Tuesday, February 12, 2013

A Pleasing Disruption: Fusion equations pop up on popular TV show


Above, in a scene from a recent episode of the top-rated CBS TV comedy, The Big Bang Theory, lead character Sheldon, a theoretical physicist, works on an equation describing turbulent diffusion in fusion devices. The equation closely resembles another included in a talk by PPPL physicist Greg Hammett at the Kavli Institute in Santa Barbara (inset left). (Graphic by Greg Czechowicz, PPPL)

Greg Hammett, a physicist at the Princeton Plasma Physics Laboratory, was minding his own business one recent evening, chilling, watching a TV show popular with Lab folks and many others – the top-rated CBS comedy, The Big Bang Theory (Episode14, titled “The Cooper-Kripke Inversion”.) Suddenly he saw it: Jim Parsons, the actor playing one of the show’s lead characters – a brilliant, though socially awkward theoretical physicist named Sheldon Cooper – was at work in front of a whiteboard. Scrawled across the board in red-orange magic marker were letters and digits representing an idea that Hammett knew quite well. To his great pleasure, Hammett spied an equation he had helped derive in his research on fusion energy. “This equation describes turbulent diffusion in fusion devices and also describes how performance can be improved by sheared flows that can reduce the turbulence,” Hammett said. “The ovals at the bottom of Sheldon’s whiteboard are meant to illustrate this stabilization mechanism – which we are studying as a possible way to improve fusion reactors – and this is an illustration that I’ve used in my talks.” 

Many researchers in the field of plasma physics have contributed to the development of this theory, fondly known to its adherents as “gyrokinetic turbulence theory.” The key people who developed this particular equation as well as the computer simulations backing them, in addition to Hammett, include: Bill Dorland at the University of Maryland; Mike Kotschenreuther, University of Texas; Mike Beer, Johns Hopkins University; and Ron Waltz of General Atomics. Dorland and Beer were former PhD students who worked with Hammett. Kotschenreuther also earned his doctoral degree from PPPL. And Hamid Biglari, who also played a significant role in the development of the turbulence improvement mechanism in this equation, earned his PhD from PPPL. He is now enjoying a prominent career on Wall Street.

PPPL Physicist Greg Hammett

For Hammett, and other fans of The Big Bang Theory at the Lab, it was a thrill to see fusion science touched upon in the show, which often intertwines high-level scientific conversations on topics such as Einstein’s quest for a unified field theory with young adult obsessions such as finding an attractive date for a Saturday night.

Another important Princeton connection is the show’s science writer-consultant, David Saltzberg, a UCLA physicist and Princeton University graduate who ensures that the show’s scientific content – including all equations -- is accurate. He obviously is very well read!

Hammett isnt sure exactly where Saltzberg found the formulas and illustrations because they have appeared in many talks he and others have given over the years that are available online, such as a talk Hammett gave in 2005 at the Kavli Institute for Theoretical Physics in Santa Barbara.

But Hammett is thinking broadly, looking to see whether the fusion strand will be woven into future installments. Late in this episode, the character Sheldon speaks with a colleague about ideas for a new fusion reactor design. He starts to explain an approach for reducing turbulence, one of the major research issues for plasma physicists at the moment, but is interrupted. "I don't know if we'll ever learn what brilliant ideas Sheldon had," Hammett said.

We can always hope!

Fusionista Kitta MacPherson is the director of communications at the Princeton Plasma Physics Laboratory and an award-winning science writer. 

Tuesday, January 22, 2013

At JLab where the nucleus is king

 FUSIONISTA: Notes from the landscape of the National Labs

I know I am lucky -- part of my job is to occasionally visit my colleagues at other DOE National Laboratories, where I get to meet some of the best scientists in the world and, equally exciting, view their top-notch, one-of-a-kind, supercool equipment.

Earlier this month, I was able to visit Dean Golembeski, director of public affairs at The Thomas Jefferson National Accelerator Facility, a place we call "JLab," mainly so we can converse about it without overly cluttering up our sentences. JLab was kind enough to host a meeting of a group of chief communications officers from all of the DOE's National Labs.

