Sunday, August 30, 2015

The annual gathering

The 2015-2016 academic year has begun! Above you see arrayed before you eyes the collection of folks who are going to make it all happen.

After a long morning of meetings, we gather on the steps to the biology building for a quick snap of the faculty and staff.

Missing from the photo this year are Adriana Banu, Geary Albright, and Scott Paulson.

Starting from the back row, left-to-right are (clear rows are hard to make out so my list is likely a bit funky):

-Shanil Virani, Harold Butner, Sean Scully
-Giovanna Scarel
-Gabriel Niculescu, Keigo Fukumura
-Kim Emerson, Chris Hughes, Mark Mattson, Ioana Niculescu, Costel Constantin, Bradley Newcomer
-Thomas O'Neil, Jacob Brown, Kevin Giovanetti, Ilarion Melnikov
-Milka Nikolic, Herb Slade, Klebert Feitosa, Anca Constantin, Steve Whisnant

New to the department this year are Jacob Brown, the laboratory manager; Ilarion Melnikov, our string theorist; and Bradley Newcomer, the new Director of the Honors Program.

Plenty of seasoned hands to move us along. Promises to be a great year.

Thursday, August 20, 2015

Summer days at JLab

From June 2nd through the 5th and 17th through the 18th, and on August 3rd, Dr. Gabriel Niculescu, accompanied by the students Alex Winkley, Justin Le, and Wayne Morris, worked together on a project at Jefferson Lab in Newport News, Virginia.   Jefferson Lab, also known as JLab, is a national accelerator facility funded by the U.S. Department of Energy.  The lab seeks to research and gather information regarding the atom’s nucleus, more specifically its structure, using the lab’s particle accelerator known as the Continuous Electron Beam Accelerator Facility (CEBAF).  The lab houses scientists from around the world as well as graduate and undergraduate students from across the country.

The JMU PNP team took a total of three trips to JLab and in that time they managed to install two frames with scintillators and photomultiplier tubes (PMTs) for the Super High Momentum Spectrometer (SHMS) to be used in Hall C at JLab.  Scintillators are used to detect ionizing radiation from particles that pass through them and are wrapped with a reflective material. When these particles pass through the scintillators they produce photons that bounce around (due to the reflective material) until they reach the ends where the PMTs are located.  Once the photons reach the Photomultiplier tubes, they utilize the photoelectric effect to convert the light produced into an analog signal.

These scintillators are mounted on two separate frames and the frames are positioned roughly 5 meters away from each other. The scintillators are attached to the frame in two layers, one layer oriented horizontally and the other vertically, forming a mesh, so that no charged particles can pass through undetected.  This setup is good for getting an accurate time of flight of the particles that pass through.

Upon completion of mounting the scintillators/PMTs to the frames, the team also had to test the PMTs to see if they could produce a strong signal. In order to accomplish this, a high voltage power supply was connected to a PMT via a coaxial cable, and then the PMT was connected to an oscilloscope via a second coaxial cable.  As the PMTs came from two different sources, it was necessary to vary the supply voltage depending on the PMT’s peak efficiency, 1200 V for one source and 1500 V for the other.  A good signal is characterized by a high signal to noise ratio and a high amplitude on the oscilloscope. Pictured below is an example of an ideal signal on an oscilloscope. 

Due to concern of light leaks in some of the scintillators, the team had to head back to JLab one more time on August 3rd.  These light leaks are spots on the scintillators where photons produced from an external source are able to enter the scintillator and, as a result, fill the signal with so much noise that the data coming from the signal is useless.  A light leak is easy to fix; an application of electrical tape in the leaking area fixes the leak just fine.  The difficulty comes with finding all of the possible light leaks, of which there were numerous on the PMTs the team had to work on. The origin of the light leaks appeared to be a result of a design flaw with the way the scintillator was attached to the PMT.  However, by the end of the day, a system had been developed and the team was able to pinpoint where light leaks existed consistently from one PMT to another. 

