https://theses.gla.ac.uk/ Theses Digitisation: https://www.gla.ac.uk/myglasgow/research/enlighten/theses/digitisation/ This is a digitised version of the original print thesis. Copyright and moral rights for this work are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge This work cannot be reproduced or quoted extensively from without first obtaining permission in writing from the author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Enlighten: Theses https://theses.gla.ac.uk/ [email protected] LASER lOIÎISATIOH STUDIES APPLICATIONS HI NUCLEAR WASTE MONITORING Ciiristine Margaxet Houston 3.Sc. Department of Chemistiy Department of Physics and Astronomy University of Glasgow Presented as a thesis for the degree of Doctor of Philosophy in the University of Glasgow. December 1986 Christine Margaret Houston, I986 ProQuest Number: 10991901 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10991901 Published by ProQuest LLO (2018). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLO. ProQuest LLO. 789 East Eisenhower Parkway P.Q. Box 1346 Ann Arbor, Ml 48106- 1346 ACKNOV/LSDGH^niJNTS I would like to thank the following people who have provided valuable assistance in the course of this work: my supervisors; Dr. Kenneth V7, D, Ledingham for constant help and advice over the past three years, and Prof. Murdoch S. Baxter whose research interests provided the initial impetus for the study my fellow research students; Mr. Michael Tov/rie and Mr. Michael II. G. Smyth in whose (amiable) company much of the experir- mental work was carried out Dr. D. T. Stewart, Dr. K. M. Smith and Mr. J. Cahill for helpful discussions and suggestions and, in particular. Dr. C. Haine for help with computing Mr. T. McCanny and Mr. D. A. Seath for technical support and advice Mr. G. Saunders for typing of the manuscript, and Mrs. M. V/aterson for annotating some of the illustrations. Finally, I would lilie to acknowledge both the financial support of the 3.E.R.C., and the forebearance of my mother, Mrs. Margaret Houston, during the period of this research. PUBLICATIONS Laser induced ionisation in proportional counters sealed with low ionisation potential vapours. Nuclear Instruments and ïîethods 225, 319 (l984) K. W, D. Ledingham, C. Haine, K. M, Smith, A. M. Cançbell, M. Towrie, C. Trager and C, H. Houston. Wavelength dependence of laser induced ionisation in proportional counters. Nuclear Instruments and I’lethods A 241, 441 (l985) K. W. D. Ledingham, C. Haine, K. M. Smith, M. H. C. Smyth, 3. T. Stevrart, ii. Towrie and C. M. Houston. Detection of phenol in proportional counter gas by ttjo-photon ionisation spectroscopy. CEHl'I - EP/85-198 (Dec. 1985) J. W. CaJhill, C. H. Houston, K, W. D. Ledin^am, C. Haine, K. M. Smith, H, H. C. Smyth, D. T. Stewart and M. Toifrie. Detection of phenol in proportional counter gas by two-photon ionisation spectroscopy. Journal of Physics 3: Atomic and Molecular Physics 19, 1989 (l986) M. Tovn?ie, J. W. Cahill, K. W. D. Ledingham, C, Haine, K. M, Smith, M. H. C. Smyth, D. T. Stewart and C. H. Houston. The detection of Cs atoms by two-photon Resonance Ionisation Spectroscopy. Proc. SPIE - Int. Soc. Opt. Eng. ("Laser Applications in Chemistry and Biophysics") 620 (1986 ) K. \I, D. Ledingham, C. Raine, K. N, Smith, M. H. C. Smyth, D. T. Stewart, M. Towrie and C. Ii. Houston. Detection of toluene in proportional counter gas by resonant two-photon ionisation spectroscopy. CEEN - EP/86-28 (Feb. 1986) S. L. T. Drysdale, C. Ii. Houston, K, W. D. Ledin^iam, C. Raine, K. II. Smith, Ii. H. C. Smyth, D. T. Stewart and Ii. Towrie. Detection of toluene in proportional counter gas by resonant tvjo-photon ionisation spectroscopy. Nuclear Instruments and Methods (to be published) S. L. T. Drysdale, K, W. D. Ledin^am, C. Raine, K. Ii. Smith, M. H. C, Smyth, D. T. Stewart, M. Towrie and C. Ii. Houston. Investigation of the effect of gas purification on the background laser ionisation in proportional chambers. ALEPH 86-30 (distr. TPCC-AL) (1986 ) S. L. T. Drysdale, A. P. Land, E. W. D. Ledin^am, C. Raine, K. Ii. Smith, M. H. C. Smyth, D. T. Ste^^art, Ii. Towrie and C. Ii. Houston. Applications of resonant ionisation spectroscopy to accelerator based H i ^ Energy Phi^’sics. "R.I.S. - 86", Swansea (198Ô) (to be published) K, W. D. Ledingham, J. V/, Cahill, S. L. T, Drysdale, C. Raine, K, H, Smith, II, K, G. Smyth, D. T. Stewart, Ii. Tov/rie and