Results for “focused experiments” — Page 27

DOE OSTI2016

SU-A-BRA-04: Incorporating Active Learning Into Medical Physics Education

Vic Montemayor - No one has been more passionate about improving the quality and effectiveness of the teaching of Medical Physics than Bill Hendee. It was in August of 2008 that the first AAPM Workshop on Becoming a Better Teacher of Medical Physics was held, organized and run by Bill Hendee. This was followed up in July of 2010 with a summer school on the same topic, again organized by Bill. There has been continued interest in alternate approaches to teaching medical physics since those initial gatherings. The momentum established by these workshops is made clear each year in the annual Innovation in Medical Physics Education session, which highlights work being done in all forms of medical physics education, from one-on-one residencies or classroom presentations to large-scale program revisions and on-line resources for international audiences. This symposium, presented on behalf of the Education Council, highlights the work of three finalists from past Innovation in Education sessions. Each will be presenting their approaches to and innovations in teaching medical physics. It is hoped that audience members interested in trying something new in their teaching of medical physics will find some of these ideas and approaches readily applicable to their own classrooms. Rebecca Howell - The presentation will discuss ways to maximize classroom learning, i.e., increasing the amount of material covered while also enhancing students’ understanding of the broader implications of the course topics. Specifically, the presentation will focus on two teaching methodologies, project based learning and flip learning. These teaching methods will be illustrated using an example of graduate medical physics course where both are used in conjunction with traditional lectures. Additionally, the presentation will focus on our experience implementing these methods including challenges that were overcome. Jay Burmeister - My presentation will discuss the incorporation of active learning techniques into a traditional medical physics classroom course. I will describe these techniques and how they were implemented as well as student performance before and after implementation. Student feedback indicated that these course changes improved their ability to actively assimilate the course content, thus improving their understanding of the material. Shahid Naqvi - My talk will focus on ways to help students visualize crucial concepts that lie at the core of radiation physics. Although particle tracks generated by Monte Carlo simulations have served as an indispensable visualization tool, students often struggle to resolve the underlying physics from a simultaneous jumble of tracks. We can clarify the physics by “coding” the tracks, e.g., by coloring the tracks according to their “starting” or “crossing” regions. The regionally-coded tracks when overlaid with dose distributions help the students see the elusive connection between dose, kerma and electronic disequilibrium. Tracks coded according to local energy or energy-loss rate can illustrate the need for stopping power corrections in electron beams and explain the Bragg peak in a proton beam. Coding tracks according to parent interaction type and order can clarify the often misunderstood distinction between primary and scatter dose. The students can thus see the “whole” simultaneously with the “sum of the parts,” which enhances their physical insight and creates a sustainable foundation for further learning. After the presentations the speakers and moderator will be open to questions and discussion with the audience members. Learning Objectives: Be able to explain Project-Based Learning and how can it be incorporated into a Medical Physics classroom. Be able to explain Flipped Learning and how can it be incorporated into a Medical Physics classroom. Be able to explain active-learning strategies for the teaching of Medical Physics. Be able to explain how Monte Carlo simulations can be used to deepen a student’s understanding of radiation physics and dosimetry.

