NEW PARTICLE ACCELERATORS COULD EXPAND USE TO SCIENCE AND INDUSTRY

FROM:  NATIONAL SCIENCE FOUNDATION
Smaller and cheaper particle accelerators?

Scientists developing technology that could expand use for medicine, national security, materials science, industry and high energy physics research
Traditionally, particle accelerators have relied on electric fields generated by radio waves to drive electrons and other particles close to the speed of light. But in radio-frequency machines there is an upper limit on the electric field before the walls of the accelerator "break down," causing it to not perform properly, and leading to equipment damage.

In recent years, however, scientists experimenting with so-called "plasma wakefields" have found that accelerating electrons on waves of plasma, or ionized gas, is not only more efficient, but also allows for the use of an electric field a thousand or more times higher than those of a conventional accelerator.

And most importantly, the technique, where electrons gain energy by "surfing" on a wave of electrons within the ionized gas, raises the potential for a new generation of smaller and less expensive particle accelerators.

"The big picture application is a future high energy physics collider," says Warren Mori, a professor of physics, astronomy and electrical engineering at University of California, Los Angeles (UCLA), who has been working on this project. "Typically, these cost tens of billions of dollars to build. The motivation is to try to develop a technology that would reduce the size and the cost of the next collider."

The National Science Foundation (NSF)-funded scientist and his collaborators believe the next generation of smaller and cheaper accelerators could enhance their value, expanding their use in medicine, national security, materials science, industry and high-energy physics research.

"Accelerators are also used for sources of radiation. When a high energy particle wiggles up and down, it generates X-rays, so you could also use smaller accelerators to make smaller radiation sources to probe a container to see whether there is nuclear material inside, or to probe biological samples," Mori says. "Short bursts of X-rays are currently being used to watch chemical bonds form and to study the inner structure of proteins, and viruses."

Just as important, albeit on a more abstract level, "the goal of the future of high-energy physics is to understand the fundamental particles of matter," he says. "To have the field continue, we need these expensive, large, and complex tools for discovery."

NSF has supported basic research in a series of grants in recent years totaling $4 million, including computational resources. The Department of Energy (DOE) has provided the bulk of the funding for experimental facilities and experiments, and has contributed to theory and simulations support.

"Mori's work is the perfect example of an innovative approach to advancing the science and technology frontiers that can come about when the deep understanding of fundamental laws of nature, of the collective behavior of charged particles that we call a plasma, is combined with state-of-the-art numerical modeling algorithms and simulation tools," says Vyacheslav (Slava) Lukin, program director in NSF's physics division.

Using DOE's SLAC National Accelerator Laboratory, the scientists from SLAC and UCLA increased clusters of electrons to energies 400 to 500 times higher than what they could reach traveling the same distance in a conventional accelerator. Equally important, the energy transfer was much more efficient than that of earlier experiments, a first to show this combination of energy and efficiency using "plasma wakefields."

In the experiments, the scientists sent pairs of electron bunches containing 5 billion to 6 billion electrons each into a laser-generated column of plasma inside an oven of hot lithium gas. The first bunch in each pair was the "drive" bunch; it blasted all the free electrons away from the lithium atoms, leaving the positively charged lithium nuclei behind, a configuration known as the "blowout regime." The blasted electrons then fell back in behind the second bunch of electrons, known as the "trailing" bunch to form a "plasma wake" that thrust the trailer electrons to higher energy.

While earlier experiments had demonstrated high-field acceleration in plasma wakes, the SLAC/UCLA team was the first to demonstrate simultaneously high efficiency and high accelerating fields using a drive and trailer bunch combination in the strong "blowout" regime. Furthermore, the accelerated electrons ended up with a relatively small energy spread.

"Because it's a plasma, there is no breakdown field limit," Mori says. "The medium itself is fully ionized, so you don't have to worry about breakdown. Therefore, the electric field in a plasma device can be pushed to a thousand or more times higher amplitude than that in a conventional accelerator."

Chandrashekhar Joshi, UCLA professor of electrical engineering, led the team that developed the plasma source used in the experiment. Joshi, the director of the Neptune Facility for Advanced Accelerator Research at UCLA is the UCLA principal investigator for this research and is a long-time collaborator with the SLAC group. The team also is made up of SLAC accelerator physicists, including Mike Litos and Mark Hogan; Mori leads the group that developed the computer simulations used in the experiments. Their findings appeared last fall in the journal Nature.

