Nuclear Fusion Research May Be Key To Advancing Computer Chips

Researchers are adapting the same methods used in fusion-energy research to create extremely thin plasma beams for a new class of "nanolithography" required to make future computer chips.

Current technology uses ultraviolet light to create the fine features in computer chips in a process called photolithography, which involves projecting the image of a mask onto a light-sensitive material, then chemically etching the resulting pattern.

New nanolithography will be needed to continue advances in computer technology and to extend Moore's law, an unofficial rule stating that the number of transistors on integrated circuits, or chips, doubles about every 18 months.

"We can't make devices much smaller using conventional lithography, so we have to find ways of creating beams having more narrow wavelengths," said Ahmed Hassanein, the Paul L. Wattelet Professor of Nuclear Engineering and head of Purdue's School of Nuclear Engineering.

The new plasma-based lithography under development generates "extreme ultraviolet" light having a wavelength of 13.5 nanometers, less than one-tenth the size of current lithography, Hassanein said.

Nuclear engineers and scientists at Purdue and the U.S. Department of Energy's Argonne National Laboratory are working to improve the efficiency of two techniques for producing the plasma: One approach uses a laser and the other "discharge-produced" method uses an electric current.

"In either case, only about 1 to 2 percent of the energy spent is converted into plasma," Hassanein said. "That conversion efficiency means you'd need greater than 100 kilowatts of power for this lithography, which poses all sorts of engineering problems. We are involved in optimizing conversion efficiency - reducing the energy requirements - and solving various design problems for the next-generation lithography."

Findings are detailed in a research paper scheduled to appear in the October-December 2009 issue of the Journal of Micro/Nanolithography, MEMS, and MOEMS. The paper was written by Hassanein, senior research scientist Valeryi Sizyuk, computer analyst Tatyana Sizyuk, and research assistant professor Sivanandan Harilal, all in the School of Nuclear Engineering.

Critical to the research is a computer simulation, called HEIGHTS - for high-energy interaction with general heterogeneous target systems - developed by Hassanein's team. Computations for a single HEIGHTS simulation using Argonne supercomputers can take several months to finish, said Hassanein, a former Argonne senior scientist who led work there to develop HEIGHTS.

The laser method creates plasma by heating xenon, tin or lithium. The plasma produces high-energy packets of light, called photons, of extreme ultraviolet light.

Plasma is a partially ionized gaslike material that conducts electricity. Because of this electrical conductivity, researchers are able to use magnetic fields to shape and control plasmas, forming beams, filaments and other structures. In experimental fusion reactors, magnetic fields are used to keep plasma-based nuclear fuel from touching the metal walls of the containment vessel, enabling the plasma to be heated to the extreme temperatures required to maintain fusion reactions.

HEIGHTS simulates the entire process of the plasma evolution: the laser interacting with the target, and the target evaporating, ionizing and turning into a plasma. The simulation also shows what happens when the magnetic forces "pinch" the plasma cloud into a smaller diameter spot needed to generate the photons.

Findings in the paper detail the laser-produced plasma beams, showing that simulations match data from laboratory experiments recently built at Purdue, Hassanein said.

"It was very exciting to see this match because it means we are on the right track," Hassanein said. "The computer simulations tell us how to optimize the entire system and where to go next with the experiments to verify that."

One design challenge stems from the fact that lenses absorb the photons that make up light, meaning they cannot be used to focus the beam. Instead, mirrors are used in the design. However, plasma condenses on the mirrors, reducing their reflectivity and limiting the efficiency of the process.

"We are trying to help find innovative ways of producing these photons, optimizing the production and mitigating the effects of the plasma on the mirrors," Hassanein said. "So we are trying to improve the entire system."

The simulation tool combines computations in plasma physics, radiation transport, atomic physics, plasma-material interactions and magnetohydrodynamics, or what happens when a target is heated, melts and turns into a plasma.

The work is based at the Center for Materials Under Extreme Environments at Purdue. Previous support came from Intel Corp and Sematech, an industry consortium formed to advance computer technology.

