Lawaranceville E-Newsletter

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

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Torulf2
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Re: Lawaranceville E-Newsletter

Postby Torulf2 » Wed Sep 24, 2014 4:39 pm

The use of Be may not make the reaktor more toxic.
They already have to be careful with the boron hydrides used.

D Tibbets
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Re: Lawaranceville E-Newsletter

Postby D Tibbets » Wed Sep 24, 2014 8:45 pm

The boron compounds are toxic, but they have not yet been used, though admittedly, they have claimed they wish to pursue this eventually, perhaps sooner than later. One point is that boron hydrides are toxic but can be easily destroyed by burning the chamber exaust in a methane flame, or perhaps just a heated air flow. The boron element is toxic though, which means it has to be sequestered, not just converted. Or, perhaps just diluted enough so that the exhaust is below EPA emmision standards for boron.

Burning boron in a reactor involves purifying the B11 isotope, so boron 10 is not an issue. There may be uses for purified boron 10 though such as in the discription by Bussard and others to supplement the output of a D-D reactor. I think it is called the D-D one half catalyzed reactor. The neutron from D-D reactions is captured by an external blanket of B10 and the subsequent breakdown to tritium and finally He3 (if you want to wait and you want a supply of He3 for a relatively aneutroniuc reactor for a ship, etc.) provides additional fuel that can be mixed in to increase final yield, as is the tritium and He3 produced directly from the D-D reaction branches.

Various nuclear reactions with various isotopes of beryllium, along with many other elements can give interesting, problematic and/ or energy yielding results. But, the rate of these reactions are trivial except for possibly radioactive dacay concerns. The contributions to energy yield is negligible. The cross section curves are very much smaller than the P-B11 reactions and thus the reaction rates are correspondingly tiny.
Also, keep in mind that any ion with a Z greater than one is harmful to the energy balance due to bremsstruhlung issues. You have to have B11, but any other elements in the plasma other than hydrogen are contaminates- poisons (in the sense that they cool the plasma). The excited beryllium that is created by the excited C12 isotope that is created by P-B11 fusion has an extreamly short half life before it breaks down into two alphas. It is around for such a short time it does not have a significant chance to participate in the bremmstruhlung producing collisions. The alphas probably produce more bremmstruhlung producing collisions with electrons, but fortunately the alphas also don't hang around long as they exit the reactor relatively fast compared to the fuel P and B11 ions.

PS: The handling of boron may not involve difficult sequestering or dillution schemes, but just as with tritium, you have to have the monitoring, ' licencing' infrastructure in place. This can be very expensive by itself. Even Tokamaks which are strictly D-T dependent reactors for potential breakeven often use D- D fuel because it is much simpler and cheaper. The extrapolation to D-T results can then be calculated with fair usefulness. The Japanese Tokamak pursued this path.
In a lab with a billion doller per year budget the additional costs are easily managed (perhaps a few million dollers per year). But with a budget of less than a million dollers per year the additional cost is intolerable.

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

Ivy Matt
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Re: Lawaranceville E-Newsletter

Postby Ivy Matt » Sat Oct 25, 2014 6:08 am

The October newsletter is out, and several new articles are up on the LPP website:

Tungsten anode goes into FF-1; aluminum cathode model is checked
Due to the cathode’s complexity, THP wanted us to check the aluminum model before cutting the tungsten piece. Sure enough, a few errors were found, including excessive variation in the distance between the vanes that will carry the current filaments. THP has estimated that higher accuracy will be obtained only with slower cutting of the tungsten. This will unfortunately lead to a further two- or three- month delay in our long-delayed tungsten cathode. However, it will be worth the wait to ensure the symmetry needed for good compression of the plasma and the high density we are aiming for.

Oy, vey.

ARPA-E alters requirements to allow aneutronic fusion and LPPFusion applies for grant
However, in the original call for applications, ARPA-E had set a requirement that fusion yield be 5 times input energy—a requirement that was unnecessary for pB11 (hydrogen –boron) aneutronic fuel and probably impossible to meet.
...
ARPA-E responded to our question on the “FAQ” section of their website that applicants could instead use a requirement that the electricity recycled back to the next pulse be no more than half the total electricity generated. (This is the same as requiring that net power be more than half of total electric power). They specifically mentioned higher efficiency with direct conversion of charged particles, typical of aneutronic fuels (although they did not mention the fuels themselves).
...
In light of these new requirements, LPPFusion has submitted a proposal to ARPA-E for a $2 million, two-year grant.

They could really use it. Assuming they get the grant, it should (I hope) be sufficient to fund them through the hydrogen-boron phase of experiments.

