Funded Research Projects

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14641/189

An index of publicly funded research projects conducted by Texas A&M affiliated researchers.

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Now showing 1 - 8 of 8

CAREER: Nuclear Microphysics of Neutron Stars, Core-Collapse Supernovae, and Compact Object Mergers
Cyclotron Institute; TAMU; https://hdl.handle.net/20.500.14641/256; National Science Foundation
The structure, phases, and dynamics of nuclear matter are key to answering fundamental questions at the interface of nuclear physics and astrophysics: How are the stable elements heavier than iron synthesized in extreme astrophysical environments? What is the composition and nature of the densest observable matter in the universe? What are the most promising astronomical sources of detectable gravitational waves? This project will integrate research and education while developing new theoretical models of the ultra-hot and ultra-dense matter encountered in core-collapse supernovae, proto-neutron stars, and binary neutron star mergers. The project will also provide theoretical support for the experimental program at rare-isotope beam facilities. As such, this project will also provide new opportunities to disseminate exciting forefront research developments in nuclear physics and nuclear astrophysics to high school students in the Texas Brazos Valley through an integrated lecture and competition series. A major long-term goal is to understand how the strong nuclear force shapes the structure, evolution, and observable emissions of high-energy astrophysical systems, such as core-collapse supernovae, neutron stars, and binary neutron star mergers. To support this effort, this project aims to develop the first microscopic models of hot and dense neutron-rich matter based on the low-energy effective field theory of strong interactions. The nuclear thermodynamic equation of state, governing neutron star structure as well as the hydrodynamic evolution of supernovae and neutron star mergers, will be calculated across the range of conditions needed for numerical simulations. This will enable more reliable predictions for the electromagnetic, neutrino, and gravitational wave signals from supernovae and neutron star mergers. The nucleon single-particle potential in nuclear matter will be computed and parametrized in a form suitable for nucleosynthesis studies of neutrino-driven winds in supernovae and the tidally ejected matter in neutron star mergers. Finally, quantum Monte Carlo simulations of dilute neutron matter at finite temperature will be carried out in order to investigate the effect of neutron pairing on transport and cooling phenomena in proto-neutron stars.
CAREER: Nuclear Microphysics of Neutron Stars, Core-Collapse Supernovae, and Compact Object Mergers
Cyclotron Institute; TAMU; https://hdl.handle.net/20.500.14641/256; National Science Foundation
The structure, phases, and dynamics of nuclear matter are key to answering fundamental questions at the interface of nuclear physics and astrophysics: How are the stable elements heavier than iron synthesized in extreme astrophysical environments? What is the composition and nature of the densest observable matter in the universe? What are the most promising astronomical sources of detectable gravitational waves? This project will integrate research and education while developing new theoretical models of the ultra-hot and ultra-dense matter encountered in core-collapse supernovae, proto-neutron stars, and binary neutron star mergers. The project will also provide theoretical support for the experimental program at rare-isotope beam facilities. As such, this project will also provide new opportunities to disseminate exciting forefront research developments in nuclear physics and nuclear astrophysics to high school students in the Texas Brazos Valley through an integrated lecture and competition series. A major long-term goal is to understand how the strong nuclear force shapes the structure, evolution, and observable emissions of high-energy astrophysical systems, such as core-collapse supernovae, neutron stars, and binary neutron star mergers. To support this effort, this project aims to develop the first microscopic models of hot and dense neutron-rich matter based on the low-energy effective field theory of strong interactions. The nuclear thermodynamic equation of state, governing neutron star structure as well as the hydrodynamic evolution of supernovae and neutron star mergers, will be calculated across the range of conditions needed for numerical simulations. This will enable more reliable predictions for the electromagnetic, neutrino, and gravitational wave signals from supernovae and neutron star mergers. The nucleon single-particle potential in nuclear matter will be computed and parametrized in a form suitable for nucleosynthesis studies of neutrino-driven winds in supernovae and the tidally ejected matter in neutron star mergers. Finally, quantum Monte Carlo simulations of dilute neutron matter at finite temperature will be carried out in order to investigate the effect of neutron pairing on transport and cooling phenomena in proto-neutron stars.
