Measuring Radiation Protection: Partners From Across The Nuclear Enterprise Evaluate The Radiation Protection Of Us Army Vehicles,
2023
Air Force Institute of Technology
Measuring Radiation Protection: Partners From Across The Nuclear Enterprise Evaluate The Radiation Protection Of Us Army Vehicles, Andrew W. Decker, Robert Prins
Faculty Publications
Recent mounting nuclear threats and postures from adversary nation-states, such as Russia, China, North Korea, and Iran, represent a clear danger to the interests and security of the United States of America and its Allies. To meet these threats, the 2022 Nuclear Posture Review requires the Department of Defense (DoD) to design, develop, and manage a combat-credible U.S. military which, among other prioritizations, is survivable. A survivable force can generate combat power despite adversary attacks. As such, the US Army must prepare today to set the conditions for successful conventional warfare on the nuclear battlefields of tomorrow. Our Army cannot …
Oh, My Darling Clementine: A Detailed History And Data Repository Of The Los Alamos Plutonium Fast Reactor,
2023
University of Nevada, Las Vegas
Oh, My Darling Clementine: A Detailed History And Data Repository Of The Los Alamos Plutonium Fast Reactor, Hannah K. Patenaude, Franz J. Freibert
College of Sciences Graduate Student Research
The Los Alamos Plutonium Fast Reactor, Clementine, provided the first fast neutron spectrum using a metallic plutonium fuel system and liquid mercury coolant. Clementine is often mentioned in the history of fast, metal-fueled, or metal-cooled designs, with little public information regarding the specifications or timeline. This paper contains a synopsis of each report regarding the development, operation, experimental results, failures, and subsequent disassembly of Clementine to explore this unique reactor within the context of modern advanced reactor development.
Fast-, Light-Cured Scintillating Plastic For 3d-Printing Applications,
2023
Air Force Institute of Technology
Fast-, Light-Cured Scintillating Plastic For 3d-Printing Applications, Brian G. Frandsen, Michael Febbraro, Thomas Ruland, Theodore W. Stephens, Paul A. Hausladen, Juan J. Manfredi, James E. Bevins
Faculty Publications
Additive manufacturing techniques enable a wide range of possibilities for novel radiation detectors spanning simple to highly complex geometries, multi-material composites, and metamaterials that are either impossible or cost prohibitive to produce using conventional methods. The present work identifies a set of promising formulations of photocurable scintillator resins capable of neutron-gamma pulse shape discrimination (PSD) to support the additive manufacturing of fast neutron detectors. The development of these resins utilizes a step-by-step, trial-and-error approach to identify different monomer and cross-linker combinations that meet the requirements for 3D printing followed by a 2-level factorial parameter study to optimize the radiation detection …
Studies On The Enrichment Feasibility Of Rare Earth-Bearing Minerals In Mine Tailings,
2023
Missouri University of Science and Technology
Studies On The Enrichment Feasibility Of Rare Earth-Bearing Minerals In Mine Tailings, Jose L. Corchado-Albelo, Lana Z. Alagha
Mining Engineering Faculty Research & Creative Works
This Study Aimed to Investigate the Potential of Enrichment of Rare-Earth-Bearing Minerals in Historic Mine Tailing using the Froth Flotation Process. Characterization Studies Indicated that Tailings Contained 11,000 Ppm of Rare Earth Elements (REEs). the Major Mineral in the Tailings Was Apatite at ~84%, Which Was Associated with Iron Oxides (~16%). TESCAN's Integrated Mineral Analysis (TIMA) Showed that Monazite Was the Main REE Mineral, and 69% of Monazite Was Locked in Apatite Grains. Characterization Studies Suggested that the Separation of REEs-Bearing Apatite from Iron Oxides is Possible using Froth Flotation, Wherein Apatite Was Floated and Iron Oxides Were Depressed. Zeta …
Automated Additive Layering Of Vat Polymerized Plastic Organic Scintillators,
2023
Air Force Institute of Technology
