UW Dynomak fusion reactor concept cheaper than coal

The UW's current fusion experiment, HIT-SI3. 

It is about one-tenth the size of the power-producing dynomak concept. 

Credit: U of Washington

Fusion energy almost sounds too good to be true – zero greenhouse gas emissions, no long-lived radioactive waste, a nearly unlimited fuel supply.

Perhaps the biggest roadblock to adopting fusion energy is that the economics haven't penciled out.

Fusion power designs aren't cheap enough to outperform systems that use fossil fuels such as coal and natural gas.

University of Washington engineers hope to change that. They have designed a concept for a fusion reactor that, when scaled up to the size of a large electrical power plant, would rival costs for a new coal-fired plant with similar electrical output.

The team published its reactor design and cost-analysis findings last spring and will present results Oct. 17 at the International Atomic Energy Agency's Fusion Energy Conference in St. Petersburg, Russia.

"Right now, this design has the greatest potential of producing economical fusion power of any current concept," said Thomas Jarboe, a UW professor of aeronautics and astronautics and an adjunct professor in physics.

The UW's reactor, called the dynomak, started as a class project taught by Jarboe two years ago.

After the class ended, Jarboe and doctoral student Derek Sutherland, who previously worked on a reactor design at the Massachusetts Institute of Technology (MIT), continued to develop and refine the concept.

UW's dynomak

The design builds on existing technology and creates a magnetic field within a closed space to hold plasma in place long enough for fusion to occur, allowing the hot plasma to react and burn.

The reactor itself would be largely self-sustaining, meaning it would continuously heat the plasma to maintain thermonuclear conditions.

Heat generated from the reactor would heat up a coolant that is used to spin a turbine and generate electricity, similar to how a typical power reactor works.

"This is a much more elegant solution because the medium in which you generate fusion is the medium in which you're also driving all the current required to confine it," Sutherland said.

There are several ways to create a magnetic field, which is crucial to keeping a fusion reactor going.

The UW's design is known as a spheromak, meaning it generates the majority of magnetic fields by driving electrical currents into the plasma itself.

This reduces the amount of required materials and actually allows researchers to shrink the overall size of the reactor.

Other designs, such as the experimental fusion reactor project (tokamak) that's currently being built in France, called Iter, have to be much larger than the UW's because they rely on superconducting coils that circle around the outside of the device to provide a similar magnetic field.

When compared with the fusion reactor concept in France, the UW's is much less expensive, roughly one-tenth the cost of Iter, while producing five times the amount of energy.

Iter's Tokamak

The UW researchers factored the cost of building a fusion reactor power plant using their design and compared that with building a coal power plant.

They used a metric called "overnight capital costs," which includes all costs, particularly startup infrastructure fees.

A fusion power plant producing 1 gigawatt (1 billion watts) of power would cost $2.7 billion, while a coal plant of the same output would cost $2.8 billion, according to their analysis.

"If we do invest in this type of fusion, we could be rewarded because the commercial reactor unit already looks economical," Sutherland said. "It's very exciting."

Right now, the UW's concept is about one-tenth the size and power output of a final product, which is still years away.

The researchers have successfully tested the prototype's ability to sustain a plasma efficiently, and as they further develop and expand the size of the device they can ramp up to higher-temperature plasma and get significant fusion power output.

The team has filed patents on the reactor concept with the UW's Center for Commercialization and plans to continue developing and scaling up its prototypes.

SPIDER: 'Spacecraft' seeks traces of the early universe over Antartica

Constructed primarily in Princeton's Jadwin Hall, SPIDER is a stratospheric spacecraft that in December will begin a 20-day orbit in Earth's stratosphere at an altitude of roughly 110,000 feet.

During that period, SPIDER's six large cameras will look for the pattern, or polarization, of gravitational waves produced by the fluctuation of energy and density that resulted from the Big Bang.

These waves, explained William Jones a Princeton University assistant professor of physics, are a "statistically unique fingerprint" that can be traced back to the beginning of the universe.

Many astronomical instruments measure various characteristics of this fingerprint, SPIDER is designed to characterize the "shape" of it, said Jones, who is the project's principal investigator.

"The ultimate goal of SPIDER is to see to what extent we can identify a very characteristic feature in that polarization that's expected to come from the earliest stages of the evolutionary growth of our universe," Jones said.

"There's a very particular pattern than can be generated only by something like a gravitational wave propagating through the surface of the cosmic microwave background [which is the glow of the heat left over from the Big Bang]," Jones said.

"That is a very particular pattern commonly referred to as a 'pinwheel' pattern on the sky. It's that particular pinwheel pattern that we're really after."

SPIDER, which used to be an acronym, but now is the project's formal name, is a multi-institutional project funded largely by a grant from NASA, as well as the David and Lucille Packard Foundation.

In addition to Princeton, the primary institutions involved are the University of Toronto; Case Western Reserve University; the California Institute of Technology and the Jet Propulsion Laboratory, a NASA-funded research center managed by Caltech; and the University of British Columbia.

