Talk-Polywell.org

a discussion forum for Polywell fusion
It is currently Sun Nov 23, 2014 9:35 am

All times are UTC




Post new topic Reply to topic  [ 756 posts ]  Go to page 1, 2, 3, 4, 5 ... 51  Next
Author Message
PostPosted: Fri Apr 09, 2010 9:31 pm 
Offline

Joined: Mon Jul 16, 2007 7:37 pm
Posts: 13717
Location: Rockford, Illinois
Quote:
Here's a brief rundown of Lawrenceville Plasma Physics, Inc.'s experimental program, which consists of 8 goals to be accomplished in late 2009 and 2010:

1. Assemble and test the machine, get a pinch. Done deal. The machine didn't blow up when it was plugged in, and it demonstrated its ability to "pinch"- transfer the magnetic energy into a magnetic bottle where fusion will happen. The pinch was expected after 20 shots, but was achieved on the second shot.

2. Produce 1 MA (million Amperes) at 25kV (thousand volts), and find the best fill gas pressure.

3. Test the critical theory of axial magnetic field.

4. Switch to Deuterium fill gas and reliably achieve 2MA at 45kV.

5. Confirm the University of Texas (2nd scaling experiment- this is the 3rd, full scale experiment) results using better instruments.

6. Heavier gasses such as Deuterium + Helium + Nitrogen, using shorter electrodes.

7. Switch to pB-11 fuel and show that some fusion is taking place.

8. Increase pB-11 burn to achieve net energy.

The first 5 goals were scheduled for the last quarter of 2009. The major challenges with meeting this timeline present opportunities for entrepreneurs in the extremely high voltage and current power storage and switching areas.

The capacitors and spark gap switches are built in a job shop manner due to the low demand and high prices for these parts. The lack of a market at present has allowed these suppliers to get away with intolerable quality and service levels, as you can read on the Focus Fusion Society forums.

It took 5 months to get the machine to fire all 12 capacitors' switches within the required timeframe of a few billionths of a second (the pulse only lasts around 1 millionth of a second) to concentrate the power on the electrodes, where the fusion cycle actually begins.

As of this writing in early April, 2010, LPP is performing the Step 6 experiments, which will hopefully confirm that the shorter electrodes and heavier fill gasses significantly increase the magnetic field and thus confirm their predictions that the increased field limits the plasma cooling due to X-rays cooling the plasmoid (magnetic bottle) more than the fusion reactions can heat it.

Classic physics doesn't teach the high field effect, although McNally did some preliminary, small scale experiments on it in 1975. This is why most physicists are highly skeptical that pB-11 fusion is even possible.

Steps 7 and 8 still have over 8 months left to accomplish.

Since many physics departments can build a FoFu-1 clone for around $50k to $100k using mothballed parts, and a DPF fusion lab could galvanize an entire student body to figure out what has to be done in what order to use this to power their campus before any other school grabs the glory, I believe that a step of faith is in order, M. Simon.

That we need to build a network of these machines that anticipates LPP's success- lead the target, if you will- rather than playing catch-up ball once LPP announces that they believe they've accomplished energy breakeven and are looking for scientific confirmation.


Talk with you next week.
Matt

Energy Made Cleanly,

_________________
Engineering is the art of making what you want from what you can get at a profit.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Apr 09, 2010 9:44 pm 
Offline

Joined: Mon Oct 15, 2007 4:14 pm
Posts: 501
Location: Portland, Oregon, USA
I am still quite skeptical of the focus fusion approach. I have difficulty with the step where the initial donut-shaped plasmoid self-assembles into the extremely dense plasmoid of the complex shape that is shown in their video. I'm not a plasma physicist. So, I am clueless about this possibility. I guess I will be convinced only if they can actually demonstrate Boron fusion in this thing.

Nonetheless, I would love to see them succeed.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Apr 09, 2010 10:33 pm 
Offline

Joined: Wed Oct 07, 2009 6:15 pm
Posts: 2263
Location: China, Italy
I am still convinced that the Polywell has a more sound physics in respect to LPP hypothesis. Yet I have to take my hat off to the accomplishments and openness of LPP people.

They are burning the ground in their experiments, and if Eric Lerner is right they might beat anyone else to accomplish Fusion.


Last edited by Giorgio on Sat Apr 10, 2010 12:19 am, edited 1 time in total.

Top
 Profile  
 
 Post subject:
PostPosted: Fri Apr 09, 2010 10:47 pm 
Offline

Joined: Mon Apr 14, 2008 2:43 pm
Posts: 991
Quote:
...Steps 7 and 8 still have over 8 months left to accomplish.


... best of luck with that ...