Automated Additive Layering Of Vat Polymerized Plastic Organic Scintillators, Chandler J. Moore
Theses and Dissertations
The current technology for fast neutron detection imaging is limited in achieving the required high spatial resolution, strong neutron discrimination, and practical time of manufacturing. Traditional fabrication methods require days of thermal polymerization and hundreds of man-hours to produce average resolution pixelated scintillator arrays. The present work helps to eliminate this limitation by developing an additive manufacturing technique to construct such detectors for use in in dual particle imaging applications. In this work, fast-, light-curing resins are used in a prototype automated assembly machine, capable of layering of individual light-cured resin layers and optical segmentation with a self-bonded specular reflector, …
Angle Resolved Photoelectron Spectroscopy Study Of Germanium Tin: Experimentally Determined Electronic Band Gap And Surface Analysis,
2023
Air Force Institute of Technology
Angle Resolved Photoelectron Spectroscopy Study Of Germanium Tin: Experimentally Determined Electronic Band Gap And Surface Analysis, Jeremy M. Hunter
Theses and Dissertations
The germanium tin band gap is responsive to wavelengths in the mid to near infrared spectrum; this shows promise in meeting the detection demands of the next generation infrared detectors. Recent developments in germanium tin (GeSn) alloy growth techniques have peaked the scientific community’s interest in GeSn based optoelectrical and detection devices. Detection materials made entirely of group IV elements are compatible with complementary metal-oxide semiconductor manufacturing techniques. Understanding the surface chemistry of this alloy is fundamental for solid state device design and must be analyzed to optimize device performance. Studies have shown that with the addition of tin, the …
Fast Engineering Model For Defect Production In Magnesium Oxide,
2023
Air Force Institute of Technology
Fast Engineering Model For Defect Production In Magnesium Oxide, Henry R. Little
Theses and Dissertations
Defect production from irradiation of materials with thicknesses much less than the mean free path for neutron interaction is explored. A model is developed using the Monte Carlo N-Particle transport code from Los Alamos National Laboratory, experimental data from irradiations at the Oak Ridge High Flux Isotope Reactor, defect production theory, and atomistic simulation results to predict the total number of F-centers resulting from neutron irradiation of a MgO rod. This model accurately predicts the concentration of atomic defects under conditions closely matching experiments at long timescales, for large geometries, and requiring only 6.9 minutes on a single CPU. Results …
Fabrication And Testing Of A Novel Layered Metascintillator For Neutron And Gamma Discrimination,
2023
Air Force Institute of Technology
Fabrication And Testing Of A Novel Layered Metascintillator For Neutron And Gamma Discrimination, Evan W. Threlkeld
Theses and Dissertations
By leveraging new developments in fast-curing of plastic scintillators, it is possible to fabricate multi-material plastic scintillators, or metascintillators, which offer improved and/or novel capabilities for radiation detection. This document proposes one geometry of metascintillator that uses layers of green and blue scintillating material to discriminate neutron/gamma radiation, details the devices necessary to fabricate it, and analyzes the metascintillator’s response to radiation. A model of the metascintillator using Geant4 and Python suggested that spectral-based neutron/gamma event discrimination is possible with 63% of gamma events and only 1% of neutron events being multi-color. Fabrication of a 500 µm per layer metascintillator …
Thermal Analysis Of Si-Igbt Based Power Electronic Modules In 50kw Traction Inverter Application,
2023
Missouri University of Science and Technology
Thermal Analysis Of Si-Igbt Based Power Electronic Modules In 50kw Traction Inverter Application, Mohammad Shahjalal, Tamanna Shams, Sadat Bin Hossain, Md Rishad Ahmed, Mominul Ahsan, Julfikar Haider, Rajib Goswami, Syed B. Alam, Atif Iqbal