07 ISOTOPE AND RADIATION SOURCES↗

DOE OSTI2016

SU-A-BRA-05: Panel Discussion

Vic Montemayor - No one has been more passionate about improving the quality and effectiveness of the teaching of Medical Physics than Bill Hendee. It was in August of 2008 that the first AAPM Workshop on Becoming a Better Teacher of Medical Physics was held, organized and run by Bill Hendee. This was followed up in July of 2010 with a summer school on the same topic, again organized by Bill. There has been continued interest in alternate approaches to teaching medical physics since those initial gatherings. The momentum established by these workshops is made clear each year in the annual Innovation in Medical Physics Education session, which highlights work being done in all forms of medical physics education, from one-on-one residencies or classroom presentations to large-scale program revisions and on-line resources for international audiences. This symposium, presented on behalf of the Education Council, highlights the work of three finalists from past Innovation in Education sessions. Each will be presenting their approaches to and innovations in teaching medical physics. It is hoped that audience members interested in trying something new in their teaching of medical physics will find some of these ideas and approaches readily applicable to their own classrooms. Rebecca Howell - The presentation will discuss ways to maximize classroom learning, i.e., increasing the amount of material covered while also enhancing students’ understanding of the broader implications of the course topics. Specifically, the presentation will focus on two teaching methodologies, project based learning and flip learning. These teaching methods will be illustrated using an example of graduate medical physics course where both are used in conjunction with traditional lectures. Additionally, the presentation will focus on our experience implementing these methods including challenges that were overcome. Jay Burmeister - My presentation will discuss the incorporation of active learning techniques into a traditional medical physics classroom course. I will describe these techniques and how they were implemented as well as student performance before and after implementation. Student feedback indicated that these course changes improved their ability to actively assimilate the course content, thus improving their understanding of the material. Shahid Naqvi - My talk will focus on ways to help students visualize crucial concepts that lie at the core of radiation physics. Although particle tracks generated by Monte Carlo simulations have served as an indispensable visualization tool, students often struggle to resolve the underlying physics from a simultaneous jumble of tracks. We can clarify the physics by “coding” the tracks, e.g., by coloring the tracks according to their “starting” or “crossing” regions. The regionally-coded tracks when overlaid with dose distributions help the students see the elusive connection between dose, kerma and electronic disequilibrium. Tracks coded according to local energy or energy-loss rate can illustrate the need for stopping power corrections in electron beams and explain the Bragg peak in a proton beam. Coding tracks according to parent interaction type and order can clarify the often misunderstood distinction between primary and scatter dose. The students can thus see the “whole” simultaneously with the “sum of the parts,” which enhances their physical insight and creates a sustainable foundation for further learning. After the presentations the speakers and moderator will be open to questions and discussion with the audience members. Learning Objectives: Be able to explain Project-Based Learning and how can it be incorporated into a Medical Physics classroom. Be able to explain Flipped Learning and how can it be incorporated into a Medical Physics classroom. Be able to explain active-learning strategies for the teaching of Medical Physics. Be able to explain how Monte Carlo simulations can be used to deepen a student’s understanding of radiation physics and dosimetry.

07 ISOTOPE AND RADIATION SOURCES↗

DOE OSTI2016

SU-A-BRA-00: Education Council Symposium: Revitalizing Your Medical Physics Classroom: Some Examples and Thoughts from the Trenches

Vic Montemayor - No one has been more passionate about improving the quality and effectiveness of the teaching of Medical Physics than Bill Hendee. It was in August of 2008 that the first AAPM Workshop on Becoming a Better Teacher of Medical Physics was held, organized and run by Bill Hendee. This was followed up in July of 2010 with a summer school on the same topic, again organized by Bill. There has been continued interest in alternate approaches to teaching medical physics since those initial gatherings. The momentum established by these workshops is made clear each year in the annual Innovation in Medical Physics Education session, which highlights work being done in all forms of medical physics education, from one-on-one residencies or classroom presentations to large-scale program revisions and on-line resources for international audiences. This symposium, presented on behalf of the Education Council, highlights the work of three finalists from past Innovation in Education sessions. Each will be presenting their approaches to and innovations in teaching medical physics. It is hoped that audience members interested in trying something new in their teaching of medical physics will find some of these ideas and approaches readily applicable to their own classrooms. Rebecca Howell - The presentation will discuss ways to maximize classroom learning, i.e., increasing the amount of material covered while also enhancing students’ understanding of the broader implications of the course topics. Specifically, the presentation will focus on two teaching methodologies, project based learning and flip learning. These teaching methods will be illustrated using an example of graduate medical physics course where both are used in conjunction with traditional lectures. Additionally, the presentation will focus on our experience implementing these methods including challenges that were overcome. Jay Burmeister - My presentation will discuss the incorporation of active learning techniques into a traditional medical physics classroom course. I will describe these techniques and how they were implemented as well as student performance before and after implementation. Student feedback indicated that these course changes improved their ability to actively assimilate the course content, thus improving their understanding of the material. Shahid Naqvi - My talk will focus on ways to help students visualize crucial concepts that lie at the core of radiation physics. Although particle tracks generated by Monte Carlo simulations have served as an indispensable visualization tool, students often struggle to resolve the underlying physics from a simultaneous jumble of tracks. We can clarify the physics by “coding” the tracks, e.g., by coloring the tracks according to their “starting” or “crossing” regions. The regionally-coded tracks when overlaid with dose distributions help the students see the elusive connection between dose, kerma and electronic disequilibrium. Tracks coded according to local energy or energy-loss rate can illustrate the need for stopping power corrections in electron beams and explain the Bragg peak in a proton beam. Coding tracks according to parent interaction type and order can clarify the often misunderstood distinction between primary and scatter dose. The students can thus see the “whole” simultaneously with the “sum of the parts,” which enhances their physical insight and creates a sustainable foundation for further learning. After the presentations the speakers and moderator will be open to questions and discussion with the audience members. Learning Objectives: Be able to explain Project-Based Learning and how can it be incorporated into a Medical Physics classroom. Be able to explain Flipped Learning and how can it be incorporated into a Medical Physics classroom. Be able to explain active-learning strategies for the teaching of Medical Physics. Be able to explain how Monte Carlo simulations can be used to deepen a student’s understanding of radiation physics and dosimetry.