Like the researchers at PPPL, the scientists at JLab are after big game. Physicists there are exploring the innermost realm of matter -- the nucleus of the atom. They think of their work, in the words of accelerator physicist Steve Suhring, as applying a "giant microscope" to nature. Their goal is to discover the origins of matter, improving our understanding of its building blocks and identifying the forces that transform it. It's a lofty goal and a perfect one for a National Lab, where scientists explore basic research for the good of the U.S. and humanity. But how, precisely, do JLab scientists study something as infinitesimal as a nucleus, located at the center of the atom, a speck in itself?

Allow me to show you how JLab does it.

Here, JLab staff scientist Ari Palczewski explains how scientists construct all the basic elements they need to make their accelerator, including supercold vacuum devices known as "cryomodules" and a giant microscope called Cyclops:


JLab accelerator physicist Steve Suhring gives one of the best descriptions I've heard of how an accelerator works, using a mere whiteboard:


Scientists at JLab may be peering into the ultrasmall, but they definitely think big.

Here's a High Resolution Magnetic Spectrometer that uses electrons to examine matter more closely. It's a whopper, weighing in at 240 tons:

And here is physicist Steve Suhring guiding me and a group of my colleagues deep underground in the long corridor that parallels the accelerator track:

We know that so many of the modern marvels we take for granted -- cell phones, MRI machines, cancer medications -- would never have existed without fundamental scientific research. Leaving JLab, I find myself grateful for the efforts of everyone there and all of the National Labs, toiling to learn and benefit all.


Fusionista Kitta MacPherson is the director of communications at the Princeton Plasma Physics Laboratory and an award-winning science writer. 


Thursday, December 6, 2012

The Expanding Palette of Fusion

More from the Fusion Power Associates meeting in Washington, D.C., concluding today:

A self portrait of fusion physicist Glen Wurden (from Los Alamos) taken in infrared wavelengths (3-5 microns), using a new state-of-the art infrared camera (FLIR Systems SC8303HD). This camera was tested on Alcator C-Mod in Sept 2012, and will be used as part of the  American/German collaboration on the new W7-X stellarator under construction in Germany, as a diagnostic to view the protective armor tiles on the vacuum vessel. The armor tiles get heated due to plasma-wall interactions.

Of hohlraums and plasmas and machines called “Z”

PPPL Director Stewart Prager described a host of scientific activities at the Lab during a talk at the annual Fusion Power Associates (FPA) meeting held in Washington, D.C. Steve Dean, the executive director of FPA, can be seen to his left. (Photo credit: Kitta MacPherson, PPPL Office of Communications)

By Kitta MacPherson

WASHINGTON, D.C. – What happens when the forces of fusion gather?

At the annual meeting of the Fusion Power Associates, held at the tony Capitol Hill Club in the shadow of the U.S. Capitol, there’s lots of talk about “plasmas” and “hohlraums” and of devices called stellarators and other machines with names like “Z.”

Starting yesterday and continuing through today, the leaders of fusion energy research in the U.S. from U.S. Department of Energy-funded laboratories, as well as from industry and publicly funded university programs, have been and will continue to line up and present, in rigorously timed 20-minute-long segments, the state of their art.  Differences in approaches to fusion from inertial confinement where pellets are zapped by lasers to magnetic confinement where a superhot gas is corked in a magnetic bottle are described. As competitive as the programs may be, all are regarded here as being under the aegis of fusion--part of the ecumenical approach of Steve Dean, the founder and executive director of the sponsoring group, the Fusion Power Associates.

The purpose of FPA, a non-profit foundation based in Gaithersburg, Md., is, according to its website, to “ensure the timely development and acceptance of fusion as a socially, environmentally, and economically attractive source of energy.” The meetings are designed to showcase management-level scientists and their technical achievements.

