News

Postings created for publication in the Physics Department web page news feed.

2020-Newsletter Department Head Greeting

Posted on by

It’s been crazy.

That holds for everybody over these past six months; UConn and the Physics Department as well. Events unfurled rapidly last March. Within a week the March Meeting of the APS was cancelled, our department had to postpone the 2020 Katzenstein Lecture with Donna Strickland, and then the University announced that students would not return to campus after spring break, with classes moving online and research labs shut down. The work of the department is now ramping back up, though many courses will remain online through spring semester 2021.

The Physics Department has seen turnover in personnel. Three long time faculty members have left the department this summer: Phil Gould has retired, Robin Cote has moved on to be the Dean of Science at UMass Boston, and Susanne Yelin has taken a position at Harvard. All three will maintain ties with us for the foreseeable future. We have some new faces as well. Professors Daniel Angles-Alcazar and Chiara Mingarelli were hired in fall 2019 on bridge positions with the Center for Computational Astrophysics of the Simons Foundation. They both spent 2019-20 at CCA, coming to Storrs full time this fall. We have hired Professor Chris Faesi to complete our initial construction of an Astrophysics group, though he will delay his start at Storrs until fall 2021. We also have hired Professor Erin Scanlon to a position at the Avery Point campus, though during 2020-21 she will spend some time at teaching at Storrs. Another addition to our department is University President Thomas Katsouleas. He is a plasma physicist with academic appointments in Electrical Engineering and Physics. Apparently, his other duties keep him busy, but he has managed to attend a few department events and a faculty meeting.

Despite the pandemic, the department has had notable events and successes. I highlight a few here. We moved into our newly renovated building in August 2019. While there have been a host of construction hiccups, the building is now mostly completed. Our new research labs are state of the art, we have new teaching spaces that allow for moving to a new method of teaching introductory physics, and bright airy spaces throughout. In November we hosted Dame Jocelyn Bell Burnell for the 2019 Katzenstein Lecture. The event was a rousing success as we packed the student union theater and had record attendance at the banquet. We have had some great research success. The most prestigious awards given to new faculty members are the CAREER awards from federal agencies. We now have an unprecedented four active CAREER awardees: Professors Andrew Puckett, Daniel McCarron, Jonathan Trump, and most recently Luchang Jin. Congratulations to all four.

Looking forward, the immediate future remains daunting. We anticipate significant pandemic restrictions for another year and budgets for the university and research agencies are unsettled. Yet the department remain strong. We continue innovative work in education and research, we have an increasing number of excellent physics students, and dedicated faculty with a particularly strong young cohort. When the situation allows, please come visit us to see how we are evolving.

Spring 2020: The Efforts of Many Made Distance Learning Possible

Posted on by

The transition to online learning that was necessitated due to the COVID-19 outbreak was not without its challenges. Faculty had roughly 10 days to adapt to a modality of instruction most were not used to. TAs had to simultaneously learn how to teach remotely while also adjusting to having the courses they were taking also be changed to a distance-based format. Instructors strived to provide reassurance to the more than 2,000 undergraduate students enrolled in physics courses that they would be able to complete their courses. Additionally, the department faced an important question: How would we be able to finish teaching the lab courses now that the campus was closed?

The remarkable efforts of faculty, graduate TAs, and our teaching staff proved to be instrumental in guaranteeing the successful completion of the spring semester. The faculty e-mail listserv was suddenly bursting with activity with instructors eager to share their experiences and help disseminate helpful information to their colleagues. This spirit of camaraderie was also shared by the graduate students, with several TAs stepping up and taking on additional workload to help peers that were facing additional challenges related to the difficult circumstances.

After Spring Break, classes resumed without additional disruptions – courses were being taught either synchronously with classes largely maintaining their original schedule, or through recorded lectures faculty would release on a regular schedule. Exam assessments were shifted to a distance-based format, with some of the larger introductory courses successfully implementing exams through their online homework platforms. The newly redesigned studio courses continued to be taught following a model that sought to promote student interactions and active learning, with several instructors continuing their use of clickers as a formative assessment tool in their distance-based courses. Collaborative problem-solving tutorial sessions continued to be administered as well, with TAs facilitating these activities through the use of breakout groups during the class sessions.

