Science: possible new route to fusion

Tri Alpha Energy plasma accelerator, Physics.org

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Time Magazine recently published an intriguing article about man's quest for clean energy in the form of fusion: Inside the Quest for Fusion, Clean Energy’s Holy Grail (subscription needed).

In Lev Grossman's very readable article, he reports that startup Tri Alpha Energy is using two linear plasma accelerators pointed at each other to achieve results that larger and far more expensive tokamaks have yet to produce. Furthermore, Tri Alpha Energy will use hydrogen nuclei and boron-11, not the conventional deuterium and tritium, to fuel the reaction. Boron requires a temperature of 3 billion degrees Celsius to fuse. So far Tri Alpha has produced a ball of superheated hydrogen plasma for five milliseconds, a record in the fusion effort. Before I move on, here's Lev's description of attempting fusion:

The heat and pressure necessary are extreme. Essentially you’re trying to replicate conditions in the heart of the sun, where its colossal mass–330,000 times that of Earth–creates crushing pressure, and where the temperature is 17 million degrees Celsius. In fact, because the amounts of fuel are so much smaller, the temperature at which fusion is feasible on Earth starts at around 100 million degrees Celsius.

That’s the first problem. The second problem is that your fuel is in the form of a plasma, and plasma, as mentioned above, is weird. It’s a fourth state of matter, neither liquid nor solid nor gas. When you torture plasma with temperatures and pressures like these, it becomes wildly unstable and writhes like a cat in a sack. So not only do you have to confine and control it, and heat it and squeeze it; you have to do all that without touching it, because at 100 million degrees, this is a cat that will instantly vaporize solid matter.

News (with a skeptical tone) of Tri Alpha's recent milestone was published by Physics.org in Tri Alpha Energy reportedly makes important breakthrough in developing fusion reactor. It's important to note that the physics community has a lot of tokamaks and funding to defend. Here's the link to Tri Alpha Energy's website.

For information on plasma acceleration, take a look at Oxford University's page on plasma accelerators. Note that a laser beam qualifies as a particle beam. Overturned scientific explanation may be good news for nuclear fusion (2011) talks about new information on the hydrogen-boron reaction.

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Electron injection ramp, Oxford University-Physics Dept.

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-- Marge

Just a soupçon of science for today

If you have an inquiring mind and like to be surprised, take a look at Science Daily.  Here are the titles and links to 4 of the articles available now:

• Acid-Wielding Worms Drill Through Bones
• Printing Living Tissues Made of Sugar (another use of 3D printing)
• Lizard-Like Robot Uses Tail to Land On Feet
• New Light Shed On Explosive Solar Activity -- "Extreme solar activity can lead to severe space storms that interfere with satellite communications and damage electric power transmission grids on Earth."

Looking at the last article, about solar activity, reminded me that I've been wanting to know how the quest for power generation by fusion is going.  Fusion promises to produce power cleanly, with no radioactive waste for disposal or threat of reactor meltdown.  But developing a reactor that produces more energy than it uses has been a problem.

This site ITER  ("The Way" in Latin) gives some very good information about fusion. ITER is an actual device; the demo is being built now. Take a look at the 60 years of progress page:

Steady progress has been made since in fusion devices around the world. The Tore Supra Tokamak that is part of the Cadarache nuclear research centre holds the record for the longest plasma duration time of any tokamak: six minutes and 30 seconds. The Japanese JT-60 achieved the highest value of fusion triple product—density, temperature, confinement time—of any device to date. US fusion installations have reached temperatures of several hundred million degrees Celsius.

 Achievements like these have led fusion science to an exciting threshold: the long sought-after plasma energy breakeven point. Breakeven describes the moment when plasmas in a fusion device release at least as much energy as is required to produce them. Plasma energy breakeven has never been achieved: the current record for energy release is held by JET, which succeeded in generating 70 percent of input power. Scientists have now designed the next-step device—ITER—which will produce more power than it consumes: for 50 MW of input power, 500 MW of output power will be produced.

Fusion research has increased key fusion plasma performance parameters by a factor of 10,000 over 50 years; research is now less than a factor of 10 away from producing the core of a fusion power plant.

-- Marge