Tag Archive for physics

Kottos Awarded Engineering Grant from the National Science Foundation

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Professor Tsampikos Kottos

Tsampikos Kottos, professor of physics, professor of integrative sciences, professor of mathematics, was awarded a $400,000 Emerging Frontiers in Research and Innovation (EFRI) engineering grant from the National Science Foundation in October. This $2 million grant is equally split among a consortium of universities, including Stanford University, University of Minnesota, and University-Wisconsin-Madison, and will last for a period of four years.

The grant is associated with “New Light and Acoustic Wave Propagation: Breaking Reciprocity and Time-Reversal Symmetry” (NewLaw) and supports “engineering-led interdisciplinary research that challenges the notions of reciprocity, time-reversal symmetry and sensitivity to defects in wave propagation and field transport,” Kottos explained. 

Office of Naval Research Supports Microwave Limiter Study in Physics Department

Tsampikos Kottos, professor of physics, professor of mathematics, and his graduate student, Eleana Makri, are studying photonic limiters, which can be used to protect optical sensors (for example, the human eye) against laser-induced damage. Kottos recently received a grant to advance his research on microwave limiters, an important class of such protection devices.

Tsampikos Kottos, professor of physics, professor of mathematics, and his graduate student, Eleana Makri, design reflective power limiters, which reflect radiation back into space. Kottos recently received a grant to advance his research on microwave limiters, an important class of such protection devices.

With support from the Office of Naval Research, researchers in Wesleyan’s Physics Department are working on ways to protect optical sensors (for example, the human eye) against laser-induced damage.

In August, Tsampikos Kottos, professor of physics, professor of mathematics, received a three-year grant from the Office of Naval Research to further his designs of “Reflective Microwave Limiters.” Typical microwave limiters have the ability to block excessive radiation through absorption. However, absorption can lead to overheating, eventually causing the destruction of the limiter.

Kottos studies reflective power limiters with his graduate student Eleana Makri and Postdoctoral Research Associate Roney Thomas. The team hopes to develop realistic designs of microwave limiters that can tolerate high power radiation via direct reflection back in space (instead of absorbing it.)

“The limiter designs that we propose would reflect excess radiation back to space while providing broadband, omnidirectional protection from high-power electromagnetic radiation. As a result, they will be able to protect sensitive equipment by two or even three orders of magnitude higher power radiation than existing limiters,” Kottos explained.

The Office of Naval Research (ONR) is an organization within the U.S. Department of the Navy that coordinates, executes, and promotes the science and technology programs of the U.S. Navy and Marine Corps through schools, universities, government laboratories, nonprofit organizations, and for-profit organizations. Due to the rapid development of high power directed energy weapons technology, the ONR is supporting research that explores new materials and protection schemes of electromagnetically sensitive components from high power incident radiation.

Morgan Speaks on Laser-Induced Breakdowns at Plasma Physics Conference

Tom Morgan

Tom Morgan

Tom Morgan, Foss Professor of Physics, recently attended the 43rd Institute of Physics U.K. Plasma Physics Conference in Isle of Skye, Scotland. He presented a flash verbal presentation and a poster contribution dealing with the properties of water following focused laser induced breakdown.

After a plasma (a gas of ions and free electrons) is formed in water by laser breakdown, the energy is dissipated through light emission, shockwaves and cavitation bubbles. When the breakdown is close to the surface of the water, surface waves and water ejection from the surface up to heights of 60 cm also occur.

All of these phenomena have been observed in the laboratory at Wesleyan in conjunction with Lutz Huwel, professor of physics, Matt Mei ’18, and international collaborators. Joining the effort from abroad are Professor Tomoyuki Murakami, Seikei University, Tokyo, and Professor Bill Graham, Queen’s University, N. Ireland.

New effects not seen before have been observed, particularly near the surface at the air-water interface. The air-water interface is ubiquitous with applications to biology, environmental studies, chemical analysis and medicine, but its detailed behavior under different conditions is not well understood. The research uses both state of the art computer simulation and experimentation to elucidate the evolutionary dynamics and structure of bulk water and the air-water interface.

“Since the meeting was in Scotland, the researchers though it appropriate to try a liquid other than water and results were reported on whiskey as well,” Morgan said.

Makri Delivers Graduate Student Talk on Reflective Photonic Limiters

Eleana Makri, a PhD candidate in physics, spoke on “Reflective Photonic Limiters: a Novel Scheme for Sensor Protection” during the Graduate Student Speaker Series Feb. 10 in Exley Science Center. Photonic limiters are devices designed to transmit low-level radiation, while blocking electromagnetic pulses of power or total energy exceeding a certain threshold.