The project was proposed in 2006 while Jones, who joined Princeton's faculty in 2008, was a scientist at the Jet Propulsion Laboratory.

ESA ARTES: Opening doors to space

Credit: ESA

The same device that opens doors on buses and planes could be used to meet peak energy demands on satellites.

Most satellites use small rechargeable batteries that can store large amounts of energy.

Supercapacitors do not hold as much, but they have a special ability to deliver very high bursts for a few seconds.

They're durable, too, and can easily last the 15 years of a satellite's life.

On municipal buses, they are charged during braking and supply electricity to open and close the doors when the vehicle stops, and help to get it moving again.

On the new EADS Airbus A380, supercapacitors help to operate the aircraft's heavy doors. In an emergency, they can even do it independently of the aircraft's central power system.

ESA recently joined forces with the Eggo company and Brno University of Technology in the Czech Republic, and Airbus Defense and Space (EADS) France to look at if these supercapacitors could be useful on telecom satellites.

While a typical space battery can deliver around 200 W/kg, banks of supercapacitors can deliver up to 50 times more power for short durations.

The studies carried out under ESA's ARTES programme found that this could keep a satellite's power supply from fluctuating as instruments draw energy.

If the electricity supply to instruments falls too low this could cause them to switch off or work below par.

Bank of supercapacitors. 

Credit: ESA

Other applications include the pyrotechnic separation mechanisms on rockets, high-power radar for Earth observation, and electric propulsion for repositioning and decommissioning satellites.

On top of this, smaller and lighter batteries could be used in combination with supercapacitors.

"Our work on supercapacitors reflects ESA's commitment to ensuring that the European and Canadian space industries remain at the very forefront of developments in electric energy storage systems for telecommunications," notes ESA's Energy Storage Engineer, Brandon Buergler.

WEGA fusion experiment passed on to the US

The first cables were disconnected in June: For 12 years young scientists were trained on WEGA, the Wendelstein-Experiment in Greifswald für die Ausbildung (Wendelstein Experiment in Greifswald for Training). 

Meanwhile the small stellarator is all packed away in crates and is on its way to new objectives in the USA. 

Credit: IPP, Iris Wessolowski

The small WEGA fusion device at Max Planck Institute of Plasma Physics (IPP) in Greifswald is being handed over to the University of Illinois in Urbana-Champaign.

The "Wendelstein-Experiment in Greifswald für die Ausbildung" (Wendelstein Experiment in Greifswald for Training) is making room for the Wendelstein 7-X large-scale device.

Urbana is succeeding Greifswald, Stuttgart and Grenoble as fourth site for the sturdy device.

WEGA has been in operation at IPP Greifswald since 2001. The small, but versatile fusion device was used for training students and young scientific personnel to bridge the time till completion of the Wendelstein 7-X large-scale device.

At the end of 2013 its time was up and WEGA had to be shut down; its place was needed for setting up the technical equipment for Wendelstein 7-X.

"This was a good opportunity for the University of Illinois", states the division head responsible at IPP, Professor Dr. Robert Wolf.

"It was just at this time that the Center for Plasma Material Interactions (CPMI) were looking for a small plasma device."

The transfer agreement was signed by IPP in mid-September 2014. Illinois are taking the responsibility and meeting the cost of dismantling WEGA, transporting it to the USA and re-assembling it at CPMI.

Under its new name, HIDRA (Hybrid Illinois Device for Research and Applications), the device will continue to be used for plasma physics and fusion research.

"We were very fortunate", says CPMI Director Professor David Ruzic, who sees numerous application possibilities for the device, including in particular investigation of the interaction between the plasma and wall material of the plasma vessel.

The objective of fusion research is to develop a power plant that, like the sun, derives energy from fusion of atomic nuclei.

Transfer of WEGA is one of several constituents of American-German collaboration around Wendelstein 7-X.

"At the age of almost 40 years, WEGA is certainly one of the longest-living fusion experiments, if not the longest ever", says Professor Wolf, who together with the WEGA team is happy that the sturdy device still has a future.

"In presumably three weeks it will start out on its hitherto longest journey, this time even across the Atlantic."

Wearable 4MM jetpack tested on speed, agility for runners - Video

"Everybody has always wanted to fly. When people hear the word 'jetpack,' that's what they really think about," said Jason Kerestes at Arizona State University.

He is one of the busy explorers at ASU trying to bridge gaps between man and machine. Kerestes has done something different with the jetpack concept.

He and team have reduced the amount of force; their device does not enable a person to fly, "but we have instantaneous thrust and we can pretty much trigger it to allow for faster movement and agile motion."

His jetpack, simply put, does not help you to fly but to run faster, and for the Defense Advanced Research Projects Agency (DARPA), his project's progress means a lot.

Kerestes has built his prototype, which is now undergoing tests and refinements.

The project is called 4MM, for 4-minute mile. The overall goal is to get any soldier or any test subject to be able to run a 4-minute mile who was not already capable of doing so.

Kerestes started doing his research "kind of by accident," he said.

As the owner of a welding business and going to ASU, students came to him; the team at the time was just at the infancy of this project.

