[dennisp]

Here’s a Nature article on this.

http://www.nature.com/news/two-laser-boron-fusion-lights-the-way-to-radiation-free-energy-1.13914

[dennisp]

It takes 1.07 pounds of coal to generate 1 kWh.

http://www.eia.gov/tools/faqs/faq.cfm?id=667&t=2

So for 150 homes using 11,280 kWh per year, we need (150 * 11280) / 2000 = 846 tons of coal.

An average railcar holds 120 tons of coal.

http://www.matts-place.com/trains/coal/coaltrain_basics.htm

So in place of one box of borax, we need about 7 railcars of coal.

[dennisp]

Which doesn’t answer the question.

A similar situation holds for the JT-60 tokamak in Japan…conditions achieved with D-D which would surpass breakeven if it were D-T. This seems to be considered a pretty significant result, so if LPP has done something comparable that would really be something.

Or is there some scaling involved with the plasma focus that makes it more of an extrapolation?

[dennisp]

Thanks for the vote. Timesplash was pretty good! Just purchased True Path.

[dennisp]

Actually that was silly, peak power tells us how many reactors we need but for overall fuel consumption we need the average. So really we’re more like 16 boxes for our 2500 homes.

Or to put it another way, one box powers about 150 homes for a year.

[dennisp]

How many threads are we talking about? What topics?

Definitely a horrible forum design.

[dennisp]

Nice, thanks Tulse. Government says U.S. average is 11,280 kWh per year, for overall average of 1.3 kW. But consumption is higher during the day, so maybe figure 2 kW.
http://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3

So our reactor is good for around 2500 homes, assuming they’re not plugging in electric cars. And to run it for a year we need 25 boxes of 20 Mule Team Borax Natural Laundry Booster.

I don’t know how many people use Borax, but the neighborhood’s probably using more than that actually doing the laundry.

[dennisp]

Cool. So 5kg of fuel is 4.4 kg boron, divided by .8 for 5.5 kg natural boron. Then divide by 11% for 50 kg Borax, or 110 lbs.

[dennisp]

Old articles seem better to me than broken links. I’d vote we keep denseplasmafocus.org up.

[dennisp]

Graham that’s really cool. I just bought the Kindle edition of Timesplash.

You might be interested in Neal Stephenson’s new site Hieroglyph. A bunch of science fiction writers have congregated there with a focus on making science fiction optimistic again, and inspiring a new generation of engineers.

Coincidentally, just today I posted something on the site about my climatecolab fusion entry: http://hieroglyph.asu.edu/forums/topic/its-the-21st-century-wheres-my-fusion-reactor/

[dennisp]

Need votes! We had a good lead but another entry just came on strong, leading us 141 to 82!

[dennisp]

Posted on nextbigfuture here:
http://nextbigfuture.com/2013/08/eric-lerner-of-lawrenceville-plamsa.html#more

and then here:
http://nextbigfuture.com/2013/08/nuclear-fusion-brainstorming-session-at.html#more

Another reddit post is here:
http://www.reddit.com/r/Futurology/comments/1ju9jw/lockheed_martin_announces_compact_fusion_reactor/

HackerNews post here:
https://news.ycombinator.com/item?id=6173263

[dennisp]

Good point. Plus if you want more thrust you can mix in some reaction mass, maybe using the x-rays for preheating it.

Some interesting links here: http://nextbigfuture.com/2010/03/dense-plasma-focus-dpf-fusion-systems.html

[dennisp]

No argument there. There’s definitely a business model for rockets, given SpaceX and the asteroid mining company, but for a while it’ll be nothing compared to the energy market.

The one advantage of the space market is that you’re a lot less cost-constrained. Your super-high-performance rocket doesn’t have to be cheaper than burning coal. Helion doesn’t look terribly expensive but I haven’t seen estimates.

I did just find out the exhaust velocity of this fusion rocket, NASA says about 30km/sec: http://www.nasa.gov/directorates/spacetech/niac/2012_phaseII_fellows_slough.html

That’s a lot less than focus fusion, which according to some forum posts around here a couple years ago would be about 3% lightspeed if we just used the ion beam directly. Thrust would be lower since there’s a lot less mass involved.

[dennisp]

Slough also started Helion Energy for power generation. They built a 1/3 scale device and last I heard needed $20 million for full scale. They just happened to get the NASA funding first.

I’d bet that if they’re successful with the rocket design they’ll have little difficulty getting funding for Helion.

On the other hand, fusion rockets would open up the solar system to large-scale exploitation and colonization, so the impact could be pretty major. (And of course focus fusion would make a nice rocket as well, perhaps better for really long trips since the exhaust velocity is so high.)

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