Optical Methods for Plasma Edge Diagnostics in Magnetic Confinement Experiments

1988 ◽  
Vol 117 ◽  
Author(s):  
E. Hintz ◽  
P. Bogen
Keyword(s):  
Atomic Hydrogen ◽  
Emission Spectroscopy ◽  
Magnetic Confinement ◽  
Laser Induced Fluorescence ◽  
Optical Methods ◽  
Plasma Edge ◽  
Plasma Parameters ◽  
Neutral Particles ◽  
Physical Quantities ◽  
Spectroscopy Laser

AbstractThe radial extension of the plasma edge being determined by the ionisation length of the atomic hydrogen, the rtanges of the main plasma parameters to be covered are: 1010 cm-3 < ne <. 1013cm-3 5 eV < Te- < 100 eV, density of neutral particles below 1010 cm-3. Physical quantities to be measured are the electron density ne and temperature Te, the density and temperature (velocity distribution) of hydrogen and of the main impurities (oxygen, carbon, metals). Relying mainly on emission spectroscopy, laser induced fluorescence and atomic beam methods, most of these quantities can be determined with the desired space and time resolution. Experimental arrangements will be described and typical results will be presented.

scholarly journals Machine Learning Prediction of Electron Density and Temperature from Optical Emission Spectroscopy in Nitrogen Plasma

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1221
Author(s):  
Jun-Hyoung Park ◽  
Ji-Ho Cho ◽  
Jung-Sik Yoon ◽  
Jung-Ho Song
Keyword(s):  
Machine Learning ◽  
Electron Temperature ◽  
Real Time ◽  
Electron Density ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
Plasma Parameters ◽  
Plasma Nitridation

We present a non-invasive approach for monitoring plasma parameters such as the electron temperature and density inside a radio-frequency (RF) plasma nitridation device using optical emission spectroscopy (OES) in conjunction with multivariate data analysis. Instead of relying on a theoretical model of the plasma emission to extract plasma parameters from the OES, an empirical correlation was established on the basis of simultaneous OES and other diagnostics. Additionally, we developed a machine learning (ML)-based virtual metrology model for real-time Te and ne monitoring in plasma nitridation processes using an in situ OES sensor. The results showed that the prediction accuracy of electron density was 97% and that of electron temperature was 90%. This method is especially useful in plasma processing because it provides in-situ and real-time analysis without disturbing the plasma or interfering with the process.

scholarly journals Optical Diagnostics for a High.Power, RF-Inductively Coupled Plasma

1988 ◽  
Vol 117 ◽  
Author(s):  
N. S. Nogar ◽  
G. L. Keaton ◽  
J. E. Anderson ◽  
M. Trkula
Keyword(s):  
Flow Rate ◽  
Inductively Coupled Plasma ◽  
Emission Spectroscopy ◽  
Local Thermodynamic Equilibrium ◽  
Laser Induced Fluorescence ◽  
Rf Power ◽  
Inductively Coupled ◽  
Spatially Resolved ◽  
Hull Design ◽  
Ar Gas

AbstractEmission spectroscopy and laser-induced fluorescence have been used to monitor the field and tail-flame regions of a Hull-design 1 inductively coupled plasma. This plasma is used for a variety of syntheses 2,3 including SiC, TiC, BN, AlN and diamond. Temporallyand spatially-resolved spectra of both pure Ar and Ar/gas mixtures have been studied as a function of RF power, pressure and flow rate. Preliminary data suggest that the system is far from local thermodynamic equilibrium.

Time-Resolved Light-Emission Spectroscopy and Ion Current Measurements from Pulsed-Laser-Evaporated Cadmium Plumes

1992 ◽  
Vol 285 ◽  
Author(s):  
Y. Rajakarunanayake ◽  
Y. Luo ◽  
A. Compaan ◽  
M.A. Tamor
Keyword(s):  
Emission Spectroscopy ◽  
Light Emission ◽  
Pulsed Laser ◽  
Laser Evaporation ◽  
Energy Distributions ◽  
Subsequent Evolution ◽  
Time Resolved ◽  
Neutral Particles ◽  
Fundamental Information ◽  
Electrical Bias

ABSTRACTWe have investigated the pulsed laser evaporation of elemental Cd targets, with the aim of understanding the velocity distributions in the plumes and the changes which occur under moderate electrical bias. We report detailed kinetic energy distributions of the species in the laser evaporated plumes. In these experiments, frequency doubled, Q-switched pulses of a Nd:YAG laser were used at a 10 Hz repetition rate to generate the plumes. The velocity distributions of individual atomic species were determined by time-of-flight (TOF) light emission spectroscopy, while the time resolved ion/atom currents were measured with a collector above the target. We have simultaneously measured the dependence of the time resolved optical and electrical signals on the electrical bias applied between target and collector. We find that the typical kinetic energies in the plume are on the order of 10-200 eV, while the ionized species travel two to three times faster than the neutral particles. These results provide fundamental information about the physics of the pulsed laser evaporation process, and subsequent evolution of the plume.

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