HPS 66th Annual Meeting
July 25th-29th 2021
WPM-C - Academic Institutions
Room 124 14:30 - 17:15
14:30 A Computerized Build-Your-Own Geiger-Mueller Radiation Detection System: Design Improvements for Performance and User-Friendliness MA Cooney*, University of Michigan
; JD Noey, University of Michigan; AJ Kent, University of Michigan; CC Huang, University of Michigan; CE O'Neil, University of Michigan; S Tawfik, University of Michigan; L Jautakas, University of Michigan; ME Trager, University of Michigan; M Li, University of Michigan; KJ Kearfott, University of Michigan
Abstract: A Build-Your-Own Geiger-Mueller radiation detection system was previously developed as an educational outreach tool. The system consists of a Geiger-Mueller tube, a Raspberry Pi Zero W computer, and a voltage-boosting circuit which also inverts and filters signals. Since the original design, alterations were made to the printed circuit board, components, case, software, and documentation to allow a more user-friendly experience. New circuit components were selected to optimally reduce noise. Some of this noise was identified as electromagnetic interference caused by an unshielded inductor. Replacement by a shielded inductor solved this interference issue. In addition, current spikes, suspected to be inductance spikes from the boost converter onboard, incapacitated the computer. This was resolved by using high voltage rated transistors and switching input voltage from 5 V to 3.3 V. A low pass filter was added to eliminate high frequency noise in the system. Test points were added to the revised printed circuit board to allow easier troubleshooting and study. The board was also reorganized and enlarged to increase understanding of the circuit itself, allow ease of soldering for inexperienced students, and avoid usage of wires for connection of the tube into the circuit. The 3-D printed case was altered to accommodate the larger circuit board, with customization made possible to increase student engagement with its manufacture. Updates were deployed to an Android and iOS application developed to wirelessly interact with the system. Finally, written materials concerned with assembly, software and experiments were to aid in the system construction, usage, and learning.
14:45 Comparison of Common Methods for Single Detector Radiation Source Localization KJ Liebler, University of Michigan
; MA Cooney*, University of Michigan; LK Chung, Stanford University; AJ Kent, University of Michigan; JD Noey, University of Michigan; KJ Kearfott, University of Michigan
Abstract: If measurements of a radiation field are made at different locations, it is possible to determine the location of a source when knowledge exists about the relationship between a source and the resulting field created as a function of distance from the source. For example, for simple point sources of both ionizing and nonionizing radiation in the absence of significant intervening absorptive or scattering material, a simple inverse-square law would describe this relationship. A variety of probabilistic techniques may be used to localize any point source where the intensity follows this inverse-square characteristic, although the method is more generally applicable. This study seeks to facilitate the discussion of the potential benefits and drawbacks of individual algorithms and techniques when considering a single detector searching for a point source. An algorithm with the ability to approximate source location involving travel in close proximity to the source might be advantageous if extremely precise positional information or rapid recovery of an item is desired. For scenarios such as those involving high intensity ionizing radiation, an algorithm that is restricted from closely approaching the source location could be advantageous for protecting personnel or radiation-sensitive instruments. After a search through literature spanning across multiple disciplines, a multitude of techniques such as maximum likelihood estimation, Monte Carlo, least-squares methods and more have been implemented and examined both in simulation and empirically to the problem of locating sources. The success of these algorithms is measured based on their accuracy when approximating the location of a source. Future research involves the analysis of more of these techniques in order to establish a more concrete framework to which their appropriate use cases can be determined.
15:00 Hardware and Software Design for an Affordable Indoor and Outdoor Weather and Radon Monitoring Station M Li*, University of Michigan
; S Tawfik, University of Michigan; ME Trager, University of Michigan; AJ Kent, University of Michigan; JD Noey, University of Michigan; KJ Kearfott, University of Michigan
Abstract: It would be potentially inspiring and educational to introduce networked sensor systems with radiation detectors to high school students curious about science, technology, engineering and math. They may then become interested in pursuing nuclear science careers. This project aims to design an affordable build-your-own weather and radiation monitoring station to be distributed to high schools. These stations would become part of a centralized system sharing data. Such stations, called Radiation Weather Station Light (RWSlite), are undergoing development by an interdisciplinary team of undergraduates. RWSlite includes sensors chosen for adequate performance at reasonable prices from education-oriented sources. Outdoor sensors measure temperature, pressure, humidity, ultraviolet index, soil temperature and moisture, wind speed, wind direction, and rainfall. Indoor sensors measure temperature, pressure, humidity, and radon. Python and Bash scripts were written on a Raspberry Pi 4B to collect data while conforming to each sensor's respective interface. Following successful testing of a breadboarded system, a printed circuit board was created to ensure compact and robust performance. A 3D-printed box is planned to house and protect the computer and sensors, with attention being paid to robust connections to the outdoor sensors. At least one commercially available home radon monitoring device with performance comparable to professional models (ftLabs RadonEye) will be incorporated. Additional radiation sensors such as Geiger-Mueller counters are planned for the future. A detailed assembly guide will be written to ensure an interactive learning experience for students who will assemble the systems for their schools. Finally, a robust database with a continuously updated website is being designed so that RWSlite systems at participating schools can automatically upload and access collected data with a centralized and safe data-sharing website.
