Tuesday, January 6, 2009

Dense Plasma Focus Device

After far too many years, the Lawrenceville Plasma Physics ‘Dense Plasma Focus Device’ is funded through a demonstration unit. I have included the recent news on funding and staffing, as well as the company’s description of the device.

I would be remiss if I did not also mention that a number of these devices are in labs around the world and knowledge and experience is been gained. This one will be the second largest.

It is remarkable that very important experiments in fusion control using multiple geometries have been starved for funding for decades while the Tokamak design has received massive funding while producing slim results for as many decades. A proof of concept experiment is not overly expensive and supports theoretical progress.

Realistically Tokamak as configured has failed. It is possible that superior modeling with present computers will improve the situation except that these other exotic systems were even more difficult to model forty years ago. It is fair to say that the aspect of Tokamak that recommended it forty years ago were the inherent symmetries that permitted successful calculation strategies.

Now we should even entertain atomic and molecular fields when we do this work. At least I have thought so, if only because attractive and repulsive forces exist at that scaling as well as shielding. If so called cold fusion has any reality at all, it is because of action at the molecular level. Today we have the computer power to experiment with such geometries.
The claim is made that their understanding of the protocol is now sufficient to generate net power and that is certainly suggested by their description below. Of course we also know just how fickle Mother Nature really is.
I would be much happier if this funding had another zero attached. Any way, no one is going to describe this as cold fusion.

December 18, 2008

Lawrenceville Plasma Physics Initiates Two-Year Experiment to Test Hydrogen-Boron Fusion
$1.2 Million Project Funded by The Abell Foundation and Individual Investors

Lawrenceville Plasma Physics Inc., a small research and development company based in West Orange, NJ, has announced the initiation of a two-year-long experimental project to test the scientific feasibility of Focus Fusion, controlled nuclear fusion using the
dense plasma focus (DPF) device and hydrogen-boron fuel. Hydrogen-boron fuel produces almost no neutrons and allows the direct conversion of energy into electricity. The goals of the experiment are first, to confirm the achievement the high temperatures first observed in previous experiments at Texas A&M University; second, to greatly increase the efficiency of energy transfer into the tiny plasmoid where the fusion reactions take place; third, to achieve the high magnetic fields needed for the quantum magnetic field effect which will reduce cooling of the plasma by X-ray emission; and finally, to use hydrogen-boron fuel to demonstrate greater fusion energy production than energy fed into the plasma (positive net energy production).

The experiment will be carried out in an experimental facility in New Jersey using a newly-built dense plasma focus device capable of reaching peak currents of more than 2 MA. This will be the most powerful DPF in North America and the second most powerful in the world. For the millionth of the second that the DPF will be operating during each pulse, its capacitor bank will be supplying about one third as much electricity as all electric generators in the United States.

A small team of three plasma physicists will perform the experiments: Eric Lerner, President of LPP; Dr. XinPei Lu and Dr. Krupakar Murali Subramanian. Mr. Lerner has been involved in the development of Focus Fusion for over 20 years. Dr. Lu is currently Professor of Physics at HuaZhong Univ. of Sci. & Tech., Wuhan, China, where he received his PhD in 2001. He has been working in the field of pulsed plasmas for over 14 years and is the inventor of an atmospheric-pressure cold plasma jet. Dr. Subramanian is currently Senior Research Scientist, AtmoPla Dept., and BTU International Inc., in N. Billerica, Massachusetts. He worked for five years on the advanced-fuel Inertial Electrostatic Confinement device at the University of Wisconsin, Madison, where he received his PhD in 2004 and where he invented new plasma diagnostic instruments.

To help in the design of the capacitor bank, LPP has hired a leading expert in DPF design and experiment, Dr. John Thompson. Dr. Thompson has worked for over twenty years with Maxwell Laboratories and Alameda Applied Sciences Corporation to develop pulsed power devices, including DPFs and diamond switches.

The $1.2 million for the project has been provided by a $500,000 investment from
The Abell Foundation, Inc, of Baltimore, Maryland, and by additional investments from a small number of individuals.

The basic technology of LPP’s approach is covered by a
patent application, which was allowed in full by the US Patent Office in November. LPP expects the patent to be issued shortly.

The Dense Plasma Focus (DPF): What it is and How it Works

The dense plasma focus device consists of two cylindrical copper or beryllium electrodes nested inside each other. The outer electrode is generally no more than 6-7 inches in diameter and a foot long. The electrodes are enclosed in a vacuum chamber with a low pressure gas filling the space between them. The plasma focus device is shown in the figure below.


A pulse of electricity from a capacitor bank (an energy storage device) is discharged across the electrodes. For a few millionths of a second, an intense current flows from the outer to the inner electrode through the gas. This current starts to heat the gas and creates an intense magnetic field. Guided by its own magnetic field, the current forms itself into a thin sheath of tiny filaments; little whirlwinds of hot, electrically-conducting gas called plasma. A picture of these plasma filaments is shown below along with a schematic drawing.


This sheath travels to the end of the inner electrode where the magnetic fields produced by the currents pinch and twist the plasma into a tiny, dense ball only a few thousandths of an inch across called a plasmoid. All of this happens without being guided by external magnets.

The magnetic fields very quickly collapse, and these changing magnetic fields induce an electric field which causes a beam of electrons to flow in one direction and a beam of ions (atoms that have lost electrons) in the other. The electron beam heats the plasmoid to extremely high temperatures, the equivalent of billions of degrees C (particles energies of 100 keV or more).

The collisions of the electrons with the ions generate a short pulse of highly-intense X-rays. If the device is being used to generate X-rays for our
X-ray source project, conditions such as electrode sizes and shapes and gas fill pressure can be used to maximize X-ray output.

If the device is being used to produce fusion energy, other conditions can minimize X-ray production, which cools the plasma. Instead, energy can be transferred from the electrons to the ions using the magnetic field effect. Collisions of the ions with each other cause fusion reactions, which add more energy to the plasmoid. So in the end, the ion beam contain more energy than was input by the original electric current. (The energy of the electron beam is dissipated inside the plasmoid to heat it.) This happens even though the plasmoid only lasts 10 ns (billionths of a second) or so, because of the very high density in the plasmoid, which is close to solid density, makes collisions very likely and they occur extremely rapidly.

The ion beam of charged particles is directed into a decelerator which acts like a particle accelerator in reverse. Instead of using electricity to accelerate charged particles, they decelerate charged particles and generate electricity. Some of this electricity is recycled to power the next fusion pulse while the excess (net) energy is the electricity produced by the fusion power plant. Some of the X-ray energy produced by the plasmoid can also be directly converted to electricity through the photoelectric effect (like solar panels).

The DPF has been in existence since 1964, and many experimental groups around the world have worked with it. LPP’s unique theoretical approach, however, is the only one that has been able to fully explain how the DPF works, and thus exploit its full capabilities.

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