Note on press coverage of Lockheed Martin fusion "breakthrough"
A number of supporters have asked us about the widespread press reports on a Lockheed Martin fusion advance. We want to point out that Lockheed’s team has published no experimental results so far in any way. Until they do, this remains just a concept, not a “breakthrough”.


Physics Of Plasmas publishes LPPFusion's runaway electron theory
Physics of Plasmas, the leading journal in the field of plasma physics, has published LPPFusion’s new paper on “Runaway electrons as a source of impurity and reduced fusion yield in the dense plasma focus”.
...
The fast-moving runaway electrons gain as much as 3 keV of energy, slamming into the anode and depositing enough heat energy to vaporize some of the metal. This vaporized metal becomes a major impurity in the plasma, disrupting the formation of plasma filaments and leading to lower density in the plasmoid that the current generates.
...
This runaway mechanism is a second main source of impurities, the first being arcing between different pieces of the electrodes. While one-piece, monolithic electrodes will eliminate all arcing, more steps need to be taken to eliminate the runaway electrons. The most important is pre-ionization. In this technique a small current breaks down the plasma resistance before the main pulse passes through—smoothing the way, as it were. The small pulse has too little energy to cause runaway electrons, and by the time the main pulse comes through, there are lots of free electrons ready to move. With many electrons, the current can be carried with each electron moving slowly and thus having little energy. Thus runaway electrons don’t occur in the main pulse either. High pressure in the gas, which make collisions of electrons with atoms more common, can help to prevent runaways as well.
...
The paper will be available for free download from Physics of Plasmas’ site for 30 days, until Nov.21, 2014.

If runaway electrons are responsible for vaporizing the anodes, I suppose pre-ionization should lengthen the anode lifetime a bit. (Note: I haven't read the paper yet.)
Temperature, density, confinement time: pick any two.

DeltaV
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Re: Lawaranceville E-Newsletter

Postby DeltaV » Sat Oct 25, 2014 4:58 pm

This is the first time, to our knowledge, that a US Department of Energy program has considered aneutronic fusion proposals.

It is a rare thing when a mouse can move an elephant, or a minnow a whale. Congrats LPP.

Ivy Matt
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Re: Lawaranceville E-Newsletter

Postby Ivy Matt » Tue Oct 28, 2014 12:36 am

Ivy Matt wrote:If runaway electrons are responsible for vaporizing the anodes, I suppose pre-ionization should lengthen the anode lifetime a bit. (Note: I haven't read the paper yet.)

Er, never mind about that. The runaway electrons are vaporizing the outside of the anode, near the insulator, not the inside of the anode. I knew that, but somehow forgot. Too many things on my mind lately.
Temperature, density, confinement time: pick any two.

Ivy Matt
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Joined: Sat May 01, 2010 6:43 am

Re: Lawaranceville E-Newsletter

Postby Ivy Matt » Thu Nov 20, 2014 7:27 am

The November newsletter is available here. News is a bit sparse. There are two items. The first is about Physics of Plasmas publishing LPP's paper on “Runaway electrons as a source of impurity and reduced fusion yield in the dense plasma focus”. I linked to that story above, but as it was published after LPP's October newsletter, it is being included in the November newsletter.

The other item is about Eric Lerner's recent visit to Sewanee: The University of the South, a private liberal arts college in Tennessee, for a two-hour seminar with students and staff of the university's physics department. Lerner's talk focused on the basic physics of Maxwell's Laws, and their relation to what goes on in the dense plasma focus:
“We’re looking for way to bridge the gap between what the average person knows—which is not much science—and what they need to know to understand how Focus Fusion works” explains Lerner. “This seminar, with a sharp group of physics undergraduates who had no previous courses in plasma physics, is part of our effort to boil down the basic concepts that we use to understand the DPF. If people get those concepts, then they’ll know much more about what a necessary, safe and feasible technology this is.”

The visit proved fruitful:
After the seminar, Physics Department chair Dr. Randolph Peterson proposed that the department seek funding for joint student projects with LPPFusion, where students would bring instruments to the FF-1 facility to study the device’s function. The proposed program might involve other Tennessee-region schools. Lerner thought this was a great idea and will help facilitate such programs with other universities as well.
Temperature, density, confinement time: pick any two.

Ivy Matt
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Joined: Sat May 01, 2010 6:43 am

Re: Lawaranceville E-Newsletter

Postby Ivy Matt » Fri Dec 26, 2014 5:41 pm

The end of the year brings a substantial update:

Tungsten cathode nears completion after long delays
According to the latest reports by California-based Tungsten Heavy Powder(THP), which is performing the work in China, machining will be complete within a few weeks and delivery to LPPFusion should occur by mid-February. The 99.95% pure tungsten piece has been in the machining process for nearly two months.

Also, regarding the beryllium electrodes:
Those beryllium electrodes will be ready when we need them. We expect to order them in January, with delivery in the first half of 2015.