Microscopic Properties of Hot and Dense QCD Matter
Cyclotron Institute; TAMU; https://hdl.handle.net/20.500.14641/494; National Science Foundation
A few micro-seconds into the cooling process of the early Universe, an extremely hot plasma of elementary particles (quarks and gluons) condensed into bound states called hadrons, the building blocks of the visible matter in the Universe. The condensation of the quark-gluon plasma (QGP) confined the quarks and gluons into hadrons and generated about 98% of the visible mass. The discovery of the mechanisms of quark confinement and hadron mass generation are central goals of fundamental research in particle and nuclear physics. Experimentally, small droplets of QGP, at record temperatures exceeding 2 trillion Kelvin, can be re-created in the laboratory by colliding atomic nuclei at high energies, at the Relativistic Heavy-Ion Collider and the Large Hadron Collider. However, it is very challenging to infer the properties of the QGP and its hadronization from the measured particle spectra. The PI, together with his graduate students and collaborators, will develop theoretical methods and apply them to unravel fundamental properties of the QGP from experimental data. His research and educational activities also encompass undergraduate research and outreach to high-school students within the Saturday Morning Physics program at Texas A&M. The heavy charm and bottom quarks, as well as electromagnetic (EM) radiation, are particularly valuable probes of the QGP. The PI will use state-of-the-art quantum many-body theory of the strong nuclear force to analyze the diffusion of heavy quarks (Brownian motion) and their subsequent hadronization. A systematic analysis of the experimental spectra of baryons (3-quark states) and mesons (quark-antiquark states) containing heavy quarks will unravel mechanisms of hadronization and provide unprecedented precision in the extraction of the heavy-quark diffusion coefficient, a key quantity to characterize the interaction strength in the QGP. The PI will further use EM radiation, which can penetrate the QGP formed in heavy-ion collisions, to analyze the mechanism of mass generation. He will investigate the spectral modifications of baryons near the hadronization transition and extract the electric conductivity, another fundamental transport parameter of the medium. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
New Directions in High Energy Nuclear Physics
Cyclotron Institute; TAMU; https://hdl.handle.net/20.500.14641/508; National Science Foundation
Among the four fundamental forces in nature the strong nuclear force stands out for being the least understood one. It drives many processes in the universe that are crucial for our existence. One particularly important aspect of the strong nuclear force is the existence of quark gluon plasma. If ordinary matter is heated up to temperatures of about 1,000,000,000,000 degrees, hotter than the core of the sun, atoms and molecules cease to exist and even protons and neutrons inside atomic nuclei melt. The remaining primordial soup of quarks and gluons filled the very early universe. We can recreate quark gluon plasma in our largest particle colliders by smashing heavy nuclei into each other. Experimental programs at the Large Hadron Collider in Europe and the Relativistic Heavy Ion Collider in the USA study the properties of quark gluon plasma. This project will support research that will improve our understanding of the formation and properties of quark gluon plasma in nuclear collisions. The PI and his collaborators will use computer simulations and advanced statistical methods to reach this goal. Funding is provided to support training for a graduate students and junior scientists in nuclear science. Quark gluon plasma in nuclear collisions emerges from the highly complex gluon fields that are initially created in nuclear collisions. The PI and his group will investigate these fields and their properties by studying how angular momentum of the droplets of quark gluon plasma is related to the initial angular momentum of the colliding nuclei. The same gluon fields will also be studied through their interaction with fast quarks. The PI and his group will be able to use the JETSCAPE framework for large scale computational simulations of nuclear collisions. They will study various aspects of jets and heavy quarks being quenched in quark gluon plasma. They will then extract properties of quark gluon plasma using multiple constraints. For example, the strength of quenching of quarks and heavy quarks, and the viscosity of quark gluon plasma can be independently measured and are mutually related. Testing these relations will be an important step towards a deeper understanding of the dynamics of quark gluon plasma. The PI and his group will also use advanced statistical methods and machine learning applied to data to understand the mechanisms of hadron formation from quarks and gluons. These results will be used to improve the state-of-the-art modeling of the hadronization process that is a crucial input to many calculations. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Radiation and Transport in QCD Matter
Cyclotron Institute; TAMU; https://hdl.handle.net/20.500.14641/494; National Science Foundation
A few micro-seconds after the Big Bang the universe was filled with an extremely hot plasma made of elementary particles, the quarks and gluons. When the expanding plasma cooled to a temperature of about two trillion degrees, quarks and gluons condensed into massive bound states called hadrons, including the protons and neutrons which make up the atomic nuclei of the matter around us. This transition generated over 95% of the visible mass in the universe, and it permanently confined quarks and gluons into hadrons. How these phenomena emerge from the strong nuclear force between quarks and gluons is a forefront question in modern science. High-energy collisions of heavy nuclei provide a unique opportunity to recreate, for a short moment, the primordial medium of the Big Bang in the laboratory. It is a formidable challenge to infer the properties of this medium from its decay products observed in large detectors. The PI will develop theoretical tools to diagnose this matter and rigorously interpret the experimental data. The PI will continue to build a thriving graduate