The University of Connecticut, Department of Physics, is proud to announce that on September 23, 2022, Professor Donna Strickland of the Department of Physics and Astronomy at the University of Waterloo will be presenting the 2020 Distinguished Katzenstein Lecture. Prof. Strickland is one of the recipients of the 2018 Nobel Prize in Physics for developing chirped pulse amplification with Gérard Mourou, her PhD supervisor. They published this Nobel-winning research in 1985 when Strickland was a PhD student at the University of Rochester in New York State. Together they paved the way for the most intense laser pulses ever created. The research has several applications today in industry and medicine, including the cutting of a patient’s cornea in laser eye surgery and the machining of small glass parts for use in cell phones.
Prof. Strickland earned a Bachelor in Engineering from McMaster University and a PhD in optics from the University of Rochester. She was a research associate at the National Research Council Canada, a physicist at Lawrence Livermore National Laboratory, and a member of technical staff at Princeton University. In 1997, she joined the University of Waterloo, where her ultrafast laser group develops high-intensity laser systems for nonlinear optics investigations. She is a recipient of a Sloan Research Fellowship, the Ontario Premier’s Research Excellence Award, and a Cottrell Scholar Award. She received the Rochester Distinguished Scholar Award and the Eastman Medal from the University of Rochester.
Prof. Strickland served as the president of the Optical Society (OSA) in 2013 and is a fellow of OSA, the Royal Society of Canada, and SPIE (International Society for Optics and Photonics). She is an honorary fellow of the Canadian Academy of Engineering and the Institute of Physics. She received the Golden Plate Award from the Academy of Achievement, is in the International Women’s Forum Hall of Fame, and holds numerous honorary doctorates.
Professor Cara Battersby has been awarded an NSF CAREER grant! “The Faculty Early Career Development (CAREER) Program is a Foundation-wide activity that offers the National Science Foundation’s most prestigious awards in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.”
Prof. Battersby’s CAREER Award is entitled “CAREER: Shining STARs Amidst the Turbulence” and is an ambitious project to complete the first-ever systematic study of turbulence in an extreme environment, the center of our galaxy. Turbulence is poorly understood yet plays a pivotal role in the setting the Initial Mass Function (IMF), which underpins all of modern astrophysics. The results from this research will be brought into under-resourced high school classrooms through lesson plans jointly developed by K-12 teachers and undergraduate students from traditionally under-represented groups. Battersby aims to recruit and retain students from under-represented groups in STEM through a new mentorship program UConn-STARs.
UConn is now home to tools that have played an instrumental role in mapping the universe — 10 large aluminum plates used as part of the Sloan Digital Sky Survey (SDSS). Measuring 32 inches across, one-eighth of an inch thick, and with thousands of tiny holes drilled in them, these plates may not be the type of instruments most people would initially picture; however, they have helped answer important questions about the universe.
Jonathan Trump, associate professor of physics, helped design the final round of plate observations for SDSS, which observed over three million objects in the sky, including stars, galaxies, and supermassive black holes from a telescope in New Mexico.
UConn’s collaboration with the Department of Defense Air Force Research Laboratory (AFRL) is launching a new project. It is titled Multiscale Modeling and Characterization of Metamaterials, Functional Ceramics and Photonics. This is a $4.7 M contract with $1M for Physics. The project’s goal is to explore and advance the understanding of electronic, photonic, magnetic, and multiferroic materials, with future applications in the aerospace industry. Two experimental condensed matter physicists Dr. Menka Jain and Dr. Ilya Sochnikov will contribute to the understanding of magnetic and multiferroic materials. The project supports 4 graduate Research Assistants in the Physics Department and is a unique life-transformative and career-building opportunity for them.
Professor Andrew Puckett’s research group is currently leading, as part of a collaboration of approximately 100 scientists from approximately 30 US and international institutions, the installation in Jefferson Lab’s Experimental Hall A of the first of a series of planned experiments known as the Super BigBite Spectrometer (SBS) Program, with beam to Hall A tentatively scheduled to begin in early September of 2021. Jefferson Lab, located in Newport News, Virginia, is a national user facility operated by the US Department of Energy, and is the world’s premiere laboratory for imaging the subatomic (and subnuclear) quark-gluon structure of protons, neutrons, and nuclei using its continuous, polarized electron beam. In addition to Professor Puckett, the UConn researchers involved in this effort are Postdoctoral Research Associate Eric Fuchey, and Graduate Research Assistants Provakar Datta and Sebastian Seeds. The first set of experiments in the SBS program, slated to run during Fall 2021, is focused on the measurement of neutron electromagnetic form factors at very large values of the momentum transfer Q2, which essentially probe the spatial distributions of electric charge and magnetism inside the neutron at very small distance scales of order 0.05-0.1 fm (1 fm = one femtometer = 10-15 m = 0.000 000 000 000 001 m), approximately 10-20 times smaller than the size of the proton and approximately 1 million times smaller than the size of a typical atom.
