One step closer to fusion...

Papabravo

Joined Feb 24, 2006
12,389
1970 was the date we were given by the boffins at the PPA (Princeton Pennsylvania Accelerator) when our Boy Scout troop visited the facility.
 

wayneh

Joined Sep 9, 2010
16,102
I remember sitting at the kitchen table with my dad as we'd have a snack and a Coke (the real stuff, from a returnable glass bottle). Sometimes he'd read his Scientific American, and I remember once he commented that fusion had been "ten years out" as long as he could recall. He passed away 33 years ago.

I think for any chance of progress, ITER needs to fail, or at least quick sucking up all of the funding. There's actually some interesting stuff going on. A good review.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
6,459
I remember sitting at the kitchen table with my dad as we'd have a snack and a Coke (the real stuff, from a returnable glass bottle). Sometimes he'd read his Scientific American, and I remember once he commented that fusion had been "ten years out" as long as he could recall. He passed away 33 years ago.

I think for any chance of progress, ITER needs to fail, or at least quick sucking up all of the funding. There's actually some interesting stuff going on. A good review.
Yes, I've heard all the fusion jokes myself too. But I think there are two ways of looking at something like this.
  • You're right until proven wrong
  • You're wrong until proven right
Given the stakes. I always choose the former. (that is, until the founds run out... LOL! )

Q: what's the difference between a stubborn and a perseverant person?
A: the end result
 

WBahn

Joined Mar 31, 2012
24,684
Apparently, a successful second test of the german device has been completed.

http://www.iflscience.com/physics/germanys-fusion-reactor-creates-hydrogen-plasma-world-first

But I wonder, how is the energy (heat) supposed to be extracted from the device and put to practical use if the thing is surrounded by "425 tonnes (470 tons) of superconducting, super-cooled magnets"?
That's not that hard to deal with -- the magnets have to be cooled, not what is inside of them. Imagine an MRI machine at a hospital -- the magnets are at liquid helium temp (~4 K) but the patient is at room temp. It wouldn't be overly challenging (in comparison to other hurdles) to have the magnets surrounding a superheated steam region.
 

Glenn Holland

Joined Dec 26, 2014
649
The main problem is creating a self-sustainable fusion reaction.

Once that's done, the next problem is extracting power from it. However the efficiency is much, much less than 1 so keeping the reaction going requires more power input than what is released.

Also, the generator would consist of magnetohydrodynamic process rather than a conventional steam turbine and a rotating machine. Incidentally, Hans Alfen presented a theoretical model of a fusion power plant based on the flow of hot plasma like the sun. The old fashioned magnetic confinement and current pulse technique utilized Alfen's theory. However, that's as far as it progressed.
 

crutschow

Joined Mar 14, 2008
23,306
I think a better approach to nuclear fusion electrical energy is a pulsed plasma approach such as from Tri Alpha Energy or LPP Fusion. The intent of these systems is to create multiple short bursts of hydrogen-boron fusion, whose byproducts are helium and energy. This reaction generate no damaging neutrons, as the deuterium-tritium fusion process used by the tokamak, stellerator and Lockheed designs does, which requires extensive shielding and generates radioactive waste.
The pulses plasma devices are relatively small, inexpensive systems, requiring no superconducting magnets, as compared to the huge, multi-billion dollar, continuous plasma machines such as the ITER tokamak, or the German stellerator. I don't see those very expensive devices with their huge superconducting magnetics ever beinging an economic source of fusion power.
 
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nsaspook

Joined Aug 27, 2009
6,265
I like their chances, too. I looked into investing in LPP but I didn't care for the arrangements. But their approach is interesting and I tend to think they're closer than anyone else.
I just looked at the website. Pretty cool stuff but it looks like they don't know diddley about real world ultra high vacuum systems.
http://lppfusion.com/ff-1-moves-toward-goldilocks-bake-out/
5 day bakeouts limited to 150C to remove water vapor because of poor UHV vacuum materials like Mylar is just bad engineering.
 

wayneh

Joined Sep 9, 2010
16,102
They're a very small group, so a lack of expertise in many areas is expected. I noticed they got their beryllium. That's a big step.
 

crutschow

Joined Mar 14, 2008
23,306
I much prefer the hydrogen-boron fusion reaction that the pulsed plasma and some laser systems are working towards as opposed to the deuterium-tritium fuel that the Tokamak (ITER) uses (which I think is a dead end).

The deuterium-tritium reaction produces a large amount of high energy neutrons which require heavy shielding and which tend to make many materials radioactive (and dangerous) over time leading to a waste disposal problem, which already is the bane of fission reactors.
And the only practical way to capture this neutron energy is to convert it to heat in the shielding to run a turbine generator, with its poor thermodynamic efficiency.

The hydrogen-boron reaction produces energic alpha particles (helium nucleus) and few neutrons, which do not generate any significant radioactivity in the shielding, and since the particles are charged, their energy can be extracted directly into an electrical current with relatively high efficiency.
 
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