Advanced Deuterium Fusion Rocket

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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Diogenes
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Advanced Deuterium Fusion Rocket

Post by Diogenes »

Don't know if anyone else posted this, but in case they didn't, here it is!



The design could achieve 6.3% of the speed of light. Winterberg also describes deuterium micro-bombs that can launch off of the earth using a total of 100 kilotons of small fallout free nuclear micro bombs for launching 1000 ton space craft that are mostly cargo. Winterberg developed the basic principle of the global positioning system and his work was the basis for the Project daedalus design.


Image


Link:

http://nextbigfuture.com/2009/10/winter ... usion.html[/url]

D Tibbets
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Post by D Tibbets »

Somewhat similar to what the National Ignition Facility (NIF) is doing, except, they are having enough problems just trying to do D-T fusion, with hours between shots. For a spacecraft the laser assemblies would have to be extreamly more compact . The NIF has two huge buildings housing thier lasers and they can only take a shot every few hours.
And, while the NIF will make plenty of neutrons, it is marginal at best in terms of brakeven. So you would need a seperate power supply (like a Polywell). If you have that there are probably cheaper, safer, and less massive ways to achieve high thrust and efficiency.
Unless you can use a ground based laser, that is focused by the ship, I don't see it as working. It is probably much easier to use conventional hydrogen bombs with the fission trigger being minimized as much as possible. Neutron radiation would probably be similar, just need to worry about those pesky fission byproducts.

[EDIT] Looking at the picture it appears the 'argon rod' is fired by the compression of an explosive, so it is consumed on each shot. But, the argon rod is fed/ charged by a laser (?), so I assume the rod is charged with alot of energy which is then released when the explosives goes off. So, the argon rod is acting like a capacitor. It would still need alot of energy fed into it so it could discharge adiquate energy when triggered, so the charging laser would have to be fed alot of energy. If the argon rod could be charged on the ground then loaded on the spaceship, I could see it being used as an efficient trigger, but, while I have heard of laser energy being stored temperarily in crystals (NIF does this), I've not heard of them being used as stable storage devices.

Dan Tibbets
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djolds1
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Post by djolds1 »

D Tibbets wrote:[EDIT] Looking at the picture it appears the 'argon rod' is fired by the compression of an explosive, so it is consumed on each shot. But, the argon rod is fed/ charged by a laser (?), so I assume the rod is charged with alot of energy which is then released when the explosives goes off. So, the argon rod is acting like a capacitor. It would still need alot of energy fed into it so it could discharge adiquate energy when triggered, so the charging laser would have to be fed alot of energy. If the argon rod could be charged on the ground then loaded on the spaceship, I could see it being used as an efficient trigger, but, while I have heard of laser energy being stored temperarily in crystals (NIF does this), I've not heard of them being used as stable storage devices.

Dan Tibbets
In Winterberg's scheme the entire spacecraft is charged up, absorbing and then discharging a fraction of the energy from each detonation. Multiple papers are available on arxiv:

http://arxiv.org/find/physics/1/au:+Win ... /0/all/0/1
http://arxiv.org/find/physics/1/au:+Win ... /0/all/0/1

He's also working on high energy metastable chemical explosives, for direct drive of fusion detonations.
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MSimon
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Post by MSimon »

A space ship full of metastable explosives? What could possibly go wrong?
Engineering is the art of making what you want from what you can get at a profit.

chrismb
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Post by chrismb »

I love the little ellipse with an all-so-simple fusion reaction. It's like a 4 year old's drawing ["daddy, I've drawn a spaceship. Built it for my birthday"!].

djolds1
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Post by djolds1 »

MSimon wrote:A space ship full of metastable explosives? What could possibly go wrong?
:twisted:

I would prefer other routes to pure fusion detonations.
chrismb wrote:I love the little ellipse with an all-so-simple fusion reaction. It's like a 4 year old's drawing ["daddy, I've drawn a spaceship. Built it for my birthday"!].
(Shrug)

Its a hohlraum.