Wednesday, June 24, 2015

Infrared radiation, Thermoelectricity and Chaos

On Wednesday June 17 2015 JMU hosted the Workshop entitled “Infrared Radiation, Thermoelectricity and Chaos”.  Dr. Giovanna Scarel was the co-organizer with Benjamin Delp, Director of JMU Research Development and Promotion.  The Workshop discussed Dr. Scarel’s infrared power generation and featured two international speakers.  Prof. Giulio Casati of Italy spoke about Conservation laws, symmetry breaking and control of the heat current.  Prof. Francisco Javier Gonzalez Contreras of México described Seebeck nanoantennas for solar energy harvesting.  Three speakers represented the U.S.A. academic world.  Prof. Gabriel A. Rincón-Mora of the Georgia Institute of Technology, presented Microwatt CMOS harvesters.  Prof. Rajeevan Amirtharajah of the University of California at Davis, discussed on Powering systems from ambient energy sources.  Finally, Prof. S. Joseph Poon of the University of Virginia, presented Practical realization of ZT>1 from the materials perspective.  The business and entrepreneurial world was represented by Dr. Ronald J. Parise of Parise Research Technologies, who introduced The Nighttime solar cell®: infrared energy to deep space.  Dr. Joseph R. Blandino of the Virginia Military Institute, and Dr. David J. Lawrence of James Madison University, presented a poster on Transient response of a thermoelectric generator subjected to spatially non-uniform heating: implications for heat and IR sensing applications.  In her presentation Dr. Scarel explained the connection among the words in the title of the Workshop.

Two posters were presented by JMU Physics students Graham Gearhart and Brian Lang.  Graham presented “Infrared source and thermoelectric device trends in infrared power generation”, while Brian discussed: The interaction between current and infrared radiation”.  Graham and Brian are part of the Scarel’s research group.  Other JMU students joined the event asking questions and networking.

Dr. Brian Utter (Physics, JMU) and Lynn Petersen (U.S. Office of Naval Research) chaired the morning and the afternoon sessions.  Dr. Yvonne Harris, vice Provost for Research and Scholarship, and Lynn Petersen opened the event in the morning and addressed the final remarks in the afternoon, respectively.

The Workshop was funded by the U.S. Office of Naval Research, the 4-VA Consortium, JMU, and The Madison Trust—Fostering Innovation and Strategic Philanthropy.

The picture below shows a moment of the event.


Saturday, May 09, 2015

Congratulations Class of 2015! Once a Duke always a Duke...

Well done all of our physics majors who graduated today, May 9th, 2015:
  • James McDermott Barney, B.S.
  • Christopher Andrew Castillo, B.S.
  • Peter Gregory Clark, B.S.
  • Nicole Christine Creange, B.S. (cum laude, graduating with distinction)
  • Keely Ryan Criddle, B.S. (graduating with distinction, service award)
  • Joshua John Dunbar, B.S.
  • Graham Perry Gearhart, B.S.
  • Morgan Elizabeth Hedden, B.A. (graduating with distinction)
  • Seth Alexander Heerschap, B.S. (graduating with distinction)
  • Gregory Michael Houchins, B.S. (magna cum laude)
  • Kevin Sean Hunter, B.S.
  • Alexandra Teodora Iuga, B.S.
  • Kirill Olegovich Korsak, B.S. (magna cum laude)
  • Brian Nicholas Lang, B.S.
  • David Alexander Loving, B.S. (magna cum laude)
  • Harkirat Singh Mann, B.S.
  • Wayne Henry Morris III, B.S.
  • Andrew R. Nutter, B.S.
  • Galen Wolcott Richard, B.S.
  • Yosyp Schwab, B.S.
  • Daniel Calvert Shorts, B.S.
  • Daniel Gregory Jenks Votaw, B.S. (magna cum laude, research award))
  • Colleen May Wallace, B.S. (magna cum laude/outstanding senior)
  • George Cross Wilkes, B.S.
  • Meris Victoria Yates, B.S.

Sunday, May 03, 2015

Links for the Love of Physics!

With the semester coming to an end and the impending doom of not having physics classes for the next few months becoming ever-increasing, fear not - for through the internet your love of all things physics can be nurtured all season long.

Make A solar system and watch it crumble over millions (or sometimes thousands) of years.

Watch some fun and educational videos.

Learn more about those SI units we adore.

Check out NASA's Astronomy picture of the day.

Read about how the everyday things we use were made.

Watch a video on the physics of comic books.

Enjoy this PBS Documentary about Feynman.

Revel in the awesomeness of some of Lewin's best lines.

Check out NPR's You're the Expert (Coming to JMU this fall!!).

-Keely Criddle
JMU Physics & Astronomy Blogger
You may want to take a moment and note today’s date. This just might be the day you’ll recount to your grandchildren when they complain about the energy bill in their first studio space-apartment. That still leaks somehow.


Anyways, yes, what I just said is an actual possibility given what’s being put on the table: a virtually unlimited, zero-emission energy source. Making it even more of an actual possibility is from whom that promise is coming from: Lockheed Martin’s Advanced Development Programs, better known as the Skunk Works. Past projects include: the P-80 Shooting Star , the first fighter jet the USAF deployed over the skies of Korea; the U-2 spyplane, famous from its eponymous “incident”; and of course, the rockstar: the SR-71 Blackbird. Not a pedigree to scoff at to say the least. With the Skunk Works’ history of doing what can’t be done, and quickly to boot, this makes for extremely exciting news.