"We were developing robots that could assist amputees," said Professor Thomas Sugar of the Human Machine Integration Lab.

"And DARPA came back to us and asked if we could develop robots that could assist able-bodied people, and make them able to run faster or do things they couldn't do."

Dr. Sugar works on mobile robot navigation and wearable robotics for the rehabilitation of stroke survivors.

Kerestes, already interested in the robotic process, welcomed the opportunity to get involved.

He said the fact that he could work at designing something and then weld up a prototype the next day substantially reduced their overall time on moving from concept to prototype.

Dr. Sugar said he and Kerestes had their doubts they could come up with something but then decided it was possible. They have seen encouraging results so far.

In trials over a 200-meter distance, with the jetpack, they saw a decrease in time and decrease in metabolic cost, the amount of energy required for a person to run at high speeds.

In a test, a subject with the jetpack on a sprint ran three seconds faster, and that was with carrying an extra 11.2 pounds of weight, the jetpack.

As for military support, Kerestes noted that in a warfare arena, a device such as this could spell the difference between life and death, "if you think of a Navy SEAL or a soldier that must get in somewhere quickly, and get out just as quickly," said Kerestes.

A 3-D model of stellar core collapse

A massive stellar core not quite managing to transition to a supernova explosion because of a small "kink" instability in its rotational axis. 

Credit: Philipp Mösta and Sherwood Richers

What happens when massive stars collapse? One potential result is a core-collapse supernova.

Astronomers can make observations of such events that tell us what is happening on the surface of a star when it explodes in a supernova, but it is considerably more difficult to know what is driving the process inside the star at its hot, dense core.

Philipp Mösta

Astrophysicists attempt to simulate these events based on the properties of different kinds of stars and knowledge of the fundamental interactions of mass and energy, hopefully providing astronomers with ready predictions that can be tested with observational data.

Christian Ott

In a recent publication, Caltech postdoctoral scholar Philipp Mösta and Christian Ott, professor of theoretical astrophysics, present a three-dimensional model of a rapidly rotating star with a strong magnetic field undergoing the process of collapse and explosion . . . or at least trying to.

Stars with a very rapid spin and a strong magnetic field are comparatively rare: no more than one in a hundred massive stars (those at least 10 times the mass of our sun) have these features.

According to Mösta and Ott's research, when these bodies undergo core collapse, small perturbations around its axis of rotation may inhibit the process that would ordinarily lead to a supernova explosion.

Previous models of the collapse of rapidly rotating magnetized stellar cores assumed perfect symmetry around the axis of rotation. In effect, these models were two-dimensional.

The models yielded the expectation that as these cores collapsed, the strong magnetic field combined with the rapid spin would squeeze the stellar material out into two narrow "jets" along the axis of symmetry, as shown at left.

Assuming perfect symmetry around the axis of rotation can be excused in part as a matter of simplifying the scenario so that it could be simulated on an ordinary computer rather than the kind of supercomputer that Mösta and Ott's three-dimensional simulations require: 20,000 processors to output 500 terabytes—over 500 trillion bytes—of data that represent only some 200 milliseconds in time.

But, says Ott, "Even working with paper and pencil, writing down equations and discussing them with other theoretical astrophysicists, we should have known that small perturbations can trigger an instability in the stellar core."

"Nothing in nature is perfect. As we learn from this model, even small asymmetries can have a dramatic effect on the process of stellar collapse and the subsequent supernova explosion."

More information: The paper, "Magnetorotational Core-collapse Supernovae in Three Dimensions," is available online: authors.library.caltech.edu/45202/1/2041-8205_785_2_L29.pdf

PPPL QUASAR Stellerator: A concept on the path to fusion energy

QUASAR stellerator design. Credit: PPPL

Completion of a promising experimental facility at the U.S. Department of Energy's Princeton Plasma Laboratory (PPPL) could advance the development of fusion as a clean and abundant source of energy for generating electricity, according to a PPPL paper published this month in the journal IEEE Transactions on Plasma Science.

The facility, called the Quasi-Axisymmetric Stellarator Research (QUASAR) experiment, represents the first of a new class of fusion reactors based on the innovative theory of quasi-axisymmetry, which makes it possible to design a magnetic bottle that combines the advantages of the stellarator with the more widely used tokamak design.

Experiments in QUASAR would test this theory.

Construction of QUASAR, originally known as the National Compact Stellarator Experiment (NCSE), was begun in 2004 and halted in 2008 when costs exceeded projections after some 80 percent of the machine's major components had been built or procured.

George "Hutch" Neilson

"This type of facility must have a place on the roadmap to fusion," said physicist George "Hutch" Neilson, the head of the Advanced Projects Department at PPPL.

Both stellarators and tokamaks use magnetic fields to control the hot, charged plasma gas that fuels fusion reactions.

While tokamaks put electric current into the plasma to complete the magnetic confinement and hold the gas together, stellarators don't require such a current to keep the plasma bottled up.

Stellarators rely instead on twisting, or 3D, magnetic fields to contain the plasma in a controlled "steady state."