Winterberg is a physicist, not a graphic design artist.
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D Tibbets
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Post by D Tibbets »

I looked at djolds1 two links. Very litte information in them. I'm not sure how you could utilize the entire spacecraft as a capaciter and discharge it into a subassembbly without significant transient currents in other parts of the spacecraft. Also, in atmosphere, if the entire spacecraft is charged to high voltage it will arc or corona discharge.
And how do you harvest the energy from the deuterium explosion to get enough energy to trigger the next cycle?. I could see a selenoid with a pusher plate capuring some of the recoil energy, but recovering the huge amount of energy needed, suggests to me the apparatus would need to be massive- to both incorperate the electrical/ magnetic systens, and structure to shield from the neutrons and kick in the pants delivered from each blast. The Project Orion spacecraft designs (not designed for the high accelerations needed for getting into orbit) looked like they had a hugh plate to absorb the recoil energy of the nuclear blasts, and I believe this was without trying to generate a huge amount of recycled energy (significantly smaller than the total energy released in the nuclear blast, but still a huge amount of energy that would need to be absorbed nondistructively in an extreamly short period of time).

http://www-istp.gsfc.nasa.gov/stargaze/Snucfly.htm


Obvously I don't know much of the details, but on the surface it seems extreamly daunting. Larry Nivens did it in his SF novel "Footfall" when he lifted a huge rocket into space with conventional nuclear bombs. Of course it took out Seatle (or was it Portland?) in the process. Perhaps, like Project Orion, this is intended only for use in deep space. That would remove some of the limitations.


Dan Tibbets
To error is human... and I'm very human.

djolds1
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Post by djolds1 »

D Tibbets wrote:I looked at djolds1 two links. Very little information in them.
The links go to numerous pdf documents. Did you follow the hyperlinks to the appropriate papers?
D Tibbets wrote:I'm not sure how you could utilize the entire spacecraft as a capaciter and discharge it into a subassembbly without significant transient currents in other parts of the spacecraft. Also, in atmosphere, if the entire spacecraft is charged to high voltage it will arc or corona discharge.
The proposed mechanism does not function in atmo - Winterberg proposes variants of "traditional" self-contained Orion pulse units to reach orbit. IIRC the argon laser method; been awhile since I perused the papers.
D Tibbets wrote:And how do you harvest the energy from the deuterium explosion to get enough energy to trigger the next cycle?. I could see a selenoid with a pusher plate capuring some of the recoil energy, but recovering the huge amount of energy needed, suggests to me the apparatus would need to be massive- to both incorperate the electrical/ magnetic systems, and structure to shield from the neutrons and kick in the pants delivered from each blast.
IIRC, Winterberg proposes to use a magnetic field to retain a cloud of electrons around the craft. The magnetic field provides a "virtual" pusher plate, and the cloud is then used as a semi-Marx Bank capacitor. I'm sure I'm misremembering some of the details.

Related papers:
Spacecraft:
http://arxiv.org/abs/0906.0740
http://arxiv.org/abs/0812.0397
http://arxiv.org/abs/0803.3636

Ground based:
http://arxiv.org/abs/0812.0394
http://arxiv.org/abs/0809.2071
http://arxiv.org/abs/0808.1905
D Tibbets wrote:The Project Orion spacecraft designs (not designed for the high accelerations needed for getting into orbit)
???