Meanwhile, back at the lab:
FF-1 upgrade continues; preparations begun for pB11 operation
Other than a complete disassembly, cleaning and re-assembly of the vacuum chamber and drift tube to eliminate all sources of impurities, the team has improved assembly techniques to achieve greater symmetry in the device and greater protection for the new cathode itself.

We have checked our 250-gm supply of decaborane—the compound of hydrogen and boron we intend to use and Chief Research Officer Dr. Hamid R. Yousefi has selected the safety equipment we need, such as glove boxes to handle the material, whose vapor is somewhat noxious. We are in the process of designing and purchasing the equipment needed to heat the device to approximately 120 C, needed to create the vapor pressure to fill the vacuum chamber. While it is still months before we are ready to run with decaborane, we will be ready to make the transition with as few delays as possible.

A light at the end of the tunnel?

LPPF and Open Science:
LPPF releases processed data to researchers and the public
LPPFusion, Inc. has made available on our website the data in our Processed Data Base to all researchers, both professional and amateur. This data provides the key observations for each shot from the start of operation of Focus Fusion-1 in 2009 through the end of 2013 for four instruments: the Main Rogowski coil (MRC), High Voltage Probe (HVP), the Near Time of Flight (NTF) and Far Time of Flight (FTF) detectors. This gives data on the current and voltage produced during a shot and the neutrons and x-rays emitted.

LPP made the raw data available earlier upon request, but this data has been processed into a more useful form and made available for download to anyone.

Recent articles in IEEE Spectrum:
IEEE Spectrum covers alternative fusion, including Focus Fusion
One of the leading technical journals in the world, IEEE Spectrum, has reported in its December, 2014 print edition on alternative routes to fusion energy. LPPF’s work is mentioned in the first few paragraphs of the story and described briefly as one of five leading fusion alternatives, along with University of Washington’s Dynamak, which is featured, and the efforts of Lockheed-Martin, Helion Corporation, and General Fusion.

Also, regarding the recent article by a couple of Google engineers on the need for "truly disruptive" energy technologies:
In 2007 Lerner was invited to speak at a Google Tech Talks session, describing just such a disruptive technology—the one which we are continuing to develop. This talk, posted online, gave extremely important publicity to our project. However, the RE<C project, then just getting started, declined to fund Focus Fusion or indeed any other fusion project.

Lastly, on LPP(F)'s rebranding attempt:
A note on our name
Readers of these reports may have noticed that we are now referring to our company as LPPFusion, Inc., not Lawrenceville Plasma Physics, Inc, and using the initials LPPF, not LPP. We are in the process of changing our name. While we have not yet changed the legal name of the company, we have wanted to drop the “Lawrenceville” name, which is confusing, since we have not been located in the town of Lawrenceville, NJ for years and our lab is in Middlesex, NJ.

Have a Merry Christmas, everyone, and an Aneutronic New Year!
Temperature, density, confinement time: pick any two.

Ivy Matt
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Joined: Sat May 01, 2010 6:43 am

Re: Lawaranceville E-Newsletter

Postby Ivy Matt » Wed Jan 28, 2015 5:03 am

LPPFusion has released their 2015 Beginning-of-Year Report. It contains a retrospective of 2014: what was accomplished (publication, fundraising, hiring staff, website redesign, release of processed data) and what wasn't (delivery of tungsten cathode, actual experimental shots), and a plan for 2015:

Q1: Complete computer and data base upgrade, install and begin testing new tungsten cathode. Density and fusion yield are expected to increase 100-fold. LPPFusion will also experiment the effects of mixing in heavier fill gases, such as nitrogen.
Q2: Move to shorter electrodes, which is expected to increase fusion yield further.
Q3: Bring current up to 2MA, increasing density and fusion yield further still.
Q4: Install beryllium electrodes, or at least a beryllium anode. Demonstrate density of over 1 gram/cc and billion-Gauss magnetic fields. Install new equipment and begin running with hydrogen-boron fuel.

Last I heard the tungsten cathode was being machined in China. I haven't heard that it's finished. Also, in the report LPPFusion mentioned they are planning a backup monolithic copper cathode.
Temperature, density, confinement time: pick any two.

RERT
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Re: Lawaranceville E-Newsletter

Postby RERT » Wed Jan 28, 2015 1:25 pm

Can anyone shed light on where they will be if they meet this schedule?

Fumbling with Wikipedia suggests that their triple-product must be very interesting with even micro-second confinement times at 1 gram/cc.

To say I'm uncertain about this is a massive understatement, so wiser comment appreciated!

Another comment would be that the engineering part of their schedule looks pretty simple to the man in the street, except maybe the current uplift.

Let's hope the physics behaves...