07 ISOTOPE AND RADIATION SOURCES↗

DOE OSTI2024

New constraints on ultraheavy dark matter from the LZ experiment

Searches for dark matter with liquid xenon time projection chamber experiments have traditionally focused on the region of the parameter space that is characteristic of weakly interacting massive particles, ranging from a few GeV / c 2 to a few TeV / c 2 . Models of dark matter with a mass much heavier than this are well motivated by early production mechanisms different from the standard thermal freeze-out, but they have generally been less explored experimentally. In this work, we present a reanalysis of the first science run of the LZ experiment, with an exposure of 0.9 tonne × yr , to search for ultraheavy particle dark matter. The signal topology consists of multiple energy deposits in the active region of the detector forming a straight line, from which the velocity of the incoming particle can be reconstructed on an event-by-event basis. Zero events with this topology were observed after applying the data selection calibrated on a simulated sample of signal-like events. New experimental constraints are derived, which rule out previously unexplored regions of the dark matter parameter space of spin-independent interactions beyond a mass of 10 17 GeV / c 2 . Published by the American Physical Society 2024

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2016

Uranium from Seawater Cost Analysis: Recent Updates

Uranium from seawater can act as an economic backstop by putting an effective ceiling on the cost of recovering uranium. Although it is not meant to be a direct competitor with conventionally mined uranium there is significant effort, by a consortium of five national labs and ten universities, to improve the recovery process. Accurately predicting the cost associated with this method of uranium production is an important factor in determining a cost ceiling for uranium fuels and assuring supply security for uranium based nuclear fuel cycles. Given the evolving nature of this technology, this paper aims to provide an update of the economic model to reflect recent progress. The recovery system analyzed here is a passive collection process under persistent development by Oak Ridge and Pacific Northwest National Labs (ORNL and PNNL). The process relies on an amidoxime based uranium adsorbents constructed by co-grafting an amidoxime precursor and a hydrophilic comonomer onto a high density polyethylene (HDPE) backbone. After further chemical processing the adsorbent fibers are braided into 60 meter segments. The braids are then sent out to sea where they are moored to the bottom of the ocean. Upon realization of their soaking campaign the braids are winched up so the uranium may be eluted off the adsorbent. The acidic chemicals used in the elution process require an alkaline regeneration procedure to be applied to the adsorbent before it can be redeployed for another campaign. The deployment and elution process is repeated as many times as economically feasible, as dictated by the severity of degradation suffered by the braid due to the elution process and exposure to seawater. A large number of design and deployment parameters influence the final uranium production cost. Some are strongly affected by the chemical technologies, such as uranium uptake and degradation rate, while others are operational parameters, such as number of adsorbent uses and length of soaking campaign. Still others are both intrinsic and affected by operational choices, such as the ocean temperature and degree of oceanic biofouling. Recent experiments have been focused on improved characterization of the effect of: oceanic temperature, a novel elution method, adsorbent degradation rates, and oceanic biofouling, and they will therefore be the focus of this paper. The degradation results presented here are likely to represent a worst case scenario. Since chemically similar adsorbents were able to achieve a much lower degradation rate with the previous acidic elution process it is very possible that modifications can be made to the new adsorbents to ameliorate the degradation suffered, especially with the new bicarbonate elution process, which is believed to be less harsh. Similarly, the 30% loss in uptake suffered as a result of biofouling is likely an upper-bound. The experiments were conducted in full light and at 20 deg. C. In reality however the braids will be submersed approximately 100 meters beneath the surface, potentially subject to a temperature gradient that may influence biofouling patterns. Also the light reaching the adsorbent surface may not be as intense as in laboratory conditions due to seawater turbidity and shadows cast by nearby braids. In light of these factors, it is appropriate to present a range of costs, reflecting the best and worst case scenarios of all of the parameters considered here. Table II shows the updated parameter ranges and uranium production costs. Ongoing work, particularly into the mitigation of biofouling and degradation, is expected to tighten this cost range and reduce the predicted cost. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2015