Nuclear Engineering and Radiation Science Faculty Research & Creative Works
Estimation of Accurate IGBT Junction Temperature is Crucial for Reliability Assessment. the Well-Known RC Lumped Approach Can Help Predict Junction Temperature. However, This Method Suffers from Inaccuracy While Characterizing the Thermal Behavior of Several IGBT Modules Mounted to the Liquid-Cooled Heatsink. Specifically, the Thermal Challenge Originates from the Thermal Cross-Coupling and Module-To-Module Heat Spreading and the Converter Cooling Condition. This Article Demonstrates a Methodology to Study the Impact of Heat Spreading, Thermal Interface Material, and Massive Size Liquid Cold-Plate on the overall Thermal Behavior. a Case Study of 50 KW Traction Inverter is Chosen to Demonstrate the Benefit of Early …
Exploring Variations In Fast Curing Plastic Scintillator Formulations: Optimizing Tpo And Evaluating The Effects Of High-Z Loading And Novel Waveshifters,
2023
Air Force Institute of Technology
Exploring Variations In Fast Curing Plastic Scintillator Formulations: Optimizing Tpo And Evaluating The Effects Of High-Z Loading And Novel Waveshifters, Andrew K. Nesbitt
Theses and Dissertations
Organic plastic scintillators are widely used due to their relative low cost, physical robustness, and fast timing properties, but typically provide lower light yields and photon sensitivity compared to other alternatives. Photocuring novel plastics offers a viable method for producing fast curing plastic scintillators. The current formulations include an acrylic polymer base and utilize diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as the photo-initiator for polymerization; however at higher concentrations of TPO may adversely affect scintillator light output. The present research refined the optimal TPO concentrations that fully cure these acrylic-base scintillators and maximize light production to 0.4-0.5% by weight. Additionally, this …
Simulation Of Neutron Generation From Laser-Driven Fusion In A Liquid D2o Sheet Using Novel Warpx Module,
2023
Air Force Institute of Technology
Simulation Of Neutron Generation From Laser-Driven Fusion In A Liquid D2o Sheet Using Novel Warpx Module, Colton R. Stoner
Theses and Dissertations
Using WarpX’s new nuclear fusion module, this work attempts to model an experimental system at the ELL at the AFIT with WarpX and draw conclusions about fusion products from resulting simulations. Recently, a table-top, high repetition rate, mixed radiation source was demonstrated at the ELL employing a HIL to fuse the deuterium nuclei present in a unique liquid target of heavy water. Analysis of the simulations predicted an isotropic output of neutrons from deuterium-deuterium fusion. These simulated neutrons were created in tens of femtoseconds from dense bodies of deuterons that were perturbed by the laser. However, it was found that …
Pulsed Power Neutron Production With Deuterated Polymer Accelerator Targets,
2023
Air Force Institute of Technology
Pulsed Power Neutron Production With Deuterated Polymer Accelerator Targets, Anthony O. Hagey
Theses and Dissertations
This document presents an investigation of the effect of deuterated polyethylene accelerator targets on the neutron fluence from a local mass injection dense plasma focus driven by the United States Naval Research Laboratory’s Hawk pulsed-power generator. After successful production of thin targets, the acquisition of thicker targets, and testing inside Hawk, it was found that the presence of a deuterated polyethylene target increased the neutron fluence. Results suggested that fluence can significantly increase with the presence of a deuterated target vs a nondeuterated target. Additive manufacturing printing was used as a production method in order to determine if deuterated accelerator …
Assessment Of Emergency Cooling Requirement For Nuclear Reactor Loss-Of-Coolant Accidents,
2023
Air Force Institute of Technology
Assessment Of Emergency Cooling Requirement For Nuclear Reactor Loss-Of-Coolant Accidents, Michael T. Lindsay
