Numerical simulation of the breakdown process of micro-discharge sustained by field emission

Guo, Chengzhi; Wu, Hao; Peng, Yanli; Wang, Zhijiang; Jiang, Wei; Zhang, Ya

doi:10.1088/1361-6463/ac923e

Cited by 12 publications

(8 citation statements)

References 67 publications

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“…This is attributed to the presence of an electric field within the cathode sheath directed towards the cathode (at 0 µm), as illustrated in figure 8(a3). During this phase, the spatial profiles of particle densities, as does the electric field shown in figure 8(a3), remain essentially constant, bearing significant similarities to the DC discharge [86], which is consistent with the observations reported in [87]. In this mode, during the afterglow phase, seed electrons are supplied by the secondary emission of the cathode.…”

Section: Runaway Breakdownsupporting

confidence: 86%

Breakdown modes in nanosecond pulsed micro-discharges at atmospheric pressure

Chen,

Wu,

Chen

et al. 2023

J. Phys. D: Appl. Phys.

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Nanosecond pulse micro-discharges at atmospheric pressure have garnered attention because of their unique physics and numerous applications. In this study, we employed a one-dimensional particle-in-cell/Monte Carlo collision model coupled with an external circuit, using an unequal weight algorithm to investigate the breakdown processes in micro-discharges driven by pulses with voltage ranging from 1 kV to 50 kV at atmospheric pressure. The results demonstrate that nanosecond pulse-driven microplasma discharges exhibit different breakdown modes under various pulse voltage amplitudes. We present the discharge characteristics of two modes: ‘no-breakdown’ when the breakdown does not occur, and ‘runaway breakdown mode’ and ‘normal breakdown mode’ when the breakdown does happen. In the runaway breakdown mode, the presence of runaway electrons leads to a phenomenon in which the electron density drops close to zero during the pulse application phase. Within this mode, three submodes are observed: local mode, transition mode, and gap mode, which arise from different secondary electron generation scenarios. As the pulse voltage amplitude increases, a normal breakdown mode emerges, characterized by the electron density not dropping close to zero during the pulse application phase. Similarly, three sub-modes akin to those in the runaway breakdown mode exist in this mode, also determined by secondary electrons. In these modes, we find that electron loss during the pulse application phase is dominated by boundary absorption, whereas during the afterglow phase, it is dominated by recombination. Ion losses are primarily governed by recombination. These findings contribute to a better understanding of the discharge mechanisms during the breakdown process.

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Section: Runaway Breakdownsupporting

confidence: 86%

Breakdown modes in nanosecond pulsed micro-discharges at atmospheric pressure

Chen,

Wu,

Chen

et al. 2023

J. Phys. D: Appl. Phys.

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“…The right term of equation ( 1) is the source term for particle including the G and L, as shown in the table 2. G denotes the generation term for particles resulting from collision ionization in the volume, and surface emission processes such as secondary electron emission from the boundary, thermionic emission [38] and field emission [39]. L represents loss term for particles (e.g.…”

Section: Theoretical Foundationsmentioning

confidence: 99%

Note on particle balance in particle-in-cell/Monte Carlo model and its implications on the steady-state simulation

Chen

et al. 2023

Plasma Sources Sci. Technol.

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The steady-state criterion for plasma numerical simulations can be determined by the particle balance relation. In this study, we utilized a one-dimensional (1D) particle-in-cell/Monte Carlo (PIC/MC) model to investigate particle transport in a capacitively coupled plasma (CCP) discharge, including particle density change, flow, generation, and loss. Our analysis revealed that the generation rate and loss rate are equivalent in both time and space, indicating a fine balance in the steady state of the discharge system. Additionally, we presented the spatio-temporal distribution and time-averaged particle transport term for electrons and ions to demonstrate how particles attain equilibrium at varying pressures. This validation method can be particularly useful in numerical simulations where determining steady state can be challenging. Our findings establish the correctness and reliability of the method.

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“…Radio frequency (RF) breakdown is a crucial factor that degrades the performance of high-gradient accelerating structures and high-power microwave (HPM) generators [1][2][3][4][5][6]. Many researchers have proposed that field electron emission (FEE) is considered to be strongly related to RF breakdown [7][8][9][10]. On the one hand, it is generally believed that explosive electron emission (EEE) developed from FEE under strong electric fields leads to breakdown in RF accelerating structures [11,12].…”

Section: Introductionmentioning

confidence: 99%

Mechanism analysis of field electron emission of titanium

Tan¹,

Wu²,

Hua³

et al. 2023

Phys. Scr.

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Field electron emission (FEE) is generally considered to be closely correlated with radio frequency (RF) breakdown in accelerating structures and high-power microwave (HPM) devices. In this study, the field emission characteristics of titanium are investigated by using a field emission test system. With the increase of the number of field emission tests and stability tests, the repeatability of the field emission characteristic curve of titanium tends to be better, and the amplitude of the current oscillation in the stability tests gradually decreases, indicating that the field emission performance of titanium gradually becomes stable. Subsequently, the field emission characteristic curve of titanium is analyzed by adopting the field emission theory of metal microprotrusions. Combined with the analysis of the electric field enhancement effects caused by the surface morphology, the dominant effect of the metal microprotrusions on the FEE of titanium is excluded from the two aspects of the electric field enhancement factor and local maximum emission current density. At last, the field emission theory of dielectric micropoints is introduced to analyze the field emission characteristics of titanium. The electric field enhancement factor of 102 ~ 103 are explained theoretically. Simultaneously, the reasonable effective emission area and local emission current density are given, which can better explain the field emission phenomena of titanium, such as the sharp decrease in emission current and repeatability of the field emission curve. Hence, it is revealed that the key factor that dominates the FEE of titanium is the dielectric impurities on the surface, rather than the metal microprotrusions.

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Numerical simulation of the breakdown process of micro-discharge sustained by field emission

Cited by 12 publications

References 67 publications

Breakdown modes in nanosecond pulsed micro-discharges at atmospheric pressure

Breakdown modes in nanosecond pulsed micro-discharges at atmospheric pressure

Note on particle balance in particle-in-cell/Monte Carlo model and its implications on the steady-state simulation

Mechanism analysis of field electron emission of titanium

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