An advanced time-dependent collisional-radiative model of helium plasma discharges

Claustre, J; Boukandou-Mombo, Charlotte; Margot, J.; Matte, J. P.; Vidal, François

doi:10.1088/1361-6595/aa8a16

Cited by 3 publications

(2 citation statements)

References 59 publications

(111 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During plasma formation, He + and He * created by C 3+ impact excitation and ionization of helium atoms transform rapidly into helium dimer ion, in fact He + 2 is well known to be the most abundant ion species in medium/ high density helium plasma 12,23,24 . Helium dimer ions formation follows fundamentally two paths:…”

Section: Discussionmentioning

confidence: 99%

Optical and spectroscopic study of a supersonic flowing helium plasma: energy transport in the afterglow

Brandi

Labate

Rapagnani

et al. 2020

Sci Rep

View full text Add to dashboard Cite

Flowing plasma jets are increasingly investigated and used for surface treatments, including biological matter, and as soft ionization sources for mass spectrometry. They have the characteristic capability to transport energy from the plasma excitation region to the flowing afterglow, and therefore to a distant application surface, in a controlled manner. The ability to transport and deposit energy into a specimen is related to the actual energy transport mechanism. In case of a flowing helium plasma, the energy in the flowing afterglow may be carried by metastable helium atoms and long-lived helium dimer ions. In this work a systematic investigation of the optical and spectroscopic characteristics of a supersonic flowing helium plasma in vacuum and its afterglow as function of the helium gas density is presented. The experimental data are compared with numerical modeling of the plasma excitation and helium dimer ion formation supported by a Computational Fluid Dynamic simulation of the helium jet. The results indicate that the plasma afterglow is effectively due to helium dimer ions recombination via a three-body reaction.The study of noble gas flowing plasma has gained much attention in recent years due to its impact on the application of cold plasma jet and torches for soft ionization and mass spectrometry 1-10 .For a flowing helium plasma the dynamics of the energy transport in the afterglow is very complicated due to the peculiar helium plasma characteristics: presence of highly energetic metastable states and energetic excited states close to the ionization limit, as well as the prominent tendency, at increasing particle density, to form helium dimer ions 11,12 . The actual mechanisms and reactions governing the energy and charge transport from the plasma excitation region to the subsequent stream is of importance to understand and optimize the flowing plasma jets performances. Flowing plasma jets are characterized and optimized by playing on the gas flow rate, the plasma excitation power, the distance to the sample to be probed and the nozzle shape [13][14][15] .There are two main mechanisms supposedly underlying the energy transport in flowing helium plasma jets and the subsequent reactive nitrogen ion formation in ambient air.One mechanism is related to the high excited state energy of metastable helium atoms (more than 20 eV) which are formed during the plasma excitation, eventually from cascade transitions from higher excited states. The helium metastable atoms, He m , have long lifetime and therefore, in principle, can live in the afterglow, giving rise eventually to nitrogen ion formation in air through de-excitation and penning ionization in air 11 ,On the other side, at increasing particle number density, the excited helium atoms and the helium ions are rapidly and efficiently transformed into helium dimer ions, + He 2 , which have a long lifetime, since they do not posses a

show abstract

Section: Discussionmentioning

confidence: 99%

Optical and spectroscopic study of a supersonic flowing helium plasma: energy transport in the afterglow

Brandi

Labate

Rapagnani

et al. 2020

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Also, regardless of the argon concentration, the metastable density always peaks slightly after the discharge current. A behaviour typical of the density of He(2 3 S) during the afterglow of a pulsed discharge [47].…”

Section: Evolution Of the He(2 3 S) Metastable Atomsmentioning

confidence: 98%

Emission and absorption diagnostics of a diffuse dielectric barrier discharge with multiple current peaks in helium at atmospheric pressure

Pellerin-Boudriau

Boisvert

Rozon

et al. 2019

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

Dielectric barrier discharge (DBD) is a simple means to sustain low-temperature diffuse discharges at atmospheric pressure. As atmospheric pressure plasma processing requires DBDs to work under various operating conditions, even diffuse discharges are often observed to exhibit multiple current peaks. In this work, multiple current peaks helium DBD is obtained by adding small concentration of argon in a nominally pure helium discharge. As the concentration of argon increases, multiple current peaks emerge while the discharge remains diffuse. Absorption spectroscopy is used to record the evolution of the He(2 3 S) metastable atom. In a nominally pure helium discharge He(2 3 S) metastable atom can reach up to 6×10 11 cm −3 . Even if quenching of the He(2 3 S) metastable atom by argon is very effective, He(2 3 S) density is found to still rise above 10 10 cm −3 in a multiple current peaks discharge with 1100 ppm of argon. Optical emission spectroscopy of He n=3 levels is also used to gain insights about the electron temperature (T e ) through the means of a collisional-radiative model. For the multiple current peaks discharge with 1100 ppm of argon concentration, T e reaches about 1.0 eV during the primary peak but only about 0.3 eV during the secondary peaks.

show abstract

Study on helium atmospheric pressure plasma jet using collisional-radiative model

Lee

Tran

2020

Physics of Plasmas

View full text Add to dashboard Cite

The helium (He) non-thermal atmospheric pressure plasma jet (APPJ) source was configured, and the He spectra were measured by applying AC power to the source. A He collisional-radiative (CR) model was developed to investigate the He spectra obtained from the APPJ source. Different atmospheric pressure (AP) processes were evaluated, and the dominant processes among them that contribute to the He spectra were determined. The plasma parameters of the APPJ were determined using the He CR model, and the He spectra were successfully reproduced. The electron density was determined to be ∼2×1012 cm−3 between the electrodes of the APPJ, and ∼9×1011cm−3 outside the quartz tube, for a frequency and bias of an AC voltage source of 5 kHz and 10 kVp.p, respectively. A parametric study was performed to explain the behavior of the electron temperature and electron density of APPJ.

show abstract

An advanced time-dependent collisional-radiative model of helium plasma discharges

Cited by 3 publications

References 59 publications

Optical and spectroscopic study of a supersonic flowing helium plasma: energy transport in the afterglow

Optical and spectroscopic study of a supersonic flowing helium plasma: energy transport in the afterglow

Emission and absorption diagnostics of a diffuse dielectric barrier discharge with multiple current peaks in helium at atmospheric pressure

Study on helium atmospheric pressure plasma jet using collisional-radiative model

Contact Info

Product

Resources

About