Liquid xenon purification, de-radonation (and de-kryptonation)

Liquid xenon detectors are at the forefront of rare event physics, including searches for neutrino-less double beta decay and WIMP dark matter. The xenon for these experiments needs to be purified from chemical impurities such as electronegative atoms and molecules, which absorb ionization electrons, and VUV (178 nm) scintillation light-absorbing chemical species. In addition, superb purification from radioactive impurities is required. Particularly challenging are radioactive noble isotopes ({sup 85}Kr,{sup 39,42}Ar,{sup 220,222}Rn). Radon is a particularly universal problem, due to the extended decay sequence of its daughters and its ubiquitous presence in detector materials. Purification and de-radonation of liquid xenon are addressed with particular focus on the experience gained with the EXO-200 neutrino-less double beta decay detector.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2022

High-rate strength response of tantalum from dynamic hole closure experiments

The science and engineering communities have significant interest in experimental platforms to evaluate and improve models for dynamic material deformation. While well-developed platforms exist, there are still gaps to fill for strain and strain rate conditions accessed during impact and other high-rate loading scenarios. To fill one such gap for strength measurements, a platform was recently developed that accesses high strain rate (≥ 10 5 /s) and large strain (≥ 50%) conditions by measuring the transient closure of a cylindrical hole using in situ x-ray imaging. In the work reported here, further refinement of the platform is performed to reduce the potential effects of porosity and anelasticity on the measurement. This helps us to isolate the strength effects that are the focus of the experiment. The updated experimental configuration employs a two-layer flyer design and elongated target to reduce the magnitude of the tensile excursions associated with rarefaction wave interactions. This allows for a more direct assessment of strength models commonly used for dynamic simulations of metals. Here we apply the new technique to well-characterized tantalum material, allowing for a robust connection to other experimental techniques. Deformation localization can be a concern in large strain experiments, and to help inform future use of the experimental platform, we use simulations with a sub-zone treatment of shear banding to explore potential localization behavior. Here we develop and utilize an experimental configuration with improved isolation of strength effects that can be applied to an expanded range of materials.

42 ENGINEERING↗

DOE OSTI2026

An Autonomous MCP Bridge to Rucio: Enhancing Data Management Accessibility for High Energy Physics

The Rucio Data Management System [1] is an important tool used by High Energy Physics experiments, including those at Fermi National Accelerator Laboratory, to store and manage exabyte-scale scientific datasets. Despite its central role in coordinating data across globally distributed storage sites, Rucio's command line interface (CLI) presents a steep learning curve, and makes it difficult for scientists to navigate through. To solve this issue, a containerized Model Context Protocol (MCP) [2] server was built that connects Large Language Models directly to Rucio, allowing AI agents to handle data tasks by using simple, natural language rather than memorized terminal commands. The core engineering focus of this project was moving the server away from slow terminal commands that require text parsing and replacing them with a native Python Client API toolset and a planned REST API framework. Moving to the Python API handles data operations directly in memory, which helps clear up formatting errors, provides the AI with clean, structured JSON data and speeds up tool execution. To prove that the system actually works, a benchmarking pipeline was also built with various questions to test the AI across four different model configurations. The questions included finding data scopes, tracking down specific datasets, and checking replication rules. Through benchmarking, early runs showed that with raw terminal text, the model would get confused and stuck, whereas switching to the Python API to feed the AI clean, structured data yielded massive improvement. By creating an intelligent and autonomous bridge to a storage network, this project shows how AI can be implemented in scientific data management, which ultimately helps scientists at Fermilab spend less time sorting through data and more time focusing on their experiments and analysis.