15:15 Computer Aided Design and Manufacturing for a University Health Physics Research Laboratory ME Trager*, University of Michigan
; JD Noey, University of Michigan; KJ Kearfott, University of Michigan; Ma Trager
Abstract: The Radiological Health Physics Laboratory at the University of Michigan conducts broad software, hardware, and applied measurement research in radiation protection. It is also engaged in developing educational tools for outreach programs relating to the nuclear sciences, hosting a graduate course in applied radiation measurements, and serving as a general maker space for nuclear engineering instrumentation and testing. To fulfill those functions, a variety of both virtual and physical specialized tools, objects, and parts are required alongside advanced graphics and photography support for technical communication and educational materials. Basic designs are accomplished using computer-aided design programs such as SolidWorks, Adobe Illustrator, and Blender. Manufacturing those designs involves a range of processes such as laser cutting, ceramic machining, and 3D printing. Because 3D printing allows parts to be designed, created, and tested in rapid succession in comparison to other manufacturing methods, it is most often used. For this reason, an Ultimaker S5 and two Crealty Ender-3 printers were purchased, enabling rapid, high-precision and dual-color capabilities. Completed and ongoing projects include a case for a build-your-own radiation detector, a GM tube test rig, a ceramic dosimeter annealing plate, an acrylic sample irradiation plate, an experiment stand for a custom spectroscopy system, an enclosure for a multi-sensor meteorological and radiological station, a temperature-controlled box for instrument testing, 3D assets for a virtual reality game, an animated teleconferencing background, various illustrated instructions manuals, and posters and presentation slide decks, including for this meeting.
16:00 Use of Naturally Occurring Radon in a Basement Storage Space to Teach First Order Linear Kinetics LK Chung*, Stanford University
; JD Noey, University of Michigan; TW Kennings, University of Michigan; KJ Keartott, University of Michigan
Abstract: Radon is naturally occurring radioactive material that is known to pose many health risks such as lung cancer. The decay of radium in soil or building materials releases radon into the air and this can be an undetected hazard in many locations. It is valuable for nuclear science students to be aware of this problem and understand how radon behaves in an enclosed and ventilated environment. Because radon diffusion and building ventilation generally follow first order linear kinetics, radon is a naturally occurring environmental tracer that presents an opportunity to illustrate compartmental modeling and application of first order coupled differential equations. An underground unoccupied storage room at a university has a radon concentration exceeding ~1,000 Bq m-3. With soil completely bordering most of the space and thick concrete walls originally built to dampen vibrations, this presents the unique opportunity as a natural radon chamber available for research and teaching. While by no means easily held at a constant temperature, pressure, and radon level, the space is continuously monitored for those environmental parameters and is extremely accessible. To best demonstrate radon kinetics while intercomparing the performance of different instruments, various radon monitors were used to measure radon levels over extended periods of time. Commercial fans were positioned within the space to dramatically force washouts of radon, simulating increased ventilations. Canisters containing charcoal and diffusion barriers, commonly used as passive integrating radon screening devices, were also deployed in the space, providing data about the kinetics of those devices. The compartmental models taught will be presented along with results obtained for the experiments and feedback from students.
16:15 Construction and Characterization of a Smart Geiger-Mueller System for a Senior and Graduate Level University Course on Applied Radiation Detection JD Noey*, University of Michigan
; AJ Kent, University of Michigan; CE O'Neil, University of Michigan; KE Barr, University of Michigan; KJ Kearfott, University of Michigan; Jo Noey
Abstract: Hands-on experience with circuits and soldering techniques, understanding key detector characteristics, and testing detector performance is essential for advanced nuclear sciences education. Undergraduate radiation detection courses typically focus on detection theory using existing tools without considering their practical function, while undergraduate circuits classes often do not include soldering. Additionally, undergraduate courses usually do not discuss standards organizations or their impacts on detector design and testing. This design of a smart Geiger-Mueller (GM) detector has affordable components and can be assembled and tested by a novice. This addresses a significant need for education about circuitry, soldering techniques, and detector standards for nuclear science students. To create the hardware for the smart GM detector, circuit components were soldered on to a printed circuit board to form a voltage booster and low pass filter that were then connected to a GM tube and a Raspberry Pi. A program to run the circuit and record counts and bluetooth enabling software were downloaded onto a microSD card to form the software component of the detector. Once detector assembly was complete, tests based on ANSI standards for GM detectors were used to completely characterize the detector. These included response to ionizing radiation, background counting rate, plateau characteristics, longitudinal sensitivity, detector noise and performance, and dead time. Students were able to effectively construct the system using provided directions and correctly answer questions about advanced reading related to nuclear electronics and GM detectors, circuit functions, and the results of detector characterization tests. One student also wrote this abstract to satisfy professional writing requirements for the course. Student feedback about this laboratory experiment, to be adopted in future course iterations, is summarized.
