Probe diagnostics of electron distributions in plasma with spatial and angular resolution

Abstract

Articles you may be interested inAssessment of plasma impedance probe for measuring electron density and collision frequency in a plasma with spatial and temporal gradients Phys. Plasmas 21, 053501 (2014); 10.1063/1.4874321Experimental measurements of spatial plasma potentials and electron energy distributions in inductively coupled plasma under weakly collisional and nonlocal electron kinetic regimes This paper discusses the spatial resolution that is required to study inhomogeneous, low-temperature plasmas and is based on a review of low-temperature plasma electron kinetics and methods for probe measurements of electron energy distribution functions (EEDFs). It is stated that EEDFs can be extracted from probe measurements by applying an appropriate probe theory. The Druyvesteyn formula is most commonly used for this extraction and has been used in numerous publications, but more general theory can be used for a wider range of gas pressures. It is demonstrated that the Druyvesteyn formula can be obtained from the general theory as a limiting case. This paper justifies the application of wall probes in plasma studies of an energetic part of EEDFs. This justification is made for an idealized probe. We briefly review the methods for studying anisotropic plasmas and their usefulness in plasma research. It is demonstrated that to determine anisotropic electron energy distribution functions, a planar, one-sided probe is most convenient. V C 2014 AIP Publishing LLC. This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 155.33.16.124 On: Tue, 25 Nov 2014 17:24:38 093506-2 V. I. Demidov and A. A. Kudryavtsev Phys. Plasmas 21, 093506 (2014) This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 155.33.16.124 On: Tue, 25 Nov 2014 17:24:38 093506-4 V. I. Demidov and A. A. Kudryavtsev Phys. Plasmas 21, 093506 (2014) This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 155.33.16.124 On: Tue, 25 Nov 2014 17:24:38 FIG. 7. Fine structure of the electron energy spectra in 200 Torr He, 0.2% Ar, modulating voltage 0.6 V, cathode-anode gap 1.7 mm, and discharge current: (1) 4 mA and (2) 8 mA. 093506-5 V. I. Demidov and A. A. Kudryavtsev Phys. Plasmas 21, 093506 (2014) This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 155.33.16.124 On: Tue, 25 Nov 2014 17:24:38 093506-6 V. I. Demidov and A. A. Kudryavtsev Phys. Plasmas 21, 093506 (2014) This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 155.33.16.124 On: Tue,

Use of plasma electron spectroscopy method to detect hydrocarbons, alcohols, and ammonia in nonlocal plasma of short glow discharge

“…In turn, for the Langmuir probe used here, the EEDF is proportional to the second derivative of the probe current with respect to the probe potential V (see, for example, [24])…”

“…The probe measurement technique is used to measure the spectra of Penning electrons. Much work has been reported over the last three decays and extensive reviews are available [24][25][26][27]. The combination of digital to analog converters and analog converters provides very fast data collection, and several commercial systems are available, including compensated probes for high frequency discharges.…”

Determination of organic impurities by plasma electron spectroscopy in nonlocal plasma at intermediate and high pressures

“…Figure 3 shows the probe characteristics and their derivatives of the measuring electrode in pure helium. The probe CVCs have a classical form with electron and ion saturation currents and a transition region between them [21].…”

“…The probe measurement technique is used to measure the spectra of Penning electrons [21][22][23]. The combination of digital to analog and analog converters provides fast data collection.…”

Measurements of plasma parameters in a hollow electrode AC glow discharge in helium

“…Probe diagnostic methods have made rapid progress in recent decades, and, in addition to single probes, double probes and emissive probes have also been proven to be useful in various situations [2,22,25,[33][34][35][36]. A significant development in probe diagnostics was made by Druyvesteyn, who demonstrated that the second derivative of the single probe current provided the electron energy distribution function (EEDF) of the plasma [36,37].…”