Akella, Kashyap [William Rainey Harper Coll.]↗

DOE OSTI2013

Formation of imploding plasma liners for fundamental HEDP studies and MIF Standoff Driver Concept

The disciplines of High Energy Density Physics (HEDP) and Inertial Confinement Fusion (ICF) are characterized by hypervelocity implosions and strong shocks. The Plasma Liner Experiment (PLX) is focused on reaching HEDP and/or ICF relevant regimes in excess of 1 Mbar peak pressure by the merging and implosion of discrete plasma jets, as a potentially efficient path towards these extreme conditions in a laboratory. In this work we have presented the first 3D simulations of plasma liner, formation, and implosion by the merging of discrete plasma jets in which ionization, thermal conduction, and radiation are all included in the physics model. The study was conducted by utilizing a smoothed particle hydrodynamics code (SPHC) and was a part of the plasma liner experiment (PLX). The salient physics processes of liner formation and implosion are studied, namely vacuum propagation of plasma jets, merging of the jets (liner forming), implosion (liner collapsing), stagnation (peak pressure), and expansion (rarefaction wave disassembling the target). Radiative transport was found to significantly reduce the temperature of the liner during implosion, thus reducing the thermal leaving more pronounced gradients in the plasma liner during the implosion compared with ideal hydrodynamic simulations. These pronounced gradients lead to a greater sensitivity of initial jet geometry and symmetry on peak pressures obtained. Accounting for ionization and transport, many cases gave higher peak pressures than the ideal hydrodynamic simulations. Scaling laws were developed accordingly, creating a non-dimensional parameter space in which performance of an imploding plasma jet liner can be estimated. It is shown that HEDP regimes could be reached with ~ 5 MJ of liner energy, which would translate to roughly 10 to 20 MJ of stored (capacitor) energy. This is a potentially significant improvement over the currently available means via ICF of achieving HEDP and nuclear fusion relevant parameters.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2013

Theoretical Research in Weak-Electromagnetic and Strong Interactions (Final Report)

Project: Theoretical and Experimental Research in Weak, Electromagnetic and Strong Interactions: Investigators: S. Nandi, K.S. Babu, F. Rizatdinova Institution: Oklahoma State University, Stillwater, OK 74078. This completed project focused on the cutting edge research in theoretical and experimental high energy physics. In theoretical high energy physics, the two investigators (Nandi and Babu) worked on a variety of topics in model-building and phenomenological aspects of elementary particle physics. This includes unification of particles and forces, neutrino physics, Higgs boson physics, proton decay, supersymmetry, and collider physics. Novel physics ideas beyond the Standard Model with testable consequences at the LHC have been proposed. These ideas have stimulated the experimental community to look for new signals. The contributions of the experimental high energy physics group has been at the D0 experiment at the Fermilab Tevatraon and the ATLAS experiment at the Large Hadron Collider. At the D0 experiment, the main focus was search for the Higgs boson in the WH channel, where improved limits were obtained. At the LHC, the OSU group has made significant contributions to the top quark physics, and the calibration of the b-tagging algorithms. The group is also involved in the pixel detector upgrade. This DOE supported grant has resulted in 5 PhD degrees during the past three years. Three postdoctoral fellows were supported as well. In theoretical research over 40 refereed publications have resulted in the past three years, with several involving graduate students and postdoctoral fellows. It also resulted in over 30 conference presentations in the same time period. We are also involved in outreach activities through the Quarknet program, where we engage Oklahoma school teachers and students in our research.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2015

Final design for thermal epithermal experiments (TEX) with ZPPR plutonium/aluminium plates with polyethylene and tantalum - 13592

Lawrence Livermore National Laboratory has completed the final design for the first phase of the Thermal Epithermal experiments (TEX), which focused on critical configurations composed of plutonium/aluminum Zero Power Physics Reactor (ZPPR) plates moderated by polyethylene with and without a tantalum diluent. {sup 239}Pu and {sup 240}Pu were identified as being the number one and two nuclear data need by the nuclear criticality safety and nuclear data communities, with special emphasis placed on performance issues of the Pu cross sections in the intermediate energy region. Preliminary TEX design recommended tantalum as the first diluent to pursue for final design, as it represented a high priority data need, showed the highest sensitivity and largest contribution to uncertainty with the Pu ZPPR system, and a large number of high quality Ta plates from the ZPPR inventory in Idaho was readily available. The goals of the new critical experiments are 1) to create assemblies that span a wide range of fission energy spectra, from thermal (below 0.625 eV), through the intermediate (0.65 eV to 100 keV), and to fast energies (above 100 keV), and 2) to easily modify the assemblies to include high priority materials like tantalum. A total of ten critical configurations were designed as part of CED-2. Five TEX experiments (Experiments 1-5) were designed to establish baseline configurations with the Pu ZPPR plates covering the thermal, intermediate, and fast fission energy regimes. For all five experiments, the ZPPR plates will be arranged in layers of 24 plates (6 plates by 4 plates), resulting in approximately a 12 inch by 12 inch footprint. Multiple layers will be stacked together with varying thicknesses of interspersed polyethylene placed between the layers to fine tune the neutron spectrum of the assembly. The other five experiments (Experiments 6-10) will be similar to the five baseline experiments, except that a tantalum layer will be placed next to each plutonium plate layer, thus diluting the stack and allowing for tests of the neutron cross section for tantalum. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

