Japan's JT-60 Tokamak Sets New Plasma Record

Dipster writes "The Japan Atomic Energy Agency has announced that its JT-60 Tokamak has almost doubled the previous record for sustained plasma production, which is now sits at 28.6 seconds. It is believed that once 400 seconds can be achieved, a sustained nuclear fusion reaction will be possible. While 28.6 seconds is a long way from 400, it raises hopes for what will be possible from the ITER reactor, expected to be finished in 2016."

fusion

[ebooborg]

as someone who worked in the energy generating business i hope fusion comes sooner rather than later!

the price of oil and gas are going thru the roof, and these two fuels are what keeping the base load plants running here in ireland (and most of the rest of the world with notable exception of france)

theres alot of buzz around wind power nowadays but alot of people dont realise that with average 20% availability (compared to 80-90% of base plants) wind power
  just doesnt cut it, and u need to have for every MW generated a backup fossil fuel generator (or pump water storage system) waiting and being ready in case the wind quite literally stops blowing

nuclear fission plants will never be built here either (the greens are quite good at scaremongering)

Re:Almost there... still

[proverbialcow]

Let's see, 400 seconds - 28.6 seconds .... works out to about 50 years.

If you assume that they'll only be able to increase the time linearly, then yes, it's about fifty years.

If you assume that they'll be able to keep refining the technology and keep doubling the time every two years, then we're only looking at 7.6118259 [2*log(400/28.6)/log(2)] years.

It's probably somewhere in between that, though I'd guess toward the lower end. (As they keep getting closer, more attention will be given to the problem, etc.)

The reason it's always 30 years off

[Anonymous Coward]

Fusion research is one of the only promising research fields whose funding has decreased substantially over the years. In 1970 it was predicted that ITER would be online in 1995, with a demo commercial reactor in 2005. Given that funding was cut once the oil crisis was over, is it reasonable to expect all deadlines to remain the same? In any case, now that construction has started on the ITER site, we are definitively 10 years from an net positive energy balance plasma, following ITER's research, speculated to end in the 2020s, we'll probably have a commercial demo in 2030/40s and large-scale implementation by 2050.

WOW!

[maddogdelta]

As a bachelor degree student in physics in the 70's and early 80's, fusion research was on of the 'hot' topics. The tokamak was the predominant fusion plant, but other fusion reactors were being investigated. In those days we measured sustained reaction times in milliseconds. Obviously I haven't been keeping up, 'cuz 28 seconds sounds like a lifetime to me now.

Why so slow? Why no larger investments?

[Lord of Ironhand]

Forgive me if I'm missing something completely obvious here, but why is progress in fusion research still progressing so slowly? Sources generally cite estimates in the 2050-2060 range for when we'll be actually using fusion power.

The actual research itself is relatively unpredictable, I understand that. But when I read that completion of the ITER (the way I see it a relatively straightforward job, I assume the blueprints are already completed) is still 10 years away, I wonder how much time could be shaved off that estimate, as well as the ~2050 estimate, if (a lot) more money were put into fusion research.

If nuclear fusion has the potential to provide a clean, efficient, lasting energy source, and thereby eventually solve the energy crises, it would seem to me that investing a far larger amount of money than is being put into it today would be a very good investment if that could mean nuclear fusion can be used a few years earlier. I think ITER's cost is estimated at about EUR 10 billion, which is a lot of money, but in the grand scheme of things (I think the world GDP is somewhere around 50 trillion) it's tiny. And seeing the large potential for creating armed conflict there is in energy shortages even these days, I'd say getting fusion sooner rather than later may very well be a real matter of life and death.

However, when I hear discussions on the energy crises, the efficiency of solar/wind/water power, whether more nuclear fission reactors should be built, fusion isn't even mentioned, let alone considered by politicians for larger investments. Is it simply because it's so far away, and that for the most of us, only our descendants would benefit from those investments?

Once again this is a serious question, I'm no expert in any of this so I honestly don't know.

