Experimental and theoretical study on emission spectra of a nitrogen photoionized plasma induced by intense EUV pulses

Saber, I.; Bartnik, A.; Skrzeczanowski, Wojciech; Wachulak, P.; Jarocki, R.; Fiedorowicz, Henryk; Limpouch, J.

doi:10.1051/epjconf/201816703006

Cited by 3 publications

(2 citation statements)

References 16 publications

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“…We use a 5–10 ns, high-voltage pulse generator (SSPG-20X, Transient Plasma Systems, Inc.) to produce a plasma discharge across two parallel copper electrodes on a glass slide separated by approximately 5 mm, as shown in Figure a. The plasma discharge can be seen here in this image as purple light. − Further details of the experimental setup are given in the Supporting Information document. A typical waveform of the pulse characteristics is plotted in Figure b and exhibits a 5–10 ns rise time.…”

Section: Methodsmentioning

confidence: 99%

Nanoparticle-Enhanced Plasma Discharge Using Nanosecond High-Voltage Pulses

Zhao¹,

Aravind²,

Yang³

et al. 2020

J. Phys. Chem. C

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By discharging nanosecond high-voltage (5 kV) pulses across an insulating substrate containing Au, Pt, or Cu nanoparticles, a 3 order of magnitude (1000×) enhancement in the generation of plasma can be achieved through local field enhancement on the surface of the nanoparticles. The lowtemperature nature of this transient plasma is crucial to maintaining the structural integrity of these delicate nanoparticles. These nanoparticles provide up to a 1000-fold enhancement in the generation of the plasma, which is localized to the surface of the nanoparticles where it is potentially useful (e.g., for catalysis). We performed both time-domain and frequency-domain calculations of the electromagnetic response of the nanoparticles based on high-resolution transmission electron microscope (HRTEM) images, which show local field enhancement of the nanosecond high-voltage pulse on the order of 3×. Since the plasma initiation depends exponentially on the peak electric field strength, this 3-fold increase in the local electric field can result in a several orders of magnitude increases in the generation of plasma at a given applied external field strength. In order to rule out plasmon-resonance enhancement, which is often associated with small metal nanoparticles, we performed finite difference time domain (FDTD) simulations in the optical frequency domain, which show that the effect of plasmon resonance is negligible for Pt nanoparticles. We therefore attribute the nanoparticle-based enhancement to the generation of plasma (an electrostatic effect) rather than enhanced coupling of light from the near field to the far field via the plasmon resonance phenomenon (an optical effect).

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Section: Methodsmentioning

confidence: 99%

Nanoparticle-Enhanced Plasma Discharge Using Nanosecond High-Voltage Pulses

Zhao¹,

Aravind²,

Yang³

et al. 2020

J. Phys. Chem. C

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“…The plasma discharge observed in air (see Figure 1e) produces purple light that corresponds to the C−B transition in nitrogen. 39,40 The glass-slide-based reactor has a low profile and fits easily underneath our high numerical aperture microscope objective lens, enabling plasma emission spectra in the visible wavelength range to be obtained with high collection efficiency, as illustrated in Figure 1b. Based on the linear relationship between the C 2 Swan band emission and C 2 radical species concentration, as established by Goyette et al, 41 we can use the Swan band spectral intensity as a proxy for CH 4 conversion.…”

Section: ■ Methodsmentioning

confidence: 99%

Au Nanoparticle Enhancement of Plasma-Driven Methane Conversion into Higher Order Hydrocarbons via Hot Electrons

Zhao

Aravind

Yang

et al. 2020

ACS Appl. Nano Mater.

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We demonstrate a more than 50-fold enhancement in the upconversion of methane to higher order hydrocarbons by discharging a nanosecond-pulsed plasma across Au nanoparticles. Here, the enhancement occurs as a result of the local field enhancement provided by the nanoparticles. The transient nature of the pulsed plasma enables the structure of these delicate nanoparticles to be preserved during the plasma discharge by producing a low-temperature plasma. Plasma emission spectroscopy shows signatures of the C 2 Swan bands with and without the presence of these nanoparticles. Mass spectrometry demonstrates that methane is converted into higher order hydrocarbons with different groups of peaks representing species with molecular masses of 35−45, 45−60, and 60−70 amu, corresponding to C 3 , C 4 , and C 5 species, respectively, under plasma discharge conditions. Electrostatic simulations show that a 3−4× enhancement in the field is produced at the nanoparticle surfaces. The exponential relation between electric field strength and plasma formation gives rise to a 50× increase in highly reactive, plasma-initiated radical species that are responsible for driving the methane upconversion process. This upconversion is important for several applications including mitigation of greenhouse emissions and improving the combustion of natural gas.

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