NASA NTRSDate not supplied

Shock-Wave/Boundary-Layer Interaction (SWBLI) Experiments in the Presence of Transition-to-Turbulence on a Flat Plate Model in the NASA LaRC 31-Inch Mach 10 Air Tunnel

Historically, there have been a limited number of studies involving Transitional Shock-Wave/Boundary-Layer Interactions (XSWBLI) in hypersonic flows, the majority of which have been performed at Mach Numbers of 7.5 and below. Additionally, there have been even fewer such experiments which incorporate non-intrusive and optical diagnostics. NASA Langley Research Center (NASA LaRC), in collaboration with The University of Texas at San Antonio (UTSA) and The University of Tennessee Space Institute (UTSI), is currently planning and preparing for a series of experimental aerodynamic tests using the NASA LaRC 31-inch Mach 10 Air Tunnel. The experiments will primarily focus on studying the dynamics of Shock-Wave/Boundary-Layer Interactions (SWBLI) in the presence of transition (XSWBLI) and turbulence (SWTBLI) on a large, flat plate model at a freestream Mach number of 10. Besides continued interest in understanding the flow at high Mach numbers, executing such tests at Mach 10 avoids some known concerns and will aid in solving new problems. XSWBLI are a highly unsteady phenomena and the generation of XSWBLI at lower Mach numbers can prove to be a significant challenge. This concern will be somewhat mitigated in the Mach 10 flow, as boundary layers become increasingly stabilized, but some difficulty in achieving transition is still expected. Modelling SWBLI in the presence of transitional and turbulent boundary layers has also proven to be difficult, so a high-Mach number experiment which applies non-intrusive and optical diagnostics will aid in solving a unique problem as well as advancing the understanding and characterization of an aerodynamic surface at Mach 10.The NASA LaRC 31-inch Wind Tunnel incorporates a test section having a cross-section of 31-inches × 31-inches and provides optical access to the test section via three (3) ultra-violet (UV) transmitting windows on the top, side, and bottom. The Mach 10 operating conditions will consist of pressures (P0) ranging from 2.4 to 10MPa (348 to 1,450 psi) at a temperature (T0) of 1,000 K (1,800 °R). The NASA LaRC 31-inch wind tunnel will deliver 1-minute blow-down runs, of which 30-45 seconds will be consumed to reach the aforementioned test conditions. The pump down time between runs will be approximately 45-60 minutes, which will provide for 6-10 test runs per day over the course of a weeklong entry. The proposed flat plate model will be constructed of stainless steel with geometry consisting of a10-inch × 30-inch upper surface and a 2-inch thickness. The model will be designed to support multiple leading-edge inserts in order to examine blunt, round, and sharp leading edges at Mach 10. Adjustments will be made to manage boundary layer thickness as well as the strength and size of the shock interaction region for each test. Measurements and diagnostics will be performed though high-speed Schlieren, on-body high-speed pressure transducers, IR thermography, and oil flow visualization. Hypersonic vehicle applications have and will continue to emerge at the forefront of aerospace. The NASA-UTSA-UTSI team realizes the value of characterizing SWBLI, XSWBLI, and SWTBLI behaviors well beyond single-digit hypersonic Mach numbers. As hypersonic vehicle speed capabilities continue to increase, measurement and diagnostic methods for Mach numbers of 10 and beyond will provide the foundation for a firm understanding of flow field behavior which will directly influence the advancement of technologies towards the design and manufacturing of high-speed aerodynamic surfaces, controls, thermal protection systems, acoustic treatments, and structural components. The use of non-intrusive and optical diagnostic methods in such experimentation is pivotal in developing the visualization and empirical data necessary to advance the aforementioned technology areas.