Theses and Dissertations
The 2022 Russia-Ukraine War marks the first time in modern history of conventional military forces targeting and seizing control of an operational nuclear power plant. Power supply and operational cooling systems are critical to avert reactor loss-of-coolant accidents (LOCA) in the event of emergency shutdown, or SCRAM. A wartime non-design based reactor accident causing loss of reactor power and coolant supply would require an emergency heat exchange via coolant to mitigate reactor core heat. At present, the military does not have a well-defined model which characterizes this requirement for operational planning should such an event occur. SCALE 6.2.4 is used …
Data Augmentation For Neutron Spectrum Unfolding With Neural Networks,
2023
Air Force Institute of Technology
Data Augmentation For Neutron Spectrum Unfolding With Neural Networks, James Mcgreivy, Juan J. Manfredi, Daniel Siefman
Faculty Publications
Neural networks require a large quantity of training spectra and detector responses in order to learn to solve the inverse problem of neutron spectrum unfolding. In addition, due to the under-determined nature of unfolding, non-physical spectra which would not be encountered in usage should not be included in the training set. While physically realistic training spectra are commonly determined experimentally or generated through Monte Carlo simulation, this can become prohibitively expensive when considering the quantity of spectra needed to effectively train an unfolding network. In this paper, we present three algorithms for the generation of large quantities of realistic and …
Incorporation Of Poly(Tfema) In Perovskite Thin Films Using A Supercritical Fluid,
2023
Virginia Commonwealth University
Incorporation Of Poly(Tfema) In Perovskite Thin Films Using A Supercritical Fluid, Kasey Handy, Gary C. Tepper
Mechanical and Nuclear Engineering Publications
A new process is reported for the incorporation of a fluoropolymer into a solid perovskite film. Poly(trifluoroethyl methacrylate) [CH2C(CH3)(CO2CH2CF3)]n was delivered to methylammonium lead iodide (CH3NH3PbI3) perovskite films by crystallizing the film in supercritical carbon dioxide/ethanol containing the dissolved fluoropolymer. The surface was characterized before and after fluoropolymer exposure using scanning electron microscopy, Raman spectroscopy, and contact angle measurements. The results indicate that the fluoropolymer was incorporated into the perovskite film during the supercritical fluid crystallization process. The incorporation of a hydrophobic fluoropolymer …
Radiation Shielding Effectiveness Of Hafnium Diboride (Hfb2) Reinforced Epoxy Composites For Enhanced Radiation Protection And Safety,
2023
Virginia Commonwealth University
Radiation Shielding Effectiveness Of Hafnium Diboride (Hfb2) Reinforced Epoxy Composites For Enhanced Radiation Protection And Safety, Furkan Erdogan
Theses and Dissertations
This thesis investigates the radiation shielding effectiveness of hafnium diboride (HfB2) reinforced epoxy composites, with the aim of enhancing radiation protection and safety in various applications. The study focuses on the development and characterization of HfB2-epoxy composites with varying weight percentages of HfB2 nanoparticles, as well as on the evaluation of their shielding effectiveness against gamma rays and thermal neutrons. The radiation shielding performance of the composites is assessed using gamma-ray spectroscopy and neutron counting, and the neutron attenuation efficacy is compared with that of 5% borated high-dense polyethylene. The results indicate that the HfB2-epoxy composites exhibit promising radiation shielding …
A Study On The Effects Of Historical Meteorological Data Set On Simulated Radioactive Dispersion From A Nuclear Power Plant Accident By Nacac Code,
2023
Faculty of Engineering
A Study On The Effects Of Historical Meteorological Data Set On Simulated Radioactive Dispersion From A Nuclear Power Plant Accident By Nacac Code, Narakhan Khunsrimek
Chulalongkorn University Theses and Dissertations (Chula ETD)