C. Ii, Houston, Multiphoton tranistions in caesium vapour. "R.I.S. - 86", Swansea (19S6) (to be published) C. H. Houston, 3, L. T. Drysdale, K. W. D. Ledingham, C. Raine, K. Ii. Smith, Ii. H. C. Smyth, D, T, Stewart and Ii. Tovo?ie. The potential of resonant ionisation mass spectroscopy for detecting environmentally important radioactive nuclides. "R.I.S. - 86", Swansea (19S6 ) (to be published) Ii. S. C. Smyth, S. L. T. Drysdale, R. Jennings, K. W. D. Ledingham, D. T. Stewart, ii. Tovnrie, C. Ii. Houston, Ii. S. Baicber and R. D. Scott. CONTENTS CHAPTER 1 RESONANCE IONISATION SPECTROSCOPY 1-1 Introduction 1 1-2 A Short History of RIS I Early experiments 2 II Single atom detection 3 IIII Single molecule detection 3 IV Diffusion studies 4 V Decay-daughter coincidence detection 5 VI Resonance ionisation spectroscopy with amplification 5 VII Elemental and molecular detection using RIS 6 VIII Resonance ionisation mass spectrometry (RH'IS) 9 IX Analysis of refractory solids by RIS 13 X Summary 16 1-3 Theory I Multiphoton ionisation 22 II Saturation conditions 23 III Resonance ionisation spectroscopy of the elements 31 IV Non-laser ionisation-step schemes 33 CHAPTER 2 AN APPLICATION OF RESONANCE IONISATION SPECTROSCOPY IN mCLEAR GEOCHE'ilSTRY 2-1 Introduction 35 2-2 Nuclear Reactor Technology 35 2-3/ 2-3 Nuclear Waste and Waste Management 39 2-4 The Application of RIS to Waste Management 47 2-5 Literature-Based Nuclide Assessment I Fission products 53 II Neutron activation products 53 CHAPTER 3 mSTRUI'ÎELÏTATION 3-1 Introduction 60 3-2 The Excimer Laser 6l 3-3 The Excimer-Punped Dye Laser 63 3-4 The Harmonic Generator 69 3-5 Experimental Chambers I Hark 1 : copper plate design 73 II I'lark 2: glass design 75 III i'lark 3% stainless steel design 'J6 3-6 The Vacuum System 80 3-7 Electronics and Data Acquisition System 82 CHAPTER 4 BAOKGRODND LASER INDUCED lOiUESATION IN PROPORTIONAL COUl'ITERS 4-1 Introduction 85 4-2 Wavelength Dependence of Laser Induced Ionisation in proportional counters 86 4-3 The Identification of Phenol as an Impurity 94 4-4 The Identification of Toluene as an Impurity 99 4-5 The Effect of Gas Purification 102 CHAPTER 5 / CHAPTER 5 I-IÜLTIPHDTON TRAI^SITIONS HI CAESIUM 5-1 Introduction 106 5-2 Glass Chamber Results 107 5-3 Stainless Steel Chamber Results I Baclcground 110 II ^^?e resolution 110 III Cs source geometry 111 IV 6s - 7p Transitions 112 V 6s - 3p Transitions 1l6 VI 6s - 9p Transitions 118 vll os - R^’-dberg State Transitions 124 VIII 6s - Higher s and 6s - d Transitions 131 CHAPTER 6 F u t u r e PROGRAIIE a n d COilCLUBIOilS 6-1 Future Programme I Introduction 135 II Resonance ionisation mass spectrometers I36 III Prospected Sensitivity 138 6-2 Conclusions I46 A P P E O H i AN APPLIGATIOIT OF RIS TO HIGH EIHRGY PHYSICS Ar-1 introduction 152 A-2 Seeding Agents 154 I THA 158 II DEA 159 III DI'IA 161 IV/ 17 HIAE 164 7 ®iA 165 71 Synopsis 1^^ 711 Phenol and Toluene 1^8 LIST OF FIGURES Figure Title to follow Page 1.11 Two photon resonance ionisation 1 1.21 Photo ionisation cycles for EISA 6 1.31 Tirfo photon resonance ionisation 22 1.32 RIS schemes 31 1.35 RIS schemes for the elements 32 1.34 Ionisation of Rydberg states by processes that do not involve photons 33 2.21 Schematic diagram of a thermal nuclear reactor 36 2.22 Detail of a thermal reactor core 36 2.23 Distribution of Nuclear Power Stations in Britain 37 2.24 ilagnox and AGR Thermal Reactors 37 2.31 Fission product yield for the thermal fission of 39 2.32 Neutron utilisation in a Thermal Reactor 40 2.33 Fuel cycle for a thermal reactor 40 2.41 Ways in which RIS can be used to count radioactive atoms 48 3.11 Instrumentation for caesium detection 60 3.21 Schematic energy level diagram for an excimer laser 62 3.31 Schematic energy level diagram for a dye molecule 64 3.32 Chemical structures of laser dyes 67 3.35 / Figure Title to follow Page 3.33 Optical schematic of the Lumonics EPD-330 dye laser 67 3.41 Second harmonic generation 71 3.51 Caesium detection chamber I'lark 1 73 3.52 Caesium chamber HafE 2 - glass design 75 3.53 Caesium chamber Mark 3 - stainless steel design 'J6 3.54 Caesium chamber Mark 3 - detail 78 3.61 Vacuum system 81 3.71 The data acquisition system 82 3.72 Signal timing 83 4.21 Proportional counter type 1 86 4.22 Proportional counter type 2 89 4.23 Background ionisation in a type 2 counter 90 4.24 Background ionisation in a clean type 2 counter 9I 4.25