Stellarator plasmas thus run little risk of disrupting or falling apart as can happen in tokamaks if the internal current abruptly shuts off.

ITER: the world's largest Tokamak

Developing systems to suppress or mitigate such disruptions is a challenge that builders of tokamaks like ITER, the international fusion experiment under construction in France, must face.

Stellarators had been the main line of fusion development in the 1950s and early 1960s before taking a back seat to tokamaks, whose symmetrical, doughnut-shaped magnetic field geometry produced good plasma confinement and proved easier to create.

But breakthroughs in computing and physics understanding have revitalized interest in the twisty, cruller-shaped stellarator design and made it the subject of major experiments in Japan and Germany.

PPPL developed the QUASAR facility with both stellarators and tokamaks in mind. Tokamaks produce magnetic fields and a plasma shape that are the same all the way around the axis of the machine—a feature known as "axisymmetry." QUASAR is symmetrical too, but in a different way.

While QUASAR was designed to produce a twisting and curving magnetic field, the strength of that field varies gently as in a tokamak, hence the name "quasi-symmetry" (QS) for the design.

This property of the field strength was to produce plasma confinement properties identical to those of tokamaks.

"If the predicted near-equivalence in the confinement physics can be validated experimentally," Neilson said, "then the development of the QS line may be able to continue as essentially a '3D tokamak.'"

More information: Neilson, G.H.; Gates, D.A.; Heitzenroeder, P.J.; Breslau, J.; Prager, S.C.; Stevenson, T.; Titus, P.; Williams, M.D.; Zarnstorff, M.C., "Next Steps in Quasi-Axisymmetric Stellarator Research," Plasma Science, IEEE Transactions on , vol.42, no.3, pp.489,494, March 2014. DOI: 10.1109/TPS.2014.2298870

Fresnel reflectors: Producing electricity on the moon at night

System for producing electricity on the Moon using reflective mirrors and a thermal engine. 

Fresnel reflectors (dark blue and grey mirrors) will concentrate solar rays into the elongated collector above. 

Beneath, there is a tube filled with fluid that transforms into a gas when heated. 

This heats the thermal mass or reservoir (grey box), which can transfer this heat to a Stirling engine (cross-shaped object) to produce electricity during the long lunar night. 

The radiator (blue) can heat rovers and crew. 

The yellow cover is a protector that prevents the heat from rapidly dissipating.

Credit: Blai Climent et al.

Scientists from the Polytechnic University of Catalonia and other international collaborators have proposed a system of mirrors, processed lunar soil and a heat engine to provide energy to vehicles and crew during the lunar night.

This would preclude the need for batteries and nuclear power sources such as those used by the Chinese rover that recently landed on the moon.

The lunar night lasts approximately 14 days, during which temperatures as low as -150 ºC have been recorded.

This complicates vehicle movement and equipment functioning on the lunar surface, requiring the transport of heavy batteries from Earth or the use of nuclear energy, as exemplified by the Chinese rover Yutu.

Now, a team of researchers from the Polytechnic University of Catalonia, along with collaborators from the USA, have studied two options for storing energy on the Moon during the day for use at night.

Michael Griffin

The details have been published in the journal Acta Astronautica, in an article featuring the participation of former NASA administrator, Michael Griffin.

"The first system consists of modifying fragments of regolith or lunar soil, incorporating elements such as aluminium, for example, such that it becomes a thermal mass," Ricard Gonzalez-Cinca, a physics researcher at the Polytechnic University of Catalonia and co-author of the study, explains to SINC.

"When the Sun's rays hit the surface, a system of mirrors reflects the light to heat the thermal mass, which later," he adds, "can transmit heat during the night to rovers and other lunar equipment."

The second system is similar, but incorporates a more sophisticated series of mirrors and a heat engine.

The mirrors are Fresnel reflectors, such as those used in some solar energy technologies on Earth, which concentrate solar rays upon a fluid-filled tube.

This heat converts the liquid into a gas, which in turn heats the thermal mass.

Afterwards, during the long lunar night, the heat is transferred to a Stirling engine to produce electricity.

"This system is better equipped than the previous model for lunar projects with greater energy needs, such as a manned mission spending the night on the moon," reports Gonzalez-Cinca.

Starting in 2020, the world's major space agencies, including NASA, the European Space Agency (ESA) and the China National Space Administration, are planning their first manned missions to our satellite.

Other countries, such as India and Japan, have also voiced their interest to send their own missions from that date onwards.

More information: Blai Climent, Oscar Torroba, Ricard Gonzalez-Cinca, Narayanan Ramachandran, Michael D. Griffin. "Heat storage and electricity generation in the Moon during the lunar night". Acta Astronautica 93: 352-358, January 2014. (Invited paper). DOI: 10.1016/j.actaastro.2013.07.024

Robot with brush, water, wiper tackles solar panel cleaning

Credit: Sinfonia Technology (previously known as Shinko Electric Company)

At large-scale solar plants, keeping the surfaces of solar panels free from dust, sand and bird droppings is not just a matter of finicky housekeeping.