Even with all these strategies rapidly coalescing, we still the faced the unprecedented situation of having to teach lab courses in a distance-based format. Through the diligent efforts of several of our faculty, teaching staff, and graduate TAs, the department was able to resume lab courses without interruptions after Spring Break. This was done by providing students with the structure they needed to complete their coursework. Several creative (and in some cases innovative) solutions were implemented for lab instruction. Howard Winston, an Assistant Professor in Residence from our Waterbury campus, transformed his living room at home into a physics lab room, where he would perform the experiments live on camera for his students while getting their input on how to run the experiment. In a span of 10 days, James Jaconetta, Hannah Morrill, and Zac Transport, our lab technicians from the Storrs campus, remarkably recorded videos performing each of the experiments and demonstrations still remaining in our course schedules. They also supplemented this video library with a list of videos also curated from other reputable internet sources to help support several instructors teaching introductory courses in Storrs and some of the regional campuses.
The collective efforts of dozens of members of our department ultimately guaranteed the successful completion of the Spring 2020 semester even in unfavorable circumstances. While there were many challenges faced throughout the period, there was no shortage of positive feedback provided by students through formal (SETs) and informal means (conversations) demonstrating an appreciation for the organization and structure provided in their courses. During the summer months, instructors and teaching staff utilized their experiences and the feedback received in the spring to improve their strategies for distance-based learning. As an example, several lab courses in the fall are now running activities through a combination of simulations and “at home” experiments students are performing with household items, smartphones, and lab kits assembled by our teaching staff and sent to students.

Ultimately, necessity is the mother of invention, and there is optimism that some of the lessons learned now are helping drive teaching innovations that will still add value to our courses even when we resume in person instruction.

Physics Alum Receives NSF CAREER Award

Posted on by

UConn Physic alum, Dr. Hyewon Pechkis, an Assistant Professor of Physics at the California State University Chico recently received the prestigious CAREER award from the National Science Foundation. This five-year grant titled “Making a Difference in First Year Underrepresented Students’ Education through Research: Quantum Coherence in a Bose Thermal Gas” will facilitate the involvement of CSU Chico undergraduates in experiments on ultracold atoms and quantum science. Hyewon was a graduate student with Prof. Ed Eyler, receiving her PhD from UConn in 2010 for her work on ultracold molecules. Congratulations Hyewon!

New Physics Faculty: Chris Faesi

Posted on by

We are very excited to extend a warm welcome to a new UConn Physics Faculty member, Dr. Christopher Faesi. Chris is an astrophysicist, specializing in both observational work and modelling, primarily in the study of star formation. He got his PhD at Harvard University, followed by a postdoc at the Max Planck Institute for Astronomy in Heidelberg. Most recently Chris was awarded a prestigious NSF Postdoctoral Fellowship at UMass Amherst, and will be on research leave this academic year, completing this Fellowship. Chris is heavily involved in several large-scale international collaborations that will probe the physics of the interstellar medium in nearby galaxies with unprecedented resolution and spectral coverage. He also has extensive experience leading mentorship and outreach activities devoted to students at all levels, as well as the general public. We are looking forward to welcoming Chris to UConn!

Prof. Kyungseon Joo named Chair of CLAS Collaboration at Jefferson Lab

Posted on by

Kyungseon Joo, a professor of physics, has been named Chair of the CLAS Collaboration, one of the largest international collaborations in nuclear physics.  CLAS involves 50 institutions from 9 countries and has about 250 collaborators.  The collaboration recently completed the upgrade of the CEBAF Large Acceptance Spectrometer (CLAS12) for operation at 11 GeV beam energy in Hall B at Jefferson National Laboratory in Newport News, VA, funded by the United States Department of Energy.

CLAS12 is based on a dual-magnet system with a superconducting torus magnet that provides a largely azimuthal field distribution that covers the forward polar angle range up to 35°, and a solenoid magnet and detector covering the polar angles from 35° to 125° with full azimuthal coverage. Trajectory reconstruction in the forward direction using drift chambers and in the central direction using a vertex tracker results in momentum resolutions of 1% and 3%, respectively. Cherenkov counters, time-of-flight scintillators, and electromagnetic calorimeters provide good particle identification. Fast triggering and high data-acquisition rates allow operation at a luminosity of 1035 cm−2s−1. These capabilities are being used in a broad scientific program to study the structure and interactions of nucleons, nuclei, and mesons, using polarized and unpolarized electron beams and targets for beam energies up to 11 GeV.

As Chair, Joo represents the collaboration in scientific, technical, and managerial concerns, while he closely works with the Lab management on scheduling experiments, organizing collaboration activities and expanding the reach of the collaboration. He currently focuses on collaboration-wide efforts to timely make first publications from CLAS12 with high impact science.

CLAS detector in Hall B at Jefferson Lab
The CLAS12 detector in the Hall B beamline. The beam enters from the right near the upstream end of the solenoid magnet and the cryogenic service tower, followed by the High Threshold Cherenkov Counter and the torus magnet with the drift chambers. The Low Threshold Cherenkov Counter, Forward Time-of-Flight, and the electromagnetic calorimeters are seen at the downstream end to the left.

