Plasma focus education

[asymmetric_implosion]

I have been talking to someone on the board and we started talking about the parts that make up a plasma focus and their limitations. I offered to start putting together some information on the plasma focus such as the pulse power methodology, electrode design and some of the basic plasma physics that governs the device and if there is interest, the differences between what is considered mainstream and the LPP approach. My thought was to incorporate some math which is vital to better understanding the device and the plasma inside it. My goal is to provide information on the plasma focus to help the enthusiastic person that has little background in plasma or pulse power technology.

I can start on whatever topic but I am seeking two things: level of interest and where to start.

Editorial comments would be welcome.

An example for the pulse power topic questions would be:

What is pulse power?
Why use it?
What are the components of a plasma focus?
What are typical specifications and limitations of these components?
Is there more than one way to build a plasma focus pulse power system?
Can current technology support a working Fo-Fu power plant?

[zapkitty]

asymmetric_implosion wrote: What is pulse power?

I’m rather afraid that, [em]despite the best of intentions[/em], that it may wind up being an excuse by vested interests to add an unneeded $5,000,000 talking point to any discussion of FF funding and applications.

And I ask again: if what FF has built up is working now why insist on talking up the 5 mil solution?

[jamesr]

Here’s a few notes to start with…

asymmetric_implosion wrote:
What is pulse power?

Any power source based on releasing the energy as series of short pulses. So for example the internal combustion engine is a pulsed power device, whereas the jet engine is a continuous power device.

Why use it?

Whether we are talking about chemical or nuclear reactions, often the easiest way to get an energy releasing reaction to proceed is to provide a limited amount of fuel, then an initial amount of energy to ignite it and let it burn in a (semi-)uncontrolled manner.

In order to design a system to burn continuously, you need to be able to get the balance of the reaction exactly right, and be able to remove the exhaust products.
Although potentially more efficient overall, it adds a lot of complexity.

In the case of Focus Fusion, the requirements needed to ignite the fuel (temperature & density) are substantially easier to achieve in a pulsed power device.

What are the components of a plasma focus?

– Energy storage – Capacitor bank
– Fuel supply – Decaborane compound of Hydrogen and Boron (enriched to be mostly Boron-11)
– Vacuum chamber – the main reaction vessel, containing:
– central cylindrical anode, with a hollowed out end
– array of surrounding rods at the cathodes.
– diagnostic sensors (pressure, temperature etc.)
– Rogowski coil for extracting energy from the ion beam
– “Onion” – layered shells of foil to extract energy from X-rays
– Vacuum pumps
– Switch gear & trigger mechanisms
– Cooling systems (to keep the anode & other parts within design limits)
– Coil to provide the small magnetic field, seeding the angular momentum of the filaments, improving performance
– Electromagnetic shielding (Faraday cage)
– Radiation shielding (neutron & gamma)
– Power conversion circuits & capacitors – to transform the pulsed output to AC feed suitable for the grid
etc..

What are typical specifications and limitations of these components?

Most of the components are standard off-the-shelf parts, apart from the electrodes themselves and the energy extraction coils & onion – for these its too soon to say.

Is there more than one way to build a plasma focus pulse power system?

The use of the hydrogen boron reaction and the requirement to get to Gigagauss field strengths, constrain the scaling of the device (such as defining the optimum anode length), effectively dictating most of the rest of the design. However there are many details that can vary, such as the number of cathodes, capacitor design etc. that can vary.

Can current technology support a working Fo-Fu power plant?

If & when the scientific feasibility is proven, then there will be a number of engineering challenges to overcome, for the anode cooling, onion design among others. However these, for example, are minor in comparison to the engineering challenges facing the mainstream magnetic and inertial confinement fusion programs at ITER & NIF.

In the bigger picture, considering a Fo-Fu power plant as a collection of 5MW black box generators, then it needs continued investment in the grid infrastructure to move away from the centralised big Gigawatt plants to a more decentralised model.

[asymmetric_implosion]

zapkitty wrote:

What is pulse power?

I’m rather afraid that, [em]despite the best of intentions[/em], that it may wind up being an excuse by vested interests to add an unneeded $5,000,000 talking point to any discussion of FF funding and applications.

And I ask again: if what FF has built up is working now why insist on talking up the 5 mil solution?

The “best intention” was to educate folks on the boards about the plasma focus. My plan was present the state of the art in each technology so people could understand how the technology works and not express my personal opinion on the next step. I welcome input from others as they might know things I don’t.

