NANOlab Center of Excellence literature database -- Query Results

	NANOlab Center of Excellence literature database Home \| Show All \| Simple Search \| Advanced Search	Login Quick Search: Field: contains: ...
	1–8 of 8 records found matching your query (RSS \| history):

Select All Deselect All

<< 1 >>

List View

Citations

Details

	Records
	Author	Gu, J.-G.; Zhang, Y.; Gao, M.-X.; Wang, H.-Y.; Zhang, Q.-Z.; Yi, L.; Jiang, W.
	Title	Enhancement of surface discharge in catalyst pores in dielectric barrier discharges			Type	A1 Journal article
	Year	2019	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	125	Issue	15	Pages	153303
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	The generation of high-density plasmas on the surface of porous catalysts is very important for plasma catalysis, as it determines the active surface of the catalyst that is available for the reaction. In this work, we investigate the mechanism of surface and volume plasma streamer formation and propagation near micro-sized pores in dielectric barrier discharges operating in air at atmospheric pressure. A two-dimensional particle-in-cell/ Monte Carlo collision model is used to model the individual kinetic behavior of plasma species. Our calculations indicate that the surface discharge is enhanced on the surface of the catalyst pores compared with the microdischarge inside the catalyst pores. The reason is that the surface ionization wave induces surface charging along the catalyst pore sidewalls, leading to a strong electric field along the pore sidewalls, which in turn further enhances the surface discharge. Therefore, highly concentrated reactive species occur on the surfaces of the catalyst pores, indicating high-density plasmas on the surface of porous catalysts. Indeed, the maximum electron impact excitation and ionization rates occur on the pore surface, indicating the more pronounced production of excited state and electron-ion pairs on the pore surface than inside the pore, which may profoundly affect the plasma catalytic process. Published under license by AIP Publishing.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000465441200022	Publication Date	2019-04-15
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979; 1089-7550	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	4	Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 2.068
	Call Number	UA @ admin @ c:irua:160397			Serial	5273
Permanent link to this record



	Author	Zhang, Y.; Wang, H.-yu; Jiang, W.; Bogaerts, A.
	Title	Two-dimensional particle-in cell/Monte Carlo simulations of a packed-bed dielectric barrier discharge in air at atmospheric pressure			Type	A1 Journal article
	Year	2015	Publication	New journal of physics	Abbreviated Journal	New J Phys
	Volume	17	Issue	17	Pages	083056
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	The plasma behavior in a parallel-plate dielectric barrier discharge (DBD) is simulated by a two-dimensional particle-in-cell/Monte Carlo collision model, comparing for the first time an unpacked (empty) DBD with a packed bed DBD, i.e., a DBD filled with dielectric spheres in the gas gap. The calculations are performed in air, at atmospheric pressure. The discharge is powered by a pulse with a voltage amplitude of −20 kV. When comparing the packed and unpacked DBD reactors with the same dielectric barriers, it is clear that the presence of the dielectric packing leads to a transition in discharge behavior from a combination of negative streamers and unlimited surface streamers on the bottom dielectric surface to a combination of predominant positive streamers and limited surface discharges on the dielectric surfaces of the beads and plates. Furthermore, in the packed bed DBD, the electric field is locally enhanced inside the dielectric material, near the contact points between the beads and the plates, and therefore also in the plasma between the packing beads and between a bead and the dielectric wall, leading to values of $4\times {10}
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Bristol	Editor
	Language		Wos	000360957800003	Publication Date	2015-08-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1367-2630;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.786	Times cited	22	Open Access
	Notes				Approved	Most recent IF: 3.786; 2015 IF: 3.558
	Call Number	c:irua:127650			Serial	3777
Permanent link to this record



	Author	Jiang, W.; Zhang, Y.; Bogaerts, A.
	Title	Numerical characterization of local electrical breakdown in sub-micrometer metallized film capacitors			Type	A1 Journal article
	Year	2014	Publication	New journal of physics	Abbreviated Journal	New J Phys
	Volume	16	Issue		Pages	113036
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	In metallized film capacitors, there exists an air gap of about 0.2 μm between the films, with a pressure ranging generally from 130 atm. Because of the created potential difference between the two films, a microdischarge is formed in this gap. In this paper, we use an implicit particle-in-cell Monte Carlo collision simulation method to study the discharge properties in this direct-current microdischarge with 0.2 μm gap in a range of different voltages and pressures. The discharge process is significantly different from a conventional high pressure discharge. Indeed, the high electric field due to the small gap sustains the discharge by field emission. At low applied voltage (~15 V), only the electrons are generated by field emission, while both electrons and ions are generated as a stable glow discharge at medium applied voltage (~50 V). At still higher applied voltage (~100 V), the number of electrons and ions rapidly multiplies, the electric field reverses, and the discharge changes from a glow to an arc regime.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Bristol	Editor
	Language		Wos	000346763400006	Publication Date	2014-11-15
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1367-2630;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.786	Times cited		Open Access
	Notes				Approved	Most recent IF: 3.786; 2014 IF: 3.558
	Call Number	UA @ lucian @ c:irua:120455			Serial	2393
Permanent link to this record