Shockwave/Boundary-Layer Interactions↗

DOE OSTI2016

THE IMPORTANCE OF WIDE-FIELD FOREGROUND REMOVAL FOR 21 cm COSMOLOGY: A DEMONSTRATION WITH EARLY MWA EPOCH OF REIONIZATION OBSERVATIONS

In this paper we present observations, simulations, and analysis demonstrating the direct connection between the location of foreground emission on the sky and its location in cosmological power spectra from interferometric redshifted 21 cm experiments. We begin with a heuristic formalism for understanding the mapping of sky coordinates into the cylindrically averaged power spectra measurements used by 21 cm experiments, with a focus on the effects of the instrument beam response and the associated sidelobes. We then demonstrate this mapping by analyzing power spectra with both simulated and observed data from the Murchison Widefield Array. We find that removing a foreground model that includes sources in both the main field of view and the first sidelobes reduces the contamination in high k{sub ∥} modes by several per cent relative to a model that only includes sources in the main field of view, with the completeness of the foreground model setting the principal limitation on the amount of power removed. While small, a percent-level amount of foreground power is in itself more than enough to prevent recovery of any Epoch of Reionization signal from these modes. This result demonstrates that foreground subtraction for redshifted 21 cm experiments is truly a wide-field problem, and algorithms and simulations must extend beyond the instrument’s main field of view to potentially recover the full 21 cm power spectrum.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2020

Grimsel Test Site - A Successful International Underground Research Laboratory for Many Decades - 20429

For more than 35 years, Nagra and its partners from around the world have been conducting underground research projects at the Grimsel Test Site (GTS, www.grimsel.com) to contribute to the development and confirmation of safe geological disposal concepts and for the characterization of suitable host rock formations. Over the years, the results of this internationally recognized research program have been, and continue to be, incorporated directly into exploration programs, modelling, safety, and engineering feasibility studies on options for deep geological repositories. Each project of the GTS program involves field-testing, laboratory studies, design and modelling tasks, and integrates all scientific and technical aspects. Each project phase is planned with a duration of three to five years to facilitate practical and administrative aspects and allow flexibility for updating the overall project plans with the latest findings. Scientific and engineering interaction among the different projects is ensured via an international steering committee meeting. Hosting an IAEA level C radiation- controlled zone, which allows use of radionuclides, including actinides such as thorium, uranium, neptunium, plutonium and americium, in in-situ experiments is one of the reasons why GTS also developed as a center of excellence for work with radioactive tracers under realistic in-situ boundary conditions. Last year, a new five-year program (2019 to 2023) started which includes projects with a planning horizon of decades. The new five-year program includes a new phase of in-situ experiments using radionuclides such as migration experiments in the Colloid Formation and Migration project (CFM), the Long-Term Diffusion experiment (LTD) and the newly established C-14 and I-129 Migration in cement project (CIM). The 'High Temperature effects on Bentonite' (HotBENT) project is starting in the current phase and is studying the effects of elevated temperatures (>175 deg. C) on bentonite materials. As a generic underground research laboratory (URL) it is expected that the GTS will provide in the coming years a platform for international collaboration, knowledge development and knowledge transfer for the next generation of scientists and engineers in the area of radioactive waste disposal and geosciences. A key role regarding knowledge transfer and training is provided by the well-established Grimsel Training Center (GTC), which (beside many URL related issues) also covers many general aspects of radioactive waste management. In this paper we provide an overview of the current program at the GTS, focusing on the experiments that study the migration of radionuclides through engineered barrier materials and the geosphere. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

