Talk-Polywell.org

Bussard mentions that Polywells could replace the furnaces in coal/oil power plants by using Polywell units. While environmentally, this makes sense, and it makes sense somewhat economically (upgrade an existing facility then to make a new one), has anybody looked deeper into this?

In what aspects?

p-11B fusion would in theory be very cheap because you could have direct conversion of the byproducts to DC. Even running D-D fusion, Bussard projected that a Polywell could easily and cheaply replace a coal or natural gas furnace.

scareduck wrote:p-11B fusion would in theory be very cheap because you could have direct conversion of the byproducts to DC. Even running D-D fusion, Bussard projected that a Polywell could easily and cheaply replace a coal or natural gas furnace.

Yes, but p-B11 fusion is not sure thing. And you already have big coal power plants, so it makes sense that you can use them and just replace coal boiler with D-D Polywell fusion reactor. You have most expensive things (steam turbines, etc.) already there, so it can be really economical.

But of course if p-B11 fusion in Polywell would work well, direct energy conversion would be the best option.

Let us be reminded that p-b11 is still the future's song. Even if it works, there is still the matter of "streamlining" the production and working out the infrastructure of such a reactor.

However, with upgrading, there are many problems avoided. You already have some of the staff, you already have the building, you already have the infrastructure, you already have over half of the system. Also, getting D-D reactors on the market is much sooner to happen then p-b11 reactors.

Mikos wrote:Yes, but p-B11 fusion is not sure thing.

Neither is Polywell D-D fusion. Q=1 with D-D is the first step, if that can even be reached.

scareduck wrote:Neither is Polywell D-D fusion. Q=1 with D-D is the first step, if that can even be reached.

I am fairly confident that at least D-D fusion with Q > 1 will be reached. Polywell concept in combination with POPS looks very promising, much more promising than tokamaks.

Zixinus wrote:Also, getting D-D reactors on the market is much sooner to happen then p-b11 reactors.

I'm not sure I agree with that. Bussard seemed quite confident that a p-B11 reactor is little more than a slightly bigger version of the D-D reactor. If so, I expect to see p-B11 be the first one to market, because (1) boron and hydrogen are a lot cheaper than deuterium, and (2) avoiding the vast majority of that pesky neutron radiation really simplifies a lot of things.

JoeStrout wrote: I'm not sure I agree with that. Bussard seemed quite confident that a p-B11 reactor is little more than a slightly bigger version of the D-D reactor. If so, I expect to see p-B11 be the first one to market, because (1) boron and hydrogen are a lot cheaper than deuterium, and (2) avoiding the vast majority of that pesky neutron radiation really simplifies a lot of things.

from http://en.wikipedia.org/wiki/Nuclear_fusion , we find that the Lawson criteria for p-B is 500 times that for D-T, and the power density is 2500 times less. This makes a lithium breeding blanket and neutrons look easy by comparison.

JoeStrout wrote: I expect to see p-B11 be the first one to market,

Right. And for an additional reason, I will call it the WB-7x effect. Since WB-7x is about the same size as WB-7, but "jacked up on the juice". One could run DD tests for a while and then you're bored. Then you switch to p-B11 fuel.......

Point being IMHO its very likely that the next device could easily make runs with both DD & P-B11. Once one can show P-B11 fusion in a test device, and repeat the tests, it blows the ITER into orbit. And P-B11 steps past DD to the front of the world stage.

JoeStrout wrote: Bussard seemed quite confident that a p-B11 reactor is little more than a slightly bigger version of the D-D reactor.

Something like, The coils were how big ? ..... break even at

DD-1.5m
PB11-2m

And 500w @

DD-2m
PB11-3m

Neither of WB-7 nor WB-8 are expected to be even Q=1. Not that there aren't a lot of things that could be learned from those machines, but until any Polywell device gets close to unity gain, it's all so much chicken-counting. Frankly I would be impressed if they can get to Q=0.3, considering Nevins predicted that in the very optimistic case (D-T fuel, but his work claimed to show that one transit through was all each ion would get before thermalizing), the upper limit on fusion would be Q<=0.21.

scareduck wrote:Neither of WB-7 nor WB-8 are expected to be even Q=1. Not that there aren't a lot of things that could be learned from those machines, but until any Polywell device gets close to unity gain, it's all so much chicken-counting. Frankly I would be impressed if they can get to Q=0.3, considering Nevins predicted that in the very optimistic case (D-T fuel, but his work claimed to show that one transit through was all each ion would get before thermalizing), the upper limit on fusion would be Q<=0.21.