research program and foster scientific outreach to regional high school students through the Saturday Morning Physics program. This project aims at quantifying fundamental transport properties of the quark-gluon plasma (QGP) and how hadron masses emerge in the quark-to-hadron transition. The transport of heavy quarks through the QGP will be evaluated using innovative quantum many-body techniques, where the heavy-quark interactions will be based on first-principles computations of lattice discretized Quantum Chromodynamics (QCD), the fundamental theory of the strong interaction. The resulting heavy-quark transport coefficients will be implemented into state-of-the-art simulations of the fireballs formed in heavy-ion collisions. In addition, electromagnetic radiation from these fireballs will be calculated to determine: (a) the temperature of the medium, and (b) how the masses of hadrons emerge as the QGP cools down. Current and future experimental programs at the Relativistic Heavy-Ion Collider and Large Hadron Collider have a large emphasis on heavy-quark and electromagnetic observables. The advances achieved through this project will provide the theoretical rigor and accuracy required to convert systematic comparisons to precision data into robust knowledge about the primordial QCD medium.
REU Site: Nuclear Science at Texas A&M
Cyclotron Institute; TAMU; https://hdl.handle.net/20.500.14641/609; National Science Foundation
This award supports the renewal of the Research Experiences for Undergraduates (REU) site in nuclear physics at Texas A&M University. The site will support twelve undergraduates per year in ten weeks of research during the summer months. Involvement in research at the undergraduate level is an important component in increasing the numbers and preparation of students entering graduate programs. This site primarily targets students who lack opportunities to do research in the field of Nuclear Science at their home institutions. The student research projects are at the leading edge of Nuclear Science, including sub-fields such as nuclear astrophysics, weak interactions, nuclear dynamics and thermodynamics, nuclear structure, the Relativistic Heavy Ion Collider (RHIC), atomic ionizations, and radiation effects. There are proposed projects both in theoretical and experimental Nuclear Science. The Cyclotron Institute is a Department of Energy (DOE) Nuclear Physics Center of Excellence. The facilities include a K500 superconducting cyclotron, a K150 cyclotron and associated state-of the art detector systems. The Cyclotron Institute and the department of physics are also home base for involvement in experiments at other facilities, and the faculty are leading scientists in the field and have a history of working with undergraduates in their research programs.
SI2-SSI: Collaborative Research: Jet Energy-Loss Tomography with a Statistically and Computationally Advanced Program Envelope (JETSCAPE) (JETSCAPE)
Cyclotron Institute; TAMU; https://hdl.handle.net/20.500.14641/508; National Science Foundation
Microseconds after the Big Bang, the universe was filled with an extremely hot fluid called the Quark-Gluon Plasma. As the universe expanded, this plasma cooled and condensed into the building blocks of ordinary matter around us: protons, neutrons, and atomic nuclei. Droplets of this fluid, which exists only at temperatures above 2 trillion Kelvin, are generated and studied in the laboratory today using collisions of high-energy heavy ions at Brookhaven National Laboratory and CERN. A key method to study the Quark-Gluon Plasma is the generation of high-energy quarks and gluons in the collision, which interact with the hot plasma and emerge as "jets" of particles that are measured by experiments. These jets provide powerful tools to study the internal structure of the plasma, analogous to tomography in medical imaging. However, interpretation of jet measurements requires sophisticated numerical modeling and simulation, and comparison of theory calculations with experimental data demands advanced statistical tools. The JETSCAPE Collaboration, an interdisciplinary team of physicists, computer scientists, and statisticians, will develop a comprehensive software framework that will provide a systematic, rigorous approach to meet this challenge. Training programs, workshops, summer schools and MOOCs, will disseminate the expertise needed to modify and maintain this framework. The JETSCAPE Collaboration will develop a scalable and portable open source software package to replace a variety of existing codes. The modular integrated software framework will consist of interacting generators to simulate (i) wave functions of the incoming nuclei, (ii) viscous fluid dynamical evolution of the hot plasma, and (iii) transport and modification of jets in the plasma. Integrated advanced statistical analysis tools will provide non-expert users with quantitative methods to validate novel theoretical descriptions of jet modification, by comparison with the complete set of current experimental data. To improve the efficiency of this computationally intensive task, the collaboration will develop trainable emulators that can accurately predict experimental observables by interpolation between full model runs, and employ accelerators such as Graphics Processing Units (GPUs) for both the fluid dynamical simulations and the modification of jets. The collaboration will create this framework with a user-friendly envelope that allows for continuous modifications, updates and improvements of each of its components. The effort will serve as a template for other fields that involve complex dynamical modeling and comparison with large data sets. It will open a new era for high-precision extraction of the internal structure of the Quark-Gluon Plasma with quantifiable uncertainties. This project advances the objectives of the National Strategic Computing Initiative (NSCI), an effort aimed at sustaining and enhancing the U.S. scientific, technological, and economic leadership position in High-Performance Computing (HPC) research, development, and deployment. This project is supported by the Division of Advanced Cyberinfrastructure in the Directorate for Computer & Information Science & Engineering and the Physics Division and the Division of Mathematical Sciences in the Directorate of Mathematical and Physical Sciences.