It can be a matter of plant profitability. Dirty panels lower power generation efficiencies.

Bird droppings on panels, for example, block the sunlight.

A Tokyo-based company has a solution. Sinfonia Technology announced late last month that it has developed a robot with camera and sensors that can move autonomously and clean solar panels at large-scale solar power plants.

Sinfonia's robot has a distinction in being "autonomous" in that, rather than tethered to rails, the robot is able to move from panel to panel, to tackle the panels' dirt and debris.

The robot is equipped with scrub brush, wiper and detergent; and also sprinkles water stored in its tank. The robot can work in the dark; it has LEDs, having wavelengths in the infrared range.

Aside from autonomy, another key distinction is that Sinfonia's robot can handle the fact that not all solar panels are alike; the robot is designed to tackle panels that tilt in different ways.

To clean tilted solar panels on a mounting system, the robot can move on a planes tilted at 5-30°. If there is a gap between panels, the robot can go over a gap of 50cm or less and can deal with a height difference of 30cm or less.

The robot is powered by a battery and is capable of wireless data transmission. A tablet can be used to check the robot's status—to check if, for example, it has enough water or to check the battery charge remaining.

Sinfonia Technology, in promoting the benefits of its panel-cleaning robots, also noted cost advantages over using manpower for cleaning panels.

Generally, experts say that, for large-scale solar panel installations, attention to keeping the panels clean makes sense.

Earlier this year, however, a study out of the Jacobs School of Engineering at University of California San Diego, in quantifying losses of electricity output due to dirty solar panels, found panels that hadn't been cleaned, or rained on, for 145 days during a summer drought in California lost on average a little less than 0.05 percent of their overall efficiency per day.

The overall conclusion was, that cleaning the panels often was not worth the cost, according to the study's engineers.

They cautioned, though, that their study focused on smaller systems and that, for very large installations, economies of scale may mean that washing panels was worth it.

Sharp, meanwhile, is another Japan-based company showing interest in devising automatic ways to clean solar panels.

Wendelstein 7-X closed: Core of fusion device completed

Precision work: One of over 250 ports being brazed in the plasma chamber. Credit: IPP, Anja Ullmann

The last open seam on the steel outer cover of the Wendelstein 7-X fusion device was closed last week.

The core of the research device is thus ready as basic skeleton and can go into operation at the Greifswald branch institute of Max Planck Institute of Plasma Physics (IPP) in 2014.

The objective of fusion research is to derive energy from fusion of atomic nuclei, just as happens in the sun.

To ignite the fusion fire, the hydrogen plasma fuel in a future power plant has to be confined in magnetic fields and heated to temperatures exceeding 100 million degrees.

Wendelstein 7-X, the world's largest fusion device of the stellarator type when completed, is intended to investigate the suitability of this configuration for a power plant.

With 70 large superconducting magnet coils in continuous operation it is then to produce a highly stable and thermally insulating magnetic cage confining the plasma.

The ring-shaped device is being installed as five almost structurally identical modules: Each of the five sections of the plasma vessel, along which 14 magnet coils are strung, is enclosed by a steel outer sheath, weighing altogether 120 tons.

Assembled like slices of cake on the machine's foundation, the five modules form a steel ring from which numerous connection ports protrude.

These link the apertures of the plasma chamber through the coil region with the outer vessel. Later, measuring instruments, pumps and heating facilities will be affixed here.

The 254th and last port was brazed in between the plasma vessel and outer vessel with millimetre precision on 28 May 2013.

The elaborate port installation lasted a good two years. This was preceded by an equally long test phase – "a huge training session" as installation head Dr. Lutz Wegener put it – during which the methods for exact placement and connection of the variously configured ports to the bizarrely shaped plasma vessel were developed.

One of the many challenges: As stainless steel inevitably shrinks at the seam when it is brazed, the components are distorted and change position.

This had also to be allowed for when brazing the five modules of the device together: Calculations and tests during installation planning had predicted here up to eight millimetres shift per seam, this being intolerable since the ports and the subsequently connected measuring instruments would be looking at the wrong place in the plasma.

View of the Wendelstein 7-X fusion device from above: All of the 254 ports are installed. Credit: IPP, Anja Ullmann

The solution: The module to be brazed, exactly monitored by laser tracker measurements, was shifted on sliding bearings about eight millimetres away from its firmly attached component opposite.

Then, to prevent anything shifting, several welders began together to close the two brazing gaps of both the plasma chamber and the outer sheath.

For the multi-layered seams with a total length of 40 metres the specialists of the MAN Diesel Turbo company took several weeks, during which the heavy module – in keeping with the shrinkage – slowly returned to its initial position in tenths of a millimetre steps.

"It is a veritable work of art to guide in the right direction such a big and heavy component during brazing", states Karsten Liesenberg, who is responsible for the vessel installation concept: "If the laser trackers showed that the module was not being shifted exactly parallel, the brazing crew had to change over to the opposite side of the seam so that the component was again put on the right track".

This precision work was repeated on the other four module boundaries. The ring is meanwhile closed and all five modules are in place with the required two millimetre precision.