Physics Department Joins APS-IDEA Network

Posted on by and

The Physics Department’s Diversity & Multiculturalism Committee (DMC) was accepted into the APS Inclusion, Diversity and Equity Alliance (APS-IDEA).

Despite years of efforts on local and national levels, the diversity in many physics departments is not reflective of the diversity nationwide. Our department is no exception in this regard. The new APS initiative was created to advance equity, diversity, and inclusion (EDI) in physics by establishing a community of transformation. The international network is formed of teams from over 90 physics departments, laboratories, and other organizations from USA, Canada, Brazil, Germany, and Finland that share the same EDI goals.

The inaugural virtual workshop took place this Summer with over 180 attendees, including APS, AIP, advisory board, and the APS-IDEA steering committee. The next workshop is scheduled for September and more workshops will be organized throughout the year. Acceptance of the departmental DMC positions the UConn Physics Department on the map of global institutions to collectively exchange ideas, learn, and enact strategies for improving EDI in physics. What can we expect? The vision of this initiative is to make physics community more inclusive. The participating teams will exchange ideas/experiences, deepen their knowledge of EDI research and effective practices, and receive guidance to prepare realistic sustainable plans for improving EDI.

Our APS-IDEA team consist of members at the Physics Department from all departmental levels (faculty, staff, graduate and undergraduate students). Current team members are: Elena Dormidontova (Chair of Diversity & Multiculturalism Committee), Gayanath Fernando, Gloria Fonseca Alvarez, Menka Jain, Aditi Mahabir, Belter Ordaz Mendoza (team contact), Dave Perry, Peter Schweitzer, Megan Sturm, Jonathan Trump, Diego Valente, and Susanne Yelin. The application was supported by the Department Head Barry Wells. All members of the Physics Department are invited and encouraged to join our APS-IDEA team. Together we can enhance inclusion and belonging in physics.

https://www.aps.org/publications/apsnews/202008/aps-idea.cfm

Professor Luchang Jin receives prestigious DOE Early Career Award

Posted on by
Assistant Professor of Physics Luchang Jin has been chosen to receive a prestigious Early Career Award from the US Department of Energy’s Office of High Energy Physics (HEP) for 2020. The amount of the award is $750,000 to be used over five years. The DOE Early Career Award is extremely competitive: this year only 16 scientists in HEP in the US were awarded such grants, and only 76 scientists across the entire DOE. Dr. Jin will use the grant to support his research using numerical methods to study how electromagnetic interactions affect the decays of mesons, subatomic particles composed of a quark and anti-quark pair. This study, carried out within the framework of the fundamental Standard Model of Particle Physics, is expected to improve our knowledge of the interactions between quarks and the Weak gauge bosons. With some luck, Professor Jin’s research may provide evidence of new interactions or particles yet to be discovered.

Jonathan Trump wins NSF Early Career Award

Posted on by
Jonathan Trump, Assistant Professor of Physics, will receive $738,090 over five years to compile a census of supermassive black holes in the universe. This will give insights into how supermassive black holes and galaxies evolve across cosmic time. Trump will also develop a bridge program for underrepresented undergraduate physics majors at UConn to increase their participation in STEM fields.
The NSF Faculty Early Career Development (CAREER) Program supports 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. Activities pursued by early-career faculty build a firm foundation for a lifetime of leadership in integrating education and research.
Trump was one of 7 junior faculty at the University of Connecticut to receive the prestigious Early Career awards from NSF in 2020. For a description of all 7 awards, see this recent article published in UConn Today.

New result for part of muon anomaly

Posted on by

 

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.

Radiation Damage Spreads

Posted on by

Radiation Damage Spreads Among Close Neighbors

X-ray absorption cascade
Direct hit. A soft x-ray (white) hits a holmium atom (green). A photo-electron zooms off the holmium atom, which releases energy (purple) that jumps to the 80-carbon fullerene cage surrounding the holmium. The cage then also loses an electron. (Courtesy of Razib Obaid)

March 17, 2020 – Kim Krieger – UConn Communications

A single x-ray can unravel an enormous molecule, physicists report in the March 17 issue of Physical Review Letters. Their findings could lead to safer medical imaging and a more nuanced understanding of the electronics of heavy metals.

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 that  it 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 is  enough 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 (10-15 s). 

The work was funded by Department of Energy, Basic Energy Sciences (BES), Division of Chemical Sciences, Geosciences, and Biosciences, under Grant No. DE-SC0012376.