Re:How long

[Geoff St. Germaine]

Also, Tore Supra has achieved discharge durations in excess of 200 seconds since 2002 and has more recently had shots in excess of 360 seconds (6 minutes). Of course Tore Supra has a significant advantage over most other tokamaks in that it has superconducting toroidal field coils, giving it a steady state toroidal magnetic field. My experience in working with these machines is that on most of them the toroidal magnetic fields seriously handicap their performance due to the massive power requirements of generating a typically > 1 T magnetic field. This brings in the requirement for expensive and bulky power supplies and energy storage devices such as large capacitor banks and flywheel generators. The Joint European Torus has two 3750 MJ flywheel generators that can supply as much as 800 MW (400 MW each) of peak power which are used for the toroidal and poloidal magnetic field coils. The magnetic field coils on JET consume more than half of the power required to run the machine. The remaining power is drawn directly from the grid. Using superconducting magnetic coils greatly reduces the power required to run a tokamak and extends the time over which the discharge can last. Tore Supra has a goal of, I believe 1000 second discharges, which is similar to what ITER will be aiming for.

Actually...

[cr0sh]

Actually, I think we certainly do have the technology - if you modify the parameters a bit:

First off, the spherical chamber: Do what Operation Plowshare did, use a nuke to build the chamber by detonating it underground. I bet that if you mined ventilation shafts at the near "edge" of the explosion, you could vent off the overpressure. The heat from the explosion would sinter the rock together. All that would be left would be to send in some remote-controlled mining equipment to "smooth" it out. You aren't talking a big sphere here, probably well less than a mile in diameter, but that is OK.

Clean out/rebuild the overpressure ventilation shafts - you will need these later.

Attach to the inside surface of the chamber many, many thousands of feet of stainless steel piping/tubing - probably 6 to 8 inches in diameter, if not larger (I am not an engineer, can you tell?). This is your "energy collector". You will run water through this.

Spray the inside of the sphere (over the top of the SS water piping) with a bunch of concrete - maybe further steel reinforce it, perhaps make an agregate with granite or something. This layer should probably be a few feet thick, probably thicker.

Now, you simply do the same thing - dropping the nukes so they explode at the center (or near). The overpressure goes out the vents (this is a "fatal flaw" - I don't know what you do with the escaping radioactive material and/or radiation from these vents). The heat heats the water in the coils, which is then used like a typical fission reactor by passing it through a heat exchanger system. The coils are buried in the concrete/granite aggregate, which holds the heat very well, so the "every 5 seconds" could probably be extended to something longer once the system is up and running (the first few "primer" explosions would have to be done in more rapid succession since they serve to heat the system up to working temperature, but later blasts can be spaced apart more as the system runs).

Now, for the hydrogen devices - you don't need the "high yield" devices used for weapons. You grab another of the Plowshare-related systems: the delivery and propulsion system from the Orion. These thermonuclear devices were designed to be about the size of a basketball, to propel a ship through space, detonated behind the ship (with an ablative pusher plate to propel it, riding the shockwave). They were extremely small fusion devices - which got them immediately sucked into the "top secret" drawer of things, of course - but they had much lower yields, and if set up properly, the explosion from them could be sized slightly smaller than the size of your sphere, so you harvest the heat, and not anything else that would possibly destroy the system in short order.

In theory, aside from the radioactivity being released, plus possibly servicing/refurbishing the system (as the concrete/granite aggregate layer ablates) - this should work. Unfortunately, even if all of that was conquered, I am not sure it would be any more efficient than a regular fission reactor, plus there is likely no way the design for those mini-hydrogen devices will ever see the light of day again outside of WW-3...

Re:fusion - can you count neutrons?

[Geoff St. Germaine]

India has proposed a combined hybrid fission/fusion reactor as have many others. The funding for India's new SST-1 http://www.ipr.res.in/sst1/SST-1.html [ipr.res.in] superconducting tokamak was secured under this pretext.

Story on that premise...

[Kadin2048]

Does anyone remember a short science fiction story that basically had that as a premise? I can't remember what it was called or who it was by, but the idea was that a civilization built a generator that provided wireless power distribution throughout not only all three dimensions, but forward into the fourth as well. So basically as soon as it was turned on, you'd have power for the rest of eternity, even if you shut it down.

The story used this as a device to show how easily people "forget the development," -- once people take something for granted, they forget how it works and how (or even if) it was built.

I remember really liking it, but I can't think of the author or title.