Thrusters powered by Ionic Wind: An efficient alternative energy source

When a current passes between two electrodes—one thinner than the other—it creates a wind in the air between.

If enough voltage is applied, the resulting wind can produce a thrust without the help of motors or fuel.

This phenomenon, called electro-hydro-dynamic thrust—or, more colloquially, "ionic wind"—was first identified in the 1960s.

Since then, researchers have theorised that ionic thrusters, if used as jet propulsion, would be extremely inefficient, requiring massive amounts of electricity to produce enough thrust to propel a vehicle.

Now researchers at MIT have run their own experiments and found that ionic thrusters may be a far more efficient source of propulsion than conventional jet engines.

In their experiments, they found that ionic wind produces 110 newtons of thrust per kilowatt, compared with a jet engine's 2 newtons per kilowatt.

Steven Barrett

The team has published its results in the Proceedings of the Royal Society. Steven Barrett, an assistant professor of aeronautics and astronautics at MIT, envisions that ionic wind may be used as a propulsion system for small, lightweight aircraft.

In addition to their relatively high efficiency, ionic thrusters are silent, and invisible in infrared, as they give off no heat—ideal traits, he says, for a surveillance vehicle.

"You could imagine all sorts of military or security benefits to having a silent propulsion system with no infrared signature," says Barrett, who co-authored the paper with graduate student Kento Masuyama.

Shooting the gap A basic ionic thruster consists of three parts: a very thin copper electrode, called an emitter; a thicker tube of aluminum, known as a collector; and the air gap in between.

Kento Masuyama

A lightweight frame typically supports the wires, which connect to an electrical power source. As voltage is applied, the field gradient strips away electrons from nearby air molecules.

These newly ionized molecules are strongly repelled by the corona wire, and strongly attracted to the collector.

As this cloud of ions moves toward the collector, it collides with surrounding neutral air molecules, pushing them along and creating a wind, or thrust.

To measure an ion thruster's efficiency, Barrett and Masuyama built a similarly simple setup, and hung the contraption under a suspended digital scale.

They applied tens of thousands of volts, creating enough current draw to power an incandescent light bulb.

They altered the distance between the electrodes, and recorded the thrust as the device lifted off the ground. Barrett says that the device was most efficient at producing lower thrust—a desirable, albeit counter-intuitive, result.

"It's kind of surprising, but if you have a high-velocity jet, you leave in your wake a load of wasted kinetic energy," Barrett explains.

"So you want as low-velocity a jet as you can, while still producing enough thrust." He adds that an ionic wind is a good way to produce a low-velocity jet over a large area.

U.S. restarts Plutonium 238 production for space probes

A glowing red hot pellet of plutonium-238 dioxide to be used in a radioisotope thermoelectric generator for space missions.

The Department of Energy has produced its first batch of non-weapons grade plutonium, used to power space probes, since a nuclear reactor shutdown 25 years ago, NASA officials said on Monday.

The U.S. space agency turned to buying radioactive plutonium-238 from Russia after safety issues prompted the Department of Energy to close its Savannah River Site in South Carolina in the late 1980s.

The Russian supply line ended in 2010, leaving NASA with a small and aged supply of plutonium for space probes flying missions that are ill-suited for solar power.

Plutonium naturally radiates heat, which can be converted into electricity by a device called a radioisotope thermo-electric generator.

NASA has been flying nuclear-powered probes since the 1970s. Ongoing missions using such probes include the Mars rover Curiosity, the Saturn-orbiting Cassini spacecraft, Pluto-bound New Horizons and the twin Voyager probes, which are leaving the solar system.

"The new plutonium is very important to us," Jim Green, the head of NASA's planetary science division, said during a briefing at a Lunar and Planetary Science Conference in Houston.

In partnership with NASA, the Department of Energy irradiated the radioactive metal neptunium-237 with neutrons at the Oak Ridge National Laboratory in Tennessee for about a month and successfully produced a small amount plutonium.

"This is just a test," Green said, adding that a report from the Energy Department on production plans and costs should be finished before the end of the year.

NASA is looking for the department to produce about 3.3 to 4.4 pounds (1.5 to 2 kg) of plutonium-238 per year.

Newly made plutonium has the added benefit of reviving older plutonium that has decayed past the point of being viable for deep space probes.

"The new material when we add with our old plutonium, which is more than 20 years old in some cases, really allows us to get the appropriate energy density out," Green said.

NASA also has been working on a more energy efficient generator, called the Advanced Stirling Radioisotope Generator, which can produce four times more electrical power per kilogram of plutonium-238.

Green said two such flight-ready generators are on schedule for completion in 2016. Neither has yet been assigned for a specific mission.

CSIRO's 64-m Parkes: Detects Enormous Outflow of Energy

Enormous outflows of charged particles from the centre of our Galaxy, stretching more than halfway across the sky and moving at supersonic speeds, have been detected and mapped with CSIRO's 64-m Parkes radio telescope.

