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Post by mattman »


The Newest Post is up: "The Physical Basis for the Polywell."

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Executive Summary:

This work explains much of the underlining physics of the Polywell reactor idea, in conversational language. The work is based off Dr. Bussards’ last machine, built in the fall of 2005. The important machine components are discussed first: the cage, electron emitters, gas puffers and the rings. A model of 1/8th the rings is posited, with the joint, center, axis and corners listed as locations of interest. The rings are placed, such that, the joint and axis magnetic fields equal each other. The orientation of the ring current, magnetic and electric fields are then described; for this work all the north poles face inward. Next, the steps to turn on the machine are discussed – as adapted from Bussards description [8]. The device is turned on in five steps: by evacuating the chamber, turning on the cage voltage, turning on the electromagnetic rings, emitting electrons and finally puffing in deuterium gas. The physics of ionizing the gas are laid out next, followed by the equilibrating of electron temperature to ~2,500 eV [8]. Critics argue that the electron and ion temperature must all be within 5% [17].

From this description of the machine, the work then shifts to simple models for the plasma and fields inside the reactor. A possible physical mechanism for the electron cloud going diamagnetic and increasing containment inside the rings is briefly mentioned. The number of electrons is then approximated. The electric potential for the electron is then estimated, across the middle of the device. This is based one of five different electron cloud shapes in the middle: an infinitesimally small point, a small sphere, a large sphere, a 14 point star and a diamagnetic cloud. Next the magnetic field is modeled at the four points of interest: the center, joint, axis and corner. This model is used to predict the magnetic field strength as the rings are moved outward. Specifically, the magnetic field, energy density and electron potential energy are all estimated. Unfortunately, the small magnetic moment of the electron means the magnetic field has a diminished role in its potential energy. Lastly, three other issues are also briefly examined. The first is the possibility of reaching the critical electron density to reduce x-ray losses; this is regarded as unlikely. The second problem addressed is sparking inside the device; which was listed as occurring in Bussards' work [8]. The last issue explores the theoretical upper bounds of how many x-rays could be reflected.

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