Well sure. That would be wonderful.

No way I'm going ahead with a full scale device until I can get WB-7x (continuous operation WB-6) running for 3 to 6 months of testing. Maybe longer.

I have studied this long enough that (for now) the question of Q doesn't interest me.

Think about this: with conventional coils (non-superconducting) the power required to run them increases as the third power if you try to follow Dr. B's scaling laws. i.e. a linear increase of B with size.

I calculated a .15 m radius coil (WB-6 size) @ 100 KW with LN2 cooling.

A 1.5 m coil and you are up to 100 MW. And break even.

So all the experiments at small size should be replicated at a double size to see if the scaling laws hold. That should give us an answer within 10% or 20%. Then make the next one 5X or 10X larger than your 2X. And superconducting.

scareduck wrote:Neither of WB-7 nor WB-8 are expected to be even Q=1. Not that there aren't a lot of things that could be learned from those machines, but until any Polywell device gets close to unity gain, it's all so much chicken-counting. Frankly I would be impressed if they can get to Q=0.3, considering Nevins predicted that in the very optimistic case (D-T fuel, but his work claimed to show that one transit through was all each ion would get before thermalizing), the upper limit on fusion would be Q<=0.21.

POPS paper clearly shows that Riders and Nevins critique of IEC fusion has been wrong - you _can_ eliminate any power loss due to Coulomb collisions.

Thats a pretty good match to what I remember coming from Dr. Bussard

MSimon wrote:
I calculated a .15 m radius coil (WB-6 size) @ 100 KW with LN2 cooling.

A 1.5 m coil and you are up to 100 MW. And break even.

Roger wrote: (I recall Dr. Bussard saying or writing something like this:)

break even at

DD-1.5m
PB11-2m

And 500w @

DD-2m
PB11-3m

MSimon wrote:.....that (for now) the question of Q doesn't interest me......
So all the experiments at small size should be replicated at a double size to see if the scaling laws hold.

Right. There are 2 fundamental issues here, scaling and "Q". I am extremely curious to see just how scaling really works. Even if Dr. Bussard over estimated scaling by 10% or 20% ...... IMHO, we can then, at that point, pursue the "Q", a tad more confident.

If the scaling laws fall flat on their arses, how/would one continue with research pursuing "Q" ?

And for the time being I will insist that being first to PB-11 fusion will redefine the field provided the scaling laws hold decently. The 1968 Soviet Tokamak redefined the field for 40 years. Proven PB_11 fusion along with proven scaling laws will give us net power "Q" 's. .. .. it will be bigger than what the Soviets did in 1968.

I think thats why MSimon calls WB-7x the great convincer.

I think of WB-6 as an on the cheap 1960's transistor radio, while WB-7x would be the Macintosh Stereo system, 50 watts per chan. Amp, flat freq response from 20hz to 20,000hz, +,- .7 Db.

Macintosh equipment was noted for being able to be overdriven by 20%, while continuing to meet flat freq response specs.

Building WB-7x means we can "Crank up the volume".

Mikos wrote: POPS paper clearly shows that Riders and Nevins critique of IEC fusion has been wrong - you _can_ eliminate any power loss due to Coulomb collisions.

Right. But to me it comes down to this, Bremm occurs when the same electrons have high density and high energy. Our knowledge of Polywell says these 2 precursors of Bremm do not occur.

JoeStrout wrote:

Zixinus wrote:Also, getting D-D reactors on the market is much sooner to happen then p-b11 reactors.

I'm not sure I agree with that. Bussard seemed quite confident that a p-B11 reactor is little more than a slightly bigger version of the D-D reactor. If so, I expect to see p-B11 be the first one to market, because (1) boron and hydrogen are a lot cheaper than deuterium, and (2) avoiding the vast majority of that pesky neutron radiation really simplifies a lot of things.

I think I have figured a way around the neutron problem for D-D fusion coils using superconducting magnets.

It is at the tail end of this post:

http://iecfusiontech.blogspot.com/2008/ ... oling.html

What it amounts to is adding a layer of B10 to the inner side of the 300K water jacket. With a thermal neutron cross section of 3800 barns it should do a good job of soaking up neutrons. The two outer water jackets thermalize the neutrons. MgB superconductivity in a magnetic field is enhanced with a total neutron flux of 1E18/cm^2. Critical temperature goes down a little.