NASA NTRS1996

Critical Velocities in Open Capillary Flow

This paper describes the proposed research program on open capillary flow and the preliminary work performed theoretically and in drop tower experiments. The work focuses on the fundamental physical understanding of the flow through capillary bound geometries, where the circumference of the cross section of the flow path contains free surfaces. Examples for such a flow configuration are capillary vanes in surface tension tanks, flow along edges and corners and flow through liquid bridges. The geometries may be classified by their cross section areas, wetted circumferences and the radii of curvature of the free surfaces. In the streaming float zone the flow path is bound by a free surface only. The ribbon vane is a model for vane types used in surface tension tanks, where a structure in proximity to the tank wall forms a capillary gap. A groove is used in heat pipes for the transportation of the condensed working fluid to the heat source and a wedge may occur in a spaceborne experiment where fluid has to be transported by the means of surface tension. The research objectives are the determination of the maximum volume flux, the observation of the free surfaces and the liquid flow inside the flow path as well as the evaluation of the limiting capillary wave speed. The restriction of the maximum volume flux is due to convective forces (flow velocity exceeding the capillary wave speed) and/or viscous forces, i.e. the viscous head loss along the flow path must be compensated by the capillary pressure due to the curved free surface. Exceeding the maximum volume flux leads to the choking of the flow path, thus the free surface collapses and.gas ingestion occurs at the outlet. The means are ground-based experimental work with plateau tanks and in a drop tower, a sounding rocket flight, and theoretical analysis with integral balances as well as full three dimensional CFD solutions for flow with free surfaces.

Dreyer, Michael↗

DOE OSTI2026

Exploring the QCD phase diagram through correlations and fluctuations

The exploration of the Quantum Chromodynamics (QCD) phase diagram is a central goal of relativistic heavy-ion collision experiments. This review focuses on the role of fluctuations and correlations as sensitive probes of the phase structure. We discuss theoretical advancements and experimental methodologies employed to map the QCD phase diagram, highlighting constraints derived from both lattice QCD calculations and existing experimental data. Key observables such as cumulants and factorial cumulants of conserved charges (e.g., net-proton, net-charge) are explored as promising signatures of phase transitions and the QCD critical point. We discuss how these quantities are measured experimentally and compared with theoretical predictions, addressing challenges and best practices for meaningful comparisons. Special attention is given to predictions and current experimental results at high baryon density, including recent findings from the STAR collaboration at RHIC. Finally, we identify open issues and future directions for fluctuation and correlation studies at lower collision energies, relevant for future measurements, for example by the CBM experiment.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2016

New State of Nuclear Matter: Nearly Perfect Fluid of Quarks and Gluons in Heavy Ion Collisions at RHIC Energies From Charged Particle Density to Jet Quenching

This article reviews several important results from RHIC experiments and discusses their implications. They were obtained in a unique environment for studying QCD matter at temperatures and densities that exceed the limits wherein hadrons can exist as individual entities and raises to prominence the quark-gluon degrees of freedom. These findings are supported by major experimental observations via measuring of the bulk properties of particle production, particle ratios and chemical freeze-out conditions, and elliptic ow; followed by hard probe measurements: high-pT hadron suppression, dijet fragment azimuthal correlations, and heavy favor probes. These measurements are presented for particles of different species as a function of system sizes, collision centrality, and energy carried out in RHIC experiments. The results reveal that a dense, strongly-interacting medium is created in central Au + Au collisions at p sNN = 200 GeV at RHIC. This revelation of a new state of nuclear matter has also been observed in measurements at the LHC. Further, the IP-Glasma model coupled with viscous hydrodynamic models, which assumes the formation of a QGP, reproduces well the experimental ow results from Au + Au at p sNN = 200 GeV. This implies that the fluctuations in the initial geometry state are important and the created medium behaves as a nearly perfect liquid of nuclear matter because it has an extraordinarily low ratio of shear viscosity to entropy density, =s 0.12. However, these discoveries are far from being fully understood. Furthermore, recent experimental results from RHIC and LHC in small p + A, d + Au and 3He+Au collision systems provide brand new insight into the role of initial and final state effects. These have proven to be interesting and more surprising than originally anticipated; and could conceivably shed new light in our understanding of collective behavior in heavy-ion physics. Accordingly, the focus of the experiments at both facilities RHIC and the LHC is on detailed exploration of the properties of this new state of nuclear matter, the QGP.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2014

Ion beam and neutron output from a sub-kilojoule dense plasma focus

We are seeking to gain a better fundamental understanding of the ion beam acceleration and neutron production dense plasma focus (DPF) device. Experiments were performed on a kilojoule level, fast rise time DPF located at LLNL. Ion beam spectra and neutron yield were measured for deuterium pinches. Visible light images of the pinch are used to determine the pinch length. In addition, an RF probe was placed just outside the cathode to measure fluctuations in E{sub z} up to 6 GHz, which is within the range of the lower hybrid frequencies. We find these oscillations arise at a characteristic frequency near 4 GHz during the pinch. Comparisons of the neutron yield and ion beam characteristics are presented. The neutron yield is also compared to scaling laws.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