Article provided courtesy: Purdue University

The VASIMR® Rocket Propulsion System - A New Day For Space Travel

Isn't it amazing how technology evolves - usually first from a concept or an idea - then to the actual implementation, and then the inevitable happens... Granted - sometimes it takes many years - but eventually the inevitable happens - the technology evolves from what it first was.

And so it seems to be happening again. This time, it has to do with the way rockets of the present and the future will be propelled. And dare we say, this technology is almost like the rocket being re-invented, instead of just evolved.

This new propulsion system will enable a trip from earth to Mars to be shortened from about 6 months, to only 39 days. So what is it you ask?

Well, instead of the usual fuel rockets use, this new engine is based on a plasma propulsion system. It is called the VASIMR®, and has been named one of the top ten emerging technologies of 2009 by the AIAA (American Institute of Aeronautics and Astronautics).

The company behind the technology, "Ad Astra Rocket Company" (AARC), summed up their vision for this technology with the following: "To revolutionize space transportation and exploration, through the development and commercialization of the VASIMR® engine and related technologies".

According to the company's website, Dr. Franklin R. Chang Díaz (who also serves as company President and CEO) was responsible for inventing the VASIMR® concept, which has been a work in progress since 1979. Work first began on the project at the The Charles Stark Draper Laboratory in Cambridge Massachusetts and continued at MIT Plasma Fusion Center. After that, the project moved to the Johnson Space Center in 1994.

The "Variable Specific Impulse Magnetoplasma Rocket" (VASIMR®) consists of 3 linked magnetic cells.

- The "Plasma Source" cell is involved in the main injection of neutral gas (usually hydrogen or other light gases) which is turned into plasma, and also involves the ionization subsystem.

- Using electromagnetic waves, the "RF Booster" cell works as an amplifier which further energizes the plasma to reach the desired temperature.

- Finally, the "Magnetic Nozzle" cell then converts the energy of the plasma into thrust.

The company claims some of the advantages of the system includes variable specific impulse and thrust at full power, an electrodeless design incorporating magnetic insulation, and high efficiency ion cyclotron resonance heating. The system also uses more abundant, less expensive fuels. These include argon, neon, and hydrogen.

But how does the rocket work? Basically we need to understand what "plasma" is. A Plasma state is achieved when a gas, or a substance in gas form, is heated to super high temperatures - tens of thousands, even millions of degrees. At these temperatures, something happens to the electrons. The electrons (which hold a negative charge) are stripped, or lost, from neutral atoms. Magnetic fields are then used to accelerate the resulting plasma to generate thrust.

This type of rocket is ideal for use in space, but it will need to catch a ride on a traditional rocket up into space. Once there, the engine can be powered by solar or nuclear power. The benefit of this type of propulsion system is that it is extremely fuel eficient for use in space - far more than traditional rocket motors. The system will be tested in 2012 on the International Space Station. Fast, efficient and long range space travel could be made possible by this new technology.

We'll certainly need to watch this....uhm, space. :)

First Direct Evidence Of Lightning Detected On Mars

University of Michigan researchers say direct evidence of lightning has been detected on Mars for the first time ever.

According to professor Chris Ruf, a professor in the departments of Atmospheric, Oceanic and Space Sciences and Electrical Engineering and Computer Sciences, the lighting bolts that were observed, were dry lightning. The lighting apparently appeared as a result of a large dust storm, and not as a result of rain, as one would think.

Researchers believe that electric activity in the Martian atmosphere, even from dust storms, carries with it important scientific implications for the red planet.

As one may imagine, these events will have an effect on atmospheric chemistry, and also for future manned exploration of the planet.

An innovative microwave detector developed at the U-M Space Physics Research Laboratory, was responsible for the discovery. Capable of differentiating between thermal and non-thermal radiation, the Kurtosis detector took microwave emission measurements from Mars for approximately five hours a day, over a 12 day period. The measurements were taken between May 22 and June 16, 2006.