Eleana Makri, a PhD candidate in physics, spoke on “Reflective Photonic Limiters: a Novel Scheme for Sensor Protection” during the Graduate Student Speaker Series Feb. 10 in Exley Science Center. Photonic limiters are devices designed to transmit low-level radiation, while blocking electromagnetic pulses of power or total energy exceeding a certain threshold.

Starr’s Nanoparticle Research Published in Science

Professor Francis Starr and his collaborators are working to self-assemble a diamond-structured lattice at will from nanoscale particles.(Image by graduate student Hamed Emamy). 

Professor Francis Starr and his collaborators are working to self-assemble a diamond-structured lattice at will from nanoscale particles. (Image by graduate student Hamed Emamy).

Professor Francis Starr, graduate student Hamad Emamy and collaborators from the Brookhaven National Lab have co-authored a paper titled “Diamond Family of Nanoparticle Superlattices” published in the prestigious journal Science on Feb. 5. Starr is professor of physics and director of the College of Integrative Sciences.

Their work proposed a solution to a decades-long challenge to self-assemble a diamond-structured lattice at will from nanoscale particles.

“Such a diamond-lattice structure has long been sought after due to its potential applications as a light controlling device, including optical transistors, color-changing materials, and optical — as opposed to electronic — computing,” Starr said.

To solve this challenge, the team utilized the specific binding properties of DNA as a tool for materials science. Specifically, they created nanoscale “atoms” that consist of 15 nanometer gold nanoparticles coated with many single-stranded DNA. The single-stranded DNA act like binding arms to connect nanoparticle/DNA “atoms” by forming double-stranded DNA links, and analogue of traditional chemical bonds between atoms. By appropriate selection of the sequence and orientation of these DNA links, the nanoparticles will spontaneously arrange themselves into the desired structure.

“This self-assembly approach not only allows for highly specific order, but also offers the potential for tremendous savings in the cost of materials production, as compared to traditional methods used in the semi-conductor industry,” Starr explained.

Emamy, a graduate student in Starr’s lab, carried out numerical simulations that helped to develop the approach and explain how to stabilize the structure. Collaborators at Brookhaven experimentally synthesized and verified the structure and properties. The effort, Starr said, represented an ideal collaboration between experiments, theory and computation.

Wesleyan Hosts Conference for Undergraduate Women in Physics

More than 200 women undergraduates from the North East who are majoring in physics attended the American Physical Society Conferences for Undergraduate Women in Physics (CUWiP)

Attendees from the American Physical Society Conferences for Undergraduate Women in Physics gathered for a group photo. Wesleyan is the first liberal arts college to host a CUWiP.  Pictured in red at far left, assistant professor Chris Othon, and pictured at far right, assistant professor Meredith Hughes co-organized the conference at Wesleyan.

More than 200 women undergraduates from the Northeast attended the American Physical Society Conferences for Undergraduate Women in Physics (CUWiP) Jan. 15-17 at Wesleyan. Wesleyan was one of nine institutions from around the country to host a conference. (View an extensive recap of the conference starting on Page 8 of this APS newsletter.)

The APS CUWiP provides female physics majors with the opportunity to experience a professional conference, information about graduate school and professions in physics, and access to other women in physics with whom they can share experiences, advice and ideas.

The program included panel discussions about graduate school and careers in physics, presentations and discussions about women in physics, laboratory tours, student research talks, a student poster session, banquet and career fair.

Scientific American Editor Moskowitz ’05 is Woman Physicist of the Month

Clara Moskowitz. (Photo by John Van Vlack)

Clara Moskowitz ’05. (Photo by John Van Vlack)

The American Physical Society (APS) named Clara Moskowitz ’05 the Woman Physicist of the Month for December 2015. A senior editor at Scientific American, she was an astronomy and physics double major at Wesleyan. It was in her senior year that she discovered her “favorite part” of her undergraduate career: her thesis.

“I was fascinated by science from a very young age,” she says, “but so many people feel separated from science—as though they can’t get it. I realized that I like writing and I like to communicate the concepts for nonscientists.” After earning a graduate degree in science journalism at the University of California, Santa Cruz, Moskowitz then joined the online publication Space.com, where she covered NASA’s space shuttle missions and other astronomy news. Two years ago, she joined the venerable Scientific American: “We try to keep it current and stay true to its legacy,” she notes.

Moskowitz recalls her favorite assignment at the magazine—which she focused on both historic import and present application: she served as editor of the theme issue on 100 years of general relativity (Sept. 2015, Vol. 313, Issue 3).
“Einstein is such a fascinating figure; he singlehandedly revolutionized science just by thinking about problems: he went through in his mind exactly what it would be like to ride a beam of light. A hundred years after he proposed the theory, we are still thinking about it, still using it—in our cellphones, GPS devices, and satellites.