Corresponding to the "Fermi Bubbles" found in 2010, the recent observations of the phenomenon were made by a team of astronomers from Australia, the USA, Italy and The Netherlands, with the findings reported in Nature.

"There is an incredible amount of energy in the outflows," said co-author Professor Lister-Staveley-Smith from The University of Western Australia node of the International Centre for Radio Astronomy Research in Perth and Deputy Director of the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO).

"The source of the energy has been somewhat of a mystery, but we know there is a lot there, about a million times as much energy as a supernova explosion (a dying star)."

CSIRO's 64-m Parkes radio telescope

From top to bottom the outflows extend 50,000 light-years [five hundred thousand million million kilometres] out of the Galactic Plane. That's equal to half the diameter of our Galaxy (which is 100,000 light-years-a million million million kilometres-across).

"Our Solar System is located approximately 30,000 light-years from the centre of the Milky Way Galaxy, but we're perfectly safe as the jets are moving in a different direction to us," said Professor Staveley-Smith.

Seen from Earth, but invisible to the human eye, the outflows stretch about two-thirds across the sky from horizon to horizon.

They match previously identified regions of gamma-ray emission detected with NASA's Fermi Space Telescope (then-called "Fermi Bubbles") and the "haze" of microwave emission spotted by the Wilkinson Microwave Anisotropy Probe (WMAP) and Planck Space Telescope.

"Adding observations by the ground-based Parkes radio telescope to those made in the past by space telescopes finally allows us to understand how these enormous outflows are powered," said Professor Staveley-Smith.

Previously it was unclear whether it was quasar-like activity of our Galaxy's central super-massive black hole or star formation that kept injecting energy into the outflows.

The recent findings, reported in Nature today, show that the phenomenon is driven by many generations of stars forming and exploding in the Galactic Centre over the last hundred million years.

Hubble Image Hercules A: Huge black hole emits two beams of matter into space.

Hercules A, a galaxy which contains a massive black hole blasting out energy and matter.

This picture is a combination of visible light seen by the Hubble Space Telescope and radio waves, coloured pink in the image, detected by the Karl G. Jansky Very Large Array.

Image credit: NASA, ESA, S. Baum and C. O'Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA)

In the heart of the galaxy Hercules A is a monster black hole: It’s about 600 times as massive as the black hole in the center of our Milky Way, making it about 2.5 billion times the Sun’s mass.

Material is actively funneling down into this black hole, forming a huge disk and blasting out the jets of material seen in the picture.

Focused tightly, those jets shoot across space at very high speed, slamming into material around them.

Eventually they lose energy and slow down, causing them to spread outward, forming the twin lobes shown.

Also when this happens, the material emits light in the radio part of the electromagnetic spectrum. The lobes of Herc A make it one of the brightest sources of radio waves in the entire sky.



The scale of this event is incredible.
Those lobes are well over 1.5 million light years across from edge to edge, 15 times the size of our entire galaxy, and they’re powerful, emitting a billion times the energy our Sun does at radio wavelengths.

The energy flowing out of Hercules A is beyond belief. The black hole blasts out 100 billion times as much energy in X-rays, as our Sun does in all wavelengths of light.

The black hole at the heart of Hercules A emits enough X-ray energy to easily vapourise our entire Earth and most of the Solar System.

Nuclear fusion-generated electricity: Is safer, more efficient energy on the horizon?

Fusion-fueled power generation has been the energy of the future for several decades.

"There's always been this sense that fusion is fifty years away," Saskia Mordijck says, but she adds that the horizon for safer and more efficient fusion-based electricity in our homes is really, truly getting closer.

Mordijck, a research assistant professor based in the Computer Science Department at William & Mary (with adjunct positions in physics and applied science), has received funding from the U.S. Department of Energy to continue her investigation of fusion energy.

She says most people are only vaguely aware of how fusion works and therefore have little idea of the advantages is offers over "traditional" nuclear power.

Fusion Energy
"Fusion energy is the exact opposite of what we have across the river in Surry where we have a nuclear power plant," she explained.

"In a nuclear power plant they actually bombard their material with small particles so it splits apart so there is energy released—that's fission."

To accomplish fusion, she says, you take two very small particles and heat them at high enough temperatures so that they fuse together.

"As a result of their fusing together they actually will release energy, as per Einstein's famous equation E=mc2.," Mordijck explained.

That's one most people recognize even if they have not had any physics."

Many advantages over fission 
When it comes to power generation, fusion has a number of advantages over fission and many of them relate to safety.

Mordijck says that the usual causes of anxiety over nuclear power generation just don't exist with fusion. Fukushima/Chernobyl-type incidents are not part of the equation.

"The nice thing about a fusion reaction is that if somehow it would go out of control, it would just stop itself automatically. If a fission reaction goes out of control, it can really go out of control," Mordijck explained.

"You can't stop it and it actually might go into a nuclear meltdown." The second set of fusion-over-fission benefits centers around radioactive waste.

Dealing with Nuclear waste
Mordijck acknowledges that certain amount of waste is inescapable, but a fusion power plant would generate only a fraction of the amount of nuclear waste that even the most efficient fission plants produce.

