Air Force Institute of Technology AFIT Scholar Theses and Dissertations Student Graduate Works 6-18-2015 Coupling Nuclear Induced Phonon Propagation with Conversion Electron Mössbauer Spectroscopy Michael J. Parker Follow this and additional works at: https://scholar.afit.edu/etd Part of the Atomic, Molecular and Optical Physics Commons Recommended Citation Parker, Michael J., "Coupling Nuclear Induced Phonon Propagation with Conversion Electron Mössbauer Spectroscopy" (2015). Theses and Dissertations. 194. https://scholar.afit.edu/etd/194 This Thesis is brought to you for free and open access by the Student Graduate Works at AFIT Scholar. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of AFIT Scholar. For more information, please contact [email protected]. COUPLING NUCLEAR INDUCED PHONON PROPAGATION WITH CONVERSION ELECTRON MÖSSBAUER SPECTROSCOPY THESIS Michael J. Parker, Capt, USAF AFIT-ENP-MS-15-J-054 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio DISTRIBUTION STATEMENT A. APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. The views expressed in this thesis are those of the author and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the United States Government. This material is declared a work of the United States Government and is not subject to copyright protection in the United States. AFIT-ENP-MS-15-J-054 COUPLING NUCLEAR INDUCED PHONON PROPAGATION WITH CONVERSION ELECTRON MÖSSBAUER SPECTROSCOPY THESIS Presented to the Faculty Department of Engineering Physics Graduate School of Engineering and Management Air Force Institute of Technology Air University Air Education and Training Command In Partial Fulfillment of the Requirements for the Degree of Master of Science in Nuclear Engineering Michael J. Parker, BS Capt, USAF April 2015 DISTRIBUTION STATEMENT A APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED AFIT-ENP-MS-15-J-054 COUPLING NUCLEAR INDUCED PHONON PROPAGATION WITH CONVERSION ELECTRON MÖSSBAUER SPECTROSCOPY Michael J. Parker, BS Captain, USAF Committee Membership: Dr, Larry W. Burggraf Chair Maj Benjamin R. Kowash Member Dr. William Bailey Member AFIT-ENP-MS-15-J-054 Abstract Mössbauer spectroscopy is a very sensitive measurement technique (~10-8 eV) which prompted motivation for the experiment described in this thesis. Namely, can a sensitive detection system be developed to detect nuclear recoils on the order of 10 to 100 of eVs? The hypothesis that this thesis tests is: Nuclear induced phonon bursts caused by Rutherford scattered alphas, decayed from 241Am, in a type-310 stainless steel material can couple with 7.3keV conversion electron Mössbauer events at the other end of the material which will have a statistically significant effect on a Mössbauer spectrum. The phonon bursts produced by the alpha collisions are expected to be very low energy at the other end of length of material. Since Mössbauer spectroscopy is sensitive and can detect the very low energy phonons, the spectrum is expected to change in at least one of the five areas after coupling occurs: broadening in the spectrum peaks, increased/decreased background counting rate, Mössbauer peak asymmetry, increased/decreased counting rate under the peak, and/or a peak centroid shift. This research aims to determine the significance of changes between spectra with phonon bursts and with no phonon bursts through hypothesis testing, where the null hypothesis is where phonons do not affect Mössbauer spectra in one of the five areas mentioned previously. After the spectra and results were analyze using an f-test and t-test comparisons, this experiment failed to reject the null result. Leading to the conclusion that additional research must be conducted. iv Acknowledgments First and foremost, I’d like to thank Dr. George John, a very intelligent and good natured man. I’d also like to thank my family, Major Kowash, and Dr. Burggraf for not giving up on me in my time of need and their support through this long, long process. Michael J. Parker v Table of Contents Page Abstract .............................................................................................................................. iv Acknowledgments................................................................................................................v Table of Contents ............................................................................................................... vi List of Figures .................................................................................................................. viii List of Tables ..................................................................................................................... xi I. Introduction .....................................................................................................................1 1.1 Motivation ................................................................................................................1 1.2 Background ..............................................................................................................2 1.3 Problem Statement ...................................................................................................3 1.4 Objectives and Approach .........................................................................................4 II. Theory ............................................................................................................................5 2.1 Mössbauer Spectroscopy ..........................................................................................5 2.1.1 Overview .......................................................................................................... 5 2.1.2 Nuclear Resonance Fluorescence ................................................................... 9 2.1.3 Natural Line Width ........................................................................................ 11 2.1.4 Recoil Energy Loss ........................................................................................ 11 2.1.5 Doppler Broadening ...................................................................................... 12 2.1.6 The Mössbauer Effect .................................................................................... 14 2.1.7 Recoil-Free Emission of Gamma Rays .......................................................... 18 2.2 Phonon Sources ......................................................................................................19 2.3 Phonon Propagation ...............................................................................................21 2.3.1 Phonons and Interactions .............................................................................. 21 2.3.2 Material Properties ....................................................................................... 22 2.4 Coupling – Mössbauer Events and Phonons - Expectations ..................................23 III. Methodology and Experimental Setup ........................................................................26 3.1 Detector Design ......................................................................................................26 3.1.1 Mössbauer Technique ................................................................................... 26 3.1.2 Mössbauer Emitter ........................................................................................ 27 3.1.3 Conversion Electron Detector ....................................................................... 29 3.1.4 Mössbauer Spectrometer ............................................................................... 34 3.1.5 Material/Absorber ......................................................................................... 38 3.1.6 Phonon Source ............................................................................................... 44 vi 3.2 Experimental Runs and Descriptions ......................................................................45 3.3 Statistical Tests ......................................................................................................53 3.3.1 Curve Fitting ................................................................................................. 53 3.3.2 Statistical Hypothesis Tests ........................................................................... 54 IV. Analysis and Results ...................................................................................................57 4.1 Data Fitting ............................................................................................................57 4.2 Statistical Analysis .................................................................................................64 4.2.1 Experimental Run Analysis ............................................................................ 65 4.2.2 In-experiment Development and Variances .................................................. 74 4.2.3 Peak Asymmetry Analysis ............................................................................... 76 4.2.4 Heat Tape ...................................................................................................... 80 V. Conclusions and Recommendations ............................................................................82 5.1 Summary ................................................................................................................82 5.2