Electrons from Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF), with energies of up to 10 GeV (=10 billion electron-volts), will scatter elastically from protons and neutrons in a liquid deuterium target in Hall A. Scattered electrons will be detected in the BigBite Spectrometer, located on the left side of the beam, while the high-energy protons and neutrons recoiling from the “hard” collisions with the beam electrons will be detected in the SBS by the newly constructed Hadron Calorimeter (HCAL), located on the right side of the beam. The SBS dipole magnet will provide a small vertical deflection of the scattered protons, which allows HCAL to distinguish them from scattered neutrons, which are undeflected by the magnetic field, but produce otherwise identical signals in HCAL.
The first group of SBS experiments, collectively known as the “GMN run group”, will answer several important questions about the “femtoscopic” structure of the neutron, including:
What is the behavior of the neutron’s magnetic form factor at large momentum transfers? The SBS experiment will dramatically expand the Q2 reach of neutron magnetic form factor data compared to all previously existing measurements, from approximately 4 –> 14 (GeV/c)2. See original experiment proposal here.
How is the charge and magnetism of the proton shared among its “up” and “down” quark constituents as a function of Q2? The proton magnetic form factor has been measured over a much wider range of Q2 than the neutron, and combined proton and neutron measurements can be used to disentangle the contributions of “up” and “down” quarks (and diquark correlations) to the proton’s structure, under the assumption of charge symmetry of the strong interactions (see, e.g., https://inspirehep.net/literature/1812076)
How important and/or significant is the contribution of two-photon-exchange to elastic electron-neutron scattering? The first SBS experiment group will perform measurements of the electric/magnetic form factor ratio for the neutron using two different techniques known as “Rosenbluth Separation” and “Polarization Transfer”, at a Q2 where these two techniques have shown significant disagreement for the proton. Both measurements will be the first of their kind for the neutron at such large Q2 values (see, e.g., Polarization Transfer Proposal and Rosenbluth Separation Proposal)
The GMN run group will start in early September and run through the fall of 2021. The broader SBS program will continue in Hall A through at least 2023, and will drastically improve our understanding of the femtoscopic quark-gluon structure of protons, neutrons, and atomic nuclei. Professor Puckett’s research in the SBS and Hall A Collaborations is supported by the US Department of Energy, Office of Science, Office of Nuclear Physics. Stay tuned!
I would like to share some thoughts on Munir Islam who recently passed away. Prof. Islam came to UConn in 1967 from a faculty position at Brown University. In the late 1970s there were two particle theorists at UConn, Profs. Kurt Haller and Munir Islam. They set about building an elementary-particle theory program here and garnered the support of then Physics Head Joe Budnick and CLAS Dean Julius Elias. They soon obtained funding for a new Department of Energy initiative to support particle theory in the Department. In 1979 they
were able to bring me in as an Associate Professor and Mark Swanson as an Assistant Professor. So eager were Kurt and Munir to bring us in, they chose to forego the summer salary that they had been awarded on the DOE grant. The impact of the DOE grant on the UConn administration was quite far reaching and led to further internal support. Within a few years I had been tenured and promoted to Full and Mark had been tenured and appointed to Associate at our Stamford branch, where he later became an administrator.
After that, Kurt and Munir were able to secure a bridge position with the DOE that would provide five years of support, provided the UConn administration would create a tenure track position for the recipient. This they agreed to do, and so we brought in Daniel Caldi at the Assistant level, who subsequently was appointed Associate with tenure. Dan eventually opted to leave us for SUNY Buffalo, but our particle group was then able to convince the UConn administration to let us keep the position, and we then hired Gerald Dunne. Gerald went up the ladder very quickly to tenured Full professor. The success of our program enabled us subsequently to bring in Alex
Kovner, followed by Tom Blum (both now tenured Full) and current Assistant Luchang Jin. The success and endurance of the particle group for more than forty years now is a testament to the foresight and the unwavering and unabating commitment of Kurt and Munir to it, and it serves as permanent memorial to both of them.
Munir Islam always retained an enthusiasm for research, an enthusiasm which did not diminish at all after he retired. He focused on fundamental problems in particle physics, with particular emphasis on the theory of the structure of the proton as revealed by high-energy proton-proton scattering. This is perhaps best evidenced in what essentially became a lifelong collaboration with his former graduate student Richard Luddy (at the right, with Prof Islam at the left in the above photograph) as the two of them grappled with Munir’s deep ideas on proton scattering during many of Munir’s later years as a Professor and then as an Emeritus. Munir had a gift for simple pictorial explanations of his research, which he was able to explain lucidly in a lecture for visiting high-school teachers and students during an open house. Munir was urbane, worldly, and wise, and it was a great joy to have him not just as a colleague but also as a friend. He will be sorely missed by all of those that knew him and especially by me as my career owes so much to him. In appreciation, Philip Mannheim.In appreciation,
Professors Tom Blum and Luchang Jin, along with colleagues at BNL and Columbia, Nagoya, and Regensburg universities have completed a first-ever calculation of the hadronic light-by-light scattering contribution to the muon’s anomalous magnetic moment with all errors controlled. The work is published in Physical Review Letters as an Editor’s Suggestion and also appeared in Physics Magazine. A recent press release from Argonne National Lab described the calculation, which was performed on Mira, Argonne’s peta-scale supercomputer.
