Temperature and Lifetime Measurements in the SSX Wind Tunnel

We describe electron temperature measurements in the SSX MHD wind tunnel using two different methods. First, we estimate Te along a chord by measuring the ratio of the C_III 97.7 nm to CIV 155 nm line intensities using a vacuum ultraviolet monochrometer. Second, we record a biasing scan to a double Langmuir probe to obtain a local measurement of Te. The aim of these studies is to increase the Taylor state lifetime, primarily by increasing the electron temperature. Also, a model is proposed to predict magnetic lifetime of relaxed states and is found of predict the lifetime satisfactorily. Furthermore, we find that proton cooling can be explained by equilibration with the electrons.

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Temperature and Lifetime Measurements in the SSX Wind Tunnel

Plasma ◽

10.3390/plasma1020020 ◽

2018 ◽

Vol 1 (2) ◽

pp. 229-241 ◽

Cited By ~ 4

Author(s):

Manjit Kaur ◽

Kaitlin Gelber ◽

Adam Light ◽

Michael Brown

Keyword(s):

Simple Model ◽

Wind Tunnel ◽

Electron Temperature ◽

Langmuir Probe ◽

Vacuum Ultraviolet ◽

Lifetime Measurements ◽

Line Intensities ◽

Thermal Equilibration ◽

Local Measurements ◽

Doppler Spectroscopy

We describe ion and electron temperature measurements in the Swarthmore Spheromak Experiment (SSX) MHD wind tunnel with the goal of understanding limitations on the lifetime of our Taylor-state plasma. A simple model based on the equilibrium eigenvalue and Spitzer resistivity predicted the lifetime satisfactorily during the first phase of the plasma evolution. We measured an average T e along a chord by taking the ratio of the C I I I 97.7 nm to C I V 155 nm line intensities using a vacuum ultraviolet (VUV) monochromator. We also recorded local measurements of T e and n e using a double Langmuir probe in order to inform our interpretation of the VUV data. Our results indicated that the plasma decayed inductively during a large part of the evolution. Ion Doppler spectroscopy measurements suggested that ions cooled more slowly than would be expected from thermal equilibration with the electrons, which maintained a constant temperature throughout the lifetime of the plasma.

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NONEQUILIBRIUM ELECTRON TEMPERATURE MEASUREMENTS IN A SUPERSONIC ARC JET USING A COOLED LANGMUIR PROBE.

10.2172/4475615 ◽

1966 ◽

Author(s):

D H Johnson

Keyword(s):

Electron Temperature ◽

Langmuir Probe ◽

Temperature Measurements ◽

Nonequilibrium Electron

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A Critical Study on the Reliability of Electron Temperature Measurements with a Langmuir Probe

Journal of geomagnetism and geoelectricity ◽

10.5636/jgg.24.415 ◽

1972 ◽

Vol 24 (4) ◽

pp. 415-427 ◽

Cited By ~ 21

Author(s):

K. HIRAO ◽

K. OYAMA

Keyword(s):

Electron Temperature ◽

Langmuir Probe ◽

Temperature Measurements ◽

Critical Study

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Probe investigating of laser plasma when intensity of radiation on the target near 109 W/cm2

ADVANCES IN APPLIED PHYSICS ◽

10.51368/2307-4469-2021-9-3-187-201 ◽

2021 ◽

Vol 9 (3) ◽

pp. 187-201

Author(s):

Sergei Davydov ◽

Alexander Dolgov ◽

Alekcey Katorov ◽

Vladislav Revazov ◽

Rustam Yakubov

Keyword(s):

Laser Radiation ◽

Electron Temperature ◽

Laser Plasma ◽

Langmuir Probe ◽

Charged Particles ◽

Temperature Measurements ◽

Metal Target ◽

Model Calculations

The appearance of third charged particles groups has been fixed when the laser radiation interacted with metal target in rarefied environ gas. The intensity of opti-cal range laser radiation was ~109 W/cm2. The opportunity of using Langmuir probe for diagnosing plasma processes with nanosecond resolution has been demonstrated. The results of electron temperature measurements have agreed with results of estimate model calculations for the two fasted groups of particles in the absorbtion area (for experimental conditionals).

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