Not only is the amount smaller, but waste from a fusion plant also stays dangerous for much shorter periods of time.

"In a fission power plant we create a lot of radioactive waste which lasts for a very long time. It lasts longer than most things that we have here on Earth, and so we have to store it somewhere.

We cannot clean it any way or form," Mordijck explained. "Whereas in a fusion power plant, the lifetime of this waste is very short.

After 50 to 100 years, it will be completely gone and it will not be more radioactive than the surrounding environment and it won't be able to contaminate anything."

Funding cuts hinder progress
Fusion energy has been working in the sun, where the fusion of hydrogen nuclei into helium has been keeping us warm for years.

Despite all the potential advantages, fusion remains an experimental technology and an underfunded one at that, Mordijck says.

 "When people say that fusion always seems to be perpetually fifty years off, we fusion scientists point out that our funding has been cut every single year, so it's hard to make any progress," she noted.

The Rimac e-M3: 1984 3 Series with a 600hp electric power

What is the Rimac e-M3 evaluation vehicle?

This emerald green monster is the Rimac e-M3 evaluation vehicle - the technological testbed used to assess the viability for an all-electric supercar, the Rimac Concept One.

The Rimac Concept One

Due to its volt-powered propulsion system, the Concept_One should be pretty efficient, too - Rimac claims a 375-mile range between charges and quotes fuel economy at a conservative estimate of 125mpg electric equivalent.

According to their figures, drive the Concept_One with a feather light right foot and you could see close to 490.

Rimac Concept_One electric supercar offers 1,088hp

NASA - A Summer of Records for J-2X Engine Testing

NASA is setting new records while testing the J-2X powerpack at the Stennis Space Center.

Image Credit: NASA/SSC

The first time was June 8, when engineers went the distance and set the Test Complex A record with a 1,150-second firing of the developmental powerpack assembly.

On July 24, engineers surpassed that record with a 1,350-second test of the engine component on the A-1 Test Stand at Stennis.

The powerpack is a system of components on the top portion of the J-2X engine. On the complete J-2X engine, the powerpack feeds the thrust chamber, which produces the engine fire and thrust.

The advantage of testing the powerpack without the thrust chamber is to operate over a wide range of conditions to understand safe limits.

The July 24 test specifically gathered data on performance of the liquid oxygen and fuel pumps during extreme conditions.

The test data provides critical information for continued development of the turbopump for use on the J-2X engine, the first human-rated liquid oxygen and liquid hydrogen rocket engine to be developed in four decades.

The J-2X is being built by Pratt & Whitney Rocketdyne for NASA’s Marshall Space Flight Center in Huntsville, Ala.

The J-2X engine will power the upper-stage of a planned two-stage Space Launch System (SLS). The SLS will launch NASA's Orion spacecraft and other payloads, and provide an entirely new capability for human exploration beyond low Earth orbit.

Designed to be safe, affordable and flexible for crew and cargo missions, the SLS will continue America's journey of discovery and exploration to destinations including nearby asteroids, Lagrange points, the moon and ultimately, Mars.

Alternative Energy Sources: Surfactant driven propulsion

A small autonomous boat powered by a volatile surfactant has been developed by scientists in Finland and Israel.

The surfactant modifies the surface tension of the liquid it floats on to create a surface tension gradient that propels the boat forward.

Propulsion induced by a surface tension gradient is known as Marangoni propulsion. It’s used in nature by small creatures such as Microvelia (small aquatic insects) to give a burst of speed to escape predators.

In man-made devices, the Marangoni effect has been used to power small ‘camphor boats’ and ‘soap boats’; however, these systems normally offer only short term propulsion or require the boat to be confined to specific channels.

To develop a longer-term propulsion system, the team led by Robin Ras at Aalto University, Finland, created a boat from a lightweight membrane made from a nano-cellulose aerogel.

The membrane is impermeable to water (and oil) but it allows the gaseous surfactants to pass through it. The team used ethanol as the fuel to power a boat floating on water.

Housed in a reservoir at the rear of the boat, a few drops of ethanol are placed on a tissue. As the ethanol evaporates, it diffuses through the membrane at the rear of the boat and lowers the surface tension of the water.

This creates the surface tension gradient that drives the boat forward. The boat is not steered so it typically travels in a circular route.

Once the boat has passed, the ethanol at the water surface evaporates, returning the surface tension to normal. Modifying the surface tension only requires a small amount of surfactant.

‘The boat ran for over 54 minutes on only 25 microlitres of fuel,’ says Ras. ‘It’s very fuel efficient while cruising at a speed of 2cm s^-1,’ he adds. To demonstrate the generality of their approach, the team showed they could also use pentane to power a boat floating on paraffin oil.

‘This is a beautiful illustration of exciting soft matter research. The researchers combine innovative materials science with fundamental surface science to construct a novel self-propelling floating device that is much more controllable and versatile than any similar device suggested before,’ says Lennart Piculell, an expert in physical chemistry at Lund University, Sweden.

‘I don't see any immediate applications, but the concept is simple and can be applied to even smaller devices.’