Spacecraft of the Future Could Be Powered By Lattice Confinement Fusion

Photo: NASA

Dr. Theresa Benyo documents beam conditions during NASA’s lattice confinement fusion experiments while Jim Scheid and Larry Forsley discuss the beam stability data.

Nuclear fusion is hard to do. It requires extremely high densities and pressures to force the nuclei of elements like hydrogen and helium to overcome their natural inclination to repel each other. On Earth, fusion experiments typically require large, expensive equipment to pull off.

But researchers at NASA’s Glenn Research Center have now demonstrated a method of inducing nuclear fusion without building a massive stellarator or tokamak. In fact, all they needed was a bit of metal, some hydrogen, and an electron accelerator.

The team believes that their method, called lattice confinement fusion, could be a potential new power source for deep space missions. They have published their results in two papers in Physical Review C.

“Lattice confinement” refers to the lattice structure formed by the atoms making up a piece of solid metal. The NASA group used samples of erbium and titanium for their experiments. Under high pressure, a sample was “loaded” with deuterium gas, an isotope of hydrogen with one proton and one neutron. The metal confines the deuterium nuclei, called deuterons, until it’s time for fusion.

“During the loading process, the metal lattice starts breaking apart in order to hold the deuterium gas,” says Theresa Benyo, an analytical physicist and nuclear diagnostics lead on the project. “The result is more like a powder.” At that point, the metal is ready for the next step: overcoming the mutual electrostatic repulsion between the positively-charged deuteron nuclei, the so-called Coulomb barrier.

Photo: NASA

Deuterons have been forced into the atomic lattice structures of these samples of erbium used in NASA's fusion experiments.

To overcome that barrier requires a sequence of particle collisions. First, an electron accelerator speeds up and slams electrons into a nearby target made of tungsten. The collision between beam and target creates high-energy photons, just like in a conventional X-ray machine. The photons are focused and directed into the deuteron-loaded erbium or titanium sample. When a photon hits a deuteron within the metal, it splits it apart into an energetic proton and neutron. Then the neutron collides with another deuteron, accelerating it.

At the end of this process of collisions and interactions, you’re left with a deuteron that’s moving with enough energy to overcome the Coulomb barrier and fuse with another deuteron in the lattice.

Key to this process is an effect called electron screening, or the shielding effect. Even with very energetic deuterons hurtling around, the Coulomb barrier can still be enough to prevent fusion. But the lattice helps again. “The electrons in the metal lattice form a screen around the stationary deuteron,” says Benyo. The electrons’ negative charge shields the energetic deuteron from the repulsive effects of the target deuteron’s positive charge until the nuclei are very close, maximizing the amount of energy that can be used to fuse.

Aside from deuteron-deuteron fusion, the NASA group found evidence of what are known as Oppenheimer-Phillips stripping reactions. Sometimes, rather than fusing with another deuteron, the energetic deuteron would collide with one of lattice’s metal atoms, either creating an isotope or converting the atom to a new element. The team found that both fusion and stripping reactions produced useable energy.

“What we did was not cold fusion,” says Lawrence Forsley, a senior lead experimental physicist for the project. Cold fusion, the idea that fusion can occur at relatively low energies in room-temperature materials, is viewed with skepticism by the vast majority of physicists. Forsley stresses this is hot fusion, but “We’ve come up with a new way of driving it.”

Photo: NASA

Bayarbadrakh Baramsai and Philip Ugorowski confer on the neutron spectroscopy system used to detect fusion neutrons.

“Lattice confinement fusion initially has lower temperatures and pressures” than something like a tokamak, says Benyo. But “where the actual deuteron-deuteron fusion takes place is in these very hot, energetic locations.” Benyo says that when she would handle samples after an experiment, they were very warm. That warmth is partially from the fusion, but the energetic photons initiating the process also contribute heat.

There’s still plenty of research to be done by the NASA team. Now they’ve demonstrated nuclear fusion, the next step is to create reactions that are more efficient and more numerous. When two deuterons fuse, they create either a proton and tritium (a hydrogen atom with two neutrons), or helium-3 and a neutron. In the latter case, that extra neutron can start the process over again, allowing two more deuterons to fuse. The team plans to experiment with ways to coax more consistent and sustained reactions in the metal.

Benyo says that the ultimate goal is still to be able to power a deep-space mission with lattice confinement fusion. Power, space, and weight are all at a premium on a spacecraft, and this method of fusion offers a potentially reliable source for craft operating in places where solar panels may not be useable, for example. And of course, what works in space could be used on Earth. 

Modified Cessna is the 'Largest' Electric Aircraft to take Flight

As reported by Engadget: Electric aircraft are ever so slightly closer to becoming a practical reality for travel. Magnix and AeroTEC have flown what they say is the world’s largest all-electric aircraft. Their modified Cessna 208B Grand Caravan, the “eCaravan,” flew for 30 minutes around Washington state’s Grand County International Airport using Magnix’s 750HP Magni500 motor instead of the usual turboprop engine. The flight was “flawless,” Magnix chief Roei Ganzarski said in a statement to FlightGlobal.

