The Three Minute Thesis (3MT) is a competition where students present their graduate thesis work in three minutes. The competition, done as part of University Research week, celebrates doctoral or master’s research and is meant to cultivate presentation and research communication with non-specialist audiences. This year, Mackenna Wood earned the top prize, which includes $1000 and the opportunity to represent UNC at the national 3MT competition in 2023.
Wood’s research, conducted as part of Andrew Mann’s lab, focuses on measuring the ages of stars. To understand the prospects for life elsewhere in the universe, we must understand the changes planets undergo over millions or billions of years. However, these timescales are too long to wait for planets to evolve in real time. Instead, Wood focuses on planets in stellar associations: groups of stars that all formed at the same time. By assigning ages to these groups and the planets within them, Wood can build up a set of ‘snapshots’ of planets at different stages of change.
Most recently, Mackenna led the discovery and age-dating of a new association, MELANGE-4, finding that the group is 27 million years old and contains 6 planets (two of which she discovered) and represents an exciting new environment to study the evolution of stars and planets.
Zack is one of 44 awardees nationwide. The DOE SCGSR program supports collaborations between graduate students and DOE laboratory scientists. Zack will work at Lawrence Berkeley National Lab for a year, starting Jan 23. The following is from: https://college.unc.edu/2022/10/hall-doe/
Ph.D. candidate Zack Bruce Hall II is one of 44 awardees of the U.S. Department of Energy (DOE) Office of Science Graduate Student Research (SCGSR) Program, which will allow him research opportunities at the DOE Lawrence Berkeley National Laboratory.
Zack Bruce Hall II
Zack Bruce Hall II is the sixth UNC-Chapel Hill student to win a U.S. DOE SCGSR award since the program’s founding in 2014. The goal of SCGSR is to prepare graduate students for science, technology, engineering, or mathematics (STEM) careers critically important to the DOE Office of Science mission by providing graduate thesis research opportunities through extended residency at DOE national laboratories. A total of 44 awardees from 36 different U.S. universities have been awarded this opportunity.
Hall’s research at UNC-Chapel Hill, conducted in Amy Nicholson’s research group in the department of physics and astronomy in the College of Arts and Sciences, seeks to understand how strongly interacting elementary particles like quarks and gluons give rise to the low-energy properties of composite matter such as hadrons and nuclei that are observed in nature. The research group uses a computational method called Lattice Quantum Chromodynamics (QCD) to calculate these interactions and it serves to connect theory with experimental results.
The research projects proposed by new SCGSR awardees demonstrate strong alignment with the priority mission areas of DOE Office of Science that have a high need for workforce development. Graduate students will conduct part of their graduate thesis research in collaboration with a DOE laboratory scientist. Hall will work with André Walker-Loud to conduct research at the Lawrence Berkeley National Laboratory for a 12-month period starting January of 2023.
“I’m grateful to have been selected for this award and excited to work with and learn from leading experts in the field, including my collaborators at Berkeley Lab,” Hall says. “I’m hoping this will expand my professional network and help me learn of possible postdoctoral research opportunities in my field.”
The SCGSR research projects are expected to advance the graduate awardee’s overall doctoral thesis while providing access to the expertise, resources, and capabilities available at the DOE laboratories and facilities.
“The Department of Energy is committed to growing the American science and technology workforce. SCGSRs are one way we contribute to nurturing the incredible talent and curiosity in students from all walks of life to meet the great scientific challenges of the world,” says Asmeret Asefaw Berhe, Director of the DOE Office of Science. “I know the future is bright for these students, and I’m honored that the Department of Energy can be a part of their stories.”
Each year, the Postdoctoral Awards for Research Excellence (PARE) are given in recognition of the research promise demonstrated by individual postdoctoral scholars. Meet this year’s recipients and learn about their areas of interest.
The PARE awards are open to postdoctoral scholars in all disciplines and are designed to assist them in their continued professional development by supporting the recipients in conference travel, purchasing books, lab materials, or engaging in other scholarly activities that directly enhance the individual’s professional growth. Each recipient receives a monetary award of $1,200 along with a plaque.