D Tibbets
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Re: Lawaranceville E-Newsletter

Postby D Tibbets » Wed Jan 28, 2015 7:42 pm

Triple product comparisons are straight forward. Varying only density (fusion can scale as the square of the density), then if a Tokamak at 10^ 19 or 10^20 particles / M^3 requires ~ 1000 seconds confinement time, then ~100 milliseconds in a Polywell at 10^22 density gives similar results, and 100 nano seconds in a DPF at a density of 10^25 also gives similar results. This is still a density well below 1 g/cc. I don't recall the precise timeline in a DPF, but I think the plasmoid forms over a few hundred nanoseconds to a few microseconds, and the fusion action occurs primarily over a few 10s of nanoseconds, which brings the comparison closer to densities of ~ 10^27 particles per cubic meter, or ~ 1 g/cc (for hydrogen isotopes). Note that this time frame is similar to atomic/ hydrogen bombs with interesting timelines in nanoseconds and which have similar particle densities.

I may be pointing out the obvious, but I have repeatedly seen misconceptions on this forum, where confinement time comparisons of Tokamaks and Polywells are implied to indicate the dismal performance of the Polywell. Comparisons, though, require the inclusion of the exponential effects of density . A density increase of 100 X results in a fusion rate 10,000 X greater with corresponding decreases in required confinement time.

In the past this comparison has been couched in the required distance the particles have to travel before a likely collision will occur. A few hundred thousand kilometers in a Tokamak is comparable to a few tens of Kilometers in a Polywell once the density contribution to the triple product is factored in. The ratios remain the same.

Note that things become more messy when D-T reactions are compared to D-D or P-B11 fuels,and machine temperature considerations and thremalization contributions are considered; and additional factors may also apply such a POPS, density gradients, central confluence/ focus, etc. But the basic ratios of time to density remain a simple comparison between the various approaches.

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

Ivy Matt
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Re: Lawaranceville E-Newsletter

Postby Ivy Matt » Tue Mar 03, 2015 8:34 am

LPPFusion has released their February report:

Tungsten Cathode Completed, En Route To FF-1
It arrived at Tungsten Heavy Powder headquarters in San Diego, California on Monday, Feb.23 from their manufacturing facilities in China. It is expected to arrive at LPPFusion’s Middlesex, NJ laboratory around March 2.
...
After carefully testing and measuring the cathode, the LPPFusion team expect to install it in the FF-1 plasma focus device and begin experiments during March.

Finally! :D

LPPFusion Upgrades Computer Network, Database, Security Procedures
LPPFusion has completed a major upgrade of our IT infrastructure. This will make it easier to rapidly analyze our data and to share it among ourselves as well as to plan future improvements in our FF-1 device.
...
When the next experiments start, data will be processed after each shot, producing values of basic plasma parameters like ion temperature and density. The processed data will then be fed into the database at the end of each day’s shots, ready for further analysis

Looks like their schedule is holding up so far. Let's hope there aren't any more delays.
Temperature, density, confinement time: pick any two.

D Tibbets
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Joined: Thu Jun 26, 2008 6:52 am

Re: Lawaranceville E-Newsletter

Postby D Tibbets » Mon Apr 20, 2015 5:05 am

The work continues in efforts to get the tungsten cathode operational, or alternate discription- the fun of engineering...

http://lawrencevilleplasmaphysics.com/t ... s-forward/

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

Maui
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Location: Madison, WI

Re: Lawaranceville E-Newsletter

Postby Maui » Mon Apr 20, 2015 5:31 am

Chief scientist Lerner made an error in not concluding from the laboratory report that the assembly would fail, an error not caught by the other team members.

This report is surprisingly personal in the way persons are singled out for both their succeses and failures. Not sure what the benefit of this is.

RERT
Posts: 118
Joined: Mon Jun 02, 2014 9:10 pm

Re: Lawaranceville E-Newsletter

Postby RERT » Mon Apr 20, 2015 1:06 pm

With that number of people, refering to e.g. 'the engineering department' would be kind of disingenuous... R.

Ivy Matt
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Re: Lawaranceville E-Newsletter

Postby Ivy Matt » Tue Apr 28, 2015 3:52 am

Another news item from the April 7 report is that the beryllium electrodes have been ordered:
The total cost of the parts will be about $135,000, although this may be somewhat reduced with the final design of the cathode.

The strength of the 97.8 % pure beryllium, 44,000 psi, is guaranteed by the manufacturer and will be confirmed by independent tests. The design considerations inspired by our recent experience with tungsten did however lead to a much cheaper way to attach the beryllium to the steel, saving about $12,000.

So the crowdfunding campaign raised enough to cover the cost of the beryllium electrodes after all. :)
Temperature, density, confinement time: pick any two.


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