 Maybe the first thing that came to mind when I said, “virtually unlimited, zero-emission energy source” was wind power, maybe tidal, or perhaps solar, but the answer is actually nuclear. Nuclear fusion, that is. Unlike nuclear fission, where one atom splits into two and releases energy as a result, nuclear fusion, when two atoms fuse into one, is not commercially employed in any nuclear power plants. That’s because the energy from fission reactions is relatively simple to harvest compared to fusion.

So, in fission reactors (pictured above) the source of heat for steam turbines comes from the fission of radioactive elements such as uranium and plutonium, where the rate of fission can be manipulated through control rods which absorb neutrons that would have split more uranium atoms. Fusion reactors, on the other hand, involve recreating conditions akin to the core of our sun, which is to say, a lot of heat and a lot of pressure. If we were to peer into the sun’s core, we’d see superheated gas is separate into its ions and electrons. Subsequently, when the ions get hot enough, they can overcome their mutual repulsion and collide, fusing together. According to Lockheed’s page, “When this happens, they release a lot of energy – about one million times more powerful than a chemical reaction and 3-4 times more powerful than a fission reaction.” With that amount of energy at humanity’s disposal, the entire technologic and economic landscape changes. Today’s science fiction pipe dreams could become tomorrow’s kickstarter projects.


Now, a team headed by MIT graduate Thomas McGuire, seen above with a compact fusion prototype, is attempting to create a compact, 100-megawatt fusion reactor; enough power for a small city of 50-100k people. McGuire and his team diverge from the fusion community’s first attempt at fusion power, the tokamak design (the same design being used in ITER), instead opting for a high beta concept  that “uses a high fraction of the magnetic field pressure, or all of its potential, so we can make our devices 10 times smaller than previous concepts.”


A goal, if achieved, would change the world in as we know it. We’re talking clean, limitless energy with no lingering radioactive waste, no risk of proliferation, all in a transportable form factor. Suddenly, daunting problems like providing clean water and electricity to the whole world becomes a lot more palatable. Looking beyond the scope of our planet, adding fusion energy into the mix with space travel nets shorter travel times, crucially cutting down on radiation exposure during transit. And with space travel, comes colonization, mining operations, and a third-thing-you’ve-seen-in-space-movies-that-you-always-wished-was-real.

The dream of cheap, green, and plentiful fusion energy, if realized, would undoubtedly become the catalyst for the next great human revolution, the true vision of the atomic age our scientists since the 50s could only envision in their dreams.

Check out the source for more technical information on the Skunk Work’s Compact Fusion project.

-Alan Chen
Guest Blogger

Friday, May 01, 2015

JMU's presence at international workshop in particle & nuclear physics

Every year the particle and nuclear physicists, experimentalist and theorists alike gather together for a weeklong workshop to discuss the latest developments in Deep Inelastic Scattering and related processes.

This year more than 200 physicists representing a plethora of international labs: LHC, KEK, RHIC, Fermilab, JLab, DESY are meeting (April 27 to May 1) at the XXIII DIS 2015 International Workshop at Southern Methodist University in Dallas Texas. The JMU Physics and Astronomy's Particle and Nuclear Physics Group (JMU PNP) were major contributors to several of the talks presented, including a talk on quark-hadron duality on the neutron delivered by Dr. Gabriel Niculescu (see photo).  As the conference started, JMU PNP members were informed that their paper on q-h duality on the neutron was accepted for publication in Physical Reviev C (PRC). 

Friday, April 24, 2015

Physics Majors outnumbered the JMU delegation at the 2015 National Conference on Undergraduate Research!

The 2015 National Conference on Undergraduate Research (NCUR) took place at Eastern Washington University in Cheney, WA from April 16-18.

JMU was represented by 11 undergraduates among which seven students were Physics Majors, as follows: 
  • Christopher Castillo - "Building the most robust catalog of voids and void galaxies" (research adviser: Dr. Anca Constantin)
  • Nicole Creange - "Surface science analysis of Gallium Oxide deposited on Gallium Nitride semiconductor" (research advisers: Drs. Jason Haraldsen and Costel Constantin)
  • Charles Crook - "Understanding superexchange   correlations in magnetically doped graphene" (research adviser: Dr. Jason Haraldsen)
  • Gregory Houchins - "Simplifying magnetic dimer calculations" (research adviser: Dr. Jason Haraldsen)
  • Galen Richard - "Variational calculations for spin canting at complex oxide interfaces" (research adviser: Dr. Jason Haraldsen)
  • Daniel Votaw - "Finding optimal parameters for use of position-sensitive ionization chamber" (research advisers: Drs. Dan Bardayan (University of Notre Dame) and Adriana Banu (JMU))
  • George Wilkes - "Plate tracking for a granular Casimir effect" (research adviser: Dr. Brian Utter)