) 547–554