polywell. When applied to the fusor, Lawson's analysis is used as an argument that conduction and radiation losses are the key impediments to reaching net power. Fusors use a voltage drop to accelerate and collide ions, resulting in fusion. The voltage drop is generated by wire cages, and these cages conduct away particles. Polywells are improvements on this design, designed to reduce conduction losses by removing the wire cages which cause them. Regardless, it is argued that radiation is still a major impediment. See also Fusion energy gain factor (Q) List of plasma (physics) articles Notes It is straightforward to relax these assumptions. The most difficult question is how to define when the ion and electrons differ in density and temperature. Considering that this is a calculation of energy production and loss by ions, and that any plasma confinement concept must contain the pressure forces of the plasma, it seems appropriate to define the effective (electron) density through the (total) pressure as . The factor of is included because usually refers to the density of the electrons alone, but here refers to the total pressure. Given two species with ion densities , atomic numbers , ion temperature , and electron temperature , it is easy to show that the fusion power is maximized by a fuel mix given by . The values for , , and the power density must be multiplied by the factor . For example, with protons and boron () as fuel, another factor of must be included in the formulas. On the other hand, for cold electrons, the formulas must all be divided by (with no additional factor for ). References External links Mathematical derivation, archived 2019 from the original Fusion power