I= INVESTIGATION OF RADIATIVE COOLING BY HEAVY GASES IN HIGH DENSITY HYDROGEN PLASMA
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Title of Thesis
INVESTIGATION OF RADIATIVE COOLING BY HEAVY GASES IN HIGH DENSITY HYDROGEN PLASMA

Author(s)
Tariq Javaid Baig
Institute/University/Department Details
Department of Physics/ Quaid-i-Azam University, Islamabad
Session
1993
Subject
Physics
Number of Pages
134
Keywords (Extracted from title, table of contents and abstract of thesis)
radiative cooling, heavy gases, high density hydrogen plasma, neon, argon, xenon, thomson scattering, ruby laser, scattering spectra

Abstract
Measurement of the scattered light spectrum from hydrogen plasmas containing small amounts of heavy impurity ions confirms the predictions of theory that the low-frequency ion-acoustic scattered light feature consists of the normal profile due to scattering from a pure hydrogen plasmas, with a narrow peak superimposed that is attributed to the impurity. The intensity of the impurity peak scales as the square of a mean charge Zeff. Measurements are reported for electron densities of 1.0 - 3.0 x 1024 m-3 and electron temperatures ranging from 10 to 80 eV.

Neon, argon, xenon were introduced at small impurity concentrations to high- density hydrogen plasmas produced in a gas liner pinch. Electron density and temperature as well as the impurity densities and temperatures were obtained as function of time by laser scattering. Energy considerations allowed the derivation of radiative energy loss coefficients for the three elements in the range from 5 eV to about 20 eV at electron densities of about 1024 m-3. The influence of the density is clearly seen when comparing different discharges; higher densities result in lower losses. Furthermore, losses are increasing towards low temperature instead of decreasing.

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1434.9 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents 0
159.01 KB
2 1 Introduction 1
285.11 KB
3 2 Theoretical Background of Light Scattering 6
220.59 KB
  2.1 Thomson Scattering 7
  2.2 Scattering Spectrum Profile 20
4 3 Experimental Setup 28
337.86 KB
  3.1 Plasma Source: Gas-Liner Pinch 29
  3.2 Light Scattering Source: Ruby Laser 38
  3.3 Detection Systems 44
5 4 Experimental Verification of Light Scattering Theory 50
248.51 KB
  4.1 Determination of Plasma Parameters from Scattering Spectrum 51
  4.2 Approximation of Evans' Theory for a Single Impurity 58
  4.3 Experimental Scattering Spectra and Spectroscopic Measurements 64
  4.4 Z-Dependence of Impurity Peak 69
6 5 Atomic Processes and Radiative Cooling in Plasma - A Review 72
118.33 KB
  5.1 Atomic Radiations 73
  5.2 Power Loss by Radiation - Radiation Cooling 75
  5.3 Charge State Distribution and Plasma Models 77
7 6 Experimental Power Losses 82
306.54 KB
  6.1 Time Evolution of Plasma Parameters 82
  6.2 Radiative Power Loss Model 92
  6.3 Experimental Power Losses 93
  6.4 Experimental Power Loss Coefficients 94
8 7 Results and Discussion 98
72.36 KB
9 8 Bibliography
55.82 KB