Top
 Profile  
 
 Post subject:
PostPosted: Fri Apr 09, 2010 11:17 pm 
Offline

Joined: Thu Mar 25, 2010 7:13 pm
Posts: 15
Location: Scotland
Quick question, and I may be barking up the wrong tree here:

Is this the same Focus fusion that appeared in a google talk a while ago?

If so, is this the same focus fusion that requires the x-rays produced to be collected for power?

If the answer is yes to both, I would be worrying / testing that x-ray collection system first. If my memory is correct, they were aiming for 80% efficiency of collection and that is where my non-physicist alarm bells started ringing.

Like I say, I'm just noting down what I am recalling, please correct me if I am wrong.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 10, 2010 12:14 am 
Offline

Joined: Sun Jul 26, 2009 12:17 pm
Posts: 300
Location: CA
Gallium wrote:
Quick question, and I may be barking up the wrong tree here:

Is this the same Focus fusion that appeared in a google talk a while ago?

If so, is this the same focus fusion that requires the x-rays produced to be collected for power?

If the answer is yes to both, I would be worrying / testing that x-ray collection system first. If my memory is correct, they were aiming for 80% efficiency of collection and that is where my non-physicist alarm bells started ringing.

Like I say, I'm just noting down what I am recalling, please correct me if I am wrong.


Yes, Yes, True

Here is the talk:

http://video.google.com/videoplay?docid ... r=goog-sl#


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 10, 2010 1:05 am 
Offline

Joined: Thu Jun 26, 2008 6:52 am
Posts: 2418
Gallium wrote:
Quick question, and I may be barking up the wrong tree here:

Is this the same Focus fusion that appeared in a google talk a while ago?

If so, is this the same focus fusion that requires the x-rays produced to be collected for power?

If the answer is yes to both, I would be worrying / testing that x-ray collection system first. If my memory is correct, they were aiming for 80% efficiency of collection and that is where my non-physicist alarm bells started ringing.

Like I say, I'm just noting down what I am recalling, please correct me if I am wrong.


On the second question- harvesting 80 % of the fusion energy of P-B11 (like in the Polywell) consists of converting the charged fusion products to electrical power. The DPF would have an advantage in that the charged particals are focused into only two opposite beams. The onl;y pratical way to collect the x-ray energy is to let it head the container and them produce electrical power through a conventional steam plant. If the Q (excess fusion energy out) is not high (eg: greater than 10, you will need to recover as much of the input energy (like bremsstrulung X-rays) and fusion energy that you can. This is one of the advantages of aneutronic fuels. The fusion products are mostly charged particles, which might allow as much as ~ 2-3 times as much pratical electrical power out at the same fusion output compared to machines burning DT type fuels. Less neutron damage and less wall thermal loads would be the other advantages. These advantages are perhaps significant for a ground based power plant. For compact mobile plants like ships or spacecraft, the advantages could become tremendous.

M. Simon or someone like him might be able to estimate the weight and volume (and operational costs?) savings in a submarine type ship... err... boat.

Dan Tibbets

Dan Tibbets

_________________
To error is human... and I'm very human.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 10, 2010 2:22 am 
Offline

Joined: Fri Jun 05, 2009 11:36 am
Posts: 58
Location: West Michigan
@kurt9, everybody's skeptical. Seems to be a Bremstrahlung thang....
The donut shape is a simplification. It's really more like an 8 or 16 tip spark plug, so the current sheath is shaped more like a daisy's petals. Then the geometry gets complicated.

The design is so small, light, and inexpensive since it uses peak currents and the resulting peak magnetic fields to burn pB-11 for tens of nS, rather than try to maintain containment current and cool the machine continually. Thus the thermal duty cycle is incredibly low- it spends most of the time removing the heat from the previous power cycle.

Although a few dozen FFs can match the PW output, PW is still simpler to engineer into ships. That said, PW would not fail gracefully in emergencies, like losing the use of one FF of 20.

@ D Tibbets, there are actually 2 direct converter subsystems- the inductive and the photovoltaic. The inductive handles most of the cap bank recharging and in one unity study, might be able to slightly exceed unity.

Electrical unity and above is almost certain to come from the X-ray to electric converter- thousands of thin foils and insulators making a sort of capacitor.

The electron beam is somewhat misleading, since it's dissipated heating the plasmoid into the ignition range and beyond. This subsystem will likely be the biggest engineering challenge. But the market will continually tweak it for decades- just like cell phones and PCs.

One other point is that to make 5MWe, the FF makes 8MWt (~17M BTU) that's useful for industrial furnaces, ovens, low pressure boilers, building heat, pre-heaters, etc.