There are compromises. Batteries consume massive amounts of space and weight, and the current eCaravan could haul just four to five passengers (instead of as many as 14) for a distance of 100 miles. Magnix and AeroTEC hope to eventually carry nine people 100 miles once the technology has advanced, but that won’t happen until after the initial aircraft’s expected certification in 2021.

Still, this could be useful in the long run. The companies envision these Caravans reviving short-hop flights that became impractical for many airlines. The operating costs would be much more feasible (a 30-minute flight costs $6 in electricity, for instance), and emissions wouldn’t be an issue. It will take a while before you could take a longer electric journey, but this could beat many alternative and less eco-friendly transport options when you need to get from city to city in a timely fashion.

Microsoft's OpenAI Supercomputer has 285,000 CPU Cores, 10,000 GPUs

As reported by Engadget: Last year, Microsoft invested $1 billion in Open AI, a company co-founded by Elon Musk that focuses on the development of human-friendly artificial intelligence. Today at the Build 2020 developer conference, we're seeing the first results of that investment. Microsoft announced that it has developed an Azure-hosted supercomputer built expressly for testing OpenAI's large-scale artificial intelligence models. 

While we've seen many AI implementations focused on single tasks, like recognizing specific objects in images or translating languages, a new wave of research is focused on massive models that can perform multiple tasks at once. As Microsoft notes, that can include moderating game streams or potentially generating code after exploring GitHub. Realistically, these large-scale models can actually make AI a lot more useful for consumers and developers alike. 

The OpenAI supercomputer is powered by 285,000 CPU cores and 10,000 GPUs (each of which are also united by speedy 400 gigabit per second connections). And while Microsoft didn't reveal any specific speed capability, the company says it's the TOP500 list of publicly disclosed supercomputers.

At this point, it's unclear how, exactly, OpenAI will take advantage of such a powerful system. But we can at least expect the results to be interesting. The non-profit is best known for developing an algorithm that could write convincing fake news, as well as proving that even bots learn to cheat while playing hide and go seek.

Maybe OpenAI will take a note from Microsoft and develop something like its Turing models for natural language generation, a large-scale AI implementation that's powering things like real-time caption generation in Teams. It's backed by 17 billion parameters for understanding language -- a particularly impressive number when competing solutions clocked 1 billion parameters last year. Microsoft also announced that it's making the Turing models open source, so developers will be able to use it for their own language processing needs soon.

Could Plasma Thrusters Really Replace Jet Engines?

A new plasma thruster could scale up to compete with traditional jet engines.    

As reported by Popular Mechanics: Chinese scientists suggest they’re bringing space plasma thrusters down to Earth, with a new kind that performs as well in the atmosphere as others do in the vacuum of space.

Using just air and electricity, researchers from the Institute of Technical Sciences at Wuhan University say they’ve overcome longtime atmospheric issues like air friction and made a plasma thruster that can compete on the ground.

In a new paper in American Institute of Physics Advances, the scientists describe how they built and tested their plasma thruster.

“We demonstrated that, given the same power consumption, its propulsion pressure is comparable to that of conventional airplane jet engines using fossil fuels,” they say, which is an extraordinary claim.

The plasma thrusters used in space are specially suited to the zero-G and very thin or nonexistent air. “Even though such a plasma engine has a very small propulsion force, after months and years of constant acceleration, the spacecraft can ultimately reach a high speed,” the researchers explain. So in the absence of friction in space, a tiny amount of power can increase in a linear way without limits, like a snowball rolling downhill that can eventually crush a house.

The plasma thruster design.

Bringing plasma thrust into the atmosphere means contending with strict design limitations. The researchers cite an MIT development of an interim “Tesla type” plasma thruster that’s more powerful than ones for space, but not quite enough for typical aircraft. Instead, these researchers have supercharged the thrust using high temperatures and the application of powerful microwaves.

The homemade heat-resistant device used to measure propulsion pressure in the experiment. The device has a small hole at the top for inserting smaller steel beads in order to adjust the threshold weight, at which the ball starts to rattle due to the effect of the plasma jet.

“In this report, we consider a microwave air plasma jet thruster using high-temperature and high-pressure plasma generated by a 2.45 GHz microwave ionization chamber for injected pressurized air,” the researchers say. A microwave oscillator called a gravitron sends microwaves down a tube that terminates with an igniter that heats the plasma. The tube intensifies the microwaves and the resulting plasma is held in a cohesive shape by the flow of fresh air.

