Nuclear fusion: Closer than we think?

[overthere]

Abundant, cheap, clean, star powered electricity would be nice. Imagine closing the coal plants, leaving the tar sand in the ground and the world losing interest in the middle east.

Is there any research on how far a star powered missile launched from, oh lets say Gaza, would get?

[Big Guy]

Could the world economy afford the results of the invention of a small workable nuclear fusion reactor with no radioactive waste? Would that not turn all energy related industries on their heads?

I would like to share a local success story based on an ancient principle;

http://www.simcoereformer.ca/2014/10/18/opa-extends-40-year-contract-to-delhi-power-generator

[Mighty AC]

Is there any research on how far a star powered missile launched from, oh lets say Gaza, would get?

We already have proven technology sufficient enough to send a missile almost anywhere on the planet. We also already have bombs that use both nuclear fission and fusion, so I'm not sure what point you are trying to make.

[overthere]

We already have proven technology sufficient enough to send a missile almost anywhere on the planet. We also already have bombs that use both nuclear fission and fusion, so I'm not sure what point you are trying to make.

I'm a weapons procurement manager for Hamas and trying to think green.

[Mighty AC]

I'm a weapons procurement manager for Hamas and trying to think green.

It's great to know that the modern terrorist is so socially responsible. These aren't your parent's extremists anymore.

[Bonam]

Could the world economy afford the results of the invention of a small workable nuclear fusion reactor with no radioactive waste? Would that not turn all energy related industries on their heads?

Even if technically viable fusion generators are developed, it is likely that the cost of the devices will for a long time be a limiting factor compared to "simpler" technologies. Any fusion reactor will be constructed from and utilize exotic materials that are far more expensive (and rare) than what one needs to make, say, a wind mill, a solar panel, or a diesel generator. Whether one is considering the niobium-tin or vanadium-gallium superconducting magnets and liquid helium coolant needed to generate the required magnetic fields, beryllium-doped graphene cladding, lithium neutron absorber blankets, neodymium-crystal laser frequency multipliers used in inertial confinement, solid gold hohlraums, or many other components, one cannot get away from the need for exotic materials with unique properties. Many of the needed elements are very rare on Earth and even more expensive to try produce through nuclear transmutation.

That being said, it's possible that on a very large scale, a fusion reactor could be economically viable. Fusion energy production has a very favorable scaling with size... everything gets exponentially better as you make your machine bigger, while the material cost only scales up proportionally to size. Big plants around 10 GW could be cost effective for general energy generation, although, most power grids are not designed to have single point sources of so much electricity and would need to be suitably upgraded.

Where fusion, once developed, will excel is in situations where performance (power and energy density), longevity, and compactness are more important than cost. That is one of the reasons the US navy is interested in fusion reactors, for example. Other applications would include power systems for "remote" outposts, such as those in the arctic and Antarctica, or backup power systems for mission-critical infrastructure (hospitals, military installations, etc). Small fusion reactors could also be of interest as neutron sources for neutron beam therapy, neutron irradiation of materials, tritium production, etc.

And of course the most interesting application for someone like myself is space power systems and space propulsion, where the use of fusion reactors could start to make the idea of interstellar (~10 ly) propulsion on human timescales (~100 years) conceivable, and flight around the solar system fast and cheap.

Edited October 21, 2014 by Bonam

[Derek 2.0]

Where fusion, once developed, will excel is in situations where performance (power and energy density), longevity, and compactness are more important than cost. That is one of the reasons the US navy is interested in fusion reactors, for example. Other applications would include power systems for "remote" outposts, such as those in the arctic and Antarctica, or backup power systems for mission-critical infrastructure (hospitals, military installations, etc). Small fusion reactors could also be of interest as neutron sources for neutron beam therapy, neutron irradiation of materials, tritium production, etc.

Indeed, brings the prospects of a truly functional railgun closer, perhaps even directed energy/plasma weapons someday.

And of course the most interesting application for someone like myself is space power systems and space propulsion, where the use of fusion reactors could start to make the idea of interstellar (~10 ly) propulsion on human timescales (~100 years) conceivable, and flight around the solar system fast and cheap.

I've read, years ago, that fusion propulsion would make travel to Mars or Jupiter's moons measured in weeks/months as opposed to years....it would seem, at such a point, permanent settlements would be feasible........it's very interesting, I hope it pans out.

[bush_cheney2004]

There has already been lots of work done on nuclear propulsion, from pulse pusher plates to inertial confinement. I specifically remember the work done at the U.S. Naval Academy called Project Longshot, which used a conventional fission reactor to power the spacecraft and support ICF propulsion.

Edited October 21, 2014 by bush_cheney2004

[Bonam]

Indeed, brings the prospects of a truly functional railgun closer, perhaps even directed energy/plasma weapons someday.

I believe the primary interest is just for safer/cleaner power generation, as a replacement to the current generation of fission reactors powering aircraft carriers and submarines. Fusion reactors would reduce the potential hazards (and, of course, political issues) associated with operation fission reactors in these vessels. In terms of available power to operate railguns or laser weapons, the power available from conventional fission reactors already in use is sufficient.

I've read, years ago, that fusion propulsion would make travel to Mars or Jupiter's moons measured in weeks/months as opposed to years....it would seem, at such a point, permanent settlements would be feasible........it's very interesting, I hope it pans out.

Me too. However, even now, the biggest cost is just getting a given amount of mass off Earth. Propelling it to Mars once you're up in Earth orbit is relatively cheap, in comparison. The large scale colonization of the solar system will likely not occur until the construction of space elevators, which would reduce launch costs by a factor of about 1000.

There has already been lots of work done on nuclear propulsion, from pulse pusher plates to inertial confinement. I specifically remember the work done at the U.S. Naval Academy called Project Longshot, which used a conventional fission reactor to power the spacecraft and support ICF propulsion.

Indeed. And there are frequent references to Project Orion (the predecessor to Longshot) in a lot of literature. Most nuclear propulsion projects got shut down over radiation concerns, since it was originally envisioned to use them not just as a space propulsion system, but also as a launch system, meaning radioactive exhaust in Earth's atmosphere (not a very popular idea). Pusher-plate style spacecraft are some of the easiest to design from a technical standpoint, but are inefficient from the point of view of propellant use. That is because the nuclear explosions used to push the spacecraft along are spherical, but only a fraction of the energy is directed towards the pusher plate (the rest is radiated into space in all the other directions). Additionally, the pusher plate also becomes part of the payload mass, which of course is at a premium due to the rocket equation.

One can feasibly achieve significantly higher delta-v with a fusion propulsion system wherein a stable fusion plasma is heated to ~ 100 million degrees and then accelerated out a magnetic nozzle (similarly to how the hot gas from a hydrogen-oxygen flame is exhausted out a physical nozzle in a chemical rocket).