The guys working on Orion most definitely DID plan on lift from Earth to space. The baseline design c.1960 was 4000 tonnes, Earth to Mars. The later 100 tonne NASA design (more promo art produced for that variant) was massively scaled down from earlier ambitions.

http://www.projectrho.com/rocket/rocket3c2.html#orion
D Tibbets wrote:looked like they had a huge plate to absorb the recoil energy of the nuclear blasts, and I believe this was without trying to generate a huge amount of recycled energy (significantly smaller than the total energy released in the nuclear blast, but still a huge amount of energy that would need to be absorbed nondistructively in an extreamly short period of time).
Later concepts (Project Daedalus, Mini-Mag Orion), proposed using magnetic fields to help absorb the blast products.

http://www.projectrho.com/rocket/rocket ... nimagorion
http://andrews-space.com/images/videos/ ... 00307).pdf
http://www.andrews-space.com/images/vid ... PLTalk.pdf
http://en.wikipedia.org/wiki/Project_Daedalus
D Tibbets wrote:Obviously I don't know much of the details, but on the surface it seems extremely daunting. Larry Nivens did it in his SF novel "Footfall" when he lifted a huge rocket into space with conventional nuclear bombs. Of course it took out Seattle (or was it Portland?) in the process.
Bellingham. :twisted:
D Tibbets wrote:Perhaps, like Project Orion, this is intended only for use in deep space. That would remove some of the limitations.
IIRC, Winterberg thinks the debris from the self-contained pure fusion pulse units would be clean enough to not be an issue.
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chrismb
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Post by chrismb »

djolds1 wrote:
chrismb wrote:I love the little ellipse with an all-so-simple fusion reaction. It's like a 4 year old's drawing ["daddy, I've drawn a spaceship. Built it for my birthday"!].
(Shrug)

Its a hohlraum.

Winterberg is a physicist, not a graphic design artist.
Exactly. I know what a hohlraum is, just like I know what a spaceship is, but that doesn't make it any more viable if my 4 year old was really good at drawing.

That's the bit that needs the work and the informative expansion/illustration, not the other bit.

Once we know what a 'working' hohlraum looks like, then I'll be happy to see it in a diagram.

djolds1
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Post by djolds1 »

chrismb wrote:Once we know what a 'working' hohlraum looks like, then I'll be happy to see it in a diagram.
Winterberg is the guy who leaked the operating principles of the Teller-Ulam design in 1981. I think we can take it as a given that his grasp of the geometry of hohlraums/radiation cases is sound.
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chrismb
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Post by chrismb »

djolds1 wrote:
chrismb wrote:Once we know what a 'working' hohlraum looks like, then I'll be happy to see it in a diagram.
Winterberg is the guy who leaked the operating principles of the Teller-Ulam design in 1981. I think we can take it as a given that his grasp of the geometry of hohlraums/radiation cases is sound.
Oh, sure. I really buy into this "I'm a big name in science, be quite and just take my word for it" style of science.

If we can take it as a given, why aren't we generating fusion energy for the grid yet?

...bloody high-priests-of-science-syndrome again... does anyone think for themselves on this forum, or is it just an audience that believes everything wikipedia says and anything from someone with a 'Dr.' or 'Prof.' in front of their name?

alexjrgreen
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Post by alexjrgreen »

chrismb wrote:Once we know what a 'working' hohlraum looks like, then I'll be happy to see it in a diagram.
Does this help?

Hohlraum Energetics
Ars artis est celare artem.

D Tibbets
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Post by D Tibbets »

In reply to djolds1 comments; I'm sure people with much more knowledge than me have crunched the numbers. My impressions are based on vague hand waving. Any nuclear propusion scheme converts nuclear potential energy into directed kinetic energy, and have to resist the thermal and radiation loads involved. The penalty I see with the pulse detination approach is the additional weight needed to absorb the blast energy, and in this case providing recycled power for the next laser ignition cycle. Of course this would have to be compared to the weight dedicated to other hypothetical power sorces (fission or fusion). Also, back in the 1950's and 60's the estimates of the laser input energy needed to achieve ignition was ,I'm guessing, several orders of magnitude less that what has been shown. This would mean several orders of magnitude more energy that has to be captured, processed and fed into more robust lasers for the next blast. I don't know how scaling would work out, but I'm guessing it would take alot more than a few hundred thousand pounds. Added weight means you need more thrust- explosive size and or frequency for the same net acceleration, which would put even larger engeenering loads on the structure and systems, especially for boosting into LEO, more 'mostly' clean fusion bombs being detonated within the atmosphere.
To error is human... and I'm very human.