Aobo Li is a postdoctoral research associate and COSMS Fellow in our Department. He is described by his professors as a “rising star in the neutrino and nuclear physics community.” He leverages artificial intelligence to facilitate the experimental search of neutrino-less double-beta decay – part of an effort to explain why there was matter left after the Big Bang instead of only pure energy. His efforts to stay informed about new tools in machine learning (and immediately learn how to best apply them to experiments) has already led to several notable achievements. Li’s expertise and leadership provide a unique educational opportunity for UNC graduate and undergraduate students.
Joshua is one of the six NC STEM Policy Fellows for 2022-2023, the third year of operation for the program (see the press release). He will be working in the NC Department of Commerce’s Office of Science, Technology & Innovation (OSTI) on a number of projects to further economic development and innovation across the state. He will primarily support and promote the One North Carolina Small Business Program, which is a State initiative to provide additional funds to local groups applying for and receiving federal SBIR and STTR awards so their projects can expand beyond initial expectations. This program was started by former OSTI Executive Director Dr. Robert McMahan, who was a Professor of Physics and Astronomy at UNC from 1989-2008. Joshua will also be engaged in a number of other efforts, including offshore wind development; activities of the Board of Science, Technology & Innovation (BSTI), such as the new Defense Innovation Initiative to increase Department of Defense investment in NC businesses; and updating the Tracking Innovation Report, which paints a picture of the current NC innovation landscape and offers insight into ways to improve business and technology development.
“Argus Panoptes, the all-seeing, manyeyed giant of Greek mythology, is about to take physical form in the mountains of North Carolina. In October, an array of 38 small telescopes will begin monitoring a slice of visible sky 1700 times the size of the full Moon. Known as the Argus Array Pathfinder, it will register changes in the stars second by second, essentially making a nightlong celestial movie. Its developers hope it will pave the way for a much larger Argus Array with 900 telescopes that by 2025 could watch the entire visible night sky.”
“The Argus telescopes join others aiming to capture short-lived or rapidly changing astrophysical events, known as transients, including exploding stars, ravenous black holes, neutron star mergers, and maybe even stars briefly eclipsed by the long-postulated hidden planet in our Solar System. The full Argus Array would watch the sky with more mirror area than all other transient telescopes put together, says team leader Nicholas Law of the University of North Carolina, Chapel Hill.”
The Multiverse Laura Mersini-Houghton is an internationally renowned cosmologist and theoretical physicist and one of the world’s leading experts on the multiverse and the origins of the universe. She talks to Gaia Vince about finding evidence that supports her multiverse theory as more than just a hypothetical collection of diverse universes, including the one that houses our planet. She also shares her story of growing up with the horrors of a brutal Albanian communist regime.
Before the Big Bang: The Origin of the Universe and What Lies Beyond, by Laura Mersini-Houghton, published July 19th, 2022.
“A revolutionary new account of our universe’s creation—and a breathtaking exploration of the landscape from which we sprang—from one of the world’s most celebrated cosmologists….
A mind-expanding journey through the multiverse, Before the Big Bang will reshape our understanding of humanity’s place in the unfathomable vastness of the cosmos.”
Nuclear resonance fluorescence (NRF) experiments using linearly polarized γ-ray beams allow for the measurement of level energies and widths, spins, parities, multipolarity mixing ratios, and branching ratios, and, therefore, represent an important tool for probing nuclear structure. These properties are equally important for nuclear astrophysics, since they enter either directly in the determination of thermonuclear reaction rates, or indirectly via energy and efficiency calibrations.