Study of Nuclear Forces and Shell Evolution through Spectroscopy of Neutron-Rich Light Nuclei
Cyclotron Institute; TAMU; https://hdl.handle.net/20.500.14641/609; DOE-Office Of Science
Iodine-129 (129I), with a half-life of half-life of 16 million years, is commonly considered the single greatest risk driver in high-level and low-level nuclear repositories. This risk stems from several basic properties of 129I, and under many geochemical conditions, it can move as an anion at nearly the rate of water through the subsurface environment. 129I is also extremely radiologically toxic because over 90% of body burden accumulates in the thyroid, which weighs only about 14g in an adult. There is also a large worldwide inventory of radioiodine as a result of its high fission yield and this inventory is rapidly increasing as a result of nuclear energy production. Radioiodine is produced at a rate of 40 GBq (1 Ci) per gigawatt of electricity produced by nuclear power. To illustrate how the properties of 129I magnify its risk, 129I accounts for only 0.00002% of the radiation released from the Savannah River Site in Aiken, South Carolina, but contributes 13% of the population dose, a six orders of magnitude magnification of risk with respect to its radioactivity. The currently favored solid phase for LLW immobilization is cement, while HLW immobilization is the incorporation of waste into glass (vitrification). However, so far, the incorporation into cement and subsequent leaching of only iodide has been seriously investigated. The major problem with this approach is that it ignores the complex speciation of iodine, i.e., it ignores iodate and organo-iodine which have different chemistries. Most of the past research was devoted to the mechanism of iodide uptake in cement hydrate phases that is sorption and/or incorporation. Very few data exist on iodate and organo-iodine incorporation in cement, even though large quantities of liquid waste containing also radioiodine have already been solidified in cement Iodine-129 from low-level waste is commonly disposed of in cementitious materials. Grout, a dense cementitious fluid, mixed with a reducing slag, is often used to immobilize radionuclides. However, the reducing environment might not be conducive to immobilize iodine. For example, the silver based immobilization technologies (e.g., AgCl, Ag-impregnated granular activated carbon, Ag-mordenite) remove iodine from the aqueous phase by promoting the formation of Ag-iodide precipitates. The solubility of AgI is eight orders of magnitude lower than it is for AgIO3. Similarly, coprecipitation of iodine into calcium carbonate phases occurs only with IO3- and not with I- and org-I. If one would want to immobilize iodine more effectively, different engineering approaches would need to be used to promote binding of I-, IO3-, or organo-I. Using laboratory experiments with grout, slag, and silver-based adsorbents, and GC-MS and I K-edge XANES and EXAFS and C K-edge XANES spectroscopy for identifying iodine speciation, the major problems with these methods have been identified as focused too much on just one of the iodine species for immobilization, while others, especially organo-I, remained mobile. Finally, we established that most of the adsorbents that are used contain sufficient amounts of organic matter to create organo-I . It is anticipated that increased attention directed at understanding and quantifying the speciation of radioiodine, as opposed to simply total radioiodine, will lead to improved remediation results to be used for long-term radioiodine disposal in cementitious waste forms.

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Browsing Funded Research Projects by Department "Cyclotron Institute"