"The near term goal of this research is to produce compact accelerators for use in universities and industry, while a longer term goal remains developing a high energy collider operating at the energy frontier of particle physics," Mori says.

-- Marlene Cimons, National Science Foundation
Investigators
Warren Mori
Frank Tsung
Viktor Decyk
Russel Caflisch
Michail Tzoufras
Philip Pritchett
Related Institutions/Organizations
University of California-Los Angeles

NATURE AND INNOVATIVE MATERIALS

FROM:  NATIONAL SCIENCE FOUNDATION 
Inspired by nature: textured materials to aid industry and military
Innovation Corps team developed metals and plastic that repel water, capture sunlight and prevent ice build-up

The lotus leaf has a unique microscopic texture and wax-like coating that enables it to easily repel water. Taking his inspiration from nature, a University of Virginia professor has figured out a way to make metals and plastics that can do virtually the same thing.

Mool Gupta, Langley Distinguished Professor in the university's department of electrical and computer engineering, and director of the National Science Foundation's (NSF) Industry/University Cooperative Research Center for Lasers and Plasmas, has developed a method using high-powered lasers and nanotechnology to create a similar texture that repels water, captures sunlight and prevents the buildup of ice.

These textured materials can be used over large areas and potentially could have important applications in products where ice poses a danger, for example, in aviation, the automobile industry, the military, in protecting communication towers, blades that generate wind energy, bridges, roofs, ships, satellite dishes, and even snowboards.

In commercial and military aviation, for example, these materials could improve airline safety by making current de-icing procedures, which include scraping and applying chemicals, such as glycol, to the wings, unnecessary.

For residents in the frigid northeast, many of whom rely on satellite systems, "it could mean they won't lose their signal, and they won't have to go outside with a hammer and chisel and break off the ice," Gupta says.

The materials' ability to trap sunlight also could enhance the performance of solar cells.

Gupta and his research team first made a piece of textured metal that serves as a mold to mass-produce many pieces of plastic with the same micro-texture. The replication process is similar to the one used in manufacturing compact discs. The difference, of course, is that the CD master mold contains specific information, like a voice, whereas, "in our case we are not writing any information, we are creating a micro-texture," Gupta says.

"You create one piece of metal that has the texture," Gupta adds. "For multiple pieces of plastic with the texture, you use the one master made of metal to stamp out multiple pieces. Thus, whatever features are in your master are replicated in the special plastic. Once we create that texture, if you put a drop of water on the texture, the water rolls down and doesn't stick to it, just like a lotus leaf. We have created a human-made structure that repels water, just like the lotus leaf."

The process of making the metal with the special texture works like this: the scientists take high-powered lasers, with energy beams 20 million times higher than that of a laser pointer, for example, and focus the beams on a metal surface. The metal absorbs the laser light and heats to a melting temperature of about 1200 degrees Centigrade, or higher, a process that rearranges the surface material to form a microtexture.

"All of this happens in less than 0.1 millionth of a second," Gupta says. "The microtexture is self-organized. By scanning the focused laser beam, we achieve a large area of microtexture. The produced microtexture is used as a stamper to replicate microtexture in polymers. The stamper can be used many, many times, allowing a low cost manufacturing process. The generated microtextured polymer surface shows very high water repellency."

In the fall of 2011, Gupta was among the first group of scientists to receive a $50,000 NSF Innovation Corps (I-Corps) award, which supports a set of activities and programs that prepare scientists and engineers to extend their focus beyond the laboratory into the commercial world.

Such results may be translated through I-Corps into technologies with near-term benefits for the economy and society. It is a public-private partnership program that teaches grantees to identify valuable product opportunities that can emerge from academic research, and offers entrepreneurship training to faculty and student participants.

The other project members are Paul Caffrey, a doctoral candidate under Gupta's supervision, and Martin Skelly of Charleston, S.C., a veteran of banking in the former Soviet Union who serves as business mentor and is involved in new business investments.

The team participated in a three-day entrepreneurship workshop at Stanford University run by entrepreneurs from Silicon Valley. "We are still pursuing the commercial potential," Gupta says. "The idea is to look at what market can use this technology, how big the market is, and how long it will take to get into it."