16:30 Educational Experiments for the Public Using a Custom Smart Geiger-Mueller Radiation Detection System JD Noey*, University of Michigan
; KJ Kearfott, University of Michigan
Abstract: Geiger-Mueller counters are simple radiation detection instruments that provide a gateway for people to experience radiation firsthand. To expose the public to the nuclear field, a build-your-own Geiger-Mueller counter controlled by a computer or cell phone was created for members of the public to assemble and interact with as a unique learning opportunity. Individuals begin by soldering components onto a printed circuit board that accommodates the microcomputer. This is followed by downloading of firmware and cellphone applications. To maximize the amount learned from the assembled system, several experiments were developed, most of which may be performed with commonly available or consumer-grade items. These exercises include electrical analysis of the circuit, usage of modelling software for 3-D printing of customized cases, and performing different types of measurements on common items in different locations. Respective manuals for each experiment were created for others to clearly follow along with the content. Readily available exempt sources have been identified, such as thorium lantern mantles and Fiestaware, so that the experiments may be performed by individuals not having any special access to licensed radioactive materials. For each experiment, learning objectives, the materials needed, procedures to be followed, the expected outcome, and feedback from participants are summarized.
16:45 Design of a Virtual Reality Game for Teaching Radiation Protection Principles DB Calco*, University of Michigan
; X Zheng, University of Michigan; AJ Sable, University of Michigan; N Abbaraju, University of Michigan; ME Trager, University of Michigan; BJ Saltus, University of Michigan; JD Noey, University of Michigan; KJ Kearfott, University of Michigan
Abstract: Virtual reality (VR) presents a unique opportunity for training, particularly since it could allow individuals to practice skills, perform actions, and solve intellectual problems in environments with no consequences if mistakes are made. Using a VR headset, this team focused on designing and developing a fully immersive experience to interest individuals in the profession of health physics while introducing the basic physics involved in radiation protection. Once the player successfully navigates the initial tutorial room, which includes interactive demonstrations of basic radiation principles, they are brought to a city where different buildings can be explored. Each building contains tasks testing radiation principles as engaging puzzles and challenges. In this way, players learn about many health physics concepts that may otherwise be inaccessible in a real-world setting due to the limitations of being able to access radioactive materials for educational purposes. To create an interesting engaging yet realistic game, the team focused on utilizing the tenants of iterative game design, restructuring the game and format until the game felt comparable to a learning experience. In addition, using basic concepts from cognitive psychology, deep processing of health physics concepts can be enhanced through recall activities, which will be interwoven throughout the tutorial room as well as in other rooms in the game. Future additions to the game would enable it to eventually provide more detailed career training concerned with radiation detector usage, surveying, decontamination, dose minimization, ALARA planning, and shielding. Ultimately, different realistic scenarios with the puzzles of actual cases in different environments could be implemented to challenge the creative thinking of even the most highly experienced professionals.
17:00 Realistic Implementation of Radiation Physics for a Virtual Reality Game Programmed in Unity for an Oculus Quest AJ Sable*, University of Michigan
; N Abbaraju, University of Michigan; X Zheng, University of Michigan; DB Calco, University of Michigan; BJ Saltus, University of Michigan; JD Noey, University of Michigan; KJ Kearfott, University of Michigan
Abstract: A virtual reality game was designed to generate interest in the health physics profession while teaching radiation protection principles. The game was implemented for a virtual reality display, an Oculus Quest, using the Unity game development software with Unity’s XR Interaction Toolkit and Android build support. The game was designed to realistically portray the physics of radioactive sources and detectors without interfering with game speed and function. The scripting is written in C# and relies heavily on object-oriented programming methods. Radiation sources, shields, and detectors are considered different metaclasses, with interactions among them defined through a driver class called the Radiation Manager. The metaclasses each have child classes, such as radiation point source being a child of radiation sources. Distances and thicknesses of material between the player and sources are computed based upon the user’s virtual position using ray cast functions included in Unity’s physics library. Instantaneous gamma dose rates as a function of distance are calculated in real-time using a point kernel function following the inverse square law. Beam absorption by shields and intervening materials is accounted for with attenuation coefficients and densities which are properties of the radiation shields class. Sources can decay as game time elapses, as radionuclide type, activity, and half-life are properties of the radiation sources class. Dosimeters integrate total dose as the player moves through the game and time elapses. It was necessary to create environments displaying rulers marking distances and clocks showing time lapses as unit tests to verify measurements. Many future enhancements are possible to increase realism for more complex scenarios. This could include the introduction of different radiation fields, modeling more complicated detector physics, or replicating environments from intricate Monte Carlo simulations.