	Author	Zhang, Y.; Jiang, W.; Bogaerts, A.
	Title	Kinetic simulation of direct-current driven microdischarges in argon at atmospheric pressure			Type	A1 Journal article
	Year	2014	Publication	Journal of physics: D: applied physics	Abbreviated Journal	J Phys D Appl Phys
	Volume	47	Issue	43	Pages	435201
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	A one-dimensional, implicit particle-in-cell Monte Carlo collision model is used to simulate the plasma kinetic properties at a steady state in a parallel-plate direct current argon glow microdischarge under various operating conditions, such as driving voltage (301000 V) and gap size (101000 µm) at atmospheric pressure. First, a comparison between rf and dc modes is shown for the same pressure, driving voltage and gap spacing. Furthermore, the effect of gap size scaling (in the range of 101000 µm) on the breakdown voltage, peak electron density and peak electron current density at the breakdown voltage is examined. The breakdown voltage is lower than 150 V in all gaps considered. The microdischarge is found to have a neutral bulk plasma region and a cathode sheath region with size varying with the applied voltage and the discharge gap. In our calculations, the electron and ion densities are of the order of 10181023 m−3, which is in the glow discharge limit, as the ionization degree is lower than 1% . The electron energy distribution function shows a two-energy group distribution at a gap of 10 µm and a three-energy group distribution at larger gaps such as 200 µm and 1000 µm, emphasizing the importance of the gap spacing in dc microdischarges.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	London	Editor
	Language		Wos	000343150500011	Publication Date	2014-10-03
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0022-3727;1361-6463;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.588	Times cited	10	Open Access
	Notes				Approved	Most recent IF: 2.588; 2014 IF: 2.721
	Call Number	UA @ lucian @ c:irua:119152			Serial	1759
Permanent link to this record



	Author	Wen, D.-Q.; Zhang, Q.-Z.; Jiang, W.; Song, U.-H.; Bogaerts, A.; Wang, Y.-N.
	Title	Phase modulation in pulsed dual-frequency capacitively coupled plasmas			Type	A1 Journal article
	Year	2014	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	115	Issue	23	Pages	233303
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Particle-in-cell/Monte Carlo collision simulations, coupled with an external circuit, are used to investigate the behavior of pulsed dual-frequency (DF) capacitively coupled plasmas (CCPs). It is found that the phase shift θ between the high (or low) frequency source and the pulse modulation has a great influence on the ion density and the ionization rate. By pulsing the high frequency source, the time-averaged ion density shows a maximum when θ = 90∘. The time-averaged ion energy distribution functions (IEDFs) at the driven electrode, however, keep almost unchanged, illustrating the potential of pulsed DF-CCP for independent control of ion density (and flux) and ion energy. A detailed investigation of the temporal evolution of the plasma characteristics indicates that several high frequency harmonics can be excited at the initial stage of a pulse period by tuning the phase shift θ, and this gives rise to strong sheath oscillations, and therefore high ionization rates. For comparison, the pulsing of the low frequency source is also studied. In this case, the ion density changes slightly as a function of time, and the time-averaged ion density shows the same trend as in the HF modulation for different phase shifts θ. Moreover, the time-averaged IEDFs at the driven electrode can be modulated, showing the potential to reduce the maximum ion bombardment energy.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000338106000008	Publication Date	2014-06-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	8	Open Access
	Notes				Approved	Most recent IF: 2.068; 2014 IF: 2.183
	Call Number	UA @ lucian @ c:irua:117415			Serial	2585
Permanent link to this record