-- Marlene Cimons, National Science Foundation

SEVEN INITIATIVES FOR SUPPORTING WARFIGHTER AUTONOMY

FROM: U.S. DEPARTMENT OF DEFENSE

Cost-saving Pilot Programs to Support Warfighter Autonomy
By Terri Moon Cronk
American Forces Press Service

WASHINGTON, June 19, 2013 - A call from the Defense Department to industry and government for autonomous technology ideas that support the warfighter has been answered with seven initiatives.


Chosen from more than 50 submissions, the selected ideas will be tested in the Autonomy Research Pilot Initiative, officials said.

"We believe autonomy and autonomous systems will be very important for how we operate in the future," said Al Shaffer, acting assistant secretary of defense for research and engineering. Autonomous systems are capable of functioning with little or no human input or supervision.

"If we had better autonomous systems for route clearance in Afghanistan, we could offload a lot of the dangerous missions that humans undertake with autonomous systems, so we have to make a big push in autonomy," Shaffer said.

The pilot research initiative's goal is to advance technologies that will result in autonomous systems that provide more capability to warfighters, lessen the cognitive load on operators and supervisors, and lower overall operational cost," explained Jennifer Elzea, a DOD spokeswoman.

"The potential cross-cutting advances of this initiative in multiple domains provide an exciting prospect for interoperability among the military services, and potentially [in] meeting future acquisitions requirements," she said. "The seven projects are at the fundamental cutting edge of the science of autonomy. The projects also integrate several scientific disciplines [such as] neurology [and] mimetics."

The seven projects are not looking at autonomous weapons systems, but rather are investigating autonomous systems for potential capabilities such as sensing and coordination among systems, Elzea noted.

The projects focus on cost savings to DOD, critical in a time of budget cuts, Shaffer said.

The program for the initiatives is estimated to cost about $45 million in a three-year period, which is not considered to be a lot of money for a government research program, DOD officials said.

"We are trying to -- especially as we go through this tough budget period -- incentivize our younger work force," Shaffer said. "Scientists work to solve problems, and what we are doing with this project is we've challenged our in-house researchers to come up with topics that will help us better understand how to do autonomous systems."

When the pilot initiatives are completed, DOD will have the intellectual property to generate a prototype or to provide to industry to produce the systems, officials said.


The seven initiatives are:
-- Exploiting Priming Effects in Autonomous Cognitive Systems: Develops machine perception that is relatable to the way a human perceives an environment. (Navy Center for Applied Research in Artificial Intelligence, Army Research Laboratory)

-- Autonomous Squad Member: Integrates machine semantic understanding, reasoning and understanding, perception into a ground robotic system. (Army Research Laboratory, Naval Research Laboratory, Navy Center for Applied Research in Artificial Intelligence)

-- Autonomy for Adaptive Collaborative Sensing: Develops intelligent intelligence, surveillance and reconnaissance capability for sensing platforms to have capability to find and track targets. (Air Force Research Laboratory, Army Research Laboratory; Naval Research Laboratory)

-- Realizing Autonomy via Intelligent Adaptive Hybrid Control: Develops flexible unmanned aerial vehicle operator interface, enabling the operator to "call a play" or manually control the system. (Air Force Research Laboratory, Space and Naval Warfare Systems Command, Naval Research Laboratory, Army Research Laboratory)

-- Autonomy for Air Combat Missions, Mixed Human/Unmanned Aerial Vehicle Teams: Develops goal-directed reasoning, machine learning and operator interaction techniques to enable management of multiple team UAVs. (Air Force Research Laboratory, Naval Research Laboratory, Naval Air Warfare Center, Army Research Laboratory)

-- A Privileged Sensing Network-Revolutionizing Human-Autonomy Integration: Develops integrated human sensing capability to enable the human-machine team. (Army Research Laboratory, Army Tank Automotive Research Center, Air Force Research Laboratory)

-- Autonomous Collective Defeat of Hard and Deeply Buried Targets: Develops small UAV teaming algorithms to enable systems to autonomously search a cave. (Air Force Research Laboratory, Army Research Laboratory, Defense Threat Reduction Agency)