I= PLASMA DYNAMICS AND CHARACTERISTICS IN GAS-LINER PINCH AND PLASMA FOCUS EXPARIMENTAL STARK WIDTH OF Kr-III LINES
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Title of Thesis
PLASMA DYNAMICS AND CHARACTERISTICS IN GAS-LINER PINCH AND PLASMA FOCUS EXPARIMENTAL STARK WIDTH OF Kr-III LINES

Author(s)
IMTIAZ AHMAD
Institute/University/Department Details
Department of Physics/ Quaid-i-Azam University, Islamabad
Session
1998
Subject
Physics
Number of Pages
Keywords (Extracted from title, table of contents and abstract of thesis)
plasma dynamics, gas-liner pinch, plasma focus, kr-iii lines, thomson scattering, broadening mechanisms, laser system

Abstract
The thesis covers two pieces of work performed on the gas-liner **** low energy Mather-type plasma focus, respectively.

Gas-Liner Punches: Specially resolved Thomson scattering spectra from plasmas produced in the gas-liner pinch are produced and analyzed. The analysis of a single Thomson spectrum yields the radial distribution of electron density, electron / ion temperature, impurity ions distribution and the redial bulk velocity over the diameter of the plasma column. The time resolution of the measurements is about 30 ns and is given by the duration of the laser pulse. The time evolution of the plasmas parameters is obtained from the successive shots.

Stark width measurements of Kr III liners of the (5s5so-5p 5 p) quintet are performed in plasmas produced in the gas liner pinch. The investigation shows that the lines are emitted spatially homogeneous and optically thin, thus, an experimental scaling law of stark width with electron density can be presented. Another plasmas regime with density/ temperature variation along the z-axis produces inhomogeneous spectra and is attributed to the instabilities generated in the compression phase of the plasma.

Plasma Focus: The characteristics of a low energy Mather €“type plasma focus with an insulator slsve contamination are investigated. It is observed that the insulator trodes, and that a slight contamination are due to the contamination improves the system performance, however, the extreme contamination makes the system less reproducible, which finely result in the neutron yield deterioration.

The current sheath during the radial collapse phase is found to interact strongly with the magnetic probe jacket and climbs over it up to several centimeters. X-ray images clearly indicate that the size as well as intensity of the X-ray source is significantly enhanced compared to the case where no probe is present. Generally, the hot spots are formed up to about 30 mm above the anode tip and are rarely observed 75 mm above the anode tip due to the refocusing of the current sheath at that height

Download Full Thesis
2373.62 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
97.63 KB
2 1 Introduction 1
88.9 KB
3 2 Thomson Scattering and Line Broadening Mechanisms 6
392.14 KB
  2.1 Thomson Scattering 6
  2.2 The Scattering Spectrum 12
  2.3 Broadening Mechanisms in Plasmas 25
4 3 Experimental Setup and Diagnostics 33
429.87 KB
  3.1 The Gas-Liner Pinch 33
  3.2 Description of the Laser System 39
  3.3 Employed Equipment 46
  3.4 Time Correction of Diagnostics 49
  3.5 The Plasma Focus 52
5 4 Spatially Resolved Plasma Parameters 57
675.29 KB
  4.1 Calibration of the Scattering System 57
  4.2 Typical Discharge Conditions 61
  4.3 Fitting Procedure 63
  4.4 Spatially Resolved Measurements 64
  4.5 Plasma Parameters 72
  4.6 Large Amount of Test Gas Injection 82
6 5 Stark Width Measurements of Krypton III 85
534.32 KB
  5.1 Calibration of the Spectrograph 87
  5.2 Spectrum Correction 88
  5.3 Experimental Results 90
7 6 Current Sheath Dynamics of the Plasma Focus 110
158.58 KB
  6.1 Effects of the Insulator Sleeve Contamination 110
  6.2 Influence of Magnetic Probe Presence 115
8 7 Summary of Results 126
59.22 KB
9 8 The Device Parameters 130
123.13 KB
  8.1 Spatially Resolved Plasma Parameters 132
  8.2 Stark Widths Data 133
  8.3 Bibliography 135