djolds1
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Post by djolds1 »

D Tibbets wrote:In reply to djolds1 comments; I'm sure people with much more knowledge than me have crunched the numbers. My impressions are based on vague hand waving.
Fair enough.
D Tibbets wrote:Any nuclear propulsion scheme converts nuclear potential energy into directed kinetic energy, and have to resist the thermal and radiation loads involved.
Thermal loads last for microseconds per pulse, and shielding when your craft masses 1000 tonnes+ is not much of an issue.
D Tibbets wrote:The penalty I see with the pulse detination approach is the additional weight needed to absorb the blast energy, and in this case providing recycled power for the next laser ignition cycle. Of course this would have to be compared to the weight dedicated to other hypothetical power sources (fission or fusion). Also, back in the 1950's and 60's the estimates of the laser input energy needed to achieve ignition was ,I'm guessing, several orders of magnitude less that what has been shown.
Winterberg has been obsessed for several years with using pulsed relativistic electron beams driven by Marx Banks to fire small DT nuclear detonations. One scheme of his from a few years back had a Q of 1000 (not a typo) on the math. Per the usual fusion rule of thumb, multiply that by 10% for the actual hardware performance.

Document:
http://www.fusor.net/board/getfile.php? ... tt_id=2414

So order of magnitude requirements on beam initiated fusion may be doable.
D Tibbets wrote:This would mean several orders of magnitude more energy that has to be captured, processed and fed into more robust lasers for the next blast. I don't know how scaling would work out, but I'm guessing it would take alot more than a few hundred thousand pounds.
Winterberg also likes fusion-fission hybrids. IOW a Teller-Ulam setup without the fission primary. Small fusion unit fires fission in a U238 layer which causes LiD to fuse which... Stack until sufficient energy is achieved. Requires minimal additional mass. Consider the above document, but have the metallic liner be U238 or Th.

Winterberg is quite the Orioneer in spirit. Or the Dr. Strangelove if you're feeling less charitable. :lol:
D Tibbets wrote:Added weight means you need more thrust- explosive size and or frequency for the same net acceleration, which would put even larger engeenering loads on the structure and systems, especially for boosting into LEO,
All issues addressed by the original Orioneers (Taylor, Dyson, etc.), and not significant problems when you have 4000 to 10,000 to 100,000 metric tonnes of structural mass to work with. The problem is getting your head around riding to orbit by setting atom bombs off under your a**. :twisted:
D Tibbets wrote:more 'mostly' clean fusion bombs being detonated within the atmosphere.
Politics. The inevitable problem with the various nuclear propulsion designs. :x
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D Tibbets
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Post by D Tibbets »

[quote="djolds1]Winterberg also likes fusion-fission hybrids. IOW a Teller-Ulam setup without the fission primary. Small fusion unit fires fission in a U238 layer which causes LiD to fuse which... Stack until sufficient energy is achieved. Requires minimal additional mass. Consider the above document, but have the metallic liner be U238 or Th.[/quote]

Initially, I thought there would be no advantage over a conventional fission triggered fusion bomb. But, I suppose that a realitively modest fusion event from a IEC fusion reaction, even at well below breakeven could provide enough neutrons to turn a small subcritical mass of uranium/ plutoniun supercritical, and through stages perhaps end up with a final blast heavily dominated by fusion. I'm guessing this could substantially reduce the recycled power requirements. The problem would be how micro could the initial neutron induced fission reaction be compared to the final , not so micro, fusion reaction. How many neutrons would you need to send a tiny pellet of plutonium supercritical ( before it blew itself apart)? Would this have any advantage to bombarding lead, barium or some other neutron doner directly? I'm guessing that it becomes logrithyically more difficult to do as the size of the subcritical fission fuel is decreased.


Dan Tibbets
To error is human... and I'm very human.

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