CrossFire Fusor

The Magnetic and Electrostatic Nuclear Fusion Reactor, or simply CrossFire Fusor, is a hypothetical nuclear fusion reactor whose fundamental idea was conceived in 2008 by Moacir L. Ferreira Jr., in order to overcome inherent limits of previous fusion approaches in producing fusion energy at significant rates.
The CrossFire Fusor uses six superconducting magnets to form a magnetic cusp region where positive ions are injected. At the magnetic cusp region, a negative voltage is applied, and at the opposite end of each magnet, a positive voltage is applied. The ions are accelerated electrostatically towards the negative potential passing through the magnetic cusp reaching the chamber interior, where the ions are confined radially by magnetic fields, and longitudinally by electric fields. The ion injection is done continuously, surrounding the magnetic cusp region to perform a three-dimensional injection. The positive voltage is controlled to confine only reactants, thus allowing the products from the fusion reactions to escape.
Comparison to previous concepts

The CrossFire Fusion Reactor combines features of many other fusion concepts such as Farnsworth-Hirsch Fusor, Bussard Polywell, Limpaecher Plasma Containment, Magnetic Mirror Machines and Penning Trap, but it differs significantly from all of them. It is most closely related to Farnsworth-Hirsch Fusor and Bussard Polywell, but it diverges from Farnsworth-Hirsch Fusor because it does not have an inner grid. It is also unlike the Bussard Polywell as it does not have recirculation of electrons while it has a well-defined voltage setup and an escape mechanism. The Polywell accelerates and confines positive ions through their attraction to negatively charged electrons, whilst the CrossFire Fusor does this using a negative voltage applied at the core region.
The initial design was originally based on a stellated polyhedron, accelerating electrostatically reactants inwardly to the central edges and products escaping from the peripheral vertices, after overcoming the electric fields. Magnets were added to act as Penning Trap on the distal ends, and to act as a magnetic mirror at the core region, confining efficiently the plasma while allowing surrounding ion injection, and controlled escaping.
Apparatus and Operation
In terms of apparatus, the CrossFire Fusor consists of a cluster of superconducting magnets, preferably six, pointing to the core region to form magnetic cusps, a set of ion sources surrounding this region, a set of electric insulators on the distal end of each magnet, and an armature to sustain the assembly. A negative voltage is applied at the cusp region and a positive voltage is applied at the armature. Each magnet has a set of independent flat pancake coils grouped together to be adjusted for controlling the level of confinement and escaping.
In terms of operation, the set of ion sources ionizes the fusion fuel exchanging electrons with the electric ground potential producing positive ions. The positive ions fall down toward inwardly the core region, passing through the magnetic cusps, reaching the chamber interior where the ions are confined radially by magnetic fields and trapped longitudinally by electric fields at the end of each magnet. The ions describe a helical orbit around the magnetic field lines, keeping away from the magnet walls. The magnetic cusps act as a magnetic mirror and the continuous ion injection makes the confinement at this region more efficient yet, i.e., the ions do not escape through the cusps due to magnetic mirror effect and continuous ion injection. When a fusion reaction takes place, its charged products overcome the confinement electric field, and can be directed for electricity production and propulsion.
Power Generation
Steam turbines can be optional when using aneutronic fuel. A method of energy conversion from positive ions into electricity consists of a positive voltage to produce an electric field to slow down the ions, converting their kinetic energy to potential energy, and an electron gun to neutralize them. The electron gun extracts electrons from a positive terminal of a capacitor which increases its stored energy (E½CV²). The electron gun current versus the positive voltage is the electric power (PV×I).
Furthermore, the fusion products, after being neutralized, can thrust a spacecraft directly, providing an ISP of over 1 million seconds.
Advantages
* Possibility of using advanced fusion fuels like hydrogen-boron and Helium-3 producing low neutron hazards.
* No inner grid, no recirculation of electrons to cause excessive cusp losses and , more a well-defined voltage setup allowing a great electrostatic acceleration with low energy consumption.
* Escape mechanism suitable for electricity generation and propulsion.
* Moderate energy consumption, continuous operation, which implies in a possibility of net gain, i.e., chance to have come close to the break-even point at which the device releases as much energy as is required to sustain a fusion reaction.
Requirements
* The magnetic fields necessary to confine the plasma should be generated preferably by superconducting magnets, in order to sustain a controlled nuclear fusion reaction.
* In case of aneutronic fusion, the magnet bore coating should be composed of alternate layers of tungsten and boron carbide(W/B<sub>4</sub>C), in order to reflect , mostly in X-ray range, back to plasma.
* The armature must be robust to hold the magnets, because the opposite magnetic fields to bottle the ions are very strong, tending to force the magnets apart.
* The fuel should be ionized with a predefined , and basic calculations must be done for dimensioning magnetic flux and electric voltages.
* The should be as low as possible, keeping the plasma in a state, which requires stronger magnetic and electric fields.
* The fuel injection must be well-dosed in small quantity, in order to prevent uncontrolled magnetic reconnection that could damage the magnets.

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