[syhprum (OP)]

The Californian installation is of course a research machine intended to study fusion not a prototype power generator despite producing a net output of about 1MJ burning up gold and tritium is a rather costly way of producing power.
I am always puzzled by the investment in nuclear fusion when nuclear fission is a well developed system but few countries are prepared to use it

[alancalverd]

The attraction of fusion, should it ever generate a continuous controllable output, is the very small quantity of potentially useful waste, the enormous quantity of universally accessible fuel, and the relatively small amount of contaminated "incidentals". Gold and tritium don't sound like practical inputs but hydrogen certainly would be.

The downside seems to be the disappearing horizon for a practical generator. It was "about 5 years" in 1957, and recedes at a rate of about 3 months per year. 

[syhprum (OP)]

I have read that the lasers that set of the implosion adsorbed 922MJ

[alancalverd]

If the output was 922.1 MJ, they have justified  the experiment.

922 MJ is the equivalent of  23 liters of diesel fuel - half the tank of a small car - so in engineering terms it's quite a small experiment, and scaling up to a bigger target can only increase the efficiency of the process.

[evan_au]

In the USA, the three-phase electrical power grid operates at 60Hz (bipolar). So you need pulses of energy at least 360 times per second*.

Last I heard, the NIF was able to achieve 1 pulse every 12 hours, and the number of pulses was limited by the damage that each pulse produces in the laser amplifiers.
https://en.wikipedia.org/wiki/National_Ignition_Facility

The NIF won't deliver electrical power to the grid, but it does allow the testing and quality control of nuclear weapons, despite the Comprehensive Nuclear Test Ban treaty.
https://en.wikipedia.org/wiki/Comprehensive_Nuclear-Test-Ban_Treaty

* If you add up the instantaneous electrical power delivered over all three phases, it adds up to a steady delivery of power.

[alancalverd]

One stroke every five minutes, Mr Watt? The steam engine will never catch on!

What use is twenty seconds' flight in a straight line, Mr Wright? I cannot possibly recommend your dangerous contraption to my investors.

[Petrochemicals]

It's lovely, but has it been repeated consistently? I'm not sure on the maths but I believe that the laser only delivers a few kj into the fuel in a small time frame due to losses in the laser process, an efficiency rate of 0.5% I think, so they have created technically self sustaining fusion many times before. But this all said, you can do alchemy with nuclear reactors and make gold, but it is far cheaper to dig a mile deep pit and refine soil at parts per billion.

We have been here before.

https://en.m.wikipedia.org/wiki/Cold_fusion

[syhprum (OP)]

Why this enthusiasm for using NRI research machines for power generation the efficiency is about  0.01% and the fuel extremely expensive ?
   

[alancalverd]

Wrong.

The yield exceeded the input, admittedly by only a tiny bit, so the efficiency (energy out/energy in) exceeded 100%. Same reason that you strike a match to light a fire. 

[syhprum (OP)]

You have to take into account the energy supplied by the lasers this is not free !
This is why it is no good as a power source.

[Colin2B]

You have to take into account the energy supplied by the lasers this is not free !
This is why it is no good as a power as a power source.

All technology progresses by steps, and this is quite a big step.

[Petrochemicals]

Why this enthusiasm for using NRI research machines for power generation the efficiency is about  0.01% and the fuel extremely expensive ?
   

It all comes dow do you define efficiency, energy in the fuel, energy in the pulse, eneryin the total operation, energy generated or energy in the entire set up versus energy harvested.

The announcement  is 25kj in 30kj out with an energy to fuel impartment ratio of  1/200. It leaves many questions.

[alancalverd]

30/25 > 1, so it's a net energy source, and potentially worth developing if you can harvest the surplus and use it to start another event. Slight problem that this is a pulse process rather than a continuous burn, but the internal combustion engine seems to have survived and still competes with turbines. 

[Petrochemicals]

]

30/25 > 1, so it's a net energy source, and potentially worth developing if you can harvest the surplus and use it to start another event. Slight problem that this is a pulse process rather than a continuous burn, but the internal combustion engine seems to have survived and still competes with turbines. 

If that's how you measure it, that's how you measure it.

[syhprum (OP)]

Interestly continuous type power sources co-exist from the smallest turbines to the massive ones in aircraft carriers while pulse type Diesels vary from chainsaw size ones to 100 000.00 HP in ferry boats.
I see no future for pulse type nuclear fusion machines only for research.   

[Petrochemicals]

Sorry, yes it was around the 2 to 3 mj Mark. Not the 20 to 30, but same difference.

3.15 megajoules of energy from a 2.05 megajoule input of laser light for an energy gain of about 1.5.[11][133][134][135] Charging the laser consumed "well above 400 megajoules 

[evan_au]

I see no future for pulse type nuclear fusion machines only for research

There are various types of pulse fusion - I read that the fusion output at NIF only lasted nanoseconds.

However, there are various forms of magnetic confinement fusion experiments where the plasma is stable while you are increasing the current (and a changing current creates a confining magnetic field for the plasma). But as soon as you reach the maximum achievable current, the magnetic field collapses and you lose plasma confinement.
- Some of these reactors have achieved plasma confinement for periods of several seconds. Now if only it could match James Watt's 5 minute cycle...
https://en.wikipedia.org/wiki/Magnetic_confinement_fusion

Controlled fusion has not yet achieved more output than the energy that went in.
- As well as the ultra-large ITER project in Europe: https://en.wikipedia.org/wiki/ITER
- There seems to be a proliferation of small-scale fusion companies trying different approaches.