The team found the contribution is not sufficient to explain the longstanding difference between the Standard Model value of the anomalous magnetic moment and the BNL experiment that measured it. The discrepancy, which could indicate new physics, should be resolved soon by a new experiment at Fermilab (E989) and improved theory calculations, including the one described here, both with significantly reduced errors. E989 is set to release their first results later this year.
Medical imaging techniques such as MRIs use heavy metals from the bottom of the periodic table as “dyes” to make certain tissues easier to see. But these metals, called lanthanides, are toxic. To protect the person getting the MRI, some chemists wrap the lanthanide inside a cage of carbon atoms.
Molecular physicist Razib Obaid and his mentor, Prof. Nora Berrah in the physics department, wanted to know more about how the lanthanides interact with the carbon cages they’re wrapped in. The cages, 80 carbon atoms strong, are called fullerenes and are shaped like soccer balls. They don’t actually bond to the lanthanide; the metal floats inside the cage. There are many similar situations in nature. Proteins, for example, often have a metal hanging out close to a giant organic (that is, mostly made of carbon) molecule.
So Obaid and his team of collaborators from Kansas State University, Pulse Institute at Stanford, Max Planck Institute at Heidelberg, and the University of Heidelberg studied how three atoms of the lanthanide element holmium inside of an 80-carbon fullerene reacted to x-rays. Their initial guess was that when an x-ray first hit one of the holmium atoms, it would get absorbed by an electron. But that electron would be so energized by the absorbed x-ray thatit would fly right out of the atom, leaving a vacant spot. That spot would than get taken by another of the holmium’s electrons, which would have to jump down from the outer edge of the atom to fill it. That electron had formerly been partnered with another electron on the outskirts of the atom. When it jumped down, its lonely ex, called an Auger electron, would zoom away from the whole molecule and get detected by the scientists. Its distinctive energy would give it away.
It sounds complicated, but that would have been the simplest (and thus most likely) scenario, the physicists thought. But it’s not what they saw.
When Obaid and his colleagues zapped the holmium-fullerene molecule with a soft x-ray (about 160 electron-volts), the number of the Auger electrons detected was too low. And too many of the electrons had energies much less than the Auger electrons should have.
After some calculating, the team figured out there was more going on than they’d guessed.
First, the x-ray would hit the holmium, which would lose an electron. The vacant spot would then be filled by the outer edge electron from the holmium atom. That much was correct. But the energy released by the jumping electron (when it jumps ‘down’ from the outskirts of the atom to the interior, it also jumps ‘down’ in energy) would then be absorbed by the carbon fullerene cage or another of the neighboring holmium atoms. In either case, the energy would cause an additional electron to zoom away from whatever absorbed it, the fullerene cage or the holmium atom.
Losing these multiple electrons destabilized the whole molecule, which would then fall apart entirely.
The end result?
“You can induce radiation damage just by striking one atom out of 84,” says Obaid. That is, a single x-ray strike isenough to destroy the entire molecule complex through this energy transfer process involving neighboring atoms. It gives some insight into how radiation damage occurs in living systems, Obaid says. It was always thought that radiation damaged tissue by stripping away electrons directly. This experiment shows that interactions between an ionized atom or molecule and its neighbors can cause even more damage and decay than the original irradiation.
The work also gives medical physicists an idea of how to limit patient’s exposure to heavy metals used as dyes in medical imaging. Shielding all parts of the body from the radiation except for those to be imaged with heavy metal dyes can potentially restrict the heavy metal exposure as well as the radiation damage, the researchers say. The next step of this work would be to understand exactly how fast this interaction with the neighbors occurs. The researchers expect it to take place in just a few femtoseconds (10-15s).
The work was funded by Department of Energy, Basic Energy Sciences (BES), Division of Chemical Sciences, Geosciences, and Biosciences, under Grant No. DE-SC0012376.
The UConn Today published an article highlighting the state of 10-year renovation of the Gant Science Complex. The Complex was first constructed between 1974 and 1978 and was home to the departments of mathematics and physics for several decades. The renovation to this 285,00 square-foot campus landmark is part of Next Generation Connecticut, the initiative to expand educational opportunities, research, and innovation in the science, technology, engineering, and math (STEM) disciplines at UConn.
The Daily Campus published an article highlighting the research of Prof. Thomas Blum about Quantum Chromodynamics, a theory which describes the interactions between elementary particles. The development of this theory could help further understanding of the Standard Model of particle physics. The Standard Model is what physicists use to describe the fundamental building blocks of everything in the universe.