Again, I answer that it was a suggestion for moving forward. FoFu-1 is working but the point was to help others understand it. Some posts leave me feeling that some folks don’t understand the technology behind the PF and want to know more. My intention was to help.

My question to you, what is my vested interest? Do you know? My guess is you do not. I offer you this; I don’t care if conventional pulse power, the LTD or some other pulse power scheme is used on the next generation of FoFu. It was a suggestion that might overcome some of the technical challenges that I know are dogging FoFu-1. I am familiar with the problems as I have faced them in my devices. My vested interest is saving others the growing pains that I suffered in my experiments. Beyond that, people can use the information as they see fit.

I don’t work for the oligarch or the man or some other nefarious entity. I work for a small business very similar to LPP with a different goal for the plasma focus. I’m no more the “bad guy” than anyone at LPP.

[asymmetric_implosion]

Jamesr, thanks for the info. I’ll add it my list. I was going to get a bit more technical and talk about things like capacitor lifetime, the design considerations, switch limitations, role of inductance, etc. Too much, too little, too confusing? I would appreciate direction input as much as technical input.

[Lerner]

I think this is great. I really don’t see your beef, zapkitty.
What is the form you see this educational material being put into, AI? A webpage, pamphlet or what? I know it is ambitous, but lots of folk say we need more videos these days.

[asymmetric_implosion]

Lerner wrote: I think this is great. I really don’t see your beef, zapkitty.
What is the form you see this educational material being put into, AI? A webpage, pamphlet or what? I know it is ambitous, but lots of folk say we need more videos these days.

I don’t know yet. I was thinking about starting with something text based so editing would be easy. Once the text was satisfactory, we could go with a video to speak to people easily.

[TheMagicalBadger]

Firstly, Hello!

I’ve been following this project for several years as a paid-up member, but read-only stalker. The summary provided by jamesr is the absolute best and simplest I have yet seen produced. I’ll leave it for other people to confirm/correct its accuracy as it’s way beyond my area of expertise 😉

It probably helps somewhat that I have a good pre-univeristy level science and maths education, although dating back 15 years ago, and I have read everything ever posted here. Even then, there have been fuzzy bits in my head e.g. if I’m telling people about how I understand the LPPX science works and why they should care how great it could be I get so far with the details/shape then it turns into something like ‘huge voltage across a gap, filaments, *mumble mumble* twisty bits, knots, compression to plasmoid, *more mumble*, fusion! Then reaction products and energy extraction which are actually one of the simpler bits to accept assuming The Mighty Onion becomes an enginering reality at some point (though one can still dream that the pure inductive leccy generation will give above break-even!)

This summary would seem to me to be the starting point/top level, along with a supporting diagram. Then having each item hyperlink to let you drill down for more detail about that component or reaction phase, photos of components both separate and in situ, and of course the science and maths for those that want it including links to relevant papers. I would guess you could duplicate this entire process for the ‘standard’ or non-lppx, quite possibly as a side-by-side view for each page to best see comparisons?

anyway, that’s just how I felt it might progress and thought it worth finally having something to say, so thanks!

[benf]

We have the MediaWiki that’s just being set up. It would be a good place to post this information.

[Lerner]

I am planning next month to start a videoed seminar on “the Physics of focus Fusion”. The idea is to explain for everyone, including those who have no physics, the three theories undelying focus fusion, which are electromagnetism, quantum mechanics and nuclear physics in the process of describing how FF works. It will have a historical structure, showing a bit of how these ideas evolved. So hopefully this will fit into this educational project.

[asymmetric_implosion]

TheMagicalBadger: Thanks for the suggestions. I like the structure you suggested so the reader can stop at a comfortable level. My plan was to keep the math and physics to high school level whenever possible, but I think these concepts need some math to support them. My thought was to start with pulse power because it is reasonably similar across all plasma focus devices. The basic components are the same in most plasma focus devices so it would be a firm footing for everyone to start from and hopefully agree on. Inside the vacuum chamber is when I expect the disagreements to begin. Many theories exist on what happens inside and most of them remain valid because of a lack of experimental data to confirm or to refute. I hope to present a few different options so the reader can see the differences and decide about which seems the most plausible.

I’ve started jotting down some notes and ideas about the presentation but a simple cohesive message is going to take a bit of time. I also expect others will have revisions, suggestions and most definitely editing before it becomes a useful tool.

