Fusion is the arguably most difficult technical, engineering, and theoretical challenge of the twenty first century. By releasing, in an exothermic reaction, the nuclear binding energy and transferring what is theoretically known as mass defect energy into thermal energy, power can be generated. Controlled fusion is a reaction of deuterium, tritium and helium. When these particles are injected into a vessel, say a torus, the 3/2 kT kinetic energy of an ideal gas basically means that each particle has a a momenta and an energy. By confining particles with electric and magnetic fields, the mean free path of particles decreases, intuitively. This means the collision frequency increases. More collisions mean more fusion. Better confining fields means more fusion. Particles follow geodesics on the principle of least action. The energy of the fusion particles is mu dot B for the magnetic energy and 1/2 m r dot squared, or the kinetic energy. If optical tweezer like lasers or quadrupole electric focusing fields are added, the particles feel an additional force of q times E. Gradients in E and B can perturb orbits. Since F dot dL is work, we can add some electric energy term to the Lagrangian. I think it is the electric dipole or induced dipole times E. After we find geodesics in our toroidal shape, we then calculate the number of particle collisions in an atomic dynamics simulation. From this equation, we find eigenmodes, loss orbits, and fusion collisions. What we need is ignition, or a process where helium has sufficient energy after the deuterium tritium collision so that it can impart enough momentum into a fusion reactant to drive a new fusion collision so the process can repeat forever - or at least until we run out of deuterium. Then neutrons are released, photons are released, and some helium ash and possible Be and Li appear. We used a heat exchanger to get usable electricity in thermoelectric conversion.
