I= TWO-STEP LASER EXCITATION SPECTRA OF NEON, ARGON AND KRYPTON
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Title of Thesis
TWO-STEP LASER EXCITATION SPECTRA OF NEON, ARGON AND KRYPTON

Author(s)
Muhammad Aslam
Institute/University/Department Details
Department of Physics/ Quaid-i-Azam University, Islamabad
Session
2000
Subject
Physics
Number of Pages
115
Keywords (Extracted from title, table of contents and abstract of thesis)
two-step laser excitation spectra, neon, argon, krypton, rydberg atoms, rare gases, optogalvanic spectroscopy

Abstract
In the present work high Rydberg states of neon, argon and krypton have been studied in the discrete and autoionization regions using two step laser excitation and optogalvanic detection technique. Three intermediate states namely mp5(m+l)p[1/2]1, mp5(m+l)p[3/2]1 and mp5(m+l)p[3/2] 2 ( m = 2, 3 and 4 for neon, argon and krypton respectively) were populated in the first step from the thermally populated mp5(m+ I )s[3/2]2 metastable level. In the second step, the high Rydberg states attached to the first ionization threshold and auto ionizing resonances attached to the second ionization threshold have been recorded. In the bound the mp5 (2p3/2) ns [3/2]1,2 and mp5 (2p3/2) nd [l/2]o,1 , [3/2]1,2, [5/2]2,3 [7/2]3 series have been identified. In the autoionization region, the strongly auto ionizing series are mp5 (2P1/2) nd [3/2]2, nd[5/2]2 and nd[5/2]3 from the mp5(m+l)p[l/2]1, mp5(m+l)p[3/2]1 and mp5(m+l)p[3/2]2 intermediate levels. The dominating observed Rydberg series from the intermediate obey the jK coupling scheme The interchannel interactions among the lower members of the series terminating to the second ionization with the series attached to the first ionization threshold have been studied using the two-channel quantum defect theory. The MQDT parameters for the auto ionizing resonances have also been extracted from the line profile analysis that are in good correlation with the parameters determined from the analysis in the discrete region. A unified set of parameters has been reported for the J = 2 and 3 channels in neon, argon and krypton.

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1352.81 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents 0
78.43 KB
2 1 Introduction 1
242.36 KB
  1.1 Rydberg Atoms 1
  1.2 Properties of Rydberg Atoms 1
  1.3 Excitation to the Rydberg States 3
  1.4 Detection of Rydberg Atoms 3
  1.5 Spectra of Rare Gases 5
  1.6 Multiphoton Excitation 8
  1.7 Gas Discharge 11
  1.8 Optogalvanic Spectroscopy 15
  1.9 Multichannel Quantum Defect Theory 18
3 2 Experimental Set-Up 20
109.28 KB
  2.1 Introduction 25
  2.2 Laser System 25
  2.3 The Discharge Cell 29
  2.4 Data Acquisition System 29
  2.5 Wavelength Calibrations 31
4 3 Laser Optogalvanic Spectra of Neon in the Discrete and Autoionization Regions 33
229.75 KB
  3.1 Introduction 33
  3.2 Excitation Scheme 34
  3.3 Experimental Results 34
5 4 Laser Optogalvanic Spectra of Argon in the Discrete and Autoionization Regions 49
364.15 KB
  4.1 Introduction 49
  4.2 Excitation Scheme 50
  4.3 Experimental Results 50
6 5 Laser Optogalvanic Spectra of Krypton in the Discrete and Autoionization Regions 73
265.4 KB
  5.1 Introduction 73
  5.2 Excitation Scheme 74
  5.3 Experimental Results 75
7 6 Discussion and Conclusions 102
154.12 KB
8 7 References 103
51.68 KB