Time and space resolved Langmuir probe measurements of a pulsed vacuum arc plasma

Chen, Lei; Jin, Dazhi; Tan, Xiaohua; Jingyi, Dai; Cheng, Liang; Hu, Side

doi:10.1016/j.vacuum.2010.09.005

Cited by 18 publications

(10 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Fig. 10, ion velocities spread from 14.5 km/s to more than 28 km/s, which is consistent with the values usually found in the literature [3,28,29]. Again the large velocity spread reveals the stochastic character of the arc formation.…”

Section: Velocitysupporting

confidence: 88%

See 1 more Smart Citation

Time evolution of plasma parameters in the jet of a low-power vacuum arc thruster

Michaux

Mazouffre

Blanchet³

2022

J Electr Propuls

View full text Add to dashboard Cite

The plasma parameters temporal evolution of a 30 W-class Vacuum Arc Thruster equipped with a Ni-Cr cathode is examined in the far-field region of the plasma jet. Measurements have been performed 20 cm downstream of the arc region where the plasma is created. The thruster operated at 1 Hz with 25 μs duration current pulses. The maximum current intensity reaches 4000 A about 8 μs after the discharge ignition. The change in the electron density, electron temperature and plasma potential during the short high-current pulse has been obtained by means of time-resolved Langmuir probe measurements. A time-of-flight technique based on a planar probe has been used to determine the mean ion velocity in the plasma jet. In addition, a Faraday cup allowed the determination of the ion current density. The electron density peaks at ∼ 8×1017 m−3 at 12 μs. The electron temperature is above 25 eV at 7 μs and then it stabilizes around 5 eV. Several ion populations are identified. The lowest ion mean velocity amounts to 20 km/s. Interestingly, combining all data allows to assess the ion mean electrical charge and its temporal behavior. The mean charge reaches 12 a few μs after ignition. It decays quickly afterwards and stays unchanged at 2 beyond 10 μs. Analysis of all the results support the idea of two distinct plasma discharge regimes.

show abstract

Section: Velocitysupporting

confidence: 88%

“…These values are in good agreement with ones obtained in other works on VAT, see e.g. [3,28,29]. In the remainder of the paper we will solely consider the first large peak on the ion current traces as the origin of other peaks is questionable.…”

Section: Velocitysupporting

confidence: 88%

Time evolution of plasma parameters in the jet of a low-power vacuum arc thruster

Michaux

Mazouffre

Blanchet³

2022

J Electr Propuls

View full text Add to dashboard Cite

show abstract

“…Most of these studies considered the Maxwellian velocity distribution for the electrons to simulate the characteristics of the plasma sheath in PIII devices. However, deviation from this well-known distribution for different plasma sources has been frequently reported in the literature (Liu et al 1994;Hori et al 1996;Segre and Pieroni 1975;Godyak et al 2002;Godyak 2005;Li 2006;Tang et al 2009;Chen et al 2010). Godyak et al (2002), Godyak (2005), Hori et al (1996) and Li (2006) measured the electron probability function in an inductively coupled plasma which commonly used as the plasma source in PIII process.…”

Section: Introductionmentioning

confidence: 99%

“…They obviously showed the electron probability function deviation from the Maxwellian form at the various powers, working pressures and conditions. Chen et al (2010) measured the temporal and spatial evolution of a pulsed vacuum arc plasma and showed that the electron energy distribution function is non-Maxwellian because the high-energy electrons depart from the Maxwellian distribution. Therefore several studies focused to describe the PIII plasma behaviour in the presence of non-Maxwellian electrons (Kushner 1985;Shiraishi and Takamura 1990;Godyak et al 1995;Demidov et al 2005;Gyergyek and erek 2005;Demidov et al 2006;Gurovich et al 2006;Sharifian and Shokri 2007;Gyergyek et al 2008) to give more realistic prediction of the involved systems.…”

Section: Introductionmentioning

confidence: 99%

Plasma immersion ion implantation characteristics with q-nonextensive electron velocity distribution

2015

View full text Add to dashboard Cite

The plasma immersion ion implantation process is investigated in the presence ofq–nonextensive electrons by using a one-dimensional fluid model. The effect of the nonextensivity parameter,q, on the plasma parameters and sheath dynamics during the implantation process is studied. The results show that the implantation dose can be enhanced in the presence of energetic electrons at the tail of the distribution function. Different parameters of plasma such as sheath thickness, ion velocity and ion density show more change at the larger values of theq–parameter. Furthermore, the results of simulation tend to what is predicted by the Maxwellian electron distribution function (q= 1).

show abstract

“…Langmuir probes are one of the most commonly used diagnosis tools for the plasma. A difficulty will arise in using a Langmuir probe in the pulsed discharge because the pulse discharge time is usual much shorter than the usual whole voltage sweep time, but if the discharge pulses have a high level of repeatability, an ingenious method can be used to construct the pulsed vacuum arc plasma parameters by a Langmuir probe [9,10] .…”

Section: Introductionmentioning

confidence: 99%

Radial and Angular Resolved Langmuir Probe Diagnosis of a Pulsed Vacuum Arc Plasma

Chen¹,

Ma²,

Li³

et al. 2011

Plasma Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Vacuum arc ion sources are known for delivering high currents of ion beams in many technological applications. There is a great need in the present ion accelerator injection research for a titanium vacuum arc source to produce high-ionized plasma, in which its parameter is extremely important to match the extractors geometry and the extraction voltage. In this paper, the radial and angular distributions of the titanium cathodic vacuum arc plasma parameters are measured by a cylindrical Langmuir probe and analyzed by the Druyvesteyn method from the I-V curves. The electron density ne is about 10 17 m −3 and the effective electron temperature T eff is in the range of 6.12∼11.11 eV in the free expansion cup before the ion extraction. The measured distribution of ne over the expansion cross-section is non-uniform and axially unsymmetrical with its form similar to the Gaussian distribution, and most of the plasma is concentrated into an area whose radius is smaller than 5 mm. T eff has a nearly uniform distribution over the expansion cross-section during the discharge. The results of the plasma parameters' non-uniformity encourage the researchers to make some optimization designs to improve the parameter distributions, and then to facilitate ion extraction.

show abstract

Time and space resolved Langmuir probe measurements of a pulsed vacuum arc plasma

Cited by 18 publications

References 17 publications

Time evolution of plasma parameters in the jet of a low-power vacuum arc thruster

Time evolution of plasma parameters in the jet of a low-power vacuum arc thruster

Plasma immersion ion implantation characteristics with q-nonextensive electron velocity distribution

Radial and Angular Resolved Langmuir Probe Diagnosis of a Pulsed Vacuum Arc Plasma

Contact Info

Product

Resources

About