“His realization that gravity is not so much a force that pulls things together—but rather that it comes from the shape of space and time—is such a beautiful idea.”

As for her success with the project, editor-in-chief Mariette DiChristina wrote, “Issue editor Clara Moskowitz and the team have created a special report that is profound yet playful and sparkles with the wonder of discovery—rather like the great man himself. We hope you enjoy reading [this issue] as much as we did putting it together.”

Said Moskowitz, “I’m constantly working hard to make science understandable. I want everyone to see what’s so cool about it.”

Reached at the American Astronomical Society’s January 2016 meeting, which she was covering for Scientific American, Moskowitz was most excited about a recent talk she attended about astronomers planning to use telescopes all over the world in conjunction, in order to capture the event horizon of the black hole that astronomers think lies at the center of our galaxy. The project—which could further prove the theory of general relativity, or call for modifications—will take its first images of the black hole in 2017.

“A lot of us are on the edge of our seats until we get the results,” Moskowitz said.

Moskowitz also was back at Wesleyan on Jan. 16 for the Conference for Undergraduate Women in Physics, where she spoke about her career path. She will present a Physics Department colloquium on March 3 about science journalism.

Morgan Speaks at Atomic Molecular Optical Workshop in Mexico

Tom Morgan

Tom Morgan

Tom Morgan, the Foss Professor of Physics, recently attended an Atomic Molecular Optical International Workshop held in Cuernavaca, Mexico.

Morgan presented two invited talks, one on highly excited unusual electronic configurations of molecular hydrogen produced by laser excitation and another on laser interactions at the interface between water and air. These topics elicit novel dynamics and provide a different perspective on H2 and H2O behavior.

He also took the opportunity to reconnect with a Mexican colleague, Professor Carmen Cisneros, Institute of Physics, University of Mexico, organizer of the workshop, with whom Morgan has collaborated in the past.

Morgan Presents Phase Space Research at Gaseous Electronics Conference

Professor Tom Morgan, Andrew Murphy '11 and Jace Haestad '11 recently presented their research "Closed Orbits in Phase Space" in Hawaii. 

Professor Tom Morgan presented “Closed Orbits in Phase Space” in Hawaii.

Tom Morgan, Foss Professor of Physics, recently attended the 68th Gaseous Electronics Conference of the American Physical Society in Honolulu, Hawaii and presented a poster dealing with the behavior of giant atoms with an electron far from the nucleus in phase space. Andrew Murphy ’11 and Jace Haestad ’11 contributed to the study.

Phase space is a momentum-velocity space that provides a different perspective on atomic behavior. Looking at atoms from this viewpoint provides a mechanism to uncover new insight into their quantum nature.

Morgan also took the opportunity to reconnect with a Japanese colleague, Professor Tomoyuki Murakami, at Seikei University, Tokyo, whom Morgan spent the month of June visiting in Tokyo. Morgan and Murakami took the occasion to work on a paper on research undertaken collaboratively with Lutz Huwel, Professor of Physics, and Professor Bill Graham of Queen’s University, N. Ireland, on the behavior of the air-water interface after focused laser induced plasma breakdown. The air-water interface is ubiquitous with applications to biology, environmental studies, chemical analysis and medicine, but its detailed behavior is not well understood. The collaboration uses both state of the art computer simulation and experimentation to elucidate its dynamics and structure.

NIST Grant Supports Research on Biological Materials, Assembly Processes

Francis Starr, director of the College of Integrative Sciences, professor of physics, received a $282,000 grant from the National Institute of Standards and Technology in September.

The grant will support “Heterogeneous Dynamics and Assembly Processes in Soft and Biological Materials,” a collaborative research project between Wesleyan and NIST. NIST is expected to fund the project through 2018 with a total amount of $1.66M.

Soft and biological materials are commonly composed of synthetic or biopolymers, or are formed as a result of the supramolecular assembly of small molecule, nanoparticle, or protein molecules into dynamic organized structures. These materials are central to developing new materials for emerging technologies related to energy storage and production, energy-saving light-weight devices, and in the development of diverse new forms of medicine and medical materials that mimic biological processes.

The realization of the promise of this large class of new materials has been limited by the inherent difficulties in understanding and controlling properties and the structural stability of these inherently complex materials. The amorphous, and often hierarchical, structure of these materials make the effective modeling of these materials a challenge.

With support from the NIST grant, Starr and his peers will investigate ways to overcome these challenges and develop these materials for their many intended applications.