	Author	Zhang, Y.; Jiang, W.; Zhang, Q.Z.; Bogaerts, A.
	Title	Computational study of plasma sustainability in radio frequency micro-discharges			Type	A1 Journal article
	Year	2014	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	115	Issue	19	Pages	193301-193311
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	We apply an implicit particle-in-cell Monte-Carlo (PIC-MC) method to study a radio-frequency argon microdischarge at steady state in the glow discharge limit, in which the microdischarge is sustained by secondary electron emission from the electrodes. The plasma density, electron energy distribution function (EEDF), and electron temperature are calculated in a wide range of operating conditions, including driving voltage, microdischarge gap, and pressure. Also, the effect of gap size scaling (in the range of 50-1000 μm) on the plasma sustaining voltage and peak electron density at atmospheric pressure is examined, which has not been explored before. In our simulations, three different EEDFs, i.e., a so-called three temperature hybrid mode, a two temperature α mode, and a two temperature γ mode distribution, are identified at different gaps and voltages. The maximum sustaining voltage to avoid a transition from the glow mode to an arc is predicted, as well as the minimum sustaining voltage for a steady glow discharge. Our calculations elucidate that secondary electrons play an essential role in sustaining the discharge, and as a result the relationship between breakdown voltage and gap spacing is far away from the Paschen law at atmospheric pressure.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000336920200010	Publication Date	2014-05-16
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	11	Open Access
	Notes				Approved	Most recent IF: 2.068; 2014 IF: 2.183
	Call Number	UA @ lucian @ c:irua:116948			Serial	458
Permanent link to this record



	Author	Zhang, Q.-Z.; Liu, Y.-X.; Jiang, W.; Bogaerts, A.; Wang, Y.-N.
	Title	Heating mechanism in direct current superposed single-frequency and dual-frequency capacitively coupled plasmas			Type	A1 Journal article
	Year	2013	Publication	Plasma sources science and technology	Abbreviated Journal	Plasma Sources Sci T
	Volume	22	Issue	2	Pages	025014-25018
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	In this work particle-in-cell/Monte Carlo collision simulations are performed to study the heating mechanism and plasma characteristics in direct current (dc) superposed radio-frequency (RF) capacitively coupled plasmas, operated both in single-frequency (SF) and dual-frequency (DF) regimes. An RF (60/2 MHz) source is applied on the bottom electrode to sustain the discharge, and a dc source is fixed on the top electrode. The heating mechanism appears to be very different in dc superposed SF and DF discharges. When only a single source of 60 MHz is applied, the plasma bulk region is reduced by the dc source, thus the ionization rate and hence the electron density decrease with rising dc voltage. However, when a DF source of 60 and 2 MHz is applied, the electron density can increase upon addition of a dc voltage, depending on the gap length and applied dc voltage. This is explained from the spatiotemporal ionization rates in the DF discharge. In fact, a completely different behavior is observed for the ionization rate in the two half-periods of the LF source. In the first LF half-period, the situation resembles the dc superposed SF discharge, and the reduced plasma bulk region due to the negative dc bias results in a very small effective discharge area and a low ionization rate. On the other hand, in the second half-period, the negative dc bias is to some extent counteracted by the LF voltage, and the sheath close to the dc electrode becomes particularly thin. Consequently, the amplitude of the high-frequency sheath oscillations at the top electrode is largely enhanced, while the LF sheath at the bottom electrode is in its expanding phase and can thus well confine the high-energy electrons. Therefore, the ionization rate increases considerably in this second LF half-period. Furthermore, in addition to the comparison between SF and DF discharges and the effect of gap length and dc voltage, the effect of secondary electrons is examined.
	Address
	Corporate Author				Thesis
	Publisher	Institute of Physics	Place of Publication	Bristol	Editor
	Language		Wos	000317275400016	Publication Date	2013-03-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0963-0252;1361-6595;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.302	Times cited	9	Open Access
	Notes				Approved	Most recent IF: 3.302; 2013 IF: 3.056
	Call Number	UA @ lucian @ c:irua:106877			Serial	1413
Permanent link to this record



	Author	Zhang, Q.-Z.; Zhao, S.-X.; Jiang, W.; Wang, Y.-N.
	Title	Separate control between geometrical and electrical asymmetry effects in capacitively coupled plasmas			Type	A1 Journal article
	Year	2012	Publication	Journal of physics: D: applied physics	Abbreviated Journal	J Phys D Appl Phys
	Volume	45	Issue	30	Pages	305203
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Both geometrical and electrical asymmetry effects in capacitive argon discharges are investigated using a two-dimensional particle-in-cell coupled with Monte Carlo collision model. When changing the ratio of the top and bottom electrode surface areas and the phase shift between the two applied harmonics, the induced self-bias was found to develop separately. By adjusting the ratio between the high and low harmonic amplitudes, the electrical asymmetry effect at a fixed phase shift can be substantially optimized. However, the self-bias caused by the geometrical asymmetry hardly changed. Moreover, the separate control of these two asymmetry effects can also be demonstrated from their power absorption profiles. Both the axial and radial plasma density distributions can be modulated by the electrical asymmetry effect.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	London	Editor
	Language		Wos	000306475200007	Publication Date	2012-07-10
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0022-3727;1361-6463;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.588	Times cited	20	Open Access
	Notes				Approved	Most recent IF: 2.588; 2012 IF: 2.528
	Call Number	UA @ lucian @ c:irua:100751			Serial	2984
Permanent link to this record