Lerner: I would be interested to see an explanation of nuclear physics and quantum mechanics for people with little background. It is a big undertaking. I wish you the best of luck.

[annodomini2]

One suggestion would be, if the math is going to go beyond the ‘high school level’ that references to sites teaching the mathematical concepts used??

[Patientman]

Education can almost work better than marketing at times. The writing of a script is extremely important as well as, what type of medium the script will work for. A video is nice, but difficulties begin when there are divisions of technical depth in the information. How to present this information has become easier as web technologies have grown.

I have been doing this type of dissemination work for more than 20 years and know it inside and out. The most expensive part is the graphics, editing, script and technology. You must understand this is a time consuming project, which requires participation by more than just one person.

If you break down all the parts of this project and set them into small containers of information, then write a script that is for both technical and lay person audiences, you will be able to interest a larger portion of the public. Educate, or grow the knowledge of the student, so you create threads that an increase in perception and understanding.

Outline a visual plan
——-Lay person— Educate on the basics-
——— general knowledge of how it works
—– Overviews
—– Relation to cosmology
—– General technical High school level
|
|
—– intermediate person —–they comprehend the concepts but may not want to learn the advanced
math (maybe later)
— Some understanding of the math involved and how it relates to DPF and
the experiment
|
|

—-Advanced Phd level Understanding
—– math, physics — go wild with details

You connect the information and videos through graphic screens that give people an option to learn a detail, such as definitions. It all starts with an outline, goals and a script. Shooting a video without these does nothing to promote or educate. You will lose your audience by the click of a button.

Lastly, If you do not create a “Story” That follows the logic of the Book:”Made to Stick” Then it will become a bunch of technical Crap know one will ever remember or care about. That would be a huge waste of time and energy.

[asymmetric_implosion]

annodomini2: A good suggestion, thanks. I don’t know of the math resources are available on line in a nice form. Wikipedia and other such resources seem to be written for people “in the know” with a memory problem. I will put some thought into how to incorporate the math and physics and not overwhelm the reader. I might assign each section level of math and physics background. My concern is the math used even in simple models tends to rely on college level math usually taken by physical science majors. I can speak only from my college experience in engineering but we took a minimum of 5 semesters of calculus and related topics. Most took at least one or two more courses. That is a heavy burden for the curious reader that wants to learn a bit more.

Patientman: Wow. I knew this would take some time and effort, but now that you laid it out it appears pretty big. My thought was to address a few high impact areas initially. The web site idea seems to be a better choice right now as the script is in development. I prefer a written medium because the reader can re-read the section to better understand the details. As I mentioned above, I think I would assign a rank or a grade to each section to give the reader a heads up before they start a section. My thought was to start the following:

-high school education with little physics-> relate ideas in terms of everyday life as much as possible. Skip the math and talk about concepts and ideas.
-high school education with high school math and physics -> show a few basic equations with algebra
-college (undergrad) general education -> up the math and physics a bit that would be expected of a college educated person.
-college (undergrad) physical sciences -> Break out the equations and discuss details that would bore or confuse the levels below.

I don’t have any intention of going beyond this for one main reason; beyond the undergrad level researchers really need to read the literature after formal training. This level of discussion and debate takes place at several meetings each year that are later distilled into papers, books and other academic mediums. If one has this level of interest, time to subscribe to journals and go to the meetings.

[TheMagicalBadger]

Just a quick thing regarding definition of education levels, from a global perspective:

Those of us not from the USA may have quite different levels of education at each of the levels you define – I don’t know how much it is real or myth but I have been told that the typical British education is somewhat above the equivalent american for the same typical age and institution – please don’t take any offence from this, it’s just meant as an example.

So just remember that you may wish to take into account potential variability in either direction and I do like to think of this as a more global project even if the key players are all in the USA doing the hard work.

I also know from personal experience that the maths/physics/chemistry I was taught at a Grammar school in the south of england was well above those from state schools at the same level, so I never experienced any ‘jump’ in required knowledge up to and including degree level. But having spoken to others when starting University some of them saw huge jumps between GCSE to A-level or A-level to university. So there can be significant variation even within the same country.

The fact that I dropped out of my chemistry degree after the first year to change to Computer Science is unrelated of course 😉

I don’t know what you can do with any of this information, however.

[Author]

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