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0 pointsupsidesinclude3y ago0 comments

Here's the thing:

In order to make inertial confinement work, this process needs to occur multiple times per second

All the fancy stuff with the hohlraum, magnetic compression, target cryo cooling must be accomplished accurately and repeatedly, BUT ALSO shot out of an "injector" to fall precisely into alignment with the lasers, in vacuum within a plasma field...

When you write it all out! Yikes!

Then! This has not included any capture of energy, so that part must be implemented as well, which would effectively mean placing all of NIF target chamber inside a thermal heat exchanger.

So, no, inertial confinement is probably the furthest from ever being a suitable arrangement from a power production standpoint.

Physicists have an uncanny ability to ignore engineering.

As a proponent of fusion and fusion research, it's important to keep the focus on what is valuable about the work being done and not mislead the general public about flights of fancy.

If you want to understand radiative pressure and plasma characteristics, this is the place to be, for sure

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6 comments · 2 top-level

zbobet20123y ago· 3 in thread

All of the problems you just described are solved for in EUV lightsources for lithography on chips at 100khz or more. These are less hard then you make them sound.

https://www.youtube.com/watch?v=5Ge2RcvDlgw

Probably the hardest part is making sure the droplet is cost effective enough that we care.

Again, to op's point, this is an incredibly shallow analysis. The question I would be pushing towards is:

What are the hardest remaining engineering problems? How likely are we to overcome them? At the end of that process will it be a cost competitive outcome?

upsidesincludeOP3y ago

These processes are not similar.

The laser does not hit the target, it hits the interior of the hohlraum. Generating x-rays, this creates radiation pressure on the cryogenically cooled target, which is inadequate for fusion without also pulsing a high magnetic field to confine the plasma (this is now inertial/magnetic confinement fusion).

The energy output is not sustained for any duration, but rather is nearly instantaneous. The plasma and debris must be cleared of the beam path for the next laser pulse and target injection.

These are the hardest remaining engineering problems if you discount the fact that energy must then be absorbed and put to use with constant material degradation of the target chamber and the necessary high output production of tritium filled beryllium capsules.

We are unlikely to overcome these challenges for substantially longer than the time period required to generate a functioning EUV machine.

dreamcompiler3y ago

This is unlike an EUV light source in that once the fusion begins, ideally you don't even need the lasers any more; the fusion from pellet (n) ignites pellet (n+1). Getting that to work is probably orders of magnitude more difficult than what just happened.

zbobet20123y ago

Why? You just feedback the energy generated from the process into the lasers. Most powerplants have an initial negative net energy.

Unklejoe3y ago· 1 in thread

> BUT ALSO shot out of an "injector" to fall precisely into alignment with the lasers, in vacuum within a plasma field...

It does sound like magic, but doesn't EUV involve some process similar to this? Something about shooting drops of tin with a laser? That sounds like magic to me too but is apparently a thing. Obviously two totally different things, but the level of magic to me is the same.

PaulHoule3y ago

The tin is reaching 400,000 K, a fusion reactor has to attain more like 100,000,000 K.

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