The findings are based on an unusual pattern where non-thermal radiation, combined with an intense Martian dust storm occurred. It was during this time only that non-thermal radiation was detected. From a scientific point of view, non-thermal radiation would suggest the presence of lightning, and this new evidence is also in line with findings regarding soil measurements from the Viking landers, 30 years ago.

Mars is the fourth planet from the sun in our solar system, and is often referred to as the 'red planet', because of its reddish appearance caused by iron oxide on Mars's surface.

As far as exploration goes, the Mars surface is also home to two Mars Exploration Rovers namely 'Spirit' and 'Opportunity', as well a three functional orbiting spacecraft - these are: Mars Odyssey, Mars Express, and the Mars Reconnaissance Orbiter.

Mars is about half the size of earth, and in addition, Mars also has two moons, Phobos and Deimos, which are small and odd shaped. Exploration and research of Mars is ongoing.

Visit the University of Michigan for more info

Nissan LEAF - The World's First Affordable Electric Car

Nissan Motor Co., Ltd. Sunday, (Aug. 2, 2009) unveiled the world's first affordable, zero-emission car - the Nissan LEAF. Nissan LEAF is a medium-size hatchback able to comfortably seat five adults with a range in excess of 160km (100 miles). The chassis has been designed specifically to be lithium-ion battery-powered.

Nissan Leaf, will be available in Japan, Europe, and the United States in the second half of 2010. The car can be summarised as being part of Nissan's radical, transformative vision for the future, and also the result of decades of investment and research.

Nissan President and CEO Carlos Ghosn has described Nissan LEAF as a 'tremendous accomplishment in which all of the company's employees can take pride'. He said the company has been working tirelessly to make possible a day when a zero-emission car - not just reduced emissions - will be possible, and said this is the first step on an exciting journey for both Nissan as a company and also the entire industry as a whole.

The most notable characteristic of the car is of course its zero emission platform and power train. In addition it also has an affordable price range, and boasts Connected Mobility: Advanced intelligent transportation (IT) system. Pricing details are not yet available, but will be released near the commencement of sales in late 2010. It is expected though that the car will be in the range of a well-equipped C-segment vehicle.

It is no coincidence that the car has been named LEAF, as this name has a direct connotation to how leaves in nature also purify air. Nissan LEAF purifies mobility, by removing emissions from the driving experience.

Nissan LEAF is expected to qualify for various significant local, regional and national tax benefits and incentives in world markets. Of course the added benefit is that Nissan LEAF has much less mechanical parts and complexity, which should make maintenance user, and pocket, friendly.

SOME TECHNICAL ASPECTS

The car is powered by laminated compact lithium-ion batteries, generating output power in excess of 90kW, while the electric motor delivers 80kW/280Nm. These performance figures are very much in line with cars in the same class to which consumers are used to today.

Nisan LEAF uses also uses its regenerative braking system to ensure maximum range efficiency. It is interesting to note that according to consumer research, about 70% of all people worldwide that drive cars, drive within the zero to 160 km (100 mile) range daily.

Now here's the very interesting part - how long will it take to recharge? According to the company, the LEAF can be charged up to 80% of its full capacity in less than 30 minutes using a quick charger. Charging the car at home will take approximately 8 hours through a 200V power outlet - which makes it perfect for an overnight charge.

Also interesting to note is the chassis and body layout - according to the company the car enjoys a completely new layout. (Although looking at a photo of the car, the changes are visually less obvious.)

The car features up-slanting light-emitting diode (LED) headlights (which consume only 10 percent of the electricity of conventional lamps), which also serves another unique purpose - it splits and redirects airflow away from door mirrors, reducing drag and external wind noise.

CONNECTED MOBILITY IT SYSTEM

In addition, Nissan LEAF features an exclusive advanced IT system, that is connected to a global data center, enabling the system to provide support, information, and entertainment for drivers at any time of the day or night.

One more state-of-the-art feature is the ability to utilize mobile phones to control air-conditioning and program charging functions. This feature is possible even when Nissan LEAF is powered down.

Source: Nissan