The small laboratory model scales up, the scientists say, to the equivalent of a commercial jet engine—enough to theoretically compete with the fossil fuel technologies we use today. From the study:

“[U]sing a high-power microwave source or an array of multiple microwave sources in parallel operation, with materials resistant to high temperature and pressure, it is possible to construct a high-performance microwave air plasma jet thruster in the future to avoid carbon emissions and global warming that arise due to fossil fuel combustion.”

All this sounds amazing, right? So what’s the catch?

Well, the super hot plasma is so hot that it might melt anything that could contain it. In order to scale up a small laboratory model into a full-size electric plasma thruster, future researchers will need to run tests on materials and construction as well as the best ways to combine everything into the most powerful thrusters. To even test the thrust, the scientists had to make a new heat-resistant measuring setup using quartz and steel.

So while this may be a milestone step, the realization of its white-hot potential is likely a decade or more away.

Machine Learning Could Check if you're Social Distancing Properly at Work

As reported by Technology Review: Andrew Ng’s startup Landing AI has created a new workplace monitoring tool that issues an alert when anyone is less than the desired distance from a colleague.

Six feet apart: On Thursday, the startup released a blog post with a new demo video showing off a new social distancing detector. On the left is a feed of people walking around on the street. On the right, a bird’s-eye diagram represents each one as a dot and turns them bright red when they move too close to someone else. The company says the tool is meant to be used in work settings like factory floors and was developed in response to the request of its customers (which include Foxconn). It also says the tool can easily be integrated into existing security camera systems, but that it is still exploring how to notify people when they break social distancing. One possible method is an alarm that sounds when workers pass too close to one another. A report could also be generated overnight to help managers rearrange the workspace, the company says.

Under the hood: The detector must first be calibrated to map any security footage against the real-world dimensions. A trained neural network then picks out the people in the video, and another algorithm computes the distances between them.

Workplace surveillance: The concept is not new. Earlier this month, Reuters reported that Amazon is also using similar software to monitor the distances between their warehouse staff. The tool also joins a growing suite of technologies that companies are increasingly using to surveil their workers. There are now myriad cheap off-the-shelf AI systems that firms can buy to watch every employee in a store, or listen to every customer service representative on a call. Like Landing AI’s detector, these systems flag up warnings in real time when behaviors deviate from a certain standard. The coronavirus pandemic has only accelerated this trend.

Dicey territory: In its blog post, Landing AI emphasizes that the tool is meant to keep “employees and communities safe,” and should be used “with transparency and only with informed consent.” But the same technology can also be abused or used to normalize more harmful surveillance measures. When examining the growing use of workplace surveillance in its annual report last December, the AI Now research institute also pointed out that in most cases, workers have little power to contest such technologies. “The use of these systems,” it wrote, “pools power and control in the hands of employers and harms mainly low-wage workers (who are disproportionately people of color).” Put another way, it makes an existing power imbalance even worse.

First Version of Apple and Google's Contact Tracing API Should be Available to Developers Next Week

As reported by TechCrunch: The first version of Apple  and Google’s  jointly developed, cross-platform contact tracing API should be available to developers as of next week, according to a conversation between Apple CEO Tim Cook and European Commissioner for internal market Thierry Breton. Breton shared a photo from his office which shows him having a video conversation with Cook, and told Les Echos that the Apple chief executive told him April 28 would be the day the contact tracing API will be available to software developers building apps that employ it on behalf of public health agencies.

Apple and Google announced they were working on the contact tracing system, which works across iOS and Android mobile device, on April 10, and detailed how the opt-in network would use randomized IDs not tied to a user’s actual identify information to communicate potential contacts with individuals with a confirmed positive COVID-19 diagnosis. It’s a decentralized system that never collects any geographic data in order to preserve individual privacy, and Apple and Google chose to collaborate on the project so that any apps built to use it will have the furthest potential reach possible in terms of user base.

The rollout of the contact tracing system is happening in two parts: First, the API is being made available to developers — that’s the part that’s happening next week. This phase was originally set for a mid-May release, but it sounds like the companies have stepped up their timeline (at least on the Apple side) based on this conversation between Breton and Cook. That makes sense, given the urgency of the need for contact tracing in order to better understand how and when to alter or relax social distancing measures.

The second part of the plan is issuing a system update to build in contact tracing at the OS level. Opt-in would be managed on the device, and both Android  and iOS smartphones with this toggle enabled would automatically be able to participate in local contact tracing efforts — whether or not they had any specific health agency apps installed. Apple and Google clarified in a follow-up Q&A session about the system that users would still be prompted to download and install a public health app from their local authority should their phone notify them of a possible contact, so that they could get additional info about next steps from a trusted source.

Note that the second phase isn’t expected until sometime later this year, but the early arrival of the first version of the API for developers is a promising sign that suggests both companies are focusing considerable effort and resources on getting this to market.

There are myriad contact tracing systems either in development or already being implemented, but a common technological backbone that makes it possible for them to cross-communicate, and that opens up broad participation across the most popular mobile devices currently in use, has the greatest chance of actually being effective.