Talk-Polywell.org

http://www.telegraph.co.uk/earth/main.j ... sun104.xml

Laser beams with enough power to light up every home in Britain for a few microseconds will be used to heat up the nuclear fuel to millions of degrees centigrade in order to trigger the reaction.

If successful, the reactor will be a prototype for future commercial power stations, providing a cleaner and safer replacement for conventional nuclear power stations, which use nuclear fission to produce energy.

Ok, I never quite followed up on it (I simply assumed that it ended up in a dead end, which seems kinda plausible), but I swear I have seen and read about something simillar in the 80ies. They were using gold covered pellets back then with several very strong lasers focused at them. I have no idea what came from all this, but I do have to wonder about this one, as it sounds very simillar.

You remembered correctly. Look up "pellet fusion" and "laser fusion" to get more details.

From the article:

Fusion fuel, deuterium and tritium is also readily available in seawater.

Err... not Tritium.

And anyway, IC fusion, because it still depends on D-T fuel, suffers from the same problems as ITER's: blasting your super-expensive reactor with neutrons. Glad to see physicists getting work, sorry it has to be this.

Yeah, so I was right
Now what is the difference between this and back then? Back then it did not work and now they are building another one for 2 billion USD and it is not even meant to generate net power, but to barely make break even and that if (and thats a big if) it works. In addition it, as John pointed out, will still have to deal with the same problems as the ITER which at least will produce net power (and by quite a margin). ITER too wont make a working reactor though due to the "other" problems.
So that IC fusion thingy is a bit of a failed investment, I would say...

There is a significant difference between HIPER and what was the 80's ICF.

And that is Fast Ignition see Here

Yeah, I got the idea behind the new one, but I did read also that it would not achieve net power, only break even and assuming that it will work as adverticed which the last couple did not.

gblaze42 wrote:There is a significant difference between HIPER and NIF and what was the 80's ICF.

And that is Fast Ignition see Here

Sorry, I'm not getting the difference between the two.
They both use the energy of a laser pulse to heat up a fuel capsule, no?
The web site discusses direct and indirect ways of doing it, but in essence it's the same thing.
Whether they can achieve net power is almost irrelevant. No utility will build an expensive reactor that has to be replaced in a year or less.

JohnP wrote:

gblaze42 wrote:There is a significant difference between HIPER and NIF and what was the 80's ICF.

And that is Fast Ignition see Here

Sorry, I'm not getting the difference between the two.
They both use the energy of a laser pulse to heat up a fuel capsule, no?
The web site discusses direct and indirect ways of doing it, but in essence it's the same thing.
Whether they can achieve net power is almost irrelevant. No utility will build an expensive reactor that has to be replaced in a year or less.

Not being a plasma physicist, I'll try to explain it as best as I can. Fasts ignition concept uses two lasers, one to compress the target and the other to heat it. When the first laser, the driver, compresses the target to maximum density the other laser, something in the petawatt energy levels, heats the target, hopefully until fusion,
The ICF experiments in the 80's used mainly just one laser for compression and heat.
What I like is that an Fast Ignition, if it works, would be ideally scaled up to a form of "fusion" drive.

Hope this helps.

Here is a decent not very technical summary of HiPER:
http://www.hiper-laser.org/docs/publications/Lasers.pdf

The point about laser fusion is that recently the technology has made it look more promising, with developments in high power pulse lasers - and specifically the possibility of using "stretched" pulse amplification to get high overall pulse power in a coherent pulse which can be compressed back to very short timescale. And therefore fast Ignition possibilities. I don't notice similar new enabling technology for ITER.

There are still a lot of unknowns in whether you can prepare fuel and run reactors at high pulse rate and for long periods of time. But the reactor cost for net energy is much smaller than ITER, with fair chance of getting it, and that seems to me to be worth investigating.

Best wishes, Tom

PS - but I think 2/3 of the motivation for hiPER is as a platform to do high energy & pressure science

I am not to sure about future versions of HiPER, but having seen the size of the lasers (plus power supplies), I doubt that it will be possible to use them for any space- based technology. One might be able to use ground based lasers for launching spacecraft, but that has a lot of additional challenges. So I kinda doubt this has any space applications. I would be happy to be proven wrong though.

JohnP wrote:From the article:

Fusion fuel, deuterium and tritium is also readily available in seawater.

Err... not Tritium.

And anyway, IC fusion, because it still depends on D-T fuel, suffers from the same problems as ITER's: blasting your super-expensive reactor with neutrons. Glad to see physicists getting work, sorry it has to be this.

The Materials used in Hyper will not have to withstand magnetic stress, also the expanding plasma will go out evenly in all directions rather than get concentrated on a narrow divertor.

On the negative side, to date the lasers fall far short of the frequency required for continuous power plant operations and each pellet for NIF will cost ~$25,000 to produce, whereas it needs to cost a fraction of a cent to be economic. Both technologies would need to go through a pretty steep learning curve.

Tokamaks are ahead in terms of pulse length and fuelling costs.

Skipjack wrote:I am not to sure about future versions of HiPER, but having seen the size of the lasers (plus power supplies), I doubt that it will be possible to use them for any space- based technology. One might be able to use ground based lasers for launching spacecraft, but that has a lot of additional challenges. So I kinda doubt this has any space applications. I would be happy to be proven wrong though.

I wouldn't say with present day laser equipment but give it a decade or two the laser capabilities will only get better and smaller. Even now they have table top Peta-watt class lasers .

See here

tomclarke wrote:Here is a decent not very technical summary of HiPER:
http://www.hiper-laser.org/docs/publications/Lasers.pdf

The point about laser fusion is that recently the technology has made it look more promising, with developments in high power pulse lasers - and specifically the possibility of using "stretched" pulse amplification to get high overall pulse power in a coherent pulse which can be compressed back to very short timescale. And therefore fast Ignition possibilities. I don't notice similar new enabling technology for ITER.

There are still a lot of unknowns in whether you can prepare fuel and run reactors at high pulse rate and for long periods of time. But the reactor cost for net energy is much smaller than ITER, with fair chance of getting it, and that seems to me to be worth investigating.

Best wishes, Tom

PS - but I think 2/3 of the motivation for hiPER is as a platform to do high energy & pressure science

I would guess that Fast Ignition ICF could easily leap-frog ITER as the main focus of fusion research if HiPER turns out to work as planned. Some of the obvious benefits are no need for high flux magnetic fields to contain the plasma. No unique technical challenges to prevent the plasma from touching the walls of the reactor and bleeding the energy from it, to name a few.

Of course there will is the challenge of rapid rate as you mentioned, but I see this as being somewhat easier than the technical challenges of ITER and plasma containment.

LOL, I guess one can call that a tabletop system, lots of very big tables though, but I guess it counts
The powersupply is not shown here though.
Lets talk again in 20 years from now