My Polywell Blog

Discuss ways to make polywell research more widely known or better understood. Includes education and outreach.

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My Polywell Blog

Post by mattman »

Polywell Fans,

I have a Modest Polywell Blog available. I have been (am still) working on a review of Dr. Todd Riders' general critique of inertial electrostatic fusion devices. I have 30+ pages of this document written, about 75% of the article reviewed. My idea is this: Take the main paper arguing against the Polywell and make it understandable to everyone. My aim is to have a power point presentation online after the document is written. Kind of a "Polywell for Dummies" talk. Here is the web address:

....And here is a preview of the document-in-the-works:

Science is a conversation. One researcher stands up and says: “this is the way it is.” They do this by writing a paper, filled with evidence which backs up their argument. A few years and sometimes decades go by and, someone else stands up and responds: “No. This is the way it is.” and so on. We are in just such a conversation about the polywell; the very early stages. The first statement - I would call the opening argument - was “The Polywell: A spherically Convergent Ion Focus Concept” published by Nicholas Krall, with assistance from Robert Bussard in 1992. In that paper, Krall explains the idea of the polywell, and gives an overview of its basic strengths and weaknesses. This caused a rumbling in the physics community and three years later an answer was advanced. This came from Dr. Todd Rider, whose 1995 paper: “A general critique of internal-electrostatic confinement fusion systems” gave theoretical reasons against the polywell working. This paper, combined with Rider’s masters and doctoral theses were often pointed too as the reason the polywell would not work. Eleven years went by. In 2006 Robert Bussard responded, in his “should Google Go Nuclear” speech and subsequent “The advent of clean nuclear fusion: super performance space power and propulsion” paper. The highlights of Bussards retort? Plasma inside the device behaves differently then expected. Phenomena such as the Whiffle ball and the virtual anode break Riders’ old assumptions. There must be something to Bussards’ response, because the Navy gave the team 7.8 million dollars.

I got a hold of Rider’s ‘95 paper. It presents a maze of theoretical assumptions and mathematical argument against the polywell. Rider tackles - one by one - phenomena inside the polywell. He steals formulas from other situations and applies them to the polywell. This is about the best one could expect; the polywell was very new idea in 1995. He makes order of magnitude arguments which both show you how many ways the polywell can fail and, how many ways Rider could have gotten it wrong. The more I dove into the paper, the more respect I had for Rider. For one man to tackle such a problem is audacious and the work is certainly scholarly. However, the topic is so complicated it is hard to imagine the work did not miss something. For most papers in science, this may not be such an issue. However the polywell could be a major invention for mankind. A way to produce cheap clean abundant electricity is not a trivial matter. In this situation, it is my stance that raw data is needed to verify these claims. I do not care if the data indicates this idea is a flop. It is too important to leave up to theory.

My favorite part of Rider’s paper, is the mass and energy balances. Rider analyzed energy flow within the reactor; quantifying the amount coming in, going out, and being exchanged between the ions and electrons. He tried to estimate how fast these energy transfers would happen. He compared these rates, to the rates of fusion. The paper also looked at the flow of mass. How many ions and electrons were entering and leaving the system. He attempted to quantify ion-ion collision time, calculate how fast ions were lost and how fast the polywell thermalized. This offers us an interesting and new perspective on the polywell.

What follows is my attempt to explain this paper. It is very complex - like navigating a maze. It is not perfect, I am sure I made mistakes. What you are reading is the result of several months of volunteer work. What have I learned? Rider made lots of assumptions. His work is not solid. The topic is maddeningly complex – and there is a good chance the analysis is flawed. It is hard to see how any one man could have account for all the factors in play inside the polywell. It makes one want to just build the thing and see what kind of results you would get.

If the polywell works, it would be a major invention, akin to the automobile or the computer. A cheap, clean way to produce abundant electricity; it would help stop global warming, help stop the energy crisis and make some people very rich. Not to mention, getting the US out of recession. This is not something we can afford to leave up to theory alone. The stakes are too high. We need data, not complex estimations. I do not care if the data indicates that the idea is a failure. I will accept that. We need to know. Riders’ paper cannot be taken as a definitive no on this idea, as you will see, he makes many estimations and approximations, stealing formulas from other fusion devices. It should make you realize how badly testing of this idea is needed. We need to know for sure. As the famous physicist Richard Feynman said: “It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong.” Please enjoy this unraveling of Riders paper.

Please let me know if you have any questions....

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Post by MSimon »

Rider was beat to death here. But there are one or two sentences in his paper that say he didn't consider all the alternatives. i.e. "recirculation".
Engineering is the art of making what you want from what you can get at a profit.

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