In the long narrow, federal style Eisenhower Room,  an observer in the space of several minutes can hear a full range of approaches to fusion from some of its best minds. Attendees can hear Mike Dunne, a leading scientist at the National Ignition Facility based at Lawrence Livermore National Laboratory in California, describe scientific advances in inertial fusion at the facility, pointing to diagrams showing cylindrical capsules called “hohlraums” that hold fusion fuel capsules. One can then listen to Stewart Prager, director of the Princeton Plasma Physics Laboratory, convey elements of progress in magnetic fusion. The Princeton lab is focusing on areas with breakthrough potential where the U.S. can lead, he said. And lest anyone think that PPPL is overly focused on a doughnut-shaped fusion reactor configuration known as a tokamak, Prager indicated his commitment to also support another configuration known as a stellarator. “We believe that stellarators are not a luxury item, we believe they are essential for fusion,” he said.

Observers at the meeting also can get a taste of the international.

Ned Sauthoff, director of the U.S. ITER program, talked about the importance of scientific research being conducted now to benefit ITER, a mammoth experimental fusion vessel under construction in Cadarache, France. “The science of ITER is happening now,” he said. “In order for it to succeed, you have to have a strong program that is related to things like burning plasmas.” The goal of ITER is to achieve 500 megawatts of fusion power. The giant tokamak is being designed to demonstrate the scientific and technological feasibility and safety features of fusion energy, Sauthoff said.

Tight budgets for domestic programs have leaders such as Miklos Porkolab, director of MIT’s Plasma Science Fusion Center, expressing concerns. “Vigorous research in the next decade is necessary on existing tokamak facilities with upgrades in heating and current drive power as well as advanced plasma diagnostics and tungsten plasma-facing components,” he said, adding that much physics remains to be explored on existing tokamaks in order to optimize ITER’s operation. The largest U.S. experimental magnetic fusion devices--at MIT, PPPL, and General Atomics--are complementary, he noted, and need sustained support.

In his presentation on fusion experiments at Los Alamos National Laboratory, Glen Wurden said he is worried about the impact of cuts to the domestic fusion program, especially in light of growing ITER commitments, and the survivability of the U.S. plasma physics and fusion research enterprise should there be additional cuts in future years. “We are dangerously approaching the tipping point,” he said.

Mark Herrmann, a physicist at Sandia National Laboratory, who was recognized for his research with an award from FPA, spoke with excitement about his work on a 10,000 square-foot experimental fusion device known as “Z”. “You have to be an optimist to be a fusion scientist,” he said with a smile.

Thursday, September 6, 2012

Dr. Z weighs in on sun killers

Could a supervillain destroy the sun that gives our planet life? When a writer for the science website Life’s Little Mysteries pondered that question, he turned to PPPL Deputy Director Michael Zarnstorff for his astrophysical expertise. Zarnstorff dismissed such notions as poisoning the sun’s fusion reaction, or siphoning off plasma to make the sun evaporate, as too far-fetched. But he said creating a black hole in the center of Old Sol might conceivably do the trick. To read how that would work, click here: http://www.lifeslittlemysteries.com/2844-star-destroying-superweapon.html
--- John Greenwald

Wednesday, May 23, 2012

U.S. Department of Energy's Plasma Science Center holds third annual meeting at PPPL

Graduate student Hongyue Wang discussed her work on plasmas in Hall thrusters with University of Michigan professor Mark Kushner during the third annual meeting of the U.S. Department of Energy's Plasma Science Center at PPPL. Wang, a student at Beihang University in Beijing, works with PPPL physicist Igor Kaganovich. Kushner directs the Plasma Science Center. (Photo credit: Elle Starkman, PPPL Office of Communications.)

More than 50 participants from a dozen U.S. research institutions gathered at the Princeton Plasma Physics Laboratory (PPPL) May 17-18 for the third annual meeting of the U.S. Department of Energy’s Plasma Science Center. The meeting featured papers on low-temperature plasmas, whose practical applications range from lighting to nanotechnology. Events at the session included a display of graduate student posters and a tour of PPPL.