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Analysis of the 0511 Mev Radiation at the Oso-7 Satellite

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Analysis of the 0511 Mev Radiation at the Oso-7 Satellite University of New Hampshire University of New Hampshire Scholars' Repository Doctoral Dissertations Student Scholarship Spring 1974 ANALYSIS OF THE 0511 MEV RADIATION AT THE OSO-7 SATELLITE PHILIP PATRICK DUNPHY Follow this and additional works at: https://scholars.unh.edu/dissertation Recommended Citation DUNPHY, PHILIP PATRICK, "ANALYSIS OF THE 0511 MEV RADIATION AT THE OSO-7 SATELLITE" (1974). Doctoral Dissertations. 1045. https://scholars.unh.edu/dissertation/1045 This Dissertation is brought to you for free and open access by the Student Scholarship at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. INFORMATION TO USERS This material was produced from a microfilm copy of the original document. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the original submitted. The following explanation of techniques is provided to help you understand markings or patterns which may appear on this reproduction. 1.The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting thru an image and duplicating adjacent pages to insure you complete continuity. 2. When an image on the film is obliterated with a large round black mark, it is an indication that the photographer suspected that the copy may have moved during exposure and thus cause a blurred image. You will find a good image of the page in the adjacent frame. 3. 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Xerox University Microfilms 300 North Zeeb Road Ann Arbor, Michigan 48106 74-21,092 DUNPHY, Philip Patrick, 1943- ANALYSIS OF THE 0.511 MeV RADIATION AT THE OSO-7 SATELLITE. University of New Hampshire, Ph.D., 1974 Physics, radiation University Microfilms, A XEROX Company, Ann Arbor, Michigan THIS DISSERTATION HAS BEEN MICROFILMED EXACTLY AS RECEIVED. ANALYSIS OF THE 0.511 MeV RADIATION AT THE OSO-7 SATELLITE by PHILIP P. DUNFHY B. S ., SETON HALL UNIVERSITY, 1965 A THESIS Submitted to the University of New Hampshire In Partial Fulfillment of The Requirements for the Degree of Doctor of Philosophy Graduate School Department of Physics March, 1974 This thesis has been examined and approved. Edward L. Chupp, Thesis^director, Professor of Physics Richard L. Kaufmann, Professor of Physics William R. Webber, Professor of Physics David G. Clark, Associate Professor of Physics ^arw & j J\- & l>epartcL Harvey K.(Shepard, Associate Professor of Physics DEDICATION To my p a re n ts iii ACKNOWLEDGEMENTS The author wishes to thank Professor Edward L. Chupp for initiating the work which led to this thesis as well as for his continuing advice and encouragement. Special thanks are also due to Dr. David J. Forrest for his numerous and enlightening discussions. Helpful comments were also given by Dr. Amar N. Suri, Dr. Claus Reppin and Mr. Chung-jen Tsai. The work of Dr. Paul R. Higbie, Miss Susan J. Croteau and Mr. Stephen Foss in developing and carrying out the computer program­ ming for the UNH-OSO project has been invaluable. The plotting and data handling done by Mrs. Dipika Patel, Mr. Indulis Gleske, and Mr. Ronald Adams was also very helpful. The task of typing initial drafts was graciously done by Mrs. Patricia Ferguson and that of the final manuscript by Mrs. Gail Mumme. The job of producing the drawings and graphs in this work was capably handled by Mr. Daniel Gats and Miss Janet Varney. This research was supported by the National Aeronautics and Space Administration under Grant NAS-5-11054-. iv TABLE OF CONTENTS LIST OF TABLES........................................................... v i i i LIST OF FIGURES......................................................................................................ix ABSTRACT.....................................................................................................................x i I . INTRODUCTION................................................................................................................1 A. Astrophysical Significance of the 0.511 MeV R a d ia tio n . .......................................................................... 1 B. History of Observations of Atmospheric and Cosmic Annihilation Radiation ................................................................................4 1. Balloon Observations ........................................................................... 4 2. Satellite Observations ....................................................................... 6 I I . DESCRIPTION OF DETECTOR....................................................................................... 9 A. Physical Description ..................................................................................... 9 B. D etecto r C h a r a c te r is tic s .......................................................................... 11 1. Energy Range and Resolution ..........................................................11 2. Photopeak Sensitivity .......................................................................12 3. Angular Response.............................................. ................................... 15 4. Time R e so lu tio n ....................................................................................15 5. Housekeeping Data ................................................................................18 C. Calibrations and Gain Stability .........................................................19 D. Description of Satellite Orbit, Aspect, and O n-tim es ............................................................................................................ 21 I I I . METHODS OF DATA ANALYSIS................................................................................... 24 A. Selection of Data Scans ............................................................................ 24 B. Selection of Peak Region ..........................................................................26 C. Fitting the Continuum Background beneath Peak .............................. 28 1. Linear Fit ...............................................................................................28 2. Exponential Fit ......................................... 28 v D. Determination of Rigidity Values ............................................. 3 3 IV. RESULTS OF DATA ANALYSIS.................................................................................. 35 A. Plan of Analysis ........................................................................................... 35 B. Parameters Affecting 0.511 MeV Flux ................................................. 36 1. Vertical Cutoff Rigidity ................................................................ 36 2. Altitude Dependence ........................................................................... 4-6 3. A spect ........................................................................................................ 50 C. Variation of 0.511 MeV flux with Cutoff Rigidity. ...................51 1. Correlation with Continuum Variation .........................51 2. Correlation with Charged-Particle Flux Variation. ..................................................................... 54 3. Rigidity Variation and Components of the FLux ..................... 56 a. Contribution of Atmospheric Flux ...................................... 56 b. Contribution of Local Production ................ 61 c. Contribution of Cosmic Flux ..................................................62 D. Solar 0.511 MeV Flux .................................................................................. 63 1. Limit for the Quiet Sun ..................................................................63 2. The A ctive Sun (August 2 to August 11, 1972) .................... 69 E. Discussion of Results ............................................................................... 85 APPENDIX 1 .................................................................................................................94 Generation of Annihilation Radiation ............................................... 94 A. General Theory ...............................................................................................94 1. Annihilation Mechanisms .................................................................. 94 2. Generation of Positrons ..................................................................97
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