So FF can be salable without achieving true electrical unity once it can lower the price of a BTU from 1,015J to around 125J.(!) All it has to do to enter the market is make electrical heat cheaper than natural gas. And paint it green. 8)

_________________
The Power To Get Things Done


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 10, 2010 4:04 am 
Offline

Joined: Mon Oct 15, 2007 4:14 pm
Posts: 501
Location: Portland, Oregon, USA
Giorgio wrote:
I am still convinced that the Polywell has a more sound physics in respect to LPP hypothesis. Yet I have to take my hat off to the accomplishments and openness of LPP people.

They are burning the ground in their experiments, and if Eric Lerner is right they might beat anyone else to accomplish Fusion.


Yes, this is good. It would be kiss-ass if they were sucessful.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 10, 2010 9:53 am 
Offline

Joined: Fri Jun 05, 2009 11:36 am
Posts: 58
Location: West Michigan
kurt9 wrote:
Giorgio wrote:
I am still convinced that the Polywell has a more sound physics in respect to LPP hypothesis. Yet I have to take my hat off to the accomplishments and openness of LPP people.

They are burning the ground in their experiments, and if Eric Lerner is right they might beat anyone else to accomplish Fusion.


Yes, this is good. It would be kiss-ass if they were sucessful.


Sure would. I talked with a candidate for the US House recently who has the physics background except for aneutronic. I'm sure the hidden objection was Bremstrahlung.

Whoever's the first to aneutronic unity is going to make it a lot easier for the entire field. :D

_________________
The Power To Get Things Done


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 10, 2010 2:27 pm 
Offline

Joined: Sun Sep 28, 2008 2:29 pm
Posts: 5191
I wish them the best of luck. It would be really cool if they got it to work. From what I understand their design is among the smallest and cheapest (if it works). That would of course be great.
I am not an expert in nuclear or plasma physics, but I do trust the judgement of people like Art Carlson to some extend. Sure he may be wrong, but he has expressed some VERY strong feelings about Lerner and his DPF (and not the good kind, I am affraid). Art is very good at what he does, though if he were the only one to be sceptical, I might be willing to dismiss it more easily. He is not though.
So I will stay sceptical, but I will also keep an eye on it. It is fun and if it works, it would only be good for all of us. The cool thing is that it is only 8 more months until we will know for sure. That is very little above my patience threshold ;)


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 10, 2010 4:26 pm 
Offline

Joined: Fri Jun 05, 2009 11:36 am
Posts: 58
Location: West Michigan
8 months is longer than mine, too, but there is peer-review to consider. And a lot of work to be done engineering the X-ray converter and its production tooling.

_________________
The Power To Get Things Done


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 10, 2010 4:31 pm 
Offline

Joined: Mon Apr 14, 2008 2:43 pm
Posts: 991
actually i think many of Lerner's followers are getting just as impatient for some good news (read 'data') as we are here at Polywell. or so suggests his forum.

iirc, his 'onion' (a direct x-ray converter) has been delayed until a later stage also. something about expense.

i love the DPF concept. they seem to be getting their teeth onto some real theory also, albeit perhaps rather speculative. his stated timeline however seems to be setting expectations terribly high.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Apr 11, 2010 5:55 am 
Offline

Joined: Fri Oct 26, 2007 8:50 pm
Posts: 1725
For anyone without a good picture of how dense plasma focus works, http://www.lawrencevilleplasmaphysics.com/index.php?option=com_content&view=article&id=62&Itemid=80 appears to be a good overview.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Apr 11, 2010 9:23 am 
Offline

Joined: Mon Apr 14, 2008 2:43 pm
Posts: 991
kurt9 wrote:
...I have difficulty with the step where the initial donut-shaped plasmoid self-assembles into the extremely dense plasmoid of the complex shape that is shown in their video....


a mathematcian friend of mine once claimed that the (compound) 'knotting' behaviour of a simple rubber band when you wind it up and wind it up, remained (as of a few years ago at least) one of the great remaining unsolved chalenges of mathematical modelling.

very few people had attempted it, largely because, all previous attempts to properly describe the phenomenon had failed miserably, ruining perfectly good reputations in pursuit of the seemingly trivial.

rather like the 'bumble bees shouldnt fly' example, often quoted.

so i have a bit less of a problem entertaining the notion that plasma is apt to behave rather like that (fastest routes to null, islands, whatever...).

i am a bit more skeptical however, that he can obtain Q>1 within the next 6 months, if at all.

Giorgio wrote:
They are burning the ground in their experiments, and if Eric Lerner is right they might beat anyone else to accomplish Fusion.


i second that.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 756 posts ]  Go to page 1, 2, 3, 4, 5 ... 51  Next

All times are UTC


Who is online

Users browsing this forum: Google [Bot] and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group