Quantifying the variability in the prediction of atmospheric dispersion code from the Influences of variations in meteorological data is investigated in this study. Historical meteorological data from 2016 to 2020 by the National Centers for Environmental Prediction (NCEP) and the overlap hypothetical accident Loss Of Offsite Power (LOOP) and Large-Break Loss Of Coolant Accident (LBLOCA) are used as initial and boundary conditions. The Fangchenggang nuclear power plant in China, close to Thailand, is considered a study location. The Nuclear Accident Consequence Assessment Code (NACAC) is used as a simulation tool for the investigation process. The NACAC prediction performance is verified …
การตรวจสอบความหนาของท่อไอน้ำด้วยวิธีถ่ายภาพด้วยรังสีเอกซ์โดยใช้แผ่นรับภาพดิจิทัล,
2023
คณะวิศวกรรมศาสตร์
การตรวจสอบความหนาของท่อไอน้ำด้วยวิธีถ่ายภาพด้วยรังสีเอกซ์โดยใช้แผ่นรับภาพดิจิทัล, ณัฐธิดา สุขใส
Chulalongkorn University Theses and Dissertations (Chula ETD)
งานวิจัยนี้มีวัตถุประสงค์เพื่อพัฒนาเทคนิคการตรวจสอบความหนาของท่อไอน้ำที่อยู่ภายใต้ฉนวนด้วยเครื่องกำเนิดรังสีเอกซ์แบบเคลื่อนที่และแผ่นรับภาพดิจิทัล เนื่องจากโดยทั่วไปแล้วท่อไอน้ำของโรงไฟฟ้าถ่านหินจะมีลักษณะเป็นท่อเรียงติดกันเหมือนกำแพงสูง การกำหนดให้แหล่งกำเนิดรังสีอยู่กึ่งกลางของแผ่นรับภาพได้พอดีนั้นทำได้ยาก งานวิจัยชิ้นนี้จึงใช้เทคนิคการส่งผ่านของรังสีแกมมา คือ Cs-137 ความแรง 200 µCi ร่วมกับอุปกรณ์นับวัดแบบช่องเดี่ยว (Single Channel Analyzers;SCA) สแกนหาตำแหน่งที่มีค่านับวัดรังสีสูงสุด จากนั้นถ่ายภาพท่อไอน้ำด้วยเครื่องกำเนิดรังสีเอกซ์แบบเครื่อนที่รุ่น XRS3 ความต่างศักย์ 270 kV ร่วมกับแผ่นรับภาพดิจิทัลรุ่น VXTD-3643FCWV ถ่ายภาพท่อไอน้ำที่ทราบความหนาเทียบกับท่อไอน้ำที่ต้องการตรวจสอบ โดยการนำภาพถ่ายรังสีมาอ่านเป็นค่าความสว่างด้วยโปรแกรม ImageJ และเปรียบเทียบด้วยวิธีคลื่นเสียงความถี่สูง ผลการวิจัยพบว่าสามารถหาตำแหน่งกึ่งกลางของแหล่งกำเนิดรังสีได้อย่างแม่นยำ ขอบเขตของภาพที่เอกซ์โพเซอร์ 90 และ 99 พัลส์ ให้พื้นที่ 18.38 × 18.38 ตารางเซนติเมตร ผู้วิจัยจึงเลือกใช้เอกซ์โพเซอร์ที่ 90 พัลส์ ในการถ่ายภาพด้วยรังสี เนื่องจากสามารถถนอมอายุการใช้งานของเครื่องเอกซเรย์ได้มากกว่า และในการหาความหนาของท่อไอน้ำมีความคลาดเคลื่อนเฉลี่ย 0.92 mm จากการเปรียบเทียบกับความหนาจริงของท่อไอน้ำ
Utilization Of Plasma Technology For De-Inking And Hydrogenation Without Catalyst,
2023
Faculty of Engineering
Utilization Of Plasma Technology For De-Inking And Hydrogenation Without Catalyst, Ika Priyanti
Chulalongkorn University Theses and Dissertations (Chula ETD)
Catalyst-free plasma technologies have been successfully utilized for de-inked and hydrogenated processes. These green methods have nonchemical contributions, operating at room temperature and atmospheric pressure, reducing the environmental impact of the process. Two plasma types and arrangements were studied in this research: corona plasma (de-inking) and dielectric barrier discharge plasma (hydrogenation). The results found that the deinkability factors were 48.58% (yellow printed paper), 64.11% (blue printed paper), and 41.11% (red printed paper) without altering the physical properties of the paper itself. The change in the tensile strength for the plasma-exposed paper was relatively little, less than 10%, compared to that …
Removal Of Perfluorooctanoic Acid (Pfoa) In Water With Dbd-Plasma-Enhanced Adsorbent,
2023
Faculty of Engineering
Removal Of Perfluorooctanoic Acid (Pfoa) In Water With Dbd-Plasma-Enhanced Adsorbent, Thera Sahara
Chulalongkorn University Theses and Dissertations (Chula ETD)
This study examined the enhancement of PFOA removal from water using DBD plasma-modified adsorbents, specifically rice husks (RHs) and granular activated carbon (GAC). RHs treated with He-O2 plasma after phosphoric acid activation demonstrated a significant increase in adsorption efficiency, improving from 46.4% to 92.0% under optimal conditions. Adjusting pH to 4 further increased efficiency to 96.7%. The adsorption process followed the Langmuir model and pseudo-second-order kinetics, with a maximum capacity of 565 mg/g. The effects of DBD plasma on GAC in the presence of natural organic matter (NOM) were also assessed. Optimal plasma treatment enhanced PFOA removal in both deionized …