In a study recently published in Physical Review C, we investigated excited states of 40Ca and 11B at level energies between 8 and 9 MeV, using the High-Intensity γ-ray Source (HIγS) at the Triangle Universities Nuclear Laboratory (TUNL). Levels in the 11B nucleus are interesting because they often provide energy and efficiency calibrations for NRF experiments, while excited states in the 40Ca nucleus are important for estimating reaction rate contributions from unobserved low-energy resonances in the 39K(p,γ)40Ca reaction – a reaction which is relevant for improving our understanding of potassium nucleosynthesis mysteries in globular clusters within our own Milky Way. One of the powerful tools available to us at HIγS is the ability to produce photon beams that are linearly polarized and nearly-monoenergetic. These beams give rise to pronounced angular correlations (can be thought of as the “radiation pattern,” or the angles at which γ-rays are emitted from the excited target) that are sensitive to both the spin and parity. As a result, measuring the angular correlation between the incident and emitted γ-rays allows for a straightforward determination of spin and parity values. One of the goals of the present work was to derive precise excitation energies of 40Ca levels that may contribute to the 39K(p,γ)40Ca thermonuclear reaction rate.
In previous literature, the spin-parity of the 8425-keV level in 40Ca is assumed to be 2−. This level then dominates the thermonuclear reaction rates in the 39K(p,γ)40Ca reaction, below a stellar temperature of 100 MK. If this level instead had a spin-parity of 2+ (not entirely ruled out by the previous literature), it would correspond to a dominant rate contribution at even higher temperatures. Additionally, a 2+ assignment would imply a contribution to the 39K(p,α)36Ar reaction rate as well. Since this spin-parity assignment has significant implications for potassium nucleosynthesis in globular clusters – of which there are still particular unsolved mysteries – it must be considered carefully. In our experiment, we obtained improved excitation energies for 40Ca as well as an unambiguous 2− assignment for the state at 8425 keV. We also obtained improved γ-ray multipolarity mixing ratios and more precise branching ratios for the 11B state at 8920 keV.
Figure 1: (Top) The peculiar globular cluster NGC 2419. It is located in the outer halo of the Milky Way, further away than the Small and Large Magellanic Clouds, at a galactocentric distance of 87.5 kpc. The recently observed strong potassium enhancements represent a puzzle for our understanding of both stellar and galactic evolution theory. Credit: ESA/Hubble & NASA. (Bottom) Setup used for our experiment. The incident gamma-ray beam moves inside a plexiglass vacuum tube and impinges on a sample (boron powder or CaO powder). The direction of the linear polarization of the beam points parallel to the horizontal plane. The front face of each detector is covered by a passive shield (yellow) to reduce backgrounds.
Two new faculty members are joining UNC Physics and Astronomy: Wei Zhang and Carl Rodriguez. Welcome!
Wei Zhang received his B.S. in Physics from Peking University, China (2008) and Ph.D. in Materials Science and Engineering from University of Washington – Seattle (2013). He did his postdoc work at Argonne National Laboratory (2013 – 16). He served in the Physics department of the Oakland University in Michigan until 2022 when he moved to UNC Chapel Hill. His scientific research is focused on the fundamental excitations of magnetically ordered materials and how they interact with other excitations, such as microwave photons, light, and phonons. His work encompasses essential aspects of these magnetic phenomena and their potential applications. He was the recipient of the IEEE Magnetic Society Early Career Award (2016) and NSF CAREER award (2020).
Carl Rodriguez will join the Department in January 2023. He received his B.A. in Physics from Reed College in Portland/OR (2010), and his Ph.D. (Physics) at Northwestern University in 2016, advised by Fred Rasio. After two postdocs at MIT and Harvard, he joined the Physics Department at Carnegie Mellon University as assistant professor in 2020. Dr. Rodriguez works at the intersection of stellar dynamics, gravitational wave physics, and computational astrophysics. He is leading a community effort to understand the formation and evolution of binary black hole systems, from their formation in stellar clusters to the final merger resulting in gravitational-wave signals.
Watch our student making a transistor in the clean room here!
In our teaching laboratories, physics students are able to use UNC state of the art microfabrication equipment to pursue their individual research projects. They learn to manage time and resources, and apply physics knowledge to achieve a scientific/technological goal. In the process, they experience the freedom and constraints of real hands-on physics research as it is carried out in professional research settings while making connections between real